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Aquaboy DX - passing sound/no delay HELP ME!

Started by Stomptown, September 19, 2013, 01:02:01 PM

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Stomptown

So I am passing sound but have no delay with my Aquaboy DX build. I am using "verified" MN3005's I bought here off the forum and am running at 9V. I omitted D2/D3 as required. Here are my voltages:

IC1 (LF353)
1: 4.47
2: 4.47
3: 4.45
4: 0 
5: 4.45
6: 4.47
7: 4.46
8: 8.96

IC2 (NE570 compander)
1: .02
2: 1.80
3: 1.80
4: 0
5: 1.21
6: 1.18
7: 8.24
8: 1.81
9: 1.81
10: 4.48
11: 4.48
12: 1.82
13: 8.95
14: 1.80
15: 1.80
16: .22

IC3/IC4 (MN3005's)
1: 8.74
2: 4.38
3: 3.31
4: 3.31
5: 0
6:4.38
7: 3.06
8: .60

Edit: here are the correct MN3101 values (I measured the wrong device initially)

IC5 (MN3101)
1: 8.75
2: 4.39
3: 0
4: 4.38
5:4.11
6:4.47
7: 4.08
8: 0.6

Edit: here are the correct TL062 values (I measured the wrong device initially)

IC6 - TL062
1: variable (~0.68-8.3V)
2: variable (~4.0-5.06V)
3: variable (~3.64-4.97V)
4: 0
5: variable (~3.87-5.06)
6: variable (~4.01-5.02)
7: variable (~3.87-5.04)
8: 8.97

HELP Please!!! (Thanks in advance)


Stomptown


Scruffie

Umm... TL062 don't look so good... you got it in backwards? Seems like it could be shorting everything out with those values.
Works at Lectric-FX

Stomptown

#3
I double checked the TL062 and it is oriented correctly. I'm getting different results though. I updated the voltages in the post above...


Stomptown


gtr2

You have not mentioned anything about calibrating the delay.  Did you follow the steps outlined in the build doc?

Josh
1776 EFFECTS STORE     
Contract PCB designer

Stomptown

I tried to calibrate following the instructions but no luck. I am passing sound but there is no delay. I am worried the chips are fake but do not know if my voltages are suspicious. Does anything look off?

twin1965

Have you got an audio probe? You need to follow the audio signal through the circuit and see where it stops. This way you'll isolate the area where the problem is. Make sure to check all solder joints too. This circuit can be tricky to troubleshoot.

Sent from my GT-I9100 using Tapatalk 4


Stomptown

I am getting sound from the pedal just no delay. Even when I remove IC4 I am passing signal. I probed all of the IC pins suggested in the build doc and I am passing sound at those points. When I probe IC3/4 on pins 3 and 4 I am passing a signal but there is a high pitch whine. My problem is that I am getting no delay (bad chips). Is it possible to signal and still have an issue that would cause no delay (other than the obvious fake chips senario)? If I am passing a clean signal should I still probe the circuit to search for an issue? I see other post where people have blown the compander or the clock so I was hoping to get someone check my voltages. Are they okay? Could they be responsible for the lack of delay?

Scruffie

Your clock makes no sense, you have clock voltages on the 3005s... but half supply at the 3101 VD input, near full at VGG (yet not at the BBD) and no voltage on 4 where it should be half.

But whine suggests your clock is going... something is wrong.
Works at Lectric-FX

murdog47


Stomptown

Okay, so I need to apologize for asking for help and being soooo disorganized.  ::)  It appears that I screwed the pooch when I initially took my voltages. I have edited the voltages above and added the updated results to this post as well. It appears I measured IC1 and recorded the values under IC5. Hey Scruffie, how do the values look now for IC5? Also, I notice that others have had higher values off pin 1 and pin 16 of the compander. Is this an issue? I should have also mentioned that I did add D2 and D3 when I initially put this together and subsequently removed them once I realized I was supposed to leave them off with the MN3005 version. I did fire it up with these diodes in the circuit. Would this burn anything up? I also posted some pics below so people can take a look at then build and see if anything is out of the ordinary. Unfortunately I used PCB mounted pots so I only posted a top shot. Again, I apologize for my disorganization. I'm still a noob when it comes to troubleshooting circuits and will try to be more clear in the future...

