I get lots of questions to my website http://www.recordtech.com/lp.htm about all things technical regarding cutting. Recently a post on Lathe Trolls, from a year ago, was brought to my attention. It was posted by "cd4cutter" who claims that all the well known data on everything RIAA is wrong. Hmmm. I don't know where he gets his information, but every disc cutting system ever made by Neumann, Ortofon and Westrex has inverse RIAA at the very input of the system. I know, I have all of these schematics in my archive. I have built three systems from scratch to drive Neumann SX-74 cutterheads and they all have inverse RIAA at the input. There is no boost in the bottom or cut in the top. No one has accused my cutting of having no bass and screaming top.
Magnetic cutterheads are velocity devices. As such they require inverse RIAA to match RIAA playback EQ. I believe cd4cutter's misinformation and obvious misunderstanding comes from two things he repeats ad nauseum. He claims modern disc cutting systems are constant amplitude. As I stated magnetic cutterheads are velocity devices. It would be necessary to apply 60dB of boost electrically to modify this curve to constant amplitude. If this were done his curves would be correct in order to bring them back to RIAA conformity. But it would make NO sense to convert to constant amplitude electrically and then partially undo this electrically. Talk about reinventing the wheel! BTW, his premise (and curves) would be correct for cutting with crystal cutterheads, which ARE constant amplitude, to match RIAA. I would think someone who has done ANY cutting to speak of would know that the cut groove DOES NOT correlate with a scope trace. Amplitude increases as frequency decreases, and not because there is boost at the low end, but because inverse RIAA falls way short of being constant amplitude.
His other misunderstanding is in regard to RIAA playback. He talks about a 6dB curve superimposed on the RIAA playback curve. This is a total falacy. The three time constants (3180us+318us+75us) create the RIAA curve. Nuthin' is superimposed on nuthin'. If he had ever measured the frequency response of a phono preamp he would know this.
He constantly talks about JAES articles on cutting. Has he ever read any? They ALL refute what he is saying. There is an excellent article on everything RIAA in Stereophile which can be read here: http://www.stereophile.com/features/cut_and_thrust_riaa_lp_equalization/index.html I had nothing to do with it,.BTW. This has the straight scoop. I suggest cd4cutter, and anyone on your forum interested in RIAA, read it.
Kevin Gray
AcousTech Mastering
Cohearent Audio
Inverse RIAA Revisited
Moderators: piaptk, tragwag, Steve E., Aussie0zborn
Inverse RIAA Revisited
Kevin Gray
Firstoff, Kevin, I will admit that this subject has been confusing. Partly because I didn't completely explain the realities of the whole scene in one single post. If you bother to do a search of this forum, you will find that I have addressed this RIAA subject in several posts on different threads. I'll try to summarize the whole picture here: In fact, what is required by most modern cutters is a combination of constant amplitude (CA) RIAA pre-emphasis in the audio band below the cutter's resonance and constant velocity (CV) RIAA pre-emphasis above that resonance. NONE of the published curves can willy-nilly be inverted and applied as "THE CORRECT" RIAA pre-emphasis because they are describing pickup characteristics, not cutter characteristics.
So, let's begin by correcting a common misconception about dynamic magnetic systems, that would be those employing moving coils OR moving magnets in transduction between either mechanical to electrical or electrical to mechanical energy. Your citation of the article in "Stereophile" magazine is a perfect example of the fact that even published authors don't get it right. The article states, and I quote directly:
"In order to cut a record groove with a constant-amplitude characteristic, it is not sufficient to provide a signal of flat frequency response to the cutting head because the latter is electromagnetic by operation, and hence, as already mentioned, a velocity transducer. It generates at the cutting stylus a velocity, not a displacement, proportional to the input voltage."
This is INCORRECT-I-MUNDO!
Dynamic transducers are NOT reciprocal devices. That is a dynamic phono cartridge (the typical kind of magnetic like a Shure or Stanton) is, indeed a velocity-responding or constant-velocity (CV) device when it is used to play a record (mechanical to electrical transduction). The typical principle mechanical resonance of a good magnetic phono cartridge is at the very top of the audio band, usually around 15kHz. Below this resonance, the device functions as a CV transducer. Above that frequency, a second and perhaps third pole is added to its response due to the system being mass loaded which reduces its output with increasing frequency. But this is above the normal audio band and it is not of concern to us here. So far, this is what most people understand.
HOWEVER, a dynamic magnetic system does NOT function as a CV device at frequencies below its principle mechanical resonance when functioning as an electrical to mechanical transducer. Instead, it functions in the constant amplitude (CA) mode. Above that resonance, the system becomes CV due to the same effects mentioned above, that is it becomes mass loaded and its response rolls off at about 6dB per octave which approximates CV response.
If you doubt this, consider how a typical dynamic loudspeaker responds at very low frequencies (those below its main resonance): If you put a DC voltage on the speaker terminals, the cone will move to a fixed displacement from its neutral position and remain there. If you increase the frequency from DC to a few Hz, the cone will move peak to peak with each peak being the same distance from neutral as it does at DC. That is the definition of constant amplitude response. A constant input voltage zero-to-peak produces a constant cone displacement zero-to-peak. If a loudspeaker were a CV device over its entire frequency range, the cone would blow out of the basket at DC as it attempted to achieve infinite excursion at zero frequency.
Now, unlike the case with magnetic phono cartridges which have their main resonance above the audio band, dynamic cutter heads like all the modern Neumann, Westrex, and Ortofon models have their principal mechanical resonance in the 1 - 2kHz range, that is smack dab in the middle of the audio band. The frequency range below resonance is said to be the "spring-loaded" or "stiffness-controlled" range, and the range above resonance is said to be the "mass-loaded" or "inertia-controlled" range.
I don't have access to a lot of technical papers, but I do have this reprint by the designers of the early Fairchild 642 stereo feedback dynamic cutterhead. This paper appeared in the Journal of the Audio Engineering Society (JAES) as delivered to the AES convention in October, 1958. The paper is titled "A New Stereo Feedback Cutterhead System" and was written by Rein Narma and Norman J. Anderson, should you care to look it up. This paper is probably available from the AES and is also included in the AES "Disc Recording Anthology, Vol. 1" published in 1980. The Fairchild head discussed here is a vertical-lateral design as opposed to the 45-45 degree systems of the later designs, but it still employs the same physics of a dynamic transducer. Much detail is written about the design of the magnetic circuits, the moving coil armature, and the special cutting amplifier designed for this head. The primary mechanical resonance of this cutter is 1200Hz, about typical of modern heads. Of particular interest here is this quotation from page 4 of the paper:
" . . . the region of the audio spectrum requiring feedback the most is that region below its mechanicl resonance where the cutter is stiffness-controlled, since it is only in this region that the lacquer loads the stylus appreciably, this loading being nonlinear. Since the cutter is constant amplitude in this region . . ."
