• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

3C24SE amp...

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kmaier said:
Aldovan, your design secrecy sounds intriguing... maybe someday you can share it, but your choice. I'm wondering if you're noticing an audible difference since increasing the plate current... or finding that the specifications of the amplifier have changed... anything?

Despite this being a DIY forum, nobody "has" to share their designs... that's a personal choice which includes showing pictures or even mentioning it. Some designs I've shared, others I won't... my choice. To each their own.

Regards, KM

OK, you don't have to share everything. But what's the point in joining a DIY discussion of how to drive 3C24 tubes saying I have a patent pending way I can't show you but it sounds great! How does it work?
"work fine", no transistors. Here's my youtube video of the amp...OK, that's nice... good for you.


If you're going to cook up the plate to getter/de-gas the tubes, do *NOT* leave the cathode hot for long. You want a HV supply ready to heat up the anode( it'll deliver some spectacular arcs in the gassy ones too ), so as not to wreck the cathode with gas. I've saved 4E27's that glowed like 866's at full boogie this way.

I got the same behavior as youdescribed: My 3c24 glow like a 866 when they start to conduct current.


When applying 600V and -20V, nothing happens. no current at all. You lower slowly manually -Ug and maybe at -18V suddenly you have this 866a white corona and more than 80mA. you can then try to hit a better Ug slowly from there to lower the white corona glow, but you have a very small corridor to keep the tube conducting and not switch off again and the white corona thing.

...I tried to de-gas it by applying five hours of heating before...nope.

Now, how do I read your procedure: Give it not a long preheating ?
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