Pcbguitarmania vu-tron

Solution
Some update:

I tried new 5089 from digikey. Same issue. No effect. So I ordered a new pcb from pcbguitarmania, since I was building this for a good friend’s bassist and my enclosure labels matched it.

Pcbguitarmania takes forever to fulfill orders - either he is shipping 1k units a day or … anyways, the new one isn’t shipped yet so I had time to debug. Decided to perform a full connectivity check.

Found a clear missing link from R12 to the Range pot. Never ever have I found this on ppcb or other sites. Not sure if missing connects are normal. I hope not.. coz they’re painful to find.

Shorted that link and it works! 5088 works as well. The NTE equivalent transistors work too. Have to say the effect circuit is absolutely fun! I’m...
Just checked kraken and it does use 5088s. AFAI can see the circuit in context of the NPN is identical except kraken uses ca3080. And the replacement 16pin 13700n is indeed the selling point for pcbguitarmania. I wonder if the Vb generated using 5088 is different then 5089.


There is a voltage map here on pg13. At least I can compare some of them with mine.

@Diynot what transistors did you use for your build?
 
Just checked kraken and it does use 5088s. AFAI can see the circuit in context of the NPN is identical except kraken uses ca3080. And the replacement 16pin 13700n is indeed the selling point for pcbguitarmania. I wonder if the Vb generated using 5088 is different then 5089.


There is a voltage map here on pg13. At least I can compare some of them with mine.

@Diynot what transistors did you use for your build?
I used 5089 and 87
 
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So just to be sure, you have gone through and verified your resistor/cap values, correct?
Yes, I’ve twice. I think I’m pretty sure about that.

I’m thinking based on @Gordo comments and the fact you’re following BOM as well, it’s very clear that I’m off-base here. Just ordered 5089s. I’ll keep you all posted.
 
Yes, I’ve twice. I think I’m pretty sure about that.

I’m thinking based on @Gordo comments and the fact you’re following BOM as well, it’s very clear that I’m off-base here. Just ordered 5089s. I’ll keep you all posted.
Maybe the higher gain of the 5089 is needed to open the envelope?
 
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One last thing, probably one of the best things you can do at this point and I say this in the most supportive way possible knowing that you said this is not representative of your normal work, but try and tighten up your build while you are waiting on those 5089s. Make sure the components are tight to the board, the solder joints are good no bridges/cold joints, Clean the board, and replace any parts the might have been damaged during troubleshooting.
 
Some update:

I tried new 5089 from digikey. Same issue. No effect. So I ordered a new pcb from pcbguitarmania, since I was building this for a good friend’s bassist and my enclosure labels matched it.

Pcbguitarmania takes forever to fulfill orders - either he is shipping 1k units a day or … anyways, the new one isn’t shipped yet so I had time to debug. Decided to perform a full connectivity check.

Found a clear missing link from R12 to the Range pot. Never ever have I found this on ppcb or other sites. Not sure if missing connects are normal. I hope not.. coz they’re painful to find.

Shorted that link and it works! 5088 works as well. The NTE equivalent transistors work too. Have to say the effect circuit is absolutely fun! I’m glad it sounded so good after all this bs.

Now I’m sitting on bunch of 5089s, 13700N and extra pcb of vutron…
 
Solution
Some update:

I tried new 5089 from digikey. Same issue. No effect. So I ordered a new pcb from pcbguitarmania, since I was building this for a good friend’s bassist and my enclosure labels matched it.

Pcbguitarmania takes forever to fulfill orders - either he is shipping 1k units a day or … anyways, the new one isn’t shipped yet so I had time to debug. Decided to perform a full connectivity check.

Found a clear missing link from R12 to the Range pot. Never ever have I found this on ppcb or other sites. Not sure if missing connects are normal. I hope not.. coz they’re painful to find.

Shorted that link and it works! 5088 works as well. The NTE equivalent transistors work too. Have to say the effect circuit is absolutely fun! I’m glad it sounded so good after all this bs.

Now I’m sitting on bunch of 5089s, 13700N and extra pcb of vutron…
Too bad you gave them more money
 
Not a bad place to be sitting, plenty of circuits out there to use the 5089s and 13700s in
I was wondering about that. I know lovepedal uses 5089s quite a lot. Some Ross compressor clones use 13700n and some other filter circuits.
I’m not much of a filter guy. This bruised and battered vutron will serve me well for a long time. If you’ve any other suggestions please let me know.
 
You can use the 5089s just about anywhere you use a 5088.

The 13700 is used on compressor circuits other than just Ross clones...

If you tell PCBGuitarMania you have an issue with the board, he'll likely send you the new one for free or give you a store credit (though you may not want another PCB from PCBGM).
 
If you tell PCBGuitarMania you have an issue with the board, he'll likely send you the new one for free or give you a store credit (though you may not want another PCB from PCBGM).
Trust me I’ve asked him. He is well aware of my (painful) journey of vutron. He has been responsive throughout… although with absolutely zero productive suggestions. He responded to my email detailing the issue with a “maybe a factory issue of your PCB”.

But he has stopped responding since my last email requesting a refund or any adjustment to the new order. I ordered The second pcb on april 21. No status updates on it. I asked him can he check if the new pcb I ordered has this issue. No response.
 
Your experience mirrors my own (order was missing PCBs, extras of others). I ordered from him when he first started up, so he bent over backwards to make it right and even gave me a PCB that wasn't even available from his store (available now, though), but no build docs. So a year later I finally traced the freebie PCB myself and made my own schematic, did the same for the Fuzz Gun PCB (again, no build docs for over a year) — he said I could have a Sagan Delay for my schematic efforts. I never took him up on the offer, and just as well — from what I've read a lot of people trying to build the Sagan Delay are running into problems with that board.

He's enthusiastic, but careless and not detail-oriented, so I guess since he first started up he's now tired of bending over backwards to fix things.

I've still got a few of his boards to build, one of which I know has issues from other people building it. If I'd built it up right away I probably wouldn't have been able to figure out what's wrong, 'cause I'd just assume the PCB is good. Now I'll be ready for anything on those remaining PCBGM builds.

Good luck with your incoming Vutron.
 
I was wondering about that. I know lovepedal uses 5089s quite a lot. Some Ross compressor clones use 13700n and some other filter circuits.
I’m not much of a filter guy. This bruised and battered vutron will serve me well for a long time. If you’ve any other suggestions please let me know.
Looking through my past build docs, these are projects I’ve built that use an lm13700 (plus or minus a ton more parts:
PPCB- Minnow, Lowtide
Aion fx- Tri-vibe
Lectric fx- Abacus (also uses a ton of 5088 that you might be able use those 5089s in)
Pcbmania (if you want to roll the dice again)- Master phaser it’s a maestro phaser clone so you might be able to find a similar board elsewhere
 
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