Ersatz Verben help!

[GammaFlex]

So I have been pulling my hair out for the past 3 days trying to get this thing to work. I have triple checked voltages, pinouts, layouts, audio path, literally just about everything I am capable of checking and it still just doesn't work. I have tried it with 4 different PT2399s and there is just nothing going on.

Here's the schematic that culturejam posted



And here's the layout I used from tagboardeffects

http://tagboardeffects.blogspot.com/2012/03/ersatz-verben-psuedo-reverb-by.html

And here's my board



It is hard to see it because the jumper on the left hides it but there is a 1k resistor going from pin 6 to the 1 lug of the "Time" pot. The regulator is a 7805, I have already tried the 78L05 and still no results.

Solder Side....



Another view....


The pot values are all as stated on the schematic except I changed the time pot to 100kB for longer delay times

Please help as I'm getting to the point of just never wanting to work with ICs at all lol

[vigilante397]

I've built this effect from the same layout so I can promise you it's fine, but here are a couple things I noticed:

1) Solder bridges: it looks like on the double link you have a pretty massive solder bridge, but since there's a connection there anyway I'm not sure the problem. BUT, the soldering looks super sketchy around the voltage regulator, and if there's a bridge there then that will be a HUGE problem.

2) Regulator: In my experience with PT2399 based circuits (I've built more delays than I care to admit) 90% of the problems come from the regulator. I always use 78L05s and have never had problems, but the main thing you need to check for is the output voltage from the regulator. If you're getting anything above 5.2 V or so you're going to be in trouble and likely fry your PT2399. So I would say leave the IC out and just give me the voltages from the regulator and we can work from there

[Luke51411]

I just built this last night from the same layout and no luck. If I turn the feedback all the way up I get oscillation of internal noise I assume. No clean or delayed signal coming through mine. I hadn't gotten to troubleshooting yet but I just figured it was a short or bad solder joint somewhere in the beginning that wasn't allowing the signal to get to the chip. I will see what I can come up with when troubleshooting later tonight. Don't give up you will figure it out! I've had it happen once that the layout was verified but was incorrect still though it was a very recent verify. It seems like a few people have had problems with this circuit judging by the comments over there. It will probably be helpful for you to post the voltages you are getting as well.

[mth5044]

You don't say what isn't working. Do you get bypassed signal? Do you get signal but no delay? Please be specific. Have you used an audio probe yet? Post your voltages.

[vigilante397]

You don't say what isn't working. Do you get bypassed signal? Do you get signal but no delay? Please be specific. Have you used an audio probe yet? Post your voltages.

+1

Voltages help us help you

[GammaFlex]

I get the signal whether it's bypassed or not, so when I flip it on I can adjust the pots and get some changes in tone but I don't get the delay effect, does that make sense?

I'm going to run over it with a knife and take care of any possible solder bridges I missed. Going to get a regulator voltage reading now.

[GammaFlex]

Alright, regulator output is reading at 4.38v

I don't have an audio probe so I can't really do much with that, going to get pin voltages now....

[Luke51411]

Regulator voltage should be right at 5v I would think. ANytime I've measured them it has been around 5.03 or something like that. What is your supply voltage at?

[GammaFlex]

Supply voltage is readin 9.38, here are the pin voltages


1: 2.56
2: 2.56
3: 2.56
4: 2.56
5: 2.56
6: 2.56
7: 2.56
8: 2.56
9: 3.86
10: 3.86
11: 2.56
12: 1.31
13: 4.9
14: 4.9
15: 2.56
16: 4.38

[Luke51411]

You should have 0 volts on 3 and 4 as they are going to ground and 0 on 5 as it is not connected. I'd look for a solder bridge in that area or a missing or incorrect jumper. What are you getting at all three pins of the regulator?

[Luke51411]

Check the pinout of your voltage regulator as I believe the L7805 in the to-220 packaget (which is what it looks like you are using) are different than the 78l05 in the to-18 package as is on the layout.

[GammaFlex]

Alright... so I have a working delay now, and here's what I found...

I removed the 7805, redid the soldering (lots of good desoldering practice) ran over the entire circuit with the iron and retouched all the points, the components were in the proper locations as I rechecked them against the layout. Cranked up the heat on the iron and eliminated all solder bridges. Also noticed something, I took some of my pin voltages backwards (dyslexia).

The sound is awesome, it has just the right amount of "lo-fi" for my needs, thanks for the help guys! it is appreciated

[Jdansti]

Glad you got it working. I built one a while back and it works fine. Something I always check when troubleshooting PT2399 based pedals is that I have a solid 5V on pin 1 of the chip.

[Luke51411]

Ok I guess it's my turn to ask for help now. I'm getting no dry or delayed signal but at a extreme settings I get oscillation of internal noise. I think the signal just isn't getting to the pt. my voltages are as follows:
I 9.1
G 0
O 4.95

1- 4.92
2- 2.45
3- 0
4- 0
5- 3.6
62.4
7 3.9
8 3.9
9 2.45
10 2.45
11 2.4
12 2.45
13 2.45
14 2.45
15 2.45
16 2.45
I built the same layout
Does the dry signal come in to pin 16 or is there somewhere else I should look for where the signal is getting broken?

[mth5044]

If you're not getting dry signal then it's likely a switch wiring problem

[Luke51411]

I don't have it wired to a switch. I have prewired jacks that I plug into a breadboard and then plug the circuit into. It's my prototyping setup.

[Jdansti]

Using the schematic, follow the signal path on your build from input to output (R1 to C1 to R3 to R5 to Mix pot, etc). Check each components' connection to make sure they are correct.

After that, if you still have a problem, you can jumper from the input tip to the output tip. You should get dry signal. Then work backwards by moving the end of the jumper connected to the output tip to each component in the signal chain until you lose signal. That point should be where your problem lies.