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Now for something different...


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So there is absolutely NO way we are going to do an A10 board due to all the issues we know about.

But it would be nice to do something simple that anyone can build. So i'm looking for tubes

that can handle at least 500 volts, anything there is bunches of that does not have stupid pricetags

attached. And its not going to be SRPP either, because done right, you need at least 5 seperate

filament supplies. 6s4's don't seem to be in plentiful supply any more. Otherwise its a circuit

board that is bigger than it should be with multiple 6ca7's...

Any ideas?

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Yeah, it was compact. And yes it blew up. Evidently quite often.

i'm thinking 3 x 6bl7 per channel, +/-400 power supplies, gilmore

triode amp style with cathode bias and DC coupled output.

Local feedback on the input, and local feedback on the output.

unbalanced input only. (i'm thinking about this last bit)

10 amps of filament current.

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For a small amp then we could do ECC83 input and 6CM7/6CS7 for the second and third stages. Can be made quite small indeed.

I know Kevin doesn't like them much, but the differential amp (aka. Egmont) is bloody tiny, fully balanced too.

Nice, I would be interested in something small like this. Need an amp for my SR-Lambdas at work.

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I built an Egmont with 6BL7 output. Worked quite well. Maybe it was just my luck, but out of 20+ tubes no two had anywhere close to matching sections and no two samples matched each other in thier differences. I was quite surprized actually. Same with the 6BX7. One the other hand, I had no problem coming up with a pretty good quad of 6P14P out of a dozen samples on hand.

I would love to see a professionally updated small/cheap all tube electrostatic amp along the lines of a "hot-rodded" Egmont.

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Glad I looked at those PCB's since I can't understand what I was thinking with the psu caps... facepalm.png

how about 12ax7,12ax7,6cm7. won't be much bigger than that.

The power supply however is going to be at least that size or


That would work. 6CM7's appear to be in plentiful supply too. We could always do a CRC psu... :)

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