OK, dynamic cutterheads are CA responding in the region below their mechanical resonance which is in the middle of the audio band. It is NOT CV responding in this region as claimed by the StereoPile author. GOT THAT?
Consequently, when changing the cutter's CA response in the lower part of the audio band to comply with the RIAA pre-emphasis curve, you DO NOT want to simply employ the inverse RIAA curve that is typically published for magnetic pickups because that curve corrects for CV response in the pickup in this frequency band. WRONG for the cutterhead.
Again, it helps to think of the record as essentially a CA recording, with two important shelved response regions. It is much closer to being CA than it is to being CV. It is essentially CA with a shelved boost in the bass region and a shelved cut in the treble region. As the StereoPile article itself denotes, CA recording was and is the theoretically desirable configuration from the standpoint of getting the most recording time on the record while still having good signal to noise ratio since the stylus excursions are not excessively large (which would reduce recording time) or excessively small (which would result in poor S/N). Consequently, most commercial cutting systems produce this quasi-CA recording characteristic when they cut. This is why you can play a record with a CA responding cartridge like a ceramic and get reasonable audio which is not hugely out of balance from the bass to the treble regions.
So, how does one cut such a quasi-CA record? Since the dynamic cutterhead is already CA responding in the bass region, all you have to do is include the shelving response in the RIAA curve that changes from flat to the boosted shelf response. YOU DO NOT use the inverse of the RIAA curve as published for a magnetic pickup! For the treble region, the cutter is CV responding and you need to add considerable boost at increasing frequency to approximate the CA response that is specified in the finished record, modified by the shelf that defines the RIAA pre-emphasis. This can be thought of as a combination of a 6dB/oct rise over the entire range above resonance, added to the RIAA pre-emphasis as specified relative to CA response. This is APPROXIMATELY the same as using the inverted RIAA magnetic cartridge playback curve above the cutter resonance, but the exact match depends on just where the cutter resonance is and exactly what the cutter response is when the feedback is properly adjusted. So the TOTAL RIAA preemphasis curve required by any individual dynamic cutter will be modifications to CA response in the bass and modifications to CV response in the treble range, with particular attention to how this interacts with the individual cutter's basic response with feedback adjusted. Again, you can't just pick up some playback curve and invert it to get the proper RIAA pre-emphasis.
So, as you can see, I DO read AES papers, and I have written a few myself and have had them published - without argument, I might add. And I DO know what I'm talking about. In the future, I would appreciate it if YOU had YOUR act together before accusing someone of disseminating falsehoods and of incompetence. Namecalling doesn't benefit anyone.
So, let's begin by correcting a common misconception about dynamic magnetic systems, that would be those employing moving coils OR moving magnets in transduction between either mechanical to electrical or electrical to mechanical energy. Your citation of the article in "Stereophile" magazine is a perfect example of the fact that even published authors don't get it right. The article states, and I quote directly:
"In order to cut a record groove with a constant-amplitude characteristic, it is not sufficient to provide a signal of flat frequency response to the cutting head because the latter is electromagnetic by operation, and hence, as already mentioned, a velocity transducer. It generates at the cutting stylus a velocity, not a displacement, proportional to the input voltage."
This is INCORRECT-I-MUNDO!
Dynamic transducers are NOT reciprocal devices. That is a dynamic phono cartridge (the typical kind of magnetic like a Shure or Stanton) is, indeed a velocity-responding or constant-velocity (CV) device when it is used to play a record (mechanical to electrical transduction). The typical principle mechanical resonance of a good magnetic phono cartridge is at the very top of the audio band, usually around 15kHz. Below this resonance, the device functions as a CV transducer. Above that frequency, a second and perhaps third pole is added to its response due to the system being mass loaded which reduces its output with increasing frequency. But this is above the normal audio band and it is not of concern to us here. So far, this is what most people understand.
HOWEVER, a dynamic magnetic system does NOT function as a CV device at frequencies below its principle mechanical resonance when functioning as an electrical to mechanical transducer. Instead, it functions in the constant amplitude (CA) mode. Above that resonance, the system becomes CV due to the same effects mentioned above, that is it becomes mass loaded and its response rolls off at about 6dB per octave which approximates CV response.
If you doubt this, consider how a typical dynamic loudspeaker responds at very low frequencies (those below its main resonance): If you put a DC voltage on the speaker terminals, the cone will move to a fixed displacement from its neutral position and remain there. If you increase the frequency from DC to a few Hz, the cone will move peak to peak with each peak being the same distance from neutral as it does at DC. That is the definition of constant amplitude response. A constant input voltage zero-to-peak produces a constant cone displacement zero-to-peak. If a loudspeaker were a CV device over its entire frequency range, the cone would blow out of the basket at DC as it attempted to achieve infinite excursion at zero frequency.
Now, unlike the case with magnetic phono cartridges which have their main resonance above the audio band, dynamic cutter heads like all the modern Neumann, Westrex, and Ortofon models have their principal mechanical resonance in the 1 - 2kHz range, that is smack dab in the middle of the audio band. The frequency range below resonance is said to be the "spring-loaded" or "stiffness-controlled" range, and the range above resonance is said to be the "mass-loaded" or "inertia-controlled" range.
I don't have access to a lot of technical papers, but I do have this reprint by the designers of the early Fairchild 642 stereo feedback dynamic cutterhead. This paper appeared in the Journal of the Audio Engineering Society (JAES) as delivered to the AES convention in October, 1958. The paper is titled "A New Stereo Feedback Cutterhead System" and was written by Rein Narma and Norman J. Anderson, should you care to look it up. This paper is probably available from the AES and is also included in the AES "Disc Recording Anthology, Vol. 1" published in 1980. The Fairchild head discussed here is a vertical-lateral design as opposed to the 45-45 degree systems of the later designs, but it still employs the same physics of a dynamic transducer. Much detail is written about the design of the magnetic circuits, the moving coil armature, and the special cutting amplifier designed for this head. The primary mechanical resonance of this cutter is 1200Hz, about typical of modern heads. Of particular interest here is this quotation from page 4 of the paper:
" . . . the region of the audio spectrum requiring feedback the most is that region below its mechanicl resonance where the cutter is stiffness-controlled, since it is only in this region that the lacquer loads the stylus appreciably, this loading being nonlinear. Since the cutter is constant amplitude in this region . . ."
OK, dynamic cutterheads are CA responding in the region below their mechanical resonance which is in the middle of the audio band. It is NOT CV responding in this region as claimed by the StereoPile author. GOT THAT?
