that must be a typo or a missing number on the specs shown for the PT. Probably 270vac. One thing for sure is a 70 vct thru a 5y3 is not going to output 330vdc.Picked up this neat symphonic console and it had a nice little 6BQ5 amp inside!
I was told the power transformer is shorted though:
anyone know if the Hammond 270ex would work as a suitable replacement?
View attachment 1326383 View attachment 1326384 View attachment 1326383 View attachment 1326384 ?
The document shows ( 5. 70vct @ .145A dc) So, 570 vct would be too much. My guess is 270 vct which is 540 vac end to end.I think that is a typo...it could be 570 VAC with both secondary taps measured, or around 290-299 from CT to a secondary leg. Keep in mind he mentioned it's a console stereo, and the PS transformer may be providing power for other things than just the amplifier. That may be why it has a 4.8 amp 6.3 volt heater winding, to power all the tubes for the console stereo.
It appears the heaters are wired in series.
The Hammond 270EX look's rather close in specs I would guess...a little higher in secondary DCR if that matters...plus or minus 20%
The document shows ( 5. 70vct @ .145A dc) So, 570 vct would be too much. My guess is 270 vct which is 540 vac end to end.
No biggie. Those Sam's fotofacts are notoriously full of mistakes and misprints. It is advisable that one uses the schematic from the manufacturer and Sam's as a back up. Although sometimes it is the only schematic that one can find in which case you need to trust the original build components and use the Sam's to verify components that are missing or when the values on the component is no longer legible.My bad. I should have read your post better. I thought 270VAC from the full winding, not from CT to each secondary.
The document appears to be a Sams Photofact, and they do have occasional errors. The best way to find out is to measure the PS xformer unloaded.
The input voltage on the primary is for 117 volts. So if used with today's 120 line input voltage, the will be some extra AC voltage on the secondary.