Super Twin Reverb 180

[Enzo]

Where are you located and what is your mains voltage?

[LarBal]

Outside of Austin TX and today mains is 122.7VAC

[LarBal]

I picked this back up after a break and still need some help with this transformer.

To recap:
This Super Twin Reverb has super high voltages, 620V plates, almost 8V heaters.
The PT in my amp is not the one on the schematic, but rather the 014679, which can be found in the Super Bass 180W amp.
The way my PT is wired, is not like either. It is a dual primary PT)

I'll attach a picture of how this 014679 PT is wired in the Bass amp then a mock up of how it's wired in my amp. It is quite different!!!!!
Note that the schematics both amps show the same color coded wires and wiring, for both amps, for both 120V and 200+V

The problem, and what is confusing to me, is that there are NOT 2 yellow wires(thermal fuse), only 1 yellow wire. That yellow wire goes directly to the switch. There is also another wire on the primary on my amp that is White/Blk , that goes to a terminal strip that goes nowhere.

I would like to try to wire it like both schematics show for 120V(and ignore the thermal fuse) , but am very confused about the single yellow wire thing, as it seems integral to the operation of it.......
but as we've observed, with the super high voltages, it's almost like this is wired for 100V mains, but I just don't see how.

Also not how in my amp the GRN/BLK and BLK connect, but go nowhere, as usually that's one of the 120V legs, in a normally wired dual primary PT

[Enzo]

Just my opinion here, but it seems the amp works, is not blowing fuses, it just has higher voltage than you expect. And it seems you have confusing diagrams, but you want to rewire it to match one of them. WHY? Your primary and secondary voltages are determined by th turns ratios in the windings. I'd not wager much on changing the wiring making a large difference.

[g1]

Your grn/blk and blk are not going no where, they are internally connected to the missing yellow.
Like Enzo said, if there were missing connections it would not work.
There are only 2 possible working combinations, series or parallel primaries. Yours must be wired up parallel which is most correct for 120V operation.

I do see on this newest drawing a reference to 210V which makes me wonder about 105V. If that's what this PT is looking for, it might explain the high voltages on secondary.

[LarBal]

That all makes good sense, thanks guys.
I ended up rebuilding the PI and driver a bit, and all the snap crackle pops went away.
6 JJs went in nicely without need to fool around with the bias circuit. Amp is really quiet not. Distortion function sounds awful, as expected.

[g1]

B+ is still over 600VDC? Does it make it's full 180watts?

[The Dude]

Yes, it works. But, will it continue to work. Those voltages are not conducive to longevity.

[LarBal]

Exactly my concern. Once I told the customer what a sextet of 6L6 costs these days, he asked if I could reuse the 6 original power tubes. They were all mismatched, but using the tube matching pot, I was able to eliminate all hum

[g1]

The original main filter caps were rated at 285V for a total 570V in their totem pole arrangement. What voltage did you replace them with? Are they getting warm? Is the CT of the HV winding going to the mid-point of the filter caps like in the schematic?

[LarBal]

The original main filter caps were rated at 285V for a total 570V in their totem pole arrangement. What voltage did you replace them with? Are they getting warm? Is the CT of the HV winding going to the mid-point of the filter caps like in the schematic?

I replaced the main filters with 220uf/350v F&Ts and 500V 22uf everywhere else. Yep the CT at the junction of the caps