I made a booboo

[Microtone]

Hi you wonderful people.

I commissioned a few prototype PCBs for a simple distortion circuit to be made with SMD.

It seems that I made a mistake in the PCB design with the final capacitor before the board output. It should be 10NF but I mistakenly got them to put a 100NF in there.

Question: If I just hang a 10NF on the end after the 100NF, will it have the same effect as just having one 10NF at the end?

Also: if yes, could I also stick it in line after the volume control without any change to the sound?

Thanks for any hints!!

[ElectricDruid]

We'd need to see a schematic to be sure, but *usually* too big is better than too small for these coupling caps. Probably all that happens is that the HPF formed by the cap and the volume control has its cutoff pushed down by a factor of ten. 10nF is a small value for a coupling cap though, so this might not be right - like I said, need the schematic.

[duck_arse]

capacitors in series - the final value is always less than the lower of the two [values].

[fryingpan]

10n means, I guess, a 1Meg volume pot. That also means that whatever you connect the pedal to will significantly increase the low-end cutoff frequency.

[ElectricDruid]

10n means, I guess, a 1Meg volume pot. That also means that whatever you connect the pedal to will significantly increase the low-end cutoff frequency.

Yeah, this is why we *really* need the schematic, or at least the relevant bit of it.

[Microtone]

Hi all,

and thank you for the really helpful replies. That helps me understand it a lot more.

Rather unexcitingly, it is just a basic electra distortion circuit that I took off the internet. There seem to be a lot of schematics available.

The only changes I made were adding a capacitor off the emitter of the transistor to ground in parallel to the resitor and dropping the (npormally 100nf) output capacitor to 10nf because it seemed to sound better to me. More of my preferred mid range tone.

But then I had a brain fart when I designed the pcb and just copied the 100nf off the schematic, forgetting my mod!!

Thanks for all the help!

[fryingpan]

Well, you can just add a 10nF or a 15nF cap in series. The first will work out to 9.1nF, the second to 13nF. It won't be a huge difference. Maybe I'd go bigger rather than smaller.

[Microtone]

Well, you can just add a 10nF or a 15nF cap in series. The first will work out to 9.1nF, the second to 13nF. It won't be a huge difference. Maybe I'd go bigger rather than smaller.

Thank you so much for taking the time to help me learn!

[antonis]

Are we talking about PCB only or about already items populated one..??

In case of the former, I can't see any issue..
In case of the later, no bueno..

@Microtone: I'd put the 100nF there and change Volume pot to 100k..
(it will lower the gain 'cause it's effectively set in parallel with Collector resistor but the Emitter resistor bypass cap you've placed will settle gain up..)

P.S.
What's the Collector resistor value used..??