Bandmaster Reverb chassis rescue - what to do?

[ampdoc1]

Don't know what you're into music wise. Here is a schematic of a build I did in a BR chassis several years ago. I just recently heard the amp on a gig, and was floored. Really a great sound for any kind of rock and roll, and with the Dumble overdrive section and a boost feature in the preamp, you get four sounds: Clean/Clean w Boost/OD/OD w Boost.

I remember going thru the amp, changing the cathode and plate resistor and caps to achieve the "best" sound (to my ears). It appears that I used a Trainwreck preamp design with Dumble plate and cathode cap/resistor values. The amp also has a Dumbleator installed, but the guy who uses the amp rarely uses that. Luckily, that is a great EL design, and can be left in the circuit without affecting the sound.

ampdoc1

[mlp-mx6]

ampdoc1,

Thanks very much! At this point I'm considering a VibroClone, but your circuit is very intriguing! It may happen...

How did you power the relays?

Also, it looks like there is a lot of gain (Wreck-style) even before the "OD" section. Can you describe the clean vs. OD of this circuit?

Thanks again!

[ampdoc1]

The relay power is from the 6.3V heater winding, and shown at the bottom, right hand side of the drawing. However, this was a very early switching design I used,..and I will be integrating one of my relay boards in the current project. My original build was entirely "point to point", starting with having removed all the original tube sockets, etc, so I had an empty chassis. I ended up putting the preamp tubes close behind the tone controls, for very short wiring pulls. I don't know if this helped, but the amp is very quiet.

Because the Dumble OD section "covers" the overdrive very well, the preamp stages (certainly based on the TW) are generally not used at gain levels that produce any distortion. The clean is very Fender-ish clean, up to the point where output distortion starts to creep in, but the TW tone controls give a "better" palate of EQ than the Fender, at least to my ears.

Because I was so excited about hearing the amp again recently, I've started a new build that is basically the same thing, but with an added EQ section which can be switched in/out. I'm considering changing one of these to Dumble EQ values, but on the attached diagram, it is shown as a duplicate of the TW EQ. This iteration also shows some alternate power amp components to replicate the "holy grail" Dumble power amp.

My band is going to be working on some demos after Christmas, and I hope to be able to use the original amp for that project. If so, I'll send you some audio files.

ampdoc1

[mlp-mx6]

Fantastic! Thanks very much.