Post a quick pic of that part of the build.420troll said:
[BUILD] CAPI FC526~500 Series~FET Limiter Kit~Official Support Thread
- Thread starter jsteiger
- Start date
Help Support GroupDIY Audio Forum:
Did you check R42 closest to C17 or the other end?
Yes. You should measure the windings for DCR. That would be from pin-5 to 8, pin-1 to 3 and pin-2 to 4.420troll said:
420troll said:I put the transformer back in and tested everything again.
The signal good at R71 & R73.
No signal at R42 and ground.
With the transformer out I get 165.4ohms across pins 1 & 3 of the CA2622 location on the main PCB.
Transformer back in.
If I turn my O scope I can see this @ R42(yellow)
My noisy sine on the balanced input in blue @ 0.024vAC
This scope is not very accurate as far as voltages and frequencies.
Frequency & voltage were measured with a true rms DMM
Attachments
The 2622 DCR looks correct.
Maybe you have the 2 transistors swapped immediately after the 2622?
Maybe you have the 2 transistors swapped immediately after the 2622?
Check DCV at the top of R36 and then R37. Check on the ends closest to R40.
Whats the word O keeper of the schematics? I have been waiting a couple of days to hear back what to do next.
Out of about 60 DIY kits from effects to synths including the ARP 2600 clone, samplers, drum machines this is the most painful support, at this rate I guess i will have a 500$(Canadian dollars the cost for me )distortion unit. I have never had a project I could not get going even faulty circuit designs i have help provide insight into what could be going wrong why do you make this so hard for me? Some hi res pictures and a schematic I am guessing I could tell you where the problem is.
:-\
Out of about 60 DIY kits from effects to synths including the ARP 2600 clone, samplers, drum machines this is the most painful support, at this rate I guess i will have a 500$(Canadian dollars the cost for me )distortion unit. I have never had a project I could not get going even faulty circuit designs i have help provide insight into what could be going wrong why do you make this so hard for me? Some hi res pictures and a schematic I am guessing I could tell you where the problem is.
:-\
I do not publish the schematic for this project. I never have. I am honestly lost as to where you are and what your problems are. I got the impression from your last post that something dramatically changed when you put it all back together. I do not have all of the test point data memorized so it would be helpful if you could post what you have vs what it should be.420troll said:
What test points would you like? all of them? I am stuck at TP.1= 0volts AC
BUT
If I put in an AC sine1kHZ and -6.1dbu or 0.380v
My test TP1 = -42.4dBu or appx 5.8mV AC
MY TP2 @ 0.161vAC
MY TP3 @ 1.286vAC
MY Output 2.57vAC appx 10.4dbu
Your notes that tell me to "Apply a 1kHz sine wave @ -30dBu to the input."
So instead of -30dbu i am putting -6.1dbu thru to get the signal to TP.1
Your calibration notes
**Audio Path**
TP1 Immediately follows the balanced receiver opamp, just before the RV6 input pot. Signal
here should be 12.4dB lower than the balanced signal level at the input of the module.
TP2 Immediately follows the signal preamp opamp, just before the RV5 output pot.
TP3 Immediately follows the output opamp, just before the T1 output transformer. Signal level
here will be approximately 6dB lower than the module’s balanced output.
Audio Path Test: With the VVR FET fully out of conductive range (RV2 fully CW), turn both
input and output pots wide open or fully CW.
Apply a 1kHz sine wave @ -30dBu to the input.
Why not include the volts AC above??
You should have the following:
TP1 = -42.4dBu or appx 5.8mV AC
TP2 = -16.3dBu or appx 117.7mV AC
TP3 = +1.73dBu or appx 939mV AC
Module’s Output = +7.75dBu
Basically it seems as all switches and knobs work meter responds but the sound is very thin unit seems to boost to the high frequencies and cut to the low frequencies on spectrum analyzer with white noise, triangle waves come out as squares on O scope
BUT
If I put in an AC sine1kHZ and -6.1dbu or 0.380v
My test TP1 = -42.4dBu or appx 5.8mV AC
MY TP2 @ 0.161vAC
MY TP3 @ 1.286vAC
MY Output 2.57vAC appx 10.4dbu
Your notes that tell me to "Apply a 1kHz sine wave @ -30dBu to the input."
So instead of -30dbu i am putting -6.1dbu thru to get the signal to TP.1
Your calibration notes
**Audio Path**
TP1 Immediately follows the balanced receiver opamp, just before the RV6 input pot. Signal
here should be 12.4dB lower than the balanced signal level at the input of the module.
TP2 Immediately follows the signal preamp opamp, just before the RV5 output pot.
TP3 Immediately follows the output opamp, just before the T1 output transformer. Signal level
here will be approximately 6dB lower than the module’s balanced output.
Audio Path Test: With the VVR FET fully out of conductive range (RV2 fully CW), turn both
input and output pots wide open or fully CW.
Apply a 1kHz sine wave @ -30dBu to the input.
Why not include the volts AC above??
You should have the following:
TP1 = -42.4dBu or appx 5.8mV AC
TP2 = -16.3dBu or appx 117.7mV AC
TP3 = +1.73dBu or appx 939mV AC
Module’s Output = +7.75dBu
Basically it seems as all switches and knobs work meter responds but the sound is very thin unit seems to boost to the high frequencies and cut to the low frequencies on spectrum analyzer with white noise, triangle waves come out as squares on O scope
You can monitor any of the 3 audio Test Points by listening or scope or whatever. If you have issues at TP1, the following audio TP's do not matter as it won't magically come back. I thought you said something changed but it seems that is when you put a higher level signal to the input which is not suggested anywhere. If your levels look fine at the input of the 2622 (R71, R732) and nothing at R42, then it still points to the 2622, which is odd. I have not had a bad one yet from this winder. Are you sure its orientated right? The outside mu-can ground wire should be facing the opamps.
You will have to pull it again and see if there is any shorting between windings. Also check from the signal pins to the outside mu-metal can. So make sure pin-1 only has DCR to 3 and not to 2, 4, 5 or 8 and also not to the outside of the can, rinse and repeat for all signal pins.
You will have to pull it again and see if there is any shorting between windings. Also check from the signal pins to the outside mu-metal can. So make sure pin-1 only has DCR to 3 and not to 2, 4, 5 or 8 and also not to the outside of the can, rinse and repeat for all signal pins.
Everything checks out with the 2622. After your tests I also put a sine wave thru pins 1&2 together as + and 3&4 as - and it amplified and put the signal out on pins 5&8 fine
What about a picture of a working unit? Or I can send you more of mine besides the one in Reply #301
What about a picture of a working unit? Or I can send you more of mine besides the one in Reply #301
