Replacement Power Transformer for Matamp Orange OR LEAD 200

[SoulFetish]

I don't think the HT will be over 800VDC due to the action of the choke between the rectifiers and the first filter cap. The actual value rather depends on it's inductance, but assuming something big to suppress ripple has been chosen that it could easily be around 630VDC. The unloaded output voltage is the average on the input e.i. 0.9 * 700 = 630VDC.

Oh... dude, thank you for this one. It was right there in front of my face the whole time. I've been out of the shop for while and my chops are getting sloppy.
Before the transformer ultimately ended up failing, I remember having this thing on my bench a while back for a good amount of service (I swear, when it left if was in great shape )
That was the first time I'd seen one of these big old Matamps on my bench so I remember the job pretty well. I remember measuring secondary DC voltages, and can confirm very similar readings to the ones Catalin posted in his example. The amp would show an unloaded high voltage in the low 700s. But it would fall rapidly to around 640V or so as the tubes began to conduct and ultimately settle under 600V to around 580V or so (if I remember correctly).
So, when it came back in and the PT needed to be replaced. I had to remove the PT anyway, so I pulled all wiring from the turret board and cleaned it up as well to make sure I didn't misread the print on the board. I knew and recorded where all the connections were made, so I was surprise to see those kinds of secondary voltages labeled. I was projecting secondary voltages according to that rectifier into a common capacitor input, and it wasn't jiving with what I remembered measuring before. But now we can all relax, because it's all starting to make sense.

Have you tried talking to Orange?

Maybe? (It's a long story) We actually sent this out months ago with the understanding that it would either be repaired or used as the basis for a replacement design. Those options are no longer available, so now we're doing this part again.