E80CC Driver

RPMac · 3329

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Offline RPMac

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on: October 21, 2012, 06:56:24 AM
Is an E80CC close enough to a 6n1p to drop in as the driver for a Paraglow or Parabee without doing any harm?



Offline Paul Birkeland

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Reply #1 on: October 21, 2012, 07:23:55 AM
Not really, the E80CC has the 12V heater with a center tap, so the pinout is different than the 6N1P.  I don't have the full complement of Legacy manuals,  but I think the Paraglow at least directly coupled, so changing to a lower gain tube like the E80CC is going to move the plate voltage around, and that will upset your 2A3 a bit.

If you want to give it a shot, post the plate and cathode voltages that the 6N1P is running at, and maybe a reminder of the R1 resistance on the C4S board (it's the smaller of the two resistors), as well as the resistance of the cathode resistor.

With this info, we can probably tweak R1 to make the E80CC hit the proper voltage, and you can rewire the heaters.  I think this is a better idea for the Paraglow than the Parabee. 

There is also the situation where you would have the Parabee II with the shunt regulated driver stage.  In that case, I'd be hesitant to recommend anything without checking with PJ.

One interesting thing to note is that without the shunt regulated driver, you could leave one section of the E80CC unheated on each side, wearing out one triode per tube while you're running, then you can swap driver tubes between amps when they wear down.  Setting your amp up for the E80CC will also allow it to work with 12AU7's as well. 

-PB


Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline RPMac

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Reply #2 on: October 22, 2012, 04:43:07 AM
I was awear of the heater change, but both amps are II's with Tucker's C4S/shunt reg boards.

The E80CC reads interesting, but a bit pricey. Thought if they were an easy drop-in(w/heater change), I'd spring for a pair.

Think I'll wait to get my BeePre going and then look into a DHT driver.
300B-Pre > 300B Driver > 300B Output????? ;D

Thanks Paul
« Last Edit: October 22, 2012, 04:44:42 AM by RPMac »