IC1 (LF353)
1: 4.47
2: 4.47
3: 4.45
4: 0 
5: 4.45
6: 4.47
7: 4.46
8: 8.96

IC2 (NE570 compander)
1: .02
2: 1.80
3: 1.80
4: 0
5: 1.21
6: 1.18
7: 8.24
8: 1.81
9: 1.81
10: 4.48
11: 4.48
12: 1.82
13: 8.95
14: 1.80
15: 1.80
16: .22

IC3/IC4 (MN3005's)
1: 8.74
2: 4.38
3: 3.31
4: 3.31
5: 0
6:4.38
7: 3.06
8: .60

Edit: here are the correct MN3101 values (I measured the wrong device initially)

IC5 (MN3101)
1: 8.75
2: 4.39
3: 0
4: 4.38
5:4.11
6:4.47
7: 4.08
8: 0.6

Edit: here are the correct TL062 values (I measured the wrong device initially)

IC6 - TL062
1: variable (~0.68-8.3V)
2: variable (~4.0-5.06V)
3: variable (~3.64-4.97V)
4: 0
5: variable (~3.87-5.06)
6: variable (~4.01-5.02)
7: variable (~3.87-5.04)
8: 8.97

And here is a pic of the top of the PCB:

Do the MN3005's look fake?

Scruffie

#12
Looks aren't everything but they do look legit.

Your problem is your MN3101 is not generating a VGG voltage on pin 8.

Yes, leaving in D3 could possibly have hurt it.

Try lifting pin 8 of the 3101 and inserting a 6k8 resistor in series with 9v there... or make a voltage divider out of a 1k and a 14k (15'd be okay) to ground (with a 10uF to stabilize it) and put it there. No guarantee but the rest of the clock looks okay (without a scope/freq counter) and if that works you know to just replace it.
Works at Lectric-FX

Stomptown

#13
Quote from: Scruffie on September 21, 2013, 03:19:08 PM

Try lifting pin 8 of the 3101 and inserting a 6k8 resistor in series with 9v there... or make a voltage divider out of a 1k and a 14k (15'd be okay) to ground (with a 10uF to stabilize it) and put it there. No guarantee but the rest of the clock looks okay (without a scope/freq counter) and if that works you know to just replace it.

So I tried this and was able to get the voltage up to 13.6V (I added a road rage to run at 15 and used a larger resistor value to get to 14/15 of VDD). I also checked pin 8 on the MN3005's and was getting 13.6V there as well, but I was still unable to get any delay when I attempted to calibrate. Any thoughts? Fake chips? Ugh...  :'(

Edit: I also plugged the mn3101 clock into my porkbarrel and it worked fine...

Edit#2: so it turns out my compander is not working. I recently rebuilt my testing rig and added a tiny tester/headphone amp but it turns out I wired the probe incorrectly. Another bonehead move. Anyway, I probed pin 7 of the compander and there is no signal. There is also no signal in pin 7 of IC3 so it's no wonder I can't calibrate. Could a dead compander explain the clock issue on pin 8 or is that a separate issue?

jimilee

Quote from: Stomptown on September 22, 2013, 04:41:20 PM
Quote from: Scruffie on September 21, 2013, 03:19:08 PM

Try lifting pin 8 of the 3101 and inserting a 6k8 resistor in series with 9v there... or make a voltage divider out of a 1k and a 14k (15'd be okay) to ground (with a 10uF to stabilize it) and put it there. No guarantee but the rest of the clock looks okay (without a scope/freq counter) and if that works you know to just replace it.

So I tried this and was able to get the voltage up to 13.6V (I added a road rage to run at 15 and used a larger resistor value to get to 14/15 of VDD). I also checked pin 8 on the MN3005's and was getting 13.6V there as well, but I was still unable to get any delay when I attempted to calibrate. Any thoughts? Fake chips? Ugh...  :'(

Edit: I also plugged the mn3101 clock into my porkbarrel and it worked fine...

Edit#2: so it turns out my compander is not working. I recently rebuilt my testing rig and added a tiny tester/headphone amp but it turns out I wired the probe incorrectly. Another bonehead move. Anyway, I probed pin 7 of the compander and there is no signal. There is also no signal in pin 7 of IC3 so it's no wonder I can't calibrate. Could a dead compander explain the clock issue on pin 8 or is that a separate issue?
There's a thread around here somewhere, midwayfair was having issues with his also. He said, if I remember, it's easy to blow the compander.
Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.