v272 gaincontrol in the feedbackloop-too much level -distort

i xchanged r15 (trimpot) with following pots:
10k,47k and 100k-as i understood :
as higher the resistor as more gain i`ll get...

none of them lets me get a clean signal if the source is too hot...
when i scream into my mic level is too high even when the gain is all the way down...

shall i use a trimpot directly on the input of the amp ?

any ideas are welcome :grin:

Remember there's a resistor on the PCB in series with the trimpot that you replaced. You can have lower gain by reducing the fixed resistor's value. If you want to keep modifications to a minimum you can simply solder a wire across that resistor. But I'm not sure it's good for the feedback resistor to go all the way to 0 ohms, as the V272 is originally made for 34 db fixed gain. So you might want to solder a resistor to the gain pot (in series) that set the minimum gain.

[quote author="Rossi"]Remember there's a resistor on the PCB in series with the trimpot that you replaced. You can have lower gain by reducing the fixed resistor's value. If you want to keep modifications to a minimum you can simply solder a wire across that resistor. But I'm not sure it's good for the feedback resistor to go all the way to 0 ohms, as the V272 is originally made for 34 db fixed gain. So you might want to solder a resistor to the gain pot (in series) that set the minimum gain.[/quote]

to me it appears that i get even more distortion with an xtra resistor in series... :sad: :sad: :sad:

Well, that's actually what I said if you go back and reread my post. You must *reduce* the overall feedback resistor value to get lower gain. Bridge the internal resistor that is in series with the gain pot. Now your gain pot is the only resistor to set the gain. That's probably not good. Determine a suitable resistor value for minimum gain (i.e. a lower value than the resistor on the PCB). Now take a resistor of the value that you just determined and solder it in series with the gain pot. Another way would be to replace the internal resistor with a lower value, but sooner or later you'll lose the original resistor and can't return your V272 to its original state.