more gain at low volume

[EL34junkie]

I just built my first Trainwreck Clone for a buddy and he loves the way it sounds cranked up but wants more gain at lower volume. I have already amped the preamp stage up by changing the 500pF cap leading into the treble pot to a 220pF (Fender Cap) and changed the 56k between leg 6 of the #2 12AX7 to the leg 2 of the 3rd 12AX7 to 170K. He loves it now except at low volume. Any suggestions would be helpful.

[Gibsonman63]

Fewer speakers.

I can definitely crank much more through a 1x12 cabinet than a 4x12. A 2x12 or a 4x12 will sound better, but moves a lot more air. Some gigs I bring a 1x12 and turn my cabinet facing the wall.

Maybe even a less efficient speaker if the voicing sounds ok.

[EL34junkie]

The cab is not the issue. We have ran it through 2 different 4 x12 cabs, 2 x 12 cab, and 1 x 12 cab and he still has the issue. All of these cabs are new as well. Marshall 4 x12, Mesa Boogie 4 x12 and 2 x12, and Vox 1 x 12. Like I said, he loves it with the volume on 10 but when you get down around 3 the gain is almost gone. He said it sounds like the first AC/DC album. We are going to try a cap test box tonight after the store closes and see if I can boost the last input tube.

[da Geezer]

Sounds like an attenuator may be in order(?)

G

[Gibsonman63]

or VVR.

Search VVR and Express. I didn't install it in mine, but I did on my Liverpool. I don't have enough time with it for a full report, but it seems to work well. The Express is a bit more complicated because the VVR has to adjust bias as you dial down B+.

There are also various PPMV schemes as well that could work for you.

But of course, nothing sounds quite as good as a well built tube amp working hard.

[EL34junkie]

Thanks Gents. I used the cap box and went across the 10k going to the 3rd leg of the 2nd 12AX7 and he loved it. Think I will try this and see what happens. Any other suggestions would be welcome still.

[billyz]

Thanks Gents. I used the cap box and went across the 10k going to the 3rd leg of the 2nd 12AX7 and he loved it. Think I will try this and see what happens. Any other suggestions would be welcome still.

Well seeing as you already bypassed the Cold Cathode stage. You could go all the way and change the 10K cathode resistor to 1.5K.

If you want more distortion start upping the Plate load resistors. 220K will get you there fast.

You can also increase the Grid load resistor to the third stage, R7 on the Kelly Schematic, try 220K or higher, even put in a pot to vary it.

[EL34junkie]

thanx billyz for that info. He has played it several times today (work in a music store) and is really diggin it for now. I will keep that in my back stock in case he comes later and wants something different.