Re: Tube amp with 2.5 Ohm speakers??

"John Byrns"
>
>>  One consideration with 2 ohm outputs is that the lower voltage,
>> higher current needed for a given power means more copper is needed,
>> or I2R losses will be higher.
>
> Are you sure about that Bret?  I don't see why more copper would be
> required to maintain the same I2R loss with a lower load than with a
> higher load?
>
> Consider as a simple example a transformer with two secondary sections,
> each section having enough turns to provide a 2 Ohm impedance.  The two
> sections can be connected in parallel to feed a 2 Ohm load, or in series
> to feed an 8 Ohm load.  The two sections connected in parallel will have
> one quarter of the resistance of the same two sections connected in
> parallel.  The current when driving the 2 Ohm load is twice what it is
> driving the 8 Ohm load, so the I2R loss is the same in both cases.  The
> same argument can be be expanded to a wider range of impedances by
> considering more secondary sections.
>
> Please explain where this argument fails?
>

** Of course it is solid.

The secondary winding on a OT can be wound for just about any impedance
load 
with  NO change in the volume or weight of copper used.

Note how mains transformers of the same VA rating and physical size come 
with a large variety of secondary voltage and current ratings.

A simple fact that has escaped the notice of the numerous congenital
menata 
defectives around here.



........  Phil