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Village Idiot
This is not recent, but I've mentioned it a few times...
It's a "Tube Screaming Preamp (B. Robertson)" into a "100 watt" one-channel power amp. From my understanding, these are used a lot to power car subwoofers and such. Being that it is a only power amp there are no external controls, it is simply a gain stage for the signal [there is an onboard gain trimmer on this one. Others I've played with don't have them]. That's where the TSPA comes in. The signal goes into the clipping stage first, and is boosted at the same time, controlled by a gain pot. The signal feeds through a presence pot and straight into the TMB finishing with a volume pot.At least, that's the circuit through my eyes. Then through the power amp. The output is an isolated banana plug.-type jack.
It is a great little practice amp. That particular power amp runs very quiet at 9v despite the obvious lack of wire routing (someday). I was using the same one that is listed as "arriving soon" at this site, and it would handle 20vdc. I powered it with a Dewalt 20v Max battery. I had to use a voltage regular to step the power down to the preamp (9v only). It ran noisy at 9v and was EXTREMELY sensitive. I fried a half-dozen or so before switching to this one.
It was fun to build, and is a hoot to play through. It easily drives an 8ohm 12" Jensen 35w
It's a "Tube Screaming Preamp (B. Robertson)" into a "100 watt" one-channel power amp. From my understanding, these are used a lot to power car subwoofers and such. Being that it is a only power amp there are no external controls, it is simply a gain stage for the signal [there is an onboard gain trimmer on this one. Others I've played with don't have them]. That's where the TSPA comes in. The signal goes into the clipping stage first, and is boosted at the same time, controlled by a gain pot. The signal feeds through a presence pot and straight into the TMB finishing with a volume pot.At least, that's the circuit through my eyes. Then through the power amp. The output is an isolated banana plug.-type jack.
It is a great little practice amp. That particular power amp runs very quiet at 9v despite the obvious lack of wire routing (someday). I was using the same one that is listed as "arriving soon" at this site, and it would handle 20vdc. I powered it with a Dewalt 20v Max battery. I had to use a voltage regular to step the power down to the preamp (9v only). It ran noisy at 9v and was EXTREMELY sensitive. I fried a half-dozen or so before switching to this one.
It was fun to build, and is a hoot to play through. It easily drives an 8ohm 12" Jensen 35w