Consequently, when changing the cutter's CA response in the lower part of the audio band to comply with the RIAA pre-emphasis curve, you DO NOT want to simply employ the inverse RIAA curve that is typically published for magnetic pickups because that curve corrects for CV response in the pickup in this frequency band. WRONG for the cutterhead.
Again, it helps to think of the record as essentially a CA recording, with two important shelved response regions. It is much closer to being CA than it is to being CV. It is essentially CA with a shelved boost in the bass region and a shelved cut in the treble region. As the StereoPile article itself denotes, CA recording was and is the theoretically desirable configuration from the standpoint of getting the most recording time on the record while still having good signal to noise ratio since the stylus excursions are not excessively large (which would reduce recording time) or excessively small (which would result in poor S/N). Consequently, most commercial cutting systems produce this quasi-CA recording characteristic when they cut. This is why you can play a record with a CA responding cartridge like a ceramic and get reasonable audio which is not hugely out of balance from the bass to the treble regions.
So, how does one cut such a quasi-CA record? Since the dynamic cutterhead is already CA responding in the bass region, all you have to do is include the shelving response in the RIAA curve that changes from flat to the boosted shelf response. YOU DO NOT use the inverse of the RIAA curve as published for a magnetic pickup! For the treble region, the cutter is CV responding and you need to add considerable boost at increasing frequency to approximate the CA response that is specified in the finished record, modified by the shelf that defines the RIAA pre-emphasis. This can be thought of as a combination of a 6dB/oct rise over the entire range above resonance, added to the RIAA pre-emphasis as specified relative to CA response. This is APPROXIMATELY the same as using the inverted RIAA magnetic cartridge playback curve above the cutter resonance, but the exact match depends on just where the cutter resonance is and exactly what the cutter response is when the feedback is properly adjusted. So the TOTAL RIAA preemphasis curve required by any individual dynamic cutter will be modifications to CA response in the bass and modifications to CV response in the treble range, with particular attention to how this interacts with the individual cutter's basic response with feedback adjusted. Again, you can't just pick up some playback curve and invert it to get the proper RIAA pre-emphasis.
So, as you can see, I DO read AES papers, and I have written a few myself and have had them published - without argument, I might add. And I DO know what I'm talking about. In the future, I would appreciate it if YOU had YOUR act together before accusing someone of disseminating falsehoods and of incompetence. Namecalling doesn't benefit anyone.
Collecting moss, phonos, and radios in the mountains of WNC
There is only one person making this difficult and that person is you. I have read your posts and you spend most of your posts telling the entire world that they have it wrong and you have it right. Who is disseminating falsehoods here???
I DO use inverse RIAA at the input of my system as does Neumann, Ortofon and Westrex, if you care to look at the schematics. (This is before the addition of feedback, in the next stage, to stomp on the resonance at approximately 1kHz)
BTW the resonance in a Neumann/Ortofon/Westrex is a bell shaped curve with lots of feedback at both ends of the spectrum, not MORE at the LF end as you state for the Fairchild. The idea of the low frequency end of the spectrum being constant amplitude just ain't the case.
I fully expected you to say that the Stereophile author has it all wrong TOO!
I guess Westrex, Ortophon and Neumann have it all wrong too. Just look at the schematics....I rest my case.
I DO use inverse RIAA at the input of my system as does Neumann, Ortofon and Westrex, if you care to look at the schematics. (This is before the addition of feedback, in the next stage, to stomp on the resonance at approximately 1kHz)
BTW the resonance in a Neumann/Ortofon/Westrex is a bell shaped curve with lots of feedback at both ends of the spectrum, not MORE at the LF end as you state for the Fairchild. The idea of the low frequency end of the spectrum being constant amplitude just ain't the case.
I fully expected you to say that the Stereophile author has it all wrong TOO!
I guess Westrex, Ortophon and Neumann have it all wrong too. Just look at the schematics....I rest my case.
Kevin Gray
Is there perhaps some confusion between the nature of the drive and feedback signals, and therefore the response of the open-loop head versus the closed-loop head-and-amplifier?
The Fairchild 642 is a unique case, where the feedback signal from the head has, or at least can have, response to DC (constant amplitude). A typical head has feedback which is not only AC coupled, but has an inductive characteristic (constant flux change rate results in constant voltage; DC has no flux change rate through the feedback coil so there is no output voltage). That is, the voltage appearing across the feedback is proportional (ignoring various problems, like the Westrex coupling between drive and FB coils) to the velocity of the coils through the magnet system. If the stylus is moved to a DC offset, the stylus moves, but the FB signal would only be present while the stylus is moving.
If you closed the loop around the head with the amplifier, and applied the DC step, you would shoot the coil out of the head, as the amplifier would attempt to maintain a constant velocity. So to equalize a head which is operating closed loop over some range of frequencies, you are applying correction from a constant velocity characteristic.
The electro-mechanical open-loop response of the head is dominated by the things mentioned previously, IE the head has either rising or flat response to the resonance point at ~1000 Hz, and then falling response above that. These are dominated by the mechanics of the head. The fairchild and Westrex articles are commenting on the characteristics of the open-loop drive signal primarily, as this is the fundamental issue to consider when designing a head (not the closed-loop response, at least not initially). Neumann has a nice plot where they show the range over which the head is nearly constant amplitude open loop, and becomes worse than constant velocity by 6dB/octave. Then they show the subsequent plot where feedback is applied and the head is now constant velocity output mechanically for a constant amplitude signal input electrically.
To make this even more confusing, some older mono heads are not true feedback controlled heads, so that even with the loop closed around the head, the mechanical response to an electrical input does not directly achieve constant velocity. I'm thinking about the Grampian head, among others. So above the range where feedback works on this head, you end up electrically equalizing the mechanical response. That's partly why full audio range feedback heads are so nice. The Westrex stereo head (unlike the Westrex mono head) does not quite have feedback through the audio range, it peters out around 12kHz with secondary resonances that would destabilize the feedback loop if any significant gain was used there. So the thing Haeco did was to add high Q tunable filters from 12kHz upward to allow the engineer to flatten the mechanical response of the head electrically in the range where it does not have feedback.
So does this make sense to everyone? Part of what each person said was correct, the open loop cutterhead response is far different from the closed loop response, and the range of frequencies over which the cutterhead feedback can be applied affects the apearance of the RIAA compensation ahead of the amplifier, as it changes the range over which the head is constant-velocity. But closed loop heads are constant velocity, open loop heads are not.
The Fairchild 642 is a unique case, where the feedback signal from the head has, or at least can have, response to DC (constant amplitude). A typical head has feedback which is not only AC coupled, but has an inductive characteristic (constant flux change rate results in constant voltage; DC has no flux change rate through the feedback coil so there is no output voltage). That is, the voltage appearing across the feedback is proportional (ignoring various problems, like the Westrex coupling between drive and FB coils) to the velocity of the coils through the magnet system. If the stylus is moved to a DC offset, the stylus moves, but the FB signal would only be present while the stylus is moving.
