Power Transformer Question

[gtto]

I am trying to replace a power transformer in a Fender Supersonic 60. I have looked at three different transformers and they all have different secondary specs. Classic Tone tranny is 484VDC which I believe is the same as stock. Mercury has 364V/514VDC. Hammond has 342V/482VDC. How much can they vary and still be ok? The Mercury seems very high compared to the other two. My transformer knowledge leaves much to be desired so maybe I am missing something here. Thanks

[g1]

Is the Fender replacement part not available?
The aftermarket types are not likely to have the extra low voltage winding, unless they are specifically designed for this model amp?

edit: I see that the classic tone is indeed a direct replacement for Fender part # 041752

[Pdavis68]

I'd be concerned about the screen grid voltages getting too high. I'd probably go with the ClassicTone one. It's really close to spec and CT are a good value, quality transformer.

Also, that 484VDC rating is based on a 93mA current draw. I suspect you'll be drawing at least 50% more than that.

[g1]

Agree with above that ClassicTone looks like a good replacement. It does have all the same windings as the stock unit.

[gtto]

Didn't mention

I didn't mention that I need a 220v transformer which Classic Tone does not have. Edcor will possibly make one for me. Mercury has one at a crazy price. I currently am using the Hammond 290VEX with a Variac @ 240V but I am not getting enough heater voltage. The Classic specs show 3.75A as do the Hammond. The tubes are 2x6L6=1.8A, 8x12ax/at7=2.4A which is 4.2A total. I haven't measured the actual heater amp draw. When I measure heater voltage across pins 2 and 7 I get 5.3 volts. I think Fender cheaped out on the transformer so they could use it in the Hot Rod Deluxe which needs less heater current. As previously stated I am for far from an expert on this subject. Let me know if I am on the wrong track.

[Pdavis68]

I'd probably go with the Edcor, then. They make quality transformers at a reasonable price. MM makes quality transformers, just not at a reasonable price...

[gtto]

I am thinking about using the existing Hammond 240v transformer and adding a separate filament transformer. This would give the heaters the correct voltage but the plate voltage would be a little on the low side like around 450VDC. Do you think this would be ok?