Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: martinman on September 12, 2026, 08:39:48 pm

Title: Combining Stout TMB + Stout Reverb
Post by: martinman on September 12, 2026, 08:39:48 pm

Hi all,

Long time DIYer here — I've built several amps over the years including a Hoffman 6V6 Plexi which I'm still running. Great platform and a great build experience.

My next project is an 18 watt EL84 build and I'm looking to combine elements from two existing Hoffman designs — the Stout TMB and the Stout Reverb — into a single build. Specifically I'm after:

• TMB tone stack from the Stout TMB
• Onboard reverb from the Stout Reverb
• Post-PI master volume added to the circuit
• Cut control added externally — I've done this successfully on my Plexi using a Lamarr design so I'm comfortable with that part

I'm comfortable with assembly and point-to-point work but I'll be honest — blending two layouts/schematics is beyond my current skill level. I'm looking for guidance on whether a combined layout exists anywhere, or whether someone can point me in the right direction on what's involved in merging these two circuits.

Rectifier preference is tube — 5Y3 ideally for the sag.

Any help appreciated. Happy to provide more detail on what I'm after tonally if that helps frame the conversation.

Thanks

Title: Re: Combining Stout TMB + Stout Reverb
Post by: dogburn on September 13, 2026, 11:13:15 am

I'd be inclined to add a one-tube reverb circuit to the Stout TMB, which would make a more simple circuit with one less tube. You can search the forum for designs along that line.

Title: Re: Combining Stout TMB + Stout Reverb
Post by: Lectroid on September 13, 2026, 11:56:01 am

I made an 18W EL84 powered amp on a Hoffman Stout TMB board. I also went with a one-tube reverb and the post-PI volume mod.  I think it turned out well.  Nice cleans and power but with lots of growl on board when required.

Title: Re: Combining Stout TMB + Stout Reverb
Post by: dogburn on September 13, 2026, 12:57:02 pm

Quote from: Lectroid on September 13, 2026, 11:56:01 am

I made an 18W EL84 powered amp on a Hoffman Stout TMB board. I also went with a one-tube reverb and the post-PI volume mod.  I think it turned out well.  Nice cleans and power but with lots of growl on board when required.

I built a Princeton Reverb, and used one-tube reverb based in part on the schematic Lectroid posted, so I can vouch for his approach and schematics.

Title: Re: Combining Stout TMB + Stout Reverb
Post by: martinman on September 14, 2026, 06:20:02 am

Thanks everyone.  I *knew* someone was as interested in this as I am! 

Any chance you can point me to a layout?  I can read schematics, but doing the translation to a board...  eh. gonna get it wrong for sure.