If you closed the loop around the head with the amplifier, and applied the DC step, you would shoot the coil out of the head, as the amplifier would attempt to maintain a constant velocity. So to equalize a head which is operating closed loop over some range of frequencies, you are applying correction from a constant velocity characteristic.
The electro-mechanical open-loop response of the head is dominated by the things mentioned previously, IE the head has either rising or flat response to the resonance point at ~1000 Hz, and then falling response above that. These are dominated by the mechanics of the head. The fairchild and Westrex articles are commenting on the characteristics of the open-loop drive signal primarily, as this is the fundamental issue to consider when designing a head (not the closed-loop response, at least not initially). Neumann has a nice plot where they show the range over which the head is nearly constant amplitude open loop, and becomes worse than constant velocity by 6dB/octave. Then they show the subsequent plot where feedback is applied and the head is now constant velocity output mechanically for a constant amplitude signal input electrically.
To make this even more confusing, some older mono heads are not true feedback controlled heads, so that even with the loop closed around the head, the mechanical response to an electrical input does not directly achieve constant velocity. I'm thinking about the Grampian head, among others. So above the range where feedback works on this head, you end up electrically equalizing the mechanical response. That's partly why full audio range feedback heads are so nice. The Westrex stereo head (unlike the Westrex mono head) does not quite have feedback through the audio range, it peters out around 12kHz with secondary resonances that would destabilize the feedback loop if any significant gain was used there. So the thing Haeco did was to add high Q tunable filters from 12kHz upward to allow the engineer to flatten the mechanical response of the head electrically in the range where it does not have feedback.
So does this make sense to everyone? Part of what each person said was correct, the open loop cutterhead response is far different from the closed loop response, and the range of frequencies over which the cutterhead feedback can be applied affects the apearance of the RIAA compensation ahead of the amplifier, as it changes the range over which the head is constant-velocity. But closed loop heads are constant velocity, open loop heads are not.
Thank you. I understand what you are saying and your last line sums it up nicely. I don't think cd4 cutter gets it. I am not really interested in what the head does open loop. I do understand that it is all part of the electromechanical system, but I obviously don't cut with it that way.
I posted for one reason and in response to one thing. In a post in the schematics section a year ago. A guy was asking the best way to do inverse RIAA and cd4 cutter jumped in and said that inverse RIAA wasn't used in modern cutters and that the REAL curve involved bass boost and treble cut. He went on to say that everybody but him has this all wrong. This is just laughable, LAUGHABLE!!!! BUT it is dangerous to newbies who don't know better.
If you look at the schematic for any Neumann/Ortofon/Westrex system you will find inverse RIAA at the input. I built my system from scratch and there is inverse RIAA at the input. Plain and simple.
The Stereophile article is very well written and informative. I got a lot of questions from audiophiles about it and I agreed with the author on most counts. Then I got a question about cd4 cutter's post on Lathe Trolls.
cd4 cutter jumps on everybody, including the Stereophile author, now, but still has not responded to what I claim. Inverse RIAA is at the input of ALL modern systems. He claims to be an electrical engineer but obviously has never looked at the schematic for a modern disk cutting system. It would seem that he has never used a modern disc cutting system or he would know that as you sweep the head with an oscillator the current rises dramatically as you increase frequency. And at low frequencies groove excursions increase dramatically as you reduce frequency. This is because the system is still way short of constant amplitude, even with inverse RIAA. If the inverse RIAA was not there you would tear the head apart at low frequencies. Imagine this with his imaginary bass boost!!!
I posted for one reason and in response to one thing. In a post in the schematics section a year ago. A guy was asking the best way to do inverse RIAA and cd4 cutter jumped in and said that inverse RIAA wasn't used in modern cutters and that the REAL curve involved bass boost and treble cut. He went on to say that everybody but him has this all wrong. This is just laughable, LAUGHABLE!!!! BUT it is dangerous to newbies who don't know better.
If you look at the schematic for any Neumann/Ortofon/Westrex system you will find inverse RIAA at the input. I built my system from scratch and there is inverse RIAA at the input. Plain and simple.
The Stereophile article is very well written and informative. I got a lot of questions from audiophiles about it and I agreed with the author on most counts. Then I got a question about cd4 cutter's post on Lathe Trolls.
cd4 cutter jumps on everybody, including the Stereophile author, now, but still has not responded to what I claim. Inverse RIAA is at the input of ALL modern systems. He claims to be an electrical engineer but obviously has never looked at the schematic for a modern disk cutting system. It would seem that he has never used a modern disc cutting system or he would know that as you sweep the head with an oscillator the current rises dramatically as you increase frequency. And at low frequencies groove excursions increase dramatically as you reduce frequency. This is because the system is still way short of constant amplitude, even with inverse RIAA. If the inverse RIAA was not there you would tear the head apart at low frequencies. Imagine this with his imaginary bass boost!!!
Kevin Gray
There's a nice presentation of how feedback and constant velocity recording works, presented on pgs 241-246 of the AES Disk Recording anthology, volume 1. It's an article from some time in 1954, about the operation of the Westrex 2B cutting system.
Perhaps one confusing thing, with feedback wrapped around the head, if you put sine waves of varying frequencies at constant electrical amplitude into the head (like 100mV p-p) you get constant mechanical velocity at the head, and declining mechanical displacement (IE it's an integrator).
The article shows nice pics of square waves recorded onto a disk and the resulting triangle wave pattern on the disk (so no RIAA filtering running). They demonstrate that the reproducing cartridge reproduces a square wave result on playback (again, no RIAA filtering in place). Of course, the groove is huge in this case...
Perhaps one confusing thing, with feedback wrapped around the head, if you put sine waves of varying frequencies at constant electrical amplitude into the head (like 100mV p-p) you get constant mechanical velocity at the head, and declining mechanical displacement (IE it's an integrator).
The article shows nice pics of square waves recorded onto a disk and the resulting triangle wave pattern on the disk (so no RIAA filtering running). They demonstrate that the reproducing cartridge reproduces a square wave result on playback (again, no RIAA filtering in place). Of course, the groove is huge in this case...
I have the article on the Fairchild stereo feedback cutterhead, it's actually a few pages later in the same book. So I was incorrect in a few ways about how the Fairchild head works. The feedback is not FM detected, but differential detected, the difference being mainly that it is not sensitive to oscillator variability. But the weirdness there is that, because their feedback source is constant amplitude (it's a displacement measurement, not velocity), they build a compensator into the transducer amplifier, which indeed acts as constant amplitude below the beginning of the cutter resonance and constant velocity at the start (say 500Hz).
