Silvertone 1474....output transformer smoke...

[acorkos]

http://elektrotanya.com/PREVIEWS/634...1474.pdf_1.png

Can someone recommend a suitable replacement output transformer for this Silvertone 1474? It's got parallel output circuits, each output transformer matched with pair of 6L6G power tubes and an 8 ohm speaker (this amp has a pair of P12Q Jensens from '62).

thx!

[Rhodesplyr]

Wow--that's a new one. I've never seen an output transformer arrangement like that--a single phase inverter driving two pairs of output tubes, each pair with its own output transformer.

If you're concerned about an exact replacement, it is possible to test the output transformer that's still good to find its primary impedance into an 8 Ohm load, but you have to have the right equipment. The older 6L6G datasheets list output transformers with primarily impedances from 6k to 9k, but you never know what an amp manufacturer will decide to use. Otherwise, there are lots of 2 x 6L6 output transformers out there to choose from. In the arrangement in this amp, you'd probably get 20-25 Watts max per pair. If the original output transformers are small, keep that in mind. If you use a replacement that's a lot more robust, with greater bandwidth, it will sound different. A photo of the original transformer might help.

Alternatively, you could run all four 6L6Gs in parallel push-pull via a single output transformer and run the speakers in parallel as a 4 Ohm load. Many early Leslie amps use 4 x 6L6G in parallel push-pull.