Green Ringer / One Knob Fuzz

[dstraiton85]

Hi All

I'm hoping someone can help a kinda noob out.

Ive built a green ringer and a one knob fuzz. The idea is to house them in the one pedal, separate footswitches and a switch to change the order.

All was going well, The green ringer works perfectly  on its own, the fuzz works fine on its own. When i play the green ringer into the fuzz, it seems to work quite well.

The issue i have is that when i play the fuzz into green ringer i get a squeal sound when im not plying the guitar.

As they all work well separately and in one order, I'm racking my brains. Is this an known issue? should i be doing something to the signal coming out the fuzz?

Thanks in advance.

Donald

[antonis]

Hi & Welcome..

Green Ringer has an output buffer, so it doesn't mind for next effect input impedance a lot..
One knob Fuzz output impedance is quite high (Collector resistor in series with Volume pot lug 3 - wiper)..

What is the value of one knob fuzz Volume pot..??

P.S.
Could you post a schematic of effects order switch wiring..??

[dstraiton85]

Thanks for this. I had a feeling there was something funny going on.

The fuzz pot is a 500k log pot.

The One knob fuzz i have is:


Only difference is im using a 100r resister at the top, and two BC108C (high gain i know) for Q1 and Q2.

The green ringer is:




Using a 20k pot. No other changes.

Thanks again

[antonis]

Very well but you didn't post the effect order switch selector..

In case of switch wiring is OK, you'll have to try placing another 220pF (or so) cap between Collector & Base of Q2 (like the one in Q1)
in Fuzz layout..

P.S.
From correct design point of view, a Fuzz output buffer should be the ultimate solution, but it shouldn't be a Fuzz anymore.. 

[dstraiton85]

Of course, sorry. Im using an order switcher from fuzz dog..

[dstraiton85]

I tried adding the 200p cap and it cut the whole sound.

Looks like i will have to tinker around with an output buffer of some sort.

Thanks again for your advice.

[antonis]

I tried adding the 200p cap and it cut the whole sound.

Can't imagine how this happen..