I wanted to run this by and see what gets sparked
The transformer has... 2 , 4 and 8 ohm outputs over a 100 watts nice big and well made not sure of the manufacture but a quality build. ( Stock )
the selector switch plate is labeled 4 / 8 / 16ohms from the factory ( Stock )
the selector switch ( mallory ) is a 2 pole 3 position ( Stock )
and the designer told me they used to snip the 2 ohm wire off and cover it. ( not used )
so i guess you would wire it like this....?
on the first leg of the switch you wire
positon 1 - to the 4 ohm wire
position 2 - to the 8 ohm wire
jump postions 1 and 2 to the second legs positions bridge them together and solder the second leg to the third position giving you a ~12 ohm load for the 16 ohm spot? the wiring seems sound but i'm wondering about strain on the transformer it's big enough to run 4 tubes but the chassis is only drilled for two.
why not combine the 2ohm wire and get a 14ohm load?
has anyone tried this and what was the result?
thanks
Transformer Ohm Wiring
Moderators: pompeiisneaks, Colossal
Transformer Ohm Wiring
My Daughter Build Stone Henge
Re: Transformer Ohm Wiring
Others may know more than me. This is my take on it.
If there are separate interleaved windings, each with a different output impedance rating, you can combine them in series, provided they are in-phase. If the leads are simple "taps" off a single winding, what you propose won't work as it simply creates a loop in the tranny -- essentially an undesirable short.
I have an interleaved transformer with 4 and 8 ohm windings that I set up for 12 ohms with a switch. It was a terrible PITA for me to work out the wiring and the switch and doubly difficult to keep it in-phase and properly grounded. IMO, it wasn't worth the effort. BTW, LOL, I always use that one with an 8 ohm load.
If you wire separate windings in series out of phase, you are subtracting, not adding. It is easier demonstrated with a power tranny...lets say you have a 100v secondary winding and a 25v secondary winding. In series, in phase, it should give you 125v. Out of phase, it will give you 75v.
Let's assume these are simple taps off a single winding. Skip the selector switch. Use two jacks. Run the 0 wire to the sleeve of both and to ground. Run the 4 ohm to one tip and the 8 ohm to the other. Now you have your choice of one or the other. If you want to use both at the same time, they are wired in parallel, meaning you must then plug an 8 ohm load into the 4 ohm jack AND a 16 ohm load into the 8 ohm jack. Essentially, the parallel jacks mean that each speaker is effectively at half it's nominal rating (Ohm's law). And, yup, I've got one wired like this, too, and I've done the two speaker thing. The problem is that the speakers are unmatched and one overpowers the other.
If there are separate interleaved windings, each with a different output impedance rating, you can combine them in series, provided they are in-phase. If the leads are simple "taps" off a single winding, what you propose won't work as it simply creates a loop in the tranny -- essentially an undesirable short.
I have an interleaved transformer with 4 and 8 ohm windings that I set up for 12 ohms with a switch. It was a terrible PITA for me to work out the wiring and the switch and doubly difficult to keep it in-phase and properly grounded. IMO, it wasn't worth the effort. BTW, LOL, I always use that one with an 8 ohm load.
If you wire separate windings in series out of phase, you are subtracting, not adding. It is easier demonstrated with a power tranny...lets say you have a 100v secondary winding and a 25v secondary winding. In series, in phase, it should give you 125v. Out of phase, it will give you 75v.
Let's assume these are simple taps off a single winding. Skip the selector switch. Use two jacks. Run the 0 wire to the sleeve of both and to ground. Run the 4 ohm to one tip and the 8 ohm to the other. Now you have your choice of one or the other. If you want to use both at the same time, they are wired in parallel, meaning you must then plug an 8 ohm load into the 4 ohm jack AND a 16 ohm load into the 8 ohm jack. Essentially, the parallel jacks mean that each speaker is effectively at half it's nominal rating (Ohm's law). And, yup, I've got one wired like this, too, and I've done the two speaker thing. The problem is that the speakers are unmatched and one overpowers the other.