Another guitarpreamp design using an oddball tube

[Alf]

Try lifting one end of the 470p cap. If your signal disappears then you have a problem. If your signal just becomes less bright then you don't.

I made the 470 p switchable and when it's out of the circuit ( bypassed) the the sound becomes less trebly so I guess it's okay.

That was a very extensive explanation, thanks a lot. It's much clearer now !


Alf

[Chuck H]

Off Topic: just saw the new Sig, Chuck! Thanks!

Justin

Certainly not the most eloquent quote I could have lifted from you, but I like it. So thank YOU

[Alf]

So now I changed the 1N ( 1000p) into a 100 pf cap (on the volume pot V1) that solved the whole problem !

It opened up the frequency range.


Thanks again , Chuck

[Chuck H]

Got right on that didn't ya

[Dave H]

Thanks Chuck, could you explain why you said a third of what's coming.....


How do I calculate that ?

A good way to look at it is to analyse the circuit with the capacitor open circuit (low frequency) and short circuit (high frequency). When the 470p across the 470k is open circuit the voltage at the cw end of the pot is 2/3 the input signal from the 22n. When the 470p is shorted the signal at the cw end of the pot is not attenuated.

[Alf]

A good way to look at it is to analyse the circuit with the capacitor open circuit (low frequency) and short circuit (high frequency). When the 470p across the 470k is open circuit the voltage at the cw end of the pot is 2/3 the input signal from the 22n. When the 470p is shorted the signal at the cw end of the pot is not attenuated.

I'll give it a try, Dave !