The Amp Garage

Yea man, I'm not sure what value I used, but a resistor from wiper to ground of the volume put just cuts the resistance to ground, decreasing the drive, in essence. It's usually done in higher gain amps to keep things tight but I guess it worked here too(it was a long time ago!!). You can stick a 1M...

Hey Aaron, yea I just saw your thread on the same amp from a few years ago. I got the Beaver caps too over here. I just did the big caps and have 570VDC B+ with no tubes, and 540 with these RCA 6550s pulling about 40ma, which seems just about right! Got it fired up and these 6550s seem to be hangin ...

more Good bit of work here

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Thought I would document this since they seem to be a bit rare. It was hell figuring out how to get the amp out of the chassis. Owner wants to drop a lil coin( on a new pair of KT88 or 6550(if these are toast). What do y'all like in the $100-$150 range? IMG_2298.JPG IMG_2297.JPG IMG_2296.JPG IMG_229...

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Back to the D180. Owner bought this new in '83 I think he said. Never been serviced. Said it turns on but sound stopped last week. One of the preamp tubes had gone south. Simple fix but owner wants a full retube and cap job. Amazing the power tubes lasted longer than the pre tubes. I havent done the...

Yep I had some other MEsa in last month(that I really should start a thread for). The OT brackets were busted, and it was duct taped to the chassis. I can't even explain it, it was so ridiculous. Anyways, called MB and they sent out a direct replacement, and very reasonably priced. Plus , owner didn...

A forum member was nice enough to send me a hand drawn sketch. I will do my best to redraw it and post. But the other side of the driver circuit is indeed fed by a highly attenuated signal taken off the OT secondary

I've never seen one, but they seem to be well liked by those who own them. Only about 1000 were made, I gather. A quick look around the web only turns up the same partial schematic you posted above, so I can't tell where the NFB signal is taken from. You could trace the whole power amp out and perh...

Anyone familiar with these amps? I've got one coming up for repair, and I pulled up a scheme to check it out. Apparently there's no power section scheme to be had, as it was never released or something, and I guess no one has traced it. It's a 6x6L6 amp, with a driver tube, and a wacky Master. Pream...

https://cartervintage.com/products/dumb ... 6207653571

for sale again

the tone stack is the same as the blues master150k/120k plates 150k plate 2.2k cathode.... the 120kplate shared cathode 900ohm, resistor. normal channel looks like 330pf .022/.022 47k slopev1b coupling cap looks like .05uf......... vib channel 250pf .022/.022 47k slope... v2b coupling cap looks lik...

Thanks a bunch Ron! That will come in handy for sure.

I worked on a few of these but never had to take off the socket PCB. What a PITA. And those standoffs! I seriously though I was going to create an endless circle of repairs just moving those delicate boards around.