The more typical curve, which is common to Ortofon, Westrex, and Neumann cutterheads, is the curve on p. 268 of the AES Disk Recording anthology vol. 1. It shows the fundamental resonance f.0 of the head positioned at 1kHz, and shows (on the same graph) the velocity curve of the open-loop head without feedback, the cutterhead current with feedback applied, and the velocity response curve with feedback applied.
BTW, the open loop electro-mechanical response of the head does matter, if you are designing a cutterhead drive system. If you are careful, you can shape the feedback coil amplifier design to increase the open loop gain and phase margin of the system, or to boost the amount of electrical feedback, say at a frequency where the cutterhead is not well controlled (this is what Fairchild was doing at low frequencies on their head). For example, Neumann inserts a resistance and parallel capacitance in series with their head to improve the phase margin at the output of their amplifier (around a 9.5 ohm, nearly constant impedance).
This is similar to what is done in a buck-mode switching power supply using voltage feedback, the output filter of the supply (inductor and cap) has a low frequency zero and pole pair, and an electrical compensator is designed to improve the bandwidth and stability margin of the open-loop response. But the closed loop response is still unity (one volt disturbance cancelled by one volt response).
The more typical curve, which is common to Ortofon, Westrex, and Neumann cutterheads, is the curve on p. 268 of the AES Disk Recording anthology vol. 1. It shows the fundamental resonance f.0 of the head positioned at 1kHz, and shows (on the same graph) the velocity curve of the open-loop head without feedback, the cutterhead current with feedback applied, and the velocity response curve with feedback applied.
BTW, the open loop electro-mechanical response of the head does matter, if you are designing a cutterhead drive system. If you are careful, you can shape the feedback coil amplifier design to increase the open loop gain and phase margin of the system, or to boost the amount of electrical feedback, say at a frequency where the cutterhead is not well controlled (this is what Fairchild was doing at low frequencies on their head). For example, Neumann inserts a resistance and parallel capacitance in series with their head to improve the phase margin at the output of their amplifier (around a 9.5 ohm, nearly constant impedance).
This is similar to what is done in a buck-mode switching power supply using voltage feedback, the output filter of the supply (inductor and cap) has a low frequency zero and pole pair, and an electrical compensator is designed to improve the bandwidth and stability margin of the open-loop response. But the closed loop response is still unity (one volt disturbance cancelled by one volt response).
Actually when feeding a square wave into the system the resulting groove looks like a triangle wave WITH inverse RIAA in the system. Try it.
The effective feedback range of an SX74 is around 20Hz to 17kHz. Neumann puts in a shelving network at those frequencies to mildy tweak the response outside of the effective feedback range. cd4 cutter shows the curve necessary to make a crystal cutterhead match RIAA and says that is the record EQ. As he likes to say WRONG WRONG WRONG!!!
Yes you are totally correct about Neumann's network for linearizing impedance. I only said I'm not interested in the head without feedback for this argument.
As I said I am only pointing out that contrary to what cd4 cutter believes, there is inverse RIAA at the input in all modern systems. To say otherwise is totally misleading. Plain, simple, PERIOD!!!
The effective feedback range of an SX74 is around 20Hz to 17kHz. Neumann puts in a shelving network at those frequencies to mildy tweak the response outside of the effective feedback range. cd4 cutter shows the curve necessary to make a crystal cutterhead match RIAA and says that is the record EQ. As he likes to say WRONG WRONG WRONG!!!
Yes you are totally correct about Neumann's network for linearizing impedance. I only said I'm not interested in the head without feedback for this argument.
As I said I am only pointing out that contrary to what cd4 cutter believes, there is inverse RIAA at the input in all modern systems. To say otherwise is totally misleading. Plain, simple, PERIOD!!!
Kevin Gray
The Curve!
Hey all
Even though this is quite a "heated" thread I for one am glad for it No other reason except for the insight of the workings of cutterheads It seems to me this is in a "nutshell" expose in a few post's rather the many pages spread in a whole lot of publications most of which extol the virtues of the cutter head written about at the time Thank you to all, and more of it please!!!
Dillon, On another subject which has allways being something without an answer for me anyway Was the short lived SX45 cutter head developed by Teldec/Neumann an attempt to overcome the CA CV conflicting issues?
As you are saying about the Fairchild head
The Fairchild head discussed here is a vertical-lateral design as opposed to the 45-45 degree systems of the later designs,
Be nice to know your view on this
Cheers
Even though this is quite a "heated" thread I for one am glad for it No other reason except for the insight of the workings of cutterheads It seems to me this is in a "nutshell" expose in a few post's rather the many pages spread in a whole lot of publications most of which extol the virtues of the cutter head written about at the time Thank you to all, and more of it please!!!
Dillon, On another subject which has allways being something without an answer for me anyway Was the short lived SX45 cutter head developed by Teldec/Neumann an attempt to overcome the CA CV conflicting issues?
As you are saying about the Fairchild head
The Fairchild head discussed here is a vertical-lateral design as opposed to the 45-45 degree systems of the later designs,
Be nice to know your view on this
Cheers
Just in case anybody following this thread is wondering who is right and who is "incorrect-I-mundo" here, I found this. Sorry, if I had found it earlier I would have made it the body of my first post.
A direct quote from page 1 of the NEUMANN VMS-66 lathe manual:
"All transducer systems which involve motion in a magnetic field are what we call "velocity responsive". This means that the stylus velocity as expressed in cm/sec. remains constant for constant voltage input to the cutterhead. If you now convert constant velocity into excursion of stylus, you obtain a line which tilts at the rate of 6 dB/octave with the low frequency up and the high end down. A record cut with constant velocity (which incidentally would mean constant light pattern width) would produce an amplitude difference across the 9 octaves from 30 Hz to 15,360 Hz, of 54 dB or a ratio of about 500 to 1! This is obviously not a feasible system, since the level remaining at the high frequency end when the low frequencies have been cut at the highest level possible, will still be submerged in the surface noise of the pressing.
We therefore have worked for the past 60 years or more, with so-called recording characteristics which have attempted to produce a constant excursion (constant amplitude) groove. Involved is a tremendous reduction in low frequencies and commensurate boost in high frequencies. Ideally speaking we'd simply like to use a 6 dB/octave sloped line opposite to the one described earlier. This produces other problems. We'll have to boost the low frequency end in playback which in turn brings up turntable rumble. while at the high frequency end we'll have to pour lots of power into the cutterhead and that would require exorbitant amounts of power and would overload it. On top of that, it results in curvatures in the high frequency signal groove which are smaller than the radius of the playback stylus. The result as always is a compromise which we today call the RIAA (standing for Recording Industries Association of America) Disk Recording Characteristic. It is identical to the NAB recording curve as well as the International IEC, CCIR and DIN standards. It is one of the few internationally adhered to standards.
