very loud preamp

[vlljpior]

I built a push-pull amp. 6sl7 phase inverter and 6v6gt tube. When i push the preamp gain to is maximun ( guitar distortion ) i'm not able to control the volume. I turn the 1 meg pot a little bit and the amp is very loud.

Should i upgrade to a 2 meg volume pot or what else i can do to reduce my peak-to-peak voltage from the preamp ?

 

[SY]

A 2 meg pot will not change anything. Your problem is either too much gain or a miswired pot (check the ground connection especially).

 

[vlljpior]

Before this amp configuration, i use it via paralle 6v6 tube and everything was o.k. After i add the 6sl7 ( phase inverter ) tube and change the configuration to puch-pull. Then i have this problem of very loud preamp.

 

[SY]

Gain.

Can you post a before and after schematic? With that, we could give some concrete suggestions.

 

[vlljpior]

I WILL SEND IT SOON

 

[Sch3mat1c]

The distortion you are getting is because the amp is overloaded, it's trying to do what it can with the large signal you are giving it. Once it starts distorting good, there isn't much you can do with a volume control on the input side. (Giving it a signal larger than one it cannot already handle isn't going to magically make it work.)

Tim

 

[Yvesm]

And ... is the volume Pot a logaritmic one ?

 

[vlljpior]

Yes the volume pot is log.

But I made some mod to the power amp section. I change the desing layout lika a fender champ deluxe. And, now, he work much better.

But, now, i have some hiss when the gain is higher... another solution... ?