Early MetroAmp 1204-43 Voltages

rip · Post by **rip** » Fri Mar 17, 2017 3:48 pm

I found a few references concerning early MetroAmp 1204-43 voltages...

Did/how has George's PT voltages varied?

I bought one awhile back, just now getting around to building the amp, curious to know if my PT's voltages are 520 or something else, is there a way to tell before I finish building it?

Thanks
Rip

Post by **VelvetGeorge** » Fri Mar 17, 2017 11:27 pm

Early on they ran pretty high. I few prototypes up around 525-530V. With Chinese KT66's it was better to bring that down a bit. Under 520V proved reliable.
I prefer the B+ much lower than the 560V in my real 45/100. It's very strident and kinda brittle, even with NOS tubes. Much sweeter in the 500-520V range IMO. Eric Johnson agreed. Said he always struggled with his on tour.

If you can measure the unloaded secondary voltage from your PT we can estimate pretty close what your B+ will end up at.

george

rip · Post by **rip** » Sat Mar 18, 2017 7:15 am

Thanks George, I bought it on 04/10/2010... I'm guessing that would have been after your prototypes?

Thanks
Rip

Post by **VelvetGeorge** » Sat Mar 18, 2017 4:45 pm

Yes, way after. Prototypes were in 2006.

george

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Early MetroAmp 1204-43 Voltages

Early MetroAmp 1204-43 Voltages

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Re: Early MetroAmp 1204-43 Voltages