This curve has an irregular slope but is, in any case, sloped less than the 6 dB per octave which would be ideal. The difference between its 30 Hz and 15 kHz level is 35.8 dB, which leaves a disparity of 18.2 dB from constant amplitude recording, a 30 Hz tone occupying about eight time as much space as 15 kHz."
Tube fan, thank you for your input. It is appreciated.
Mossboss, sorry but I have no literature on the heads before the SX-68
I would suggest you contact Flo Kauffman or Al Grundy
A direct quote from page 1 of the NEUMANN VMS-66 lathe manual:
"All transducer systems which involve motion in a magnetic field are what we call "velocity responsive". This means that the stylus velocity as expressed in cm/sec. remains constant for constant voltage input to the cutterhead. If you now convert constant velocity into excursion of stylus, you obtain a line which tilts at the rate of 6 dB/octave with the low frequency up and the high end down. A record cut with constant velocity (which incidentally would mean constant light pattern width) would produce an amplitude difference across the 9 octaves from 30 Hz to 15,360 Hz, of 54 dB or a ratio of about 500 to 1! This is obviously not a feasible system, since the level remaining at the high frequency end when the low frequencies have been cut at the highest level possible, will still be submerged in the surface noise of the pressing.
We therefore have worked for the past 60 years or more, with so-called recording characteristics which have attempted to produce a constant excursion (constant amplitude) groove. Involved is a tremendous reduction in low frequencies and commensurate boost in high frequencies. Ideally speaking we'd simply like to use a 6 dB/octave sloped line opposite to the one described earlier. This produces other problems. We'll have to boost the low frequency end in playback which in turn brings up turntable rumble. while at the high frequency end we'll have to pour lots of power into the cutterhead and that would require exorbitant amounts of power and would overload it. On top of that, it results in curvatures in the high frequency signal groove which are smaller than the radius of the playback stylus. The result as always is a compromise which we today call the RIAA (standing for Recording Industries Association of America) Disk Recording Characteristic. It is identical to the NAB recording curve as well as the International IEC, CCIR and DIN standards. It is one of the few internationally adhered to standards.
This curve has an irregular slope but is, in any case, sloped less than the 6 dB per octave which would be ideal. The difference between its 30 Hz and 15 kHz level is 35.8 dB, which leaves a disparity of 18.2 dB from constant amplitude recording, a 30 Hz tone occupying about eight time as much space as 15 kHz."
Tube fan, thank you for your input. It is appreciated.
Mossboss, sorry but I have no literature on the heads before the SX-68
I would suggest you contact Flo Kauffman or Al Grundy
Kevin Gray
Cutting Heads and all that lovely stuff
Ok all on this thread here is a bit of interesting stuff from the T.Paravicini S.Ricker efforts
This a most interesting bit:
In order to try to calculate the frequency, I cut a few grooves' worth of this signal at a 10-inch diameter. I turned the eye-piece of the microscope sideways, and counted 7 complete cycles per 0.001-inch division. I did the basic math and figured it was right at 61 kHz, more than 2 octaves higher than the FM carrier (15 kHz) we used in cutting the JVC CD-4 Quadraphonic records! (That’s 122kHz when played back at 33 1/3 rpm!)
and here is a link to the story behind it http://www.positive-feedback.com/Issue2/mastering.htm
Fascinating stuff It seems that some limitations on cutting heads can be overcome after all
I certainly wont be going down that path Had a few scares already with high freq cuts where the head trips out with head temperature going through the roof But it seems that there brave souls out there Or cutters with healthy bank balances
Cheers
This a most interesting bit:
In order to try to calculate the frequency, I cut a few grooves' worth of this signal at a 10-inch diameter. I turned the eye-piece of the microscope sideways, and counted 7 complete cycles per 0.001-inch division. I did the basic math and figured it was right at 61 kHz, more than 2 octaves higher than the FM carrier (15 kHz) we used in cutting the JVC CD-4 Quadraphonic records! (That’s 122kHz when played back at 33 1/3 rpm!)
and here is a link to the story behind it http://www.positive-feedback.com/Issue2/mastering.htm
Fascinating stuff It seems that some limitations on cutting heads can be overcome after all
I certainly wont be going down that path Had a few scares already with high freq cuts where the head trips out with head temperature going through the roof But it seems that there brave souls out there Or cutters with healthy bank balances
Cheers
Yes, I have seen bias noise on lacquers many times. It usually doesn't make it to the pressing, however. The undulations are so small they don't fill properly on the pressing and just disappear. I have cut several projects from DSD (SACD) and they have lots of noise shaping out to 50kHz in the recording. It goes on the disk too!
It's all a "p*ssing contest" at those frequencies. I don't see the big deal. I also love the claim about square wave response to 100kHz. Yeah right, megahertz bandwidth on a phonograph record. Sure. And with an Ortofon cutterhead. Talk about dangerous. They blow out if you breath on them wrong. Half speed is the only way they work. In the '80s, Future Disc had their's rebuilt every three months. I'm not kidding!!!
It's all a "p*ssing contest" at those frequencies. I don't see the big deal. I also love the claim about square wave response to 100kHz. Yeah right, megahertz bandwidth on a phonograph record. Sure. And with an Ortofon cutterhead. Talk about dangerous. They blow out if you breath on them wrong. Half speed is the only way they work. In the '80s, Future Disc had their's rebuilt every three months. I'm not kidding!!!
Kevin Gray
Just reread the Positive Feedback thingy. Sorry, I misread the part about square wave response. He said 100Hz not 100kHz.
My custom system cuts beautiful 1kHz square waves. I don't recall what they look like at 100Hz but the limitation would be the head. All I know is my system is ruler flat to 10Hz I don't recall the LF 3dB point , but I think it's around 4 Hz. The electronics are flat below 1Hz.
My custom system cuts beautiful 1kHz square waves. I don't recall what they look like at 100Hz but the limitation would be the head. All I know is my system is ruler flat to 10Hz I don't recall the LF 3dB point , but I think it's around 4 Hz. The electronics are flat below 1Hz.
