How can I re-gain some gain?

[Madison]

I started out with this idea 5X3. (EL34s not 6L6s)
I added a T/M/B to it so it ended up being basically an AA964 (minus the tremolo).

The amp sounds good and clean but it lost it's 5E3 charm and grind.
When I bypass the TMB it comes more alive.
Also, I haven't changed these yet  this yet but my tone pots are T-250k M-25K B-1M
The bass probably needs to be a 250K I think. Would replacing some of the tone pots add gain?

I have one additional triode open.
I prefer not to change the entire board over to a LTPI unless I absolutely have too (I know, I should have in the first place!).

Any ideas?
Thanks

[sluckey]

The bass probably needs to be a 250K I think. Would replacing some of the tone pots add gain?

Yes, the bass should be a 250K. If you replace the mid pot with a 250K it will become a 'raw' pot. You'll get lot's of controllable gain back.

[tubenit]

You can try adding a midboost or a PAB (preamp boost) to your tone stack.  I think you would find that it gives some ooomph back to the amp's gain.

With respect, Tubenit

[jojokeo]

The Raw/mid boost/PAB switch all just give more overall signal bandwidth & strength do to less of a loading effect similar to converting to only using a Tone control instead of the mid-scooped tone stack. This will give you more of that Tweed tone and feel back. As for more gain, are you running the 12ay on V1? Obviously use a 12ax for more gain. If you want to play with circuit then raise V1's load resistors to 220k and/or lower the shared cathode resistor by half as it's effectively a 1k5 on both triodes currently. Also, you could raise/double the 56k's on the pi & see if you like this effect on the amp or not?

[Madison]

I will try the pot change first and then a boost switch somehow (I already have the switch drilled, just need to hook it up)

>>As for more gain, are you running the 12ay on V1? Obviously use a 12ax for more gain.

Tried both, not happy yet

 >>>If you want to play with circuit then raise V1's load resistors to 220k and/or lower the shared cathode resistor by half as it's effectively a 1k5 on both triodes currently.

Check, still not regaining what I was hoping for

>>Also, you could raise/double the 56k's on the pi & see if you like this effect on the amp or not?'

I did in fact try thing.
Pretty interesting.
It brought a lot of hiss into the circuit.

I was still hoping I could use the unused triode somehow.

Will swap out the pots and report back.

It's close but no cigar.

There are some other threads I need to look at too for some ideas.

Thanks a lot!

[Madison]

Now  T/M/B are @ 250K.
Gain is pretty good.
Treble is ok.
Mid pot is really aggressive..... almost to much so.
Bass doesn't do much at all as far as lower frequencies go.
I messed with the coupling caps on that go to the bass but it didn't so much.
Switch the Bass pot to a 500K ?
Then I loose the some gain again?
 

[jojokeo]

I didn't realize you wanted to use the extra triode the way you mentioned it w/ the pi response. Shoot you can do whatever you want. If the tone stack cap increases don't give you the bass response you want then you have to raise the coupling cap(s). You know what to do...

[catnine]

 I went through something similar and trust me I am no expert . I tried the BF tone stack but I didn't have amid control . I started out with a 5E3 . and then thought about the standard BF tone stack with just the bass and treb and vol . However that sort of tone stack sucked all the feel out of that amp.

 I still had the slit phase PI . I had and extra triode to play with but didn't use it. I just went back to the simple tone stack used on the 6G2 or 5F2A and that got me back to a better sound .

 You almost need another gain stage before the PI it seems to get back the gain sort of like the 5E5-A uses , it's as close as I could find that still uses a split phase inverter. Plus 6L6's sort of lose the breakup that 6V6's provide.

 One other thing I found that may help since you seem to be trying to get back some bass is change the amp from cathode bias to adj/fixed bias or add a dpdt switch to have both .

[Madison]

Looks like I will try to enact this extra triode just to see what happens.

I'd just do a regular 5E3 set up but the cassis is already drilled and labeled.

Thanks guys