# Tone Vendor - completely silent



## skrattadu (Mar 29, 2021)

Hey guys, I just wired up a the Tone Vendor MKI and it's not working. I've built many pedals before so I know the basic checklist to go through... check for shorts, re-flow solder joints, check the switch, etc. This one just isn't working. I'm thinking maybe it's the transistors?
Also, I subbed a 22uf electrolytic for the 25uf since I don't have any 25s laying around, could that be it?
Bypass works, when I hit the switch, it's dead silent.
Any help would be appreciated!!


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## Betty Wont (Mar 29, 2021)

Are you sure of your transistor pinout. Some of the russian transistors are different.


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## skrattadu (Mar 29, 2021)

I just put them in there so they matched the holes... how can I tell which is which?


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## Betty Wont (Mar 29, 2021)

Datasheets and multimeter/transistor tester. Look up the models of transistors you have.


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## skrattadu (Mar 29, 2021)

Found the diagram for it.
Base
Collector
Emitter
now... how do I know which leg goes where on the PCB? I tried following the schematic and I still got nothin'.


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## skrattadu (Mar 29, 2021)

Nevermind, I figured it out! Pinout was wrong. Thanks!


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## music6000 (Mar 29, 2021)

This is Pinout for PCB


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## skrattadu (Mar 29, 2021)

Thanks, got it! One more question: I had to change an electrolytic and now there's a high pitched squeal... did I fry that capacitor? What else could cause that noise?


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## Coda (Mar 29, 2021)

skrattadu said:


> Thanks, got it! One more question: I had to change an electrolytic and now there's a high pitched squeal... did I fry that capacitor? What else could cause that noise?



Is it constant? Or just with the gain control up?...


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## skrattadu (Mar 29, 2021)

Update: I figured out it's only when I have the power connected to the daisy chain with the rest of my pedals. It's fine when I connect the 1-Spot directly into it. It goes away if I turn the gain all the way down but right as soon as a nudge it up to about 8:00 it starts again and doesn't get any louder as I turn it up. I know that tone benders usually have problems when connected in a daisy chain, but PedalPCB says this has an onboard voltage inverter so it shouldn't be a problem...
edit: when using an isolated power source, it gives off a really high pitched dog whistle type sound... it's so high it's almost above the range of my hearing.


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## music6000 (Mar 30, 2021)

skrattadu said:


> Update: I figured out it's only when I have the power connected to the daisy chain with the rest of my pedals. It's fine when I connect the 1-Spot directly into it. It goes away if I turn the gain all the way down but right as soon as a nudge it up to about 8:00 it starts again and doesn't get any louder as I turn it up. I know that tone benders usually have problems when connected in a daisy chain, but PedalPCB says this has an onboard voltage inverter so it shouldn't be a problem...
> edit: when using an isolated power source, it gives off a really high pitched dog whistle type sound... it's so high it's almost above the range of my hearing.


Did you have to twist C & B Legs on your transistors, make sure they are not touching!


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## giovanni (Mar 30, 2021)

Did you try with a battery?


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## skrattadu (Mar 30, 2021)

So I went through and took the transistors off and re-soldered them and added a low pass filter to the output jack and that fixed the super high frequency ring. Still getting that squeal when hooked up to the daisy chain, and I figured out that it only happens when hooked up to other pedals. I hooked it up to the daisy chain for power and went guitar--->bender--->amp and it worked fine, but when I put it on my board with all my other pedals, it squeals.


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## music6000 (Mar 30, 2021)

skrattadu said:


> So I went through and took the transistors off and re-soldered them and added a low pass filter to the output jack and that fixed the super high frequency ring. Still getting that squeal when hooked up to the daisy chain, and I figured out that it only happens when hooked up to other pedals. I hooked it up to the daisy chain for power and went guitar--->bender--->amp and it worked fine, but when I put it on my board with all my other pedals, it squeals.


See if you can get a *7660SCPAZ* & swap out the *TC1044SCPA,* it's the only one I use & never had an issue!
I should ask where you got your TC1044SCPA, alot of members have had trouble with them from different vendors squealing.


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## skrattadu (Mar 30, 2021)

Update: Hooked it up to a battery and put it on my board and the same thing happened.


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## music6000 (Mar 30, 2021)

skrattadu said:


> Update: Hooked it up to a battery and put it on my board and the same thing happened.


See if you can get a *7660SCPAZ* & swap out the *TC1044SCPA!*
Mr PedalPCB has never had an Issue with TC1044SCPA .
I should ask where you got your TC1044SCPA, alot of members have had trouble with them from different vendors squealing.
*7660SCPAZ,* it's the only one I use & never had an issue!


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## music6000 (Mar 30, 2021)

Can you show a Picture of your Soldered side.
If your Board is not clean, it may be causing your issue!


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## skrattadu (Mar 30, 2021)

I got it from Tayda. I will clean off the solder side and see what happens.


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## skrattadu (Mar 30, 2021)

Cleaned the board, still squealing. I'll try one of those new chips!
What is it about the chip that might cause squealing when hooked up to other pedals?


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## skrattadu (Apr 3, 2021)

Swapped out the chip and it works perfectly! Thanks!!


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## skrattadu (Mar 29, 2021)

Hey guys, I just wired up a the Tone Vendor MKI and it's not working. I've built many pedals before so I know the basic checklist to go through... check for shorts, re-flow solder joints, check the switch, etc. This one just isn't working. I'm thinking maybe it's the transistors?
Also, I subbed a 22uf electrolytic for the 25uf since I don't have any 25s laying around, could that be it?
Bypass works, when I hit the switch, it's dead silent.
Any help would be appreciated!!


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## music6000 (Apr 3, 2021)

skrattadu said:


> Swapped out the chip and it works perfectly! Thanks!!


Did you use the *7660SCPAZ ?*


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## skrattadu (Apr 3, 2021)

Yessir!


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## yazooligan (Dec 7, 2021)

skrattadu said:


> Hey guys, I just wired up a the Tone Vendor MKI and it's not working. I've built many pedals before so I know the basic checklist to go through... check for shorts, re-flow solder joints, check the switch, etc. This one just isn't working. I'm thinking maybe it's the transistors?
> Also, I subbed a 22uf electrolytic for the 25uf since I don't have any 25s laying around, could that be it?
> Bypass works, when I hit the switch, it's dead silent.
> Any help would be appreciated!!
> View attachment 10671


What transistors did you use for this, and do you have any more?


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## skrattadu (Dec 7, 2021)

yazooligan said:


> What transistors did you use for this, and do you have any more?


I used GT108G transistors and I do not have any more of them. I have also used MP40s for Tone Benders and I think they work great too!


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## Dan0h (Dec 7, 2021)

It’s cool when things work out.


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## yazooligan (Dec 7, 2021)

skrattadu said:


> I used GT108G transistors and I do not have any more of them. I have also used MP40s for Tone Benders and I think they work great too!


Could I use three matched MP-40A’s?


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