Soldano Hot-Mod

[ny_racer_xxx]

I know this subject has come up before and I came across the Schem in a Schem Heaven, but.....
Has anybody tried to build a piggyback 12ax7 that will plug into a single socket?
Just thought it might be an easier way to try different gain stages without hacking up the amp......

CR

[zaphod_phil]

Well IIRC the hot mod, used a Triple-triode tube mounted on a 12AX7 dual triode socket, to replace the last gain stage and CF in a Plexi-style preamp, with 2 gain stages and a CF. Therefore, it would also work in an 18W TMB preamp (which helps keep this on topic). Is this what you want to do...?

[ny_racer_xxx]

Phil, in a word...yes
I want to experiment with different types of gain stages in my TMB without hacking up the amp. I can use that 6K11 tube, but thought if I did it with a pair of 12ax7's, might be a better sound. I guess I could just wire 3 of 4 triodes like the Hotmod for starters...

CR

[phsyconoodler]

I have a soldano HotMod but I forgot I had it and haven't tried it in an 18 watt yet.
Looking at the schematic at schematic heaven,it shows two grounded resistors.I wonder where the ground reference is in that schematic?

[ny_racer_xxx]

Hey Noodle!!! From what I read on the web that was the issue with that setup. The ground caused all kinds of grief. I was going to build a pigtail with a connector on it, and ground one to the chassis.

CR

[zaphod_phil]

I can use that 6K11 tube, but thought if I did it with a pair of 12ax7's, might be a better sound.

I just wonder if it might be mechanically a little tricky to do, since you would have some kind of board with two 12AX7 sockets mounted on another 12AX7 base. And would there be room for it inside your amp....??

[jckid66]

is there a more common tube available from what I hear the 6k11 is pretty hard to come by


Bill