LJ SCULLY LS 76 as good as a neuman vms 70?

[jjgolden]

yes, The pitch computer sees the audio first, then the delayed signal is cut. Think of the preview (or non-delayed signal) as a look ahead so that the pitch computer can know what's coming and either tighten or widen the space between the grooves so they don't over cut each other or waste space.

JJG

[petermontg]

Brillant I know now whats going on. I've only ever cut on a manual system and trying to sort bringing a manual scully here. I was curious to understand it for possible adding one someday down the road. Thanks JJG and thanks for the link for the plug-in also.

[jjgolden]

Hey Your welcome Peter, glad to help.

JJG

[Serif]

... is there a preview happening in the pitch computer by 1.8secs so the delayed head signal acts in unison with pitch computer
...

1.8 seconds is the time it takes the tt to revolve once if the angular velocity is 33 1/3 rpm. If you cut at 45 rpm and actually need a full revolution advance signal, it should be 1.3 seconds. Also, if the source is a tape machine, the advance repro head needs to be the correct amount of inches of tape in front of the program repro head. This depends on the timing requirement of the automated feed and depth computing, the speed of the tape recording, and also the cutting speed. At 33 1/3 rpm lacquer disc recording speed and 30 ips tape recording speed, the distance between the advance and program heads to achieve a full revolution look-ahead should be 54 inches.

MCI JH-110M. Or, modify the ATR for fixed advance length, and for slower tape speeds or faster disc speeds you can delay the advance signal with ADDA. Trimming the amount of look-ahead, while leaving the program signal pristinely analog.



Cheers,
A. Taybel

[petermontg]

Jesus thanks serif i totaly passed over 33 vs 45rpm. I say ill stick it from a digital source. Id have to bring a decent ATR into the country and learn how to maintain it. could be a right pain in the a*se nobody around to show or give some pointers.

[opcode66]

If using a Nuemann VMS system the times are as follows. This is directly from the manual.

[Serif]

If using a Nuemann VMS system the times are as follows. This is directly from the manual...

Yes, the only advanced feed and depth systems I am aware of which require a full turn-table revolution for look-ahead is the LS-76 (1976) and the Sontec Compudisk (1985?). I don't think there were any Studer preview machines that looked ahead by more than 0,6 revolutions. This is why the VMS times are less (well, the VMS times are why the Studer times are less...). Only by having knowledge of the maximum excursion from an entire revolution ago, as well as the absolute polarity of that signal, can the feed and depth control nestle long-held organ notes like Marcel waves in hair.

On the other hand, it would appear that most records in my collection were cut at a fairly consistent 192 LPI. In most cases, this is a result of the sustained expansion caused by incessant fortes, which precludes the packing of tighter grooves. But, it's interesting that the expanded pitch is so consistent from record to record. The only time most Pop music seems to get densely packed is at the fades out. Ok, something like Pink Floyd's Welcome to the Machine is rather like Classical in macro-dynamics and needs to be de-expanded for the first movement in order to save some fidelity for when the orchestra start banging. However, most sides will be able to be cut without any automation, it seems. Learn the score, practice a few times, and adjust on-the-fly. Simple?




Cheers,
Chuck Spindle

[Serif]

Jesus thanks serif i totaly passed over 33 vs 45rpm. I say ill stick it from a digital source. Id have to bring a decent ATR into the country and learn how to maintain it. could be a right pain in the a*se nobody around to show or give some pointers.

You might well benefit from having an ATR or Studer for source, even if you vary your feed and depth manually. However, for automated variable feed and depth, you'd have to modify these machines, provided you wanted either of the following:

A) ATR with advance repro head.

B) preview Studer with longer-than-0,6 revolutions look-ahead.


The ATR modification has to be done at ATR Services, or similar. First, you make the -102 machine a -104. This adds the extra electronics for the extra audio channels. Next, it requires work on the deck to put in a second repro head (since there are no preview ATR's that come stock) and to install a roller which is a fixed distance from the program head. This fixed distance won't be appropriate for all tape, disk, and automation system needs. However, it will be as long a distance as that required to delay the advance signal from program the most which you will ever need. Then, if you pick a disc cutting speed and/or tape recording speed and/or automation system which requires less of a delay, the advance signal is digitzed, during the disc recording, and the digital advance signal is delayed by the exact number of tenths of a second to produce the timing handshake you want by the time the advance signal is reconstructed and put out of the advance signal DAC and into the automation system's inputs. That's right; you delay the advance!

The last quote I had on an ATR modification was over $5k (I don't know if that was to convert before or after conversion to ATR-104, however).

The good news is that this mod does allow you to use one of the lowest flutter reproducers made, _and_ it doesn't require the digitization of the program signal (which is the one which counts, since it's what makes the grooves wiggle).


