Multiple secondaries hook-up!!!

[Klimon]

Hello!

I'm laying the last wires in my diy amp but am getting very confused about the wiring of the opt secondaries. The trafo in question is German-made and has two secondaries (8 and 4 ohms), each with TWO ends --- I'm not an expert in electronics but the way I see it these trafo's have two separate secondary windings, not one 8 ohm sec. with an 'intermediary' tap for 4 ohms...

My plan was to use two separate 'plus' taps, one for 8 ohms and one 4 ohms // and one shared 'minus' tap for both impedances. Can I, with the transformer configuration described above, connect one end of both secondaries to form the single 'minus' tap, then use both the other ends as separate 8 and 4 ohms taps?

Hope this makes sense to anyone, thanks in advance for the helping hand!

Simon

 

[Klimon]

update;

the secondaries are evidently connected (measured them with ohmmeter)... and I'm still confused

 

[kevinkr]

I'd contact the manufacturer for further clarification of the secondary connections.. Are you sure that this transformer does not have a single very conventional secondary with a common and taps at 4, 8 and 16 ohms? (4 wires) It would be very unusual for an output transformer to have two entirely independent secondaries one of 4 ohms and the other 8 ohms.

 

[Klimon]

I contacted the trafo-winder and he says both are connected internally "in a special manner" and require separate + AND - taps which is somewhat a nuisance because I'll need switches to connect the "-" (only one at a time) to ground.

Simon

 

[kevinkr]

Why not just use clustered pairs of binding posts for 4 ohm and 8 ohm operation - that way you can avoid the need for switches altogether. You could put one pair above the other for example..

Definite bummer that "special connection."