Advice on 5e5a/tremolo build?

[Diverted]

Hi all,

New to the site. Great stuff!
I wanted to get some clarity on something ... I'm getting ready to start building a Fender 5e5a circuit onto an old radio amplifier chassis I have. My plan is to add tremolo — I was hoping to use the circuit from the 6G3, which requires half of a 12ax7.
The chassis I'm using has three nine-pin sockets and no room for more (same as stock 5e5a), so in order to make the 6g3 tremolo circuit work I was planning on taking out the normal channel. That would free up half of V1 for the tremolo. Perfect??! Or so I thought.

I've seen a few posts here and there that using a bias-modulating tremolo like that on the 6G3 isn't ideal in a higher powered amp, and that pretty much all use signal-modulating tremolo (which from the circuits I've seen requires both halves of a 12ax7).
If this is true, then I'm going to have to rethink the amp design because I don't have space on the chassis to add another tube.

So, my questions are: Why won't a 6G3-style tremolo work on a higher powered amp? Too much stress on output transformer? I know just enough to be dangerous and am not second-guessing engineers; I would just like to understand the reason.
And second, can anyone recommend schematics to use for a Fenderish push pull 6L6 amp with tremolo, using a max of three nine-pin tubes? Only one channel necessary.
Who knows, I might ditch all of this entirely and build a Supro Thunderbolt on the chassis

Thanks!

[sluckey]

Why won't a 6G3-style tremolo work on a higher powered amp?

That tremolo circuit works fine on tubes such as 6V6 or EL84 that require small bias and small drive signal. But 6L6s want more bias and more drive signal. That means that the tremolo signal must also be stronger.

And second, can anyone recommend schematics to use for a Fenderish push pull 6L6 amp with tremolo, using a max of three nine-pin tubes? Only one channel necessary.

Just build Hoffman's AB763 with NORMAL channel only.

     http://el34world.com/Hoffman/files/Hoffman_AB763_2.pdf

Just eliminate the vibrato channel. That would be everything below the red dotted line on page 5 of the above pdf.

[sluckey]

If your heart is set on a 5E5A, just drop the second channel as you originally stated and build this Supro one triode tremolo that wiggles the preamp tube rather than the output tubes. Very easy to do...

http://el34world.com/charts/Schematics/files/supro/Supro%201690T.pdf

[tubenit]

I would go with Sluckey's suggestions.  He is far more knowledgeable then I am.

The 5E5 and the 5E5-A are different amps.  With 5E5 Pro being cathode biased & 5E5-A fixed biased.

I found what is reported to be a proven schematic for a 5E5 with one tube reverb. That would meet your  three 12A_7 criteria.

I then deleted the one tube reverb and substituted tremolo.  However, I don't know if this would work as I have not built it?  And I don't have a layout for either of these ideas.

This may be going in a different direction then what you are wanting, but I thought I'd post it incase someone else might have an interest?

With respect, Tubenit

[MaBerY]

I have modded my 135 twin and my 5E5-A to use a bias wiggler and they work fine in both cases.
I used a solid state bias oscillator in a piggybag chassis for the oscillator and an offboard reverb amplifier in my 5E5-A due to space contstraints.