Inverse RIAA curve Circuit + Info
Moderators: piaptk, tragwag, Steve E., Aussie0zborn
- cuttercollector
- Posts: 431
- Joined: Sun Jun 11, 2006 4:49 pm
- Location: San Jose, CA
I have used a last generartion Shure V15 VxMR as a cd4 cartridge with good results. The Panasonic cd4 strain gauge/piezo sounds quite OK with stereo discs too. I have a used Micro-Acoustics which I have never tried, but might soon. I remember a friend having one back when they were new and it sounded really good!
Re: RIAA Ecoder Jamaica Style
helloDoug 6N wrote:Hi:
Can anyone tell me the value of the capacitor above the 100k resistor which is above the cutter switch? Between A-3 And A-4.
I cannot make out the printing on the diagram.
Thanks in advance
Doug
i use 318 nanofarad, 0,318 microfarad, MKP the big one at the right in the pic
This preamp works good! its the original, no adds, exactly the Flo schematics
I believe the 318 nanos cap its a part of the filter first step, i need change a little for plus or minus hi frecuency response, but now sounds good
i waiting the current sensor, the last add
Great computer I think the owner of that computer is a great care taker of that thing.,
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irs problems
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irs problems
Yeah Carlos is in Aragon He may not have IRS issues Is this what you mean?ProbZer wrote:Great computer I think the owner of that computer is a great care taker of that thing.,
________________
irs problems
Cheers
Hi,
The op-amp based circuit would not translate well to a tube version. It relies on a high open loop gain. I think the easy way to do a tube based IRIAA would be to use Flo's passive circuit with tube makeup gain, input buffering and output summing for the feedback. IIRC, that circuit had a 20db loss at midband. Some 12AX7's should work well for that.
The best bet would be to pick up an old tube preamp on ebay (e.g. Dyna, Heathkit, Eico, Fisher, etc) and modify it to do the IRIAA. It would give you a big leg up as opposed to contruction from scratch.
Mark
The op-amp based circuit would not translate well to a tube version. It relies on a high open loop gain. I think the easy way to do a tube based IRIAA would be to use Flo's passive circuit with tube makeup gain, input buffering and output summing for the feedback. IIRC, that circuit had a 20db loss at midband. Some 12AX7's should work well for that.
The best bet would be to pick up an old tube preamp on ebay (e.g. Dyna, Heathkit, Eico, Fisher, etc) and modify it to do the IRIAA. It would give you a big leg up as opposed to contruction from scratch.
Mark
If your sound is distorted then I can think of a couple things immediately. One, you might have wired your op-amp incorrectly (i.e. you did not wire up the correct pins for voltage, input, output, feedback). Two, you might have wired the resistor on the op-amp such that it is not damping the feedback current and the op-amp is running at full amplification.
Check your pinout diagram for your op-amps and make sure you wired all of your correctly.
Check your pinout diagram for your op-amps and make sure you wired all of your correctly.
Thats the thing.... I checked the wiring a couple times. Checked datasheet of op-amp for pins... no philosophy here, straight as is on the schematics by Flo.opcode66 wrote:If your sound is distorted then I can think of a couple things immediately. One, you might have wired your op-amp incorrectly (i.e. you did not wire up the correct pins for voltage, input, output, feedback). Two, you might have wired the resistor on the op-amp such that it is not damping the feedback current and the op-amp is running at full amplification.
Check your pinout diagram for your op-amps and make sure you wired all of your correctly.
Thanks for help... will go to sleep and check again tomorrow.
D
Hi,
Some things to check. Measure the DC voltage on the output pins of each opamp with no signal applied. They all should be near 0Vdc. Anything over .1 Volt would indicate a hookup problem. If you have a scope, check for oscillation. Note that bypass caps are not shown on the schematic, but their use is implied and necessary. At a bare minimum, you should have .1uf caps located close to the power supply pins for each opamp. Also you should be sure your power and grounding methods are nice low impedance runs.
Mark
Some things to check. Measure the DC voltage on the output pins of each opamp with no signal applied. They all should be near 0Vdc. Anything over .1 Volt would indicate a hookup problem. If you have a scope, check for oscillation. Note that bypass caps are not shown on the schematic, but their use is implied and necessary. At a bare minimum, you should have .1uf caps located close to the power supply pins for each opamp. Also you should be sure your power and grounding methods are nice low impedance runs.
Mark
- subkontrabob
- Posts: 284
- Joined: Fri Oct 30, 2009 5:40 am
- Location: Helsinki, Finland
By saying testing board, do you mean breadboard?d wrote:I just did on testing board and without any luck.
http://en.wikipedia.org/wiki/Breadboard
Yep. You are right - breadboard.subkontrabob wrote:By saying testing board, do you mean breadboard?d wrote:I just did on testing board and without any luck.
http://en.wikipedia.org/wiki/Breadboard
all of flo's info is gone.. wish i would have saved them, coz i could use it now..lol
I found this, it as all the components listed..
http://www.hagtech.com/pdf/iriaa.pdf
you can get the board for $50, or you can make it ur self..
I am interested as to wat people have to say, before i spend time building it
I found this, it as all the components listed..
http://www.hagtech.com/pdf/iriaa.pdf
you can get the board for $50, or you can make it ur self..
I am interested as to wat people have to say, before i spend time building it
generally its for reproduction.. but i like to play wif it sometimes..
Hi Jay,
$50 is pretty steep for a simple blank PCB, but he's probably not getting rich making these.
One issue I see with his design is that it is low impedance (you should drive from a 50 ohm source). I didn't run a SPICE simulation to see how much source impedance affects the response, but most modern SS electronics should be ok with it.
Flo's is version is very similar, but much higher impedance.
Mark
$50 is pretty steep for a simple blank PCB, but he's probably not getting rich making these.
One issue I see with his design is that it is low impedance (you should drive from a 50 ohm source). I didn't run a SPICE simulation to see how much source impedance affects the response, but most modern SS electronics should be ok with it.
Flo's is version is very similar, but much higher impedance.
Mark
well, i was just going to get the parts, and make it on a breadboard, if it works, then move it to a perf board.
mmm.. it's interesting that you think the impedance is low, since it talks about hooking up a CD player as the input..
I wanted to build flo's, it's gone.. do you have the image, and parts list?
mmm.. it's interesting that you think the impedance is low, since it talks about hooking up a CD player as the input..
I wanted to build flo's, it's gone.. do you have the image, and parts list?
generally its for reproduction.. but i like to play wif it sometimes..
Hi Jay,
Check you email. I have sent the images I have from Flo. Let me know if you don't get them.
It is low impedance. Note the indication for 50 ohm input on the schematic. However, most SS devices have very low output impedances, CD players included, so it should be no problem. It might be an issue if you try to drive it from an older tube based device.
Mark
Check you email. I have sent the images I have from Flo. Let me know if you don't get them.
It is low impedance. Note the indication for 50 ohm input on the schematic. However, most SS devices have very low output impedances, CD players included, so it should be no problem. It might be an issue if you try to drive it from an older tube based device.
Mark