Ceriatone Forum

Ceriatone => Overtone => Topic started by: citizen on February 21, 2011, 03:21:32 PM



Title: 1/2 power switch impedance change?
Post by: citizen on February 21, 2011, 03:21:32 PM
Hi All

 I have a Bluesmaster 100 OTS which I use with an 8 ohm EVM12L.

If I use the half power switch on this amp, should I change the impedance selector switch as I've just read that if you drop the power by half, the amp impedance doubles?

Thanks for any advice.

Cheers

Kieran


Title: Re: 1/2 power switch impedance change?
Post by: plasticvonaband on February 21, 2011, 03:47:15 PM
nah, all you are doing with the half power switch is running the output tubes in triode mode instead of pentode mode, that's how it drops the wattage down. the impedance switch should remain at 8 ohms if you have an 8 ohm speaker.


Title: Re: 1/2 power switch impedance change?
Post by: citizen on February 21, 2011, 04:17:34 PM
Ok - cheers for that :)


Title: Re: 1/2 power switch impedance change?
Post by: JD0x0 on February 21, 2011, 07:07:41 PM
nah, all you are doing with the half power switch is running the output tubes in triode mode instead of pentode mode, that's how it drops the wattage down. the impedance switch should remain at 8 ohms if you have an 8 ohm speaker.
Actually im pretty sure the "half power switch" does remove the two outer tubes but the amp creates a dummy load so the amp "thinks" it's still using all the power tubes and the impedence is unaffected. At least thats how Nik wired the earlier "half power" switch.

A pentode/triode works as well but I think this is more intended for 50 watt (two power tube) amps. Triode/Pentode is going to have a mushier sound in triode where removing the two outer tubes (on 4 tube amp) should leave the tone relatively unchanged.

Either way, no the impedance does not need to be changed unless you manually remove the two outer tubes.


Title: Re: 1/2 power switch impedance change?
Post by: plasticvonaband on February 21, 2011, 07:12:20 PM
you are right JD, i just noticed he has a 100 watter, so it prolly works a lil differently than mine does, but either way, ya no impedance change should be needed