Ceriatone 18/36W half power switch

[Junkmale]

Guys, I've read elsewhere on this forum (can't find it now) that Niks design for the half power switch on his 18/36w is not a good way to go. Something about burning out tubes. Is this the general opinion? Has anyone had a bad experience with this configuration?

[ChrisU]

I would use the switch to remove the input signal from pin 2 of 1 of each pair, grounding the pins.

[Zemaitis]

Not yet...... and I have used it on 2 amps I built.

[zaphod_phil]

No idea what Nik's method is. I would switch in something like a 47k cathode resistor on one pair of tubes, so the tubes go into permanent cut-off. This would actually help extend tube life.

[Chubsman]

In the early stages of the ceriatone half power switch he had not yet perfected the cathode bias resitor value when switched to 2 power tubes... pretty sure he has it down now.

I have it installed in a 36W and it works fine. doesn't make a 36w into a 18w... but it does make the amp breakup sooner on the volume dial.

[Junkmale]

Thanks everyone for your replies. Attached is Niks layout if anyone's interested. Cheers.