vox tube change

[Yobleduwop]

Hey Guys,

Just wanted to check before i wrecked something beautiful,
Seen the AC-30's are cathode biased you can simply unplug and change the EL84 power tubes, right?

Thanks

[Peter Clothier]

Hey Guys,

Just wanted to check before i wrecked something beautiful,
Seen the AC-30's are cathode biased you can simply unplug and change the EL84 power tubes, right?

Thanks

Yes. But your amp and your ears will appreciate you installing a quad balanced set of EL84's available from all reputable suppliers. I did one last week with JJ Tesla valves. It sounded bloody luvly.

Peter.

[Yobleduwop]

Thats exactly the quad i bought, using it for recording so hopefully it pays off

[Yobleduwop]

Is it possible to only put 2 tubes in a EL84? to theorleticly get half power?
Thanks Joel

[Peter Clothier]

Is it possible to only put 2 tubes in a EL84? to theorleticly get half power?
Thanks Joel

Not really,
The primary impedance of your output transformer is designed to match your 4 output valves. There is a thread or 2 on this forum which goes into this question in some detail.
Personally, I've never really understood why anyone would want to do this with an AC30. Unless of course you're trying to replicate an AC15. If so........ Get an AC15 and dont devalue your AC30.

[Albert Kreuzer]

Is it possible to only put 2 tubes in a EL84? to theorleticly get half power?
Thanks Joel

No. The remaining tubes would draw way too much current through the cathode resistor and melt down.
And of course what Peter said.

Best regards,
Albert
www.albertkreuzer.com