model t speaker outs, series or parallel?

[guest]

I know I'm an idiot, but here's my dilemma.  I have an older Model T which has two speaker outputs.  I was wondering if when using both outputs at the same time does the total speaker load run in series or parallel?  Both cabinets I have only have inputs.

Second question, is it alright if I were to use two cabinets that run at different ohms (16 and 8)?

Thanks in advance.

[PSYKO]

The speaker outputs should be parallel.  Running 8 ohm and 16 ohm cabinets together shouldnt be a problem.  Just calculate total system impedance and make sure it doesnt go below 4 ohms (or whatever the rated minimum impedance of your head is)

[Tom Loizeaux]

PSYKO is correct. The vintage Sunn Model T outputs are in parallel. Calculate the total impedance and dial in the closest setting on the back of the amp. You can use a 4 ohm and 8 ohm cabinet at the same trime, but the 4 ohm cabinet will probably sound louder.

Tom

[elektron]

The Sunn speaker outputs are in parallel but you must match them to the output transformer... if you use an 8 ohm and a 4 ohm you have roughly 6 ohms in parallel and the taps on the transformer are 4, 8 and 16. NO-6! Operating at an impedance different than the output transformer was designed to use will cause the failure of the transformer.  There is lots of literature on impedance mismatch and damage it can cause... I refer you to "the tube amp book" and "How to service your own Tube Amplifier" by Tom Mitchell.... my own experience servicing amps is the same... don't mix cabinets of different impedances!

[elektron]

sorry -- I did math wrong... should be 2.66 ohms if you use and 8 ohm cab and a 4 ohm cab.....  I was thinking 16 and 8 which is 5.33 and I said roughly 6.....

[Isaac]

Nevertheless, amps are more forgiving than people seem to think. For total load of 2.66 ohms, use the 2 ohm setting, and you'll not have any problems.