Kevin Gray
Cutter Heads
Hey All
Well as I said there needs to be a good bank balance Every 3 Months blowing a head would an expensive excersise indeed I certainly agree with the term "Dangerous" I am surprised that these things are allowed to go into the input chain of the system The rules in our place are quite simple We Must listen to the masters prior to cutting and look at the waveform If one suspects a problem with any master submitted than we simply sent it back to them unless permission is granted to "adjust" it So far so good it has not been an issue in getting leave to do whatever is required It certainly makes it a lot more safer Since we are a custom vinyl pressing place we get all sorts of great weird and downright rubish sent to us to be cut pressed etc Some of it is done by pro's others in the venue or in someones bedroom One can imagine, you dealing right across the spectrum Sure it takes a while longer to do the cut But at least we know what we are dealing with prior The safety of the cutting head comes first
I have seen "bias noise" on lacquers myself but I had no idea what it was I did not consider that the head would respond to such a high frequency and yes you are right it does not seem to make it on the pressings One lives and learns Thanks for the insight
Cheers
Well as I said there needs to be a good bank balance Every 3 Months blowing a head would an expensive excersise indeed I certainly agree with the term "Dangerous" I am surprised that these things are allowed to go into the input chain of the system The rules in our place are quite simple We Must listen to the masters prior to cutting and look at the waveform If one suspects a problem with any master submitted than we simply sent it back to them unless permission is granted to "adjust" it So far so good it has not been an issue in getting leave to do whatever is required It certainly makes it a lot more safer Since we are a custom vinyl pressing place we get all sorts of great weird and downright rubish sent to us to be cut pressed etc Some of it is done by pro's others in the venue or in someones bedroom One can imagine, you dealing right across the spectrum Sure it takes a while longer to do the cut But at least we know what we are dealing with prior The safety of the cutting head comes first
I have seen "bias noise" on lacquers myself but I had no idea what it was I did not consider that the head would respond to such a high frequency and yes you are right it does not seem to make it on the pressings One lives and learns Thanks for the insight
Cheers
I hear ya. When I was still doing a lot of Rap and Dance music on vinyl I was constantly pulling out what little hair I have left!
The top end would rip your ears off. Cutter current and temp were going sky high and if you filtered or HF limited the client just couldn't understand why it couldn't sound just like his CD.
The low end can be as much of a problem as the top. The boom-boom stuff can be at or near arm/cartridge resonance and will skip no matter how deep you cut, so that often has to be filtered. BTW if you are using a Neumann system, if you ever see the current meters moving to low frequency stuff that is telling you that the circuit breaker is about to cut out to protect against low frequency excursions that could damage the head. If you start seeing that movement, put in a high pass filter at 15-30 Hz
Were do you cut, Mossboss? UK?
The top end would rip your ears off. Cutter current and temp were going sky high and if you filtered or HF limited the client just couldn't understand why it couldn't sound just like his CD.
The low end can be as much of a problem as the top. The boom-boom stuff can be at or near arm/cartridge resonance and will skip no matter how deep you cut, so that often has to be filtered. BTW if you are using a Neumann system, if you ever see the current meters moving to low frequency stuff that is telling you that the circuit breaker is about to cut out to protect against low frequency excursions that could damage the head. If you start seeing that movement, put in a high pass filter at 15-30 Hz
Were do you cut, Mossboss? UK?
Kevin Gray
Cutting Heads
Hey Kev
We are down under Melbourne Australia Only one left I am afraid At least the only cutting lathe operating Fully in house from cut to finshed product (It gets painfull) There another lathe sitting in a friends lounge room which comes handy He does a cut or two for us when ours is down Only 4 cuts in the last two years thankfully
We have a full VMS system 74 head B rack, with a 72 console well loaded all standard modules and keeping it this way I am not good enough to improve on god old Georg as you have repeatedly pointed out on another point
Yes this boom boom will do it as well as the static that seems to be popular with metal dudes The last time a cut of a metal band's 4 albums resulted in most of the MJ output trannies being cooked about 16 or so of them Strange only the NPN's and one pnp which was not quite dead just down The head did trip Temperature was not that bad It seems that this High Freq static sends the system into oscillation without anything obvious
Oh Yeah dont worry about the filters they come on quite frequently at preview listening time with notes on the cutting sheet Run it through Nuendo feed it through the VMS and compare it to the master on the delay line Anything that is drastic is refered to the client for appro If they do not like it to bad they can cook someone elses head It has happened twice now where we just simply said NO In one instance the O/S people where he send his stuff to told him to stick it So he come back to us and said that he has "re-mastered it" we told the man we are not going to be in it unless we get the mix do it for a fee to suit and if his happy we will than cut it and proceed with a test pressing 5 jobs since that one and praises We are simply vinyl people love our lathe and the smell of fresh hot vinyl in the morning (So long as the shit does not gas off and rust's everything in sight overnight) That is all
By the way one is a bit limited with depth control on anything that has no computer on it like a Zuma or the goodies on the 80's But we are doing OK There are 100's of thousands of records out there that where cut without a Zuma or on the DMM 80's most do sound great some are excellent and anywhere in between So not much has changed really
Oh Yeah The guy that has put out thousands of 7's for a lot of local Aussie bands in the 60's & 70's did it on a portable Presto His machine is now displayed in a museum in Perth WA along with other memorabilia related to him and the bands he promoted
I made it my buissines to get some of the records he did and the sound on them is amazingly good It just goes to show that all these knobs as well as the "plug ins" which are banned in our joint do not improve the end result by such a margin so as to warrant their constant use in my view I am sure I am going to be blasted on this but we as well as others are living proof of great cuts given that the job was done well in the first place No more No less All that one needs is there on the VMS or a good cutting system that was produced for pro use
Cheers
and keep it coming I do like the heated exchanges when they result in clearing up issues
We are down under Melbourne Australia Only one left I am afraid At least the only cutting lathe operating Fully in house from cut to finshed product (It gets painfull) There another lathe sitting in a friends lounge room which comes handy He does a cut or two for us when ours is down Only 4 cuts in the last two years thankfully
We have a full VMS system 74 head B rack, with a 72 console well loaded all standard modules and keeping it this way I am not good enough to improve on god old Georg as you have repeatedly pointed out on another point
Yes this boom boom will do it as well as the static that seems to be popular with metal dudes The last time a cut of a metal band's 4 albums resulted in most of the MJ output trannies being cooked about 16 or so of them Strange only the NPN's and one pnp which was not quite dead just down The head did trip Temperature was not that bad It seems that this High Freq static sends the system into oscillation without anything obvious
Oh Yeah dont worry about the filters they come on quite frequently at preview listening time with notes on the cutting sheet Run it through Nuendo feed it through the VMS and compare it to the master on the delay line Anything that is drastic is refered to the client for appro If they do not like it to bad they can cook someone elses head It has happened twice now where we just simply said NO In one instance the O/S people where he send his stuff to told him to stick it So he come back to us and said that he has "re-mastered it" we told the man we are not going to be in it unless we get the mix do it for a fee to suit and if his happy we will than cut it and proceed with a test pressing 5 jobs since that one and praises We are simply vinyl people love our lathe and the smell of fresh hot vinyl in the morning (So long as the shit does not gas off and rust's everything in sight overnight) That is all
By the way one is a bit limited with depth control on anything that has no computer on it like a Zuma or the goodies on the 80's But we are doing OK There are 100's of thousands of records out there that where cut without a Zuma or on the DMM 80's most do sound great some are excellent and anywhere in between So not much has changed really
Oh Yeah The guy that has put out thousands of 7's for a lot of local Aussie bands in the 60's & 70's did it on a portable Presto His machine is now displayed in a museum in Perth WA along with other memorabilia related to him and the bands he promoted
I made it my buissines to get some of the records he did and the sound on them is amazingly good It just goes to show that all these knobs as well as the "plug ins" which are banned in our joint do not improve the end result by such a margin so as to warrant their constant use in my view I am sure I am going to be blasted on this but we as well as others are living proof of great cuts given that the job was done well in the first place No more No less All that one needs is there on the VMS or a good cutting system that was produced for pro use
Cheers
and keep it coming I do like the heated exchanges when they result in clearing up issues
Marcos, thanks, good to be here. I guess I qualify as a lathe troll if ever there was one! Steve has a nice thing going here.
