The Amp Garage

Great advice! I'll try your approach- Am also considering a 500k resistor between wiper and grid and then use a 500 k pot. That way it should be impossible to dial MV into the shitty sounding range, -no? Markus V yeah, it'll make it a 500k - 1M pot, which for a 1M audio pot would limit it to the 7 ...

I have found the same thing with the Rocket. I will back off the bootstrapped MV just a bit, 3 o'clock or so. It seems the PI is just a tad too overdriven, but that is enough to drop the signal into a cleaner range and I can bring the volume up as high as 12 o'clock. Great overdrive sound with the v...

A friend and me had our guitars stolen, only to have our drummer find them hanging at the local guitar center for sale. This after they were reported stolen to the police with serial numbers and all. They even had the nerve to ask me for the $50 they paid the guy for them when I went to go get it ba...

Brian, I'm getting ready to wire a bootstrapped MV into my amp. On the schematic you posted it has the pots labeled with X and 0. Do you know what those designate? I haven't seen that type of labeling before. 0 is the lug that the wiper touches if you have the pot tuned to zero. I do not know if th...

I am very surprised that this has been allowed to go on for so long, some four years now, just allowed to run free and do whatever they please. WTF? Seems it was pretty easy to deal with. We may see these things not be an issue soon enough though.

Yes the JJ 6V6 are reportedly 6L6 in disguise. :wink: Stanz, I don't believe you are even biased at 50% at that setting. I think you could increase your headroom by increasing the bias current. How about 20 ma? The bias chart I have doesn't even go beyond 400v on the plates!! You may want to consid...

But we're not talking about the economy, and what would you pay for that kind of press?

Well, I have it sorted out, but not sure that I got the exact cause as I have been trying numerous solutions. Int he end, I took out the "JCM800" switch, which cascaded the first two stages instead of mixing them, (it has enough gain already), and moved the 470K mixing resistors to right on the tube...

I did find the 470k/470k mixing resistor region to be quite microphonic. I installed a VVR so there is an added cap just after the mixing resistors. A piece of shielded wire killed the oscillation/microphony issue. Dave - I had seen your video before, too bad there are no sound clips of it. Looks f...

I find the lack of a dc blocking cap between V2a and V2b to be rather disconcerting, though I am no expert. Maybe try one of those. I have not built a plexi before, but a whole bunch of these have been built over the years. I am more looking for an explanation if anyone has one, more for curiosity ...

The plate resistors are all carbon film. In looking at the schematic, it dawns on me, the input to V2b is separated from the B+ supply be only the 100k resistor. How the heck does that work? Doesn't that mean the plate voltage from V2a is also on the grid for V2b? Any special type of resistor I shou...

I have seen mention of this but am unfamiliar with how to check and why it is important.

did try tubes, but I can always recheck that.

Finished wiring it a few nights ago and did the usual voltage test, then added tubes. All appeared as it should. So the final test, grab the guitar, and let 'er rip. http://mhuss.com/Plexi6V6/Plexi6V6c.gif It actually sounds great, but there is a constant noise underneath. Verbal descriptions can be...

6v6 plexi that I can switch to JCM800 mode. Footswitch to toggle between ch 1 or ch 2, and a 2nd switch to turn on both channels. This would be for plexi mode obviously. Got a schematic to share? :D I do not have a schematic for this specific build, but it is primarily Mark Huss' design with the sw...