Refresh my memory, does that one have OpAmps too? If not, then something similar to a Fender Twin power tranny would work. Of course you need to compare mounting dimensions. Try Antique Electronic Supply . Look up part number P-T290FX . If it does have a low voltage supply for the pre amp then you may have to be a little creative and add a smaller tranny for that part of the power supply. I haven't seen a Spectra amp around here in years.