Single ended 6L6 amp options

[bmccowan]

Several years ago I built a single ended EL-84 amp. It was mostly based on the Weber Smokin' Joe 1, but built into a 5E3 size chassis with a vintage P12R speaker. I never liked it very much and it went to the basement. With available time created by Covid, I decided to do something with it. Yesterday, I converted it to a SE 6L6 amp. Big difference and it sounds very good now.
But I want to experiment with it a bit before I button it back up.
Because its in a larger than needed chassis I have room. Its a simple champ type circuit with an extra gain/volume pot.
I could maybe add a switch for changing the cathode resistor/cap combination on the preamp tube, or maybe add adjustable feedback or ?? Not needing to fix anything - no real goals, just wanting to play around with some options. Voltage is down in the Valco/Gibson range (325V) rather than typical Fender values - but I'm not looking for more volume or headroom.
Schematic of where its at now is attached. Any and all ideas are welcome. 

[DummyLoad]

are the inductors up to the task of double duty?


--pete

[TIMBO]

This is one I did.
https://el34world.com/Forum/index.php?topic=22730.msg242857#msg242857

[tubeswell]

Add a vibro-champ Trem at the second preamp triode?

[bmccowan]

A one tube reverb or a vibrochamp circuit are good ideas - I have an open spot for a 9pin tube. PT is 150ma and 5a for the heaters. OT is 10W.

[Willabe]

Take a look at this, a 1 tube, 12DW7, reverb, Ampeg style, transformer-less.

This is built as an add on, in a separate chassis box, but you can build it into the amp chassis. I've heard reviews that the Swart amps have a great sounding reverb.

I want to build this. But we're buying a new house, moving soon, have to wait until we get moved in and I get my shop set back up.

https://guitar.com/guides/diy-workshop/build-tube-spring-reverb-unit-amplifier/

[bmccowan]

Willabe - that is a cool project - thanks. And congrats on the new house. My wife and I are building a small house in Maine on some old farmland. Building it mostly ourselves and had to stall on the project when the virus made it difficult to carry on. Frustrating.
But my tube amp tools are all here and some time is freed up. In the last two months in addition to this project, I built a Plexi 6V6, finished an 18W I had stalled on, repaired/rewired a GA-30 and a National Sportsman. So my junk pile is getting smaller and my pile of underplayed working amps is getting larger! I imagine others are also finding the extra time useful (my wife has a different definition of "useful")

[Willabe]

2Deaf, tubeswell and DummyLoad and others, might have adjustments/mods for the circuit.

https://guitar.com/guides/diy-workshop/build-tube-spring-reverb-unit-amplifier/

[bmccowan]

Again, thanks for the ideas. I am certainly going to incorporate one-tube reverb in a future project. For this one, I decided it took too much rejiggering of my board. So, instead I wired in a Framus style mid control. I've only played it a few minutes at this point, but it seams a very cool addition. I kept the original tone control in place and simply inserted the mid pot downstream of the vol pot - easy if you have the real estate. Anyways, I now have a nice SE 6L6 amp, replacing a SE EL84 amp that I really didn't like much!

[newguitarsmell]

What transformers did you use in that amp? Curious.
Thanks

[bmccowan]

The PT is the Weber w025130 - I used the lower secondary winding - 540/150ma. That is unchanged from when the amp was 1xEL84. If I were building the amp today I would use a similar spec PT from Classic Tone (buy American!) The OT I changed to a 5K 10W OT10SE from Musical Power Supplies (USA made)
Its really great to see companies making quality transformers at reasonable prices in the States