Hello all

I have a 100 watt 5150 tube head. On the back the impedance selector can be switched to 16, 8, or 4 ohm. The cabinet im using is 16 ohm. I was told by another band member that i can run another 8 ohm cabinet from the head. If I do run a 8 ohm load with the 16 ohm load, i believe the impedance would be 5.33 ohms correct? Will this ruin my amplifier? if not what should I set the impedance switch on the head to?

Let me know


Pretty sure that doing that would mess it up. I think you could run two 8ohm cabs for an load of 16ohms.
You can run 2 cabs of equal ohms. But mixing ohms is not a very good idea the cabs would not get equal power. The 8 ohm would get most of the amps signal.
i emailed my local tech here, he said that

" The switch on the back of the amplifier, gives choices between the 4, 8, or 16 ohm output transformer taps. On any given tap, you can safely use a higher load (resistance in ohms (Ω). It is unsafe to use a lower load and this can damage the tubes or output transformer. Your example below (5.33Ω is ok to use with the 4 ohm tap."

it seems viable, any suggestions?