Has Fryette ever offered, or could it offer custom shop, a single power amp with channel A 90W KT88 and channel B 50W EL34? Ideally, MIDI switchable, so that clean and rhythm go through the first channel for maximum headroom, but when I go to my lead tone, it goes through the second channel for the EL34 midrange warmth. I don’t want to spend $4000 on both power amps, plus a switching unit, while also only using one channel on each.
Hi Gabriel and welcome!
Thanks for the cool idea! We will add it to the list of suggestions 
As a one-off unit, the shop would not have the time to design and fabricate this of you, and if they could, buying two power amps would still be the cheapest option.
However, you might find a DIY building out there who would be willing to design and make you a KT88 100W with a 50W EL34 amp built-in. But a word of warning: the tone is not really in the tubes, well, not all the tone anyway. It is distributed across the whole assembly. You might be able to achieve the same result by just using the KT88s and tweaking things. Also, you will need a 100W+ power supply, but that same power supply would find it very easy when powering the 50W sub-amp. It would feel quite stiff because of virtually no sag.
Take a look at the new GPDI/IR,
it has basic voicing:
- Pittbull
- Deliverance
- Clean
And also has a sag circuit to control the how the power supply sags under demands of power (play hard more sag etc.)
If you want more control over volume, I would use and reamp it using a PS-100, this way you can have the sound you like at two different volume levels.
I understand that the whole circuit plays a role in the overall tone. In essence, what I want is a modern, very high headroom and tight channel, and a warm, saggy, more “vintage” one reminiscent of old JTM45s. I find that using the extremely tight rhythm tone for solos makes it spiky and ear-piercing.
I’m getting into the Synergy ecosystem, but I’m not a fan of the SYN5050. 6L6s have never been my thing, and I feel that one is not versatile enough. The 2/90/2 has been on my bookmarks for a while; the KT88 is my favourite power valve. But the reason I’m going the Synergy route is because I want to have “all the classic amps” in one, and a “hybrid” power amp would definitely work towards that goal.
Aside from MIDI controlling, wouldn’t it be just sticking together half of each in a single unit? If they’re two fully separate channels, with no components shared between them, it should work, no? Then an external switcher could do the job of selecting the channel. Not saying “make me one right now”, just trying to learn. Of course, designing it from the ground up would maximise the distinctive character of each side.
This maybe isn’t that helpful to your use case but I’ll say it anyway. The Pittbull 50/CL with its channel assignable silicon vs tube rectifier does this out of the box. I use the red vs. green channel to do exactly what you’re describing (use the red channel in “normal” (tube recto) mode to smooth out the lead tone). I run the channel volume on the red channel almost all out, since the tube rectifier affords quite a bit less headroom, so the overall volume is only slightly more than the green channel when it has a much more reasonable channel volume set.
This is all maybe suggesting that unless you need to run both “sounds” at the same time, maybe what you’re really looking for is a power amp which has a MIDI footswitchable setting for the power supply. Steve has said on youtube several times that the flavor of tube really has little predictable impact on tone by itself – it’s the circuit around the tube that defines that. there’s no reason you can’t get a midrangey warm tone out of a KT88 or 6L6 based power amp if it was designed that way.