Finally, as I mentioned before, the machine which is already capable of making full use of the Compudisk and the on-board LS-76 Scully automation is the MCI JH-110M, which can come with 1/4" and 1/2" rollers and heads, as well as 1/4-track (preview!). This machine does both 1/2, and 1/1, revolution preview, depending on how you thread the tape.


- Chip Swarf

[Nickou]

The last quote I had on an ATR modification was over $5k (I don't know if that was to convert before or after conversion to ATR-104, however).

very erxpensive for a very simple mod ...it is just and only one head , 2 preamps and some rollers on a table putted on the left side of your tape machine ..
I did one for my c37, and the cost did not reach 300 € ... so 5 k is a lot ...

[Nickou]

If using a Nuemann VMS system the times are as follows. This is directly from the manual...

Yes, the only advanced feed and depth systems I am aware of which require a full turn-table revolution for look-ahead is the LS-76 (1976) and the Sontec Compudisk (1985?). I don't think there were any Studer preview machines that looked ahead by more than 0,6 revolutions. This is why the VMS times are less (well, the VMS times are why the Studer times are less...).




Cheers,
Chuck Spindle

The stuka vinylium ultrapitch98 allows you to choose your delay time from 0 revolution to 1 , Jvo did a 0 revolution picth time for tape machine without preview head

[Serif]

The last quote I had on an ATR modification was over $5k (I don't know if that was to convert before or after conversion to ATR-104, however).

very erxpensive for a very simple mod ...it is just and only one head , 2 preamps and some rollers on a table putted on the left side of your tape machine ..
I did one for my c37, and the cost did not reach 300 € ... so 5 k is a lot ...

The mastering ATR 1/2" 2-track head, alone, is 875 USD (over 2.2x Euro 300). Then you also want a 1/4" head, at close to 500 USD. Then you want the ATR physical alignment to the head shoe. Then you want the precise 54" placement (for 30 ips/33.333.../full-rev) of the new roller and its securing to the deck with a sturdy and true plank, which requires tools, know-how, sweat, and courage. Then you want the whole mod tested and insured and removable without much ado. Yes, 5k is a lot, but, if it includes the extra electronics - also rebuilt and tested at ATR - well, you are getting a significant upgrade.

- Mae Tricks

[Serif]

The stuka vinylium ultrapitch98 allows you to choose your delay time from 0 revolution to 1 , Jvo did a 0 revolution picth time for tape machine without preview head

No time sounds like a dream come true. However, if it's truly 0 time, as would be furnished by a single-head repoducer, then only the left channel information would be acted on for feed, and none of the depth would be acted on?


- Doug Intuit

[Nickou]

I don t know the details of how it works .. for that the best is asking to jvo or flozky some details
with no delay , the pitch controller use only the right side as "preview"
and it works , no over cut , nothing


anyway , I realy recommend the ultrapitch, it is a fantastic tool

[petermontg]

It would be pitch98 i would be adding to the scully.

Serif thanks so much for the information. It opens some possible avenues with tape. Your like like the wiki on tape machines. Am going to take what you've said there on board and look more into an ATR.

With regards to the MCI JH-110M does this only work with LS-76 and the Compudisk pitch.

[Nickou]

If you want a good lathe , yes a scully with a ultrapitch will gives you exellent results

about the mci , it can works with any lathe ...

If you want a telefunken m15 or a studer a80 with preview , pm me

[Serif]

The MCI JH-110M does full-revolution and 1/2-revolution look-ahead. I don't know if any other turn-table speed / automation system timing is threadable with it... If you can alter the timing of the automation, which, I don't believe is possible on the LS-76 on-board sysyem, you could use one or the other threading, as desired. But, if you are using an LS-76, you can't use a stock Studer or Ampex and get the maximum benefit of its groove nestling capability (or that of the Compudisk, or UltraPitch 98, ftm).


- Rube E. Schank

[Serif]

I don t know the details of how it works .. for that the best is asking to jvo or flozky some details
with no delay , the pitch controller use only the right side as "preview"
and it works , no over cut , nothing


anyway , I realy recommend the ultrapitch, it is a fantastic tool

I wonder if this requires mono cutting to use the 0 revolution "preview." Otherwise, if it's only going on right channel information, and if the left channel was louder somewhere than the loudest peak on the right, it could cutover, yes?

Normally, the system looks at the outside wall (right channel) in advance for feed and depth adjustments, and the inside wall (left channel), both in real time, for feed, and, in advance, for depth adjustments. The sum of both channels is saved, since either one can be bigger, during a given fraction of revolution.

For what it's worth, the full revolution look-ahead doesn't make only one change in feed per revolution, if more than one is warranted. It can make up to five moves in pitch per revolution, and stores a memory 25 times per revolution. This is done with on-board 6-bit AD and DA, at 20 kHz sampling rate (Less than 10kHz bandwidth - treble, as you may know, is not quite important to automation).


- Yves Ningcuts