6SN7 low plate voltage for lower gain?

[Ryssen]

Well it´s playing now,and no problem starting the bass amp before.Maybe the bassamp has built in cap for input I rally cant see it so small..
Only a little problem a little scraping sound and noise in one channel,if I tap the tube it is only noise in one channel,if i wiggle the tube in the tube socket i dissapares.
Now I will adjust the levels with Nadja to the mid and tweeter.

 

[Ryssen]

There between the speaker and the bassamp...

 

[Ryssen]

Indeed, as inferred, SemperFi;


(For a 12AT7/6SN7 e.g. Ra = 47K; Rf = 180K; Rg = 82K for gain of the order of 2.)

I need more gain!...
When I get the bass as I want,the meter on Nadja is hitting red.
If I paralell Rg with a 10Kohm resistor do I get 10X then (about)?

 

[Ryssen]

Bump to the question above.
And What gain will there be if I just remove the feedbackresistor?

 

[Ryssen]

I got 8....

 

[Ryssen]

Now i got the amont of bass that I need,now I just want a pair of basshorns instead of the bassreflex,but thats another story...

 

[soulmerchant]

Hmm,thanks for the build tips.sorry to say that I allready made the box and theres no place for another tube.
If I dont get this one working (will connect the bassamp tomorrow)I will make a new top for the box and build with youre schema.

But I wonder,ain´t caps supposed to block DC?Then why dont they?

Ketje's schematic just has a little neon lamp added. Cheap and effective and doesn't really need much space at all. It can easily go under the hood.