Ampeg B15S replacement ot

[mresistor]

Since I have to replace the ot in my ampeg B15S amp..  I ask for your consideration of this option ..   


Hammond 1650HA  40 watts   
Hammond 1650PA  60 watts


the amp uses two 7027A power tubes and the Plate v could be a high as 570 v due to high wall v   https://drtube.com/datasheets/7027a-rca1959.pdf


MM has one for $260   and   Mojo has one for $299   very expensive


I think I can mount this hammond under the stock transformer  can  without potting  and still have the stock look.. 


btw  anyone know how to de-pot a potted transformer from the 70's?   I think I would warm it up in the oven and then dump the goo out..  but  I don't know

[mresistor]

According to what I have learned that primary impedance of the stock OT is 6K .. and resistance of 300 ohms.

[Willabe]

Is the mojo OT potted? If so that costs more to pot the OT.

It's a bass amp so I would go with a larger/higher wattage OT, given a choice.

Many guys here have used Hammond iron, with great results.

[Willabe]

.....the amp uses two 7027A power tubes and the Plate v could be a high as 570 v due to high wall v   https://drtube.com/datasheets/7027a-rca1959.pdf

The data sheet shows 600dcv max for the plate and 500dcv max for grid 2/screen. It also shows 600dcv max for both plate and grid 2/screen if using a tap from the plate wind (UL). UL taps limit the screen grid current.

All 4 schematics in Doug's library show 575dcv plate and 580dcv on screens with 470ohm 2w screen R's. 

So use at least a 1K 5w R for the screens to help limit the screen grid current.

Real 7027's will take the dcv in your amp, so the data sheet say's and new 7027's?   

[mresistor]

Thanks Willabe - for sure I will change the screen resistors. Crazy high voltages in this amp.