Mossboss: Glad to hear they have a lathe cranking in Australia. I got an email and some follow up pressings from a young guy cutting in Japan and he's doing some very nice sounding stuff. I couldn't agree with you more about plug-ins. They have their place, but not in my cutting room. I have a "hardware" L2 that I sometimes use for CD work, but not for vinyl.
Getting back to the world scene, has there been much exchange of info on locating parts for Neumann stuff here on Trolls? There's always some odd part that's really difficult to find.
I tend to shy away from heated debates, but the guy was posting the same misinformation over and over again, and each time like he was the only one who understands this stuff and EVERYONE else has it wrong. Jeeeeeez!
I told him how my system is configured and how "the big 3" do it and he's telling me how it really needs to be done. Pretty funny really...
I'm just a little surprised that guys like Al Grundy and Flo Kauffman didn't correct him sooner.
On the other hand, if it wasn't for getting a flood of emails about his posts after the Stereophile RIAA article opened a can of worms, I might have let it go too.
Feel free to PM me if you have any questions.
Mossboss: Glad to hear they have a lathe cranking in Australia. I got an email and some follow up pressings from a young guy cutting in Japan and he's doing some very nice sounding stuff. I couldn't agree with you more about plug-ins. They have their place, but not in my cutting room. I have a "hardware" L2 that I sometimes use for CD work, but not for vinyl.
Getting back to the world scene, has there been much exchange of info on locating parts for Neumann stuff here on Trolls? There's always some odd part that's really difficult to find.
I tend to shy away from heated debates, but the guy was posting the same misinformation over and over again, and each time like he was the only one who understands this stuff and EVERYONE else has it wrong. Jeeeeeez!
I told him how my system is configured and how "the big 3" do it and he's telling me how it really needs to be done. Pretty funny really...
I'm just a little surprised that guys like Al Grundy and Flo Kauffman didn't correct him sooner.
On the other hand, if it wasn't for getting a flood of emails about his posts after the Stereophile RIAA article opened a can of worms, I might have let it go too.
Feel free to PM me if you have any questions.
Kevin Gray
Cutting heads Neumann etc
Hey All and Kevin
Thanks for the Invite and I did forget to welcome you So welcome
This is a good forum we have a rather broad range of posters from the newbies to old hands It is good cause it has no bias towards anything so there is a fair and reasonable exchange of ideas opinions and al that kind of stuff with a lot of help provided as well by almost any member here
Unlike some other forums we get a good exchange of ideas and our Forum Master inteferes very little if at all Although he keeps this going very well Our Thanks to Mr E S
Over the years we have accumulated a good little store of spares and components for these beast's so if you are stuck for anything Holler we may be able to assist No I do not want to sell anything just keep the ones used by pro's running so it will be on a "Hey I am stuck have you this" If we do you get it and when we are stuck we would be looking for the same deal In my view there are to many bits sitting on shelves doing no one any good while they are there and when you need it urgently the price is almost "gouging" Phew
I had some exchanges with the guy in Japan but it was the cutter from Kassei I think, is that the same person?
Well heated exchanges are ok to You cant make an omelete unless you break some eggs But sometimes you dont want one so you leave your eggs alone
There are two items that are non analogue in our input chain the RME D to A convertor with 4 channels out into the good old TC time delay unit The console is pretty well loaded with all that is required and more So we just keep on cranking away at it
Oh We do have another plant here in Sydney Australia part of the Vinyl Factory the UK based concern where they do press on a couple EMI 1400 presses from plates send out from the UK They get the cutting done at Abbey Road in the UK I suppose that is a plus for some people to get on the gravy train Than again some Gear Slutz (the forum) refer to as "Shaby Road" That is an interesting thread to read But than on the other hand, opinions are like the proverbial human orifice Every one got one of those and an opinion Forums can be scarry things
Welcome aboard Kev
(This is an all over the place post)
Cheers
Cheers
Thanks for the Invite and I did forget to welcome you So welcome
This is a good forum we have a rather broad range of posters from the newbies to old hands It is good cause it has no bias towards anything so there is a fair and reasonable exchange of ideas opinions and al that kind of stuff with a lot of help provided as well by almost any member here
Unlike some other forums we get a good exchange of ideas and our Forum Master inteferes very little if at all Although he keeps this going very well Our Thanks to Mr E S
Over the years we have accumulated a good little store of spares and components for these beast's so if you are stuck for anything Holler we may be able to assist No I do not want to sell anything just keep the ones used by pro's running so it will be on a "Hey I am stuck have you this" If we do you get it and when we are stuck we would be looking for the same deal In my view there are to many bits sitting on shelves doing no one any good while they are there and when you need it urgently the price is almost "gouging" Phew
I had some exchanges with the guy in Japan but it was the cutter from Kassei I think, is that the same person?
Well heated exchanges are ok to You cant make an omelete unless you break some eggs But sometimes you dont want one so you leave your eggs alone
There are two items that are non analogue in our input chain the RME D to A convertor with 4 channels out into the good old TC time delay unit The console is pretty well loaded with all that is required and more So we just keep on cranking away at it
Oh We do have another plant here in Sydney Australia part of the Vinyl Factory the UK based concern where they do press on a couple EMI 1400 presses from plates send out from the UK They get the cutting done at Abbey Road in the UK I suppose that is a plus for some people to get on the gravy train Than again some Gear Slutz (the forum) refer to as "Shaby Road" That is an interesting thread to read But than on the other hand, opinions are like the proverbial human orifice Every one got one of those and an opinion Forums can be scarry things
Welcome aboard Kev
(This is an all over the place post)
Cheers
Cheers