Ampeg SVT 3 pro PT secondaries

[Swampy]

Hey Everyone,

I have a SVT pro 3 on the bench with a secondary that's opened. The local distributor quoted an 8 to 12 week turnaround on getting a replacement (I'm in Melbourne, Australia) so I though maybe getting one custom wound is a better idea.

There are three secondary windings, a HT for the tubes, a winding for the mosfets and the tube filament winding. If anyone has any info on the HT winding AC voltage and the mosfet winding AC voltage so I can give some specs to the winding company it would be super appreciated.

Cheers,
Swamp

[Jazz P Bass]

Ampeg SVT3 Pro Schematic

I have attached the schematic.
Hopefully that will provide you with some insight.

[J M Fahey]

I find it some sort of a joke that, since Ampegs are now produced in VietNam, a "relatively" short path to Australia, they should have to cross the Pacific both ways before arriving.
Oh well.
A short time ago there was a similar case, when somebody (in USA) needed an replacement Accutronics reverb tank for his H&K amp, and it had to be delivered from Germany.
As of your transformer, it does not seem that difficult to rewind.
You have no filament winding because they are used in series, fed regulated DC from the main power lines, so you only need to provide two 50VAC main windings plus an auxiliary 220VAC at, say, 20mA for the tubes.
In this case wire size will be dictated more by winding convenience than actual current consumption.
It won't have as many turns as imagined because the huge transformer core will need less turns_per_volt.

[MarkusBass]

I think that SVT 3Pro is manufactured in Korea (the distance to Australia is much greater than to Vietnam). But I would also rewind the old transformer. This is a simple task. And cheap. And quick :-).

Mark