by tubes4hifi » Thu Apr 15, 2004 5:32 pm
actually the HKs look slightly different than the photo I posted.
These are from a TA3000 receiver which has the identical amp circuit as the A300, a well known and regarded power amp.
HK used a voltage doubler with a resultant B+ of 360VDC to power four 7408 tubes (6V6, similar to EL84 but octal, bigger glass).
Since it was used in a receiver there is actually more current available, and two sets of 6.3V filament windings, one with 2.6A and the other with 1.6A.
The power trans is 3.75 x 3.0 inches, and requires a cutout in the chassis (as shown in the photo).
The OPTs are 2.25 x 2.25 with added side wings for mounting (they look similar to the Hammond 125).