madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: GammaFlex on July 14, 2014, 05:34:30 PM

Title: Ersatz Verben help!
Post by: GammaFlex on July 14, 2014, 05:34:30 PM
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, crossed points, solder joints, sockets, 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

(https://farm3.staticflickr.com/2927/14652036084_b2d22bb1cb_z.jpg)

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

(https://farm4.staticflickr.com/3835/14674049793_1701d8462e_z.jpg)

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....

(https://farm3.staticflickr.com/2910/14653732062_4c02d15ddd_z.jpg)

Another view....
(https://farm3.staticflickr.com/2936/14653736232_688e21b8b5_z.jpg)

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.
Title: Re: Ersatz Verben help!
Post by: midwayfair on July 14, 2014, 05:44:06 PM
So what ARE your voltages?

Have you audio probed pins 11-16?
Title: Re: Ersatz Verben help!
Post by: flanagan0718 on July 14, 2014, 05:58:28 PM
Looks like there a a few bridges to say the least.
-Check where the regulator is
-check under the IC socket. make sure you have the double jumper
-check where the Pot wires are soldered on.
-check for correct pinout on 7805
-Pin voltages are good too!
Title: Re: Ersatz Verben help!
Post by: selfdestroyer on July 14, 2014, 07:33:35 PM
Run a razorblade down the middle of the traces and then do a continuity test on the traces and see if you have any shorts. I have built this from the same layout by Mark so I know it "should" work.

Cody
Title: Re: Ersatz Verben help!
Post by: culturejam on July 14, 2014, 07:45:48 PM
I'm pretty sure it should be 78L05. I think the only part I had at the time was the 7805 and I was too ignorant to know the difference.
Title: Re: Ersatz Verben help!
Post by: GammaFlex on July 14, 2014, 08:29:09 PM
here's the pin voltages, I just retook them so that I know they're fresh

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

I'm going to check for solder bridges and maybe put the 78L05 back in? We'll see what happens..
Title: Re: Ersatz Verben help!
Post by: midwayfair on July 14, 2014, 09:36:06 PM
Look at the datasheet.

http://sound.westhost.com/pt2399.pdf

And the schematic for the pedal you're building. You have half supply on a pin that should be grounded. You have half supply on a put that should be your supply voltage. You have more than half supply, all the way up to supply voltage, on multiple audio pins, all of which should be 2.5V.

You must have NUMEROUS problems, including solder bridges and missed connections, for this to happen. You need to pull out the multimeter and use the continuity setting, not your eyes.
Title: Re: Ersatz Verben help!
Post by: GammaFlex on July 14, 2014, 09:41:38 PM
I did, I know it sucks that's why I'm troubleshooting it.
Title: Re: Ersatz Verben help!
Post by: GammaFlex on July 15, 2014, 12:11:29 AM
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). Now the voltages read correctly, it works well, and I'm happy.
Title: Re: Ersatz Verben help!
Post by: flanagan0718 on July 15, 2014, 12:49:09 AM
Awesome! A working vero is an accomplishment! Congrats!


Sent from my iPhone using Tapatalk
Title: Re: Ersatz Verben help!
Post by: jimilee on July 15, 2014, 01:07:30 AM
Is that just slapback delay? I like it.