I built a Prizetone kit with Larger Classic Tone transformers. The PT is a 40-18016 and the OT is a 40-18090. The amp has a hum. The hum is always there and increases when I roll back the guitar volume. The volume of the hum also increases as I change the volume knob of the amp. The hum increases with the tweed switch on (as you would expect). So far I have tried swapping tubes, different speaker cabs, different guitars, different outlets, all with the same result. I also noticed that the indicator bulb fluctuates in brightness just a bit but is not related to playing the amp. None of the other controls affect the hum and it does not change with the vibrato on or off. I have the bias set as low as it will go and increasing it adds more hum. Output tranny specs are here:
http://www.classictone.net/40-18090.pdf. Power tranny specs are here:
http://www.classictone.net/40-18016.pdf.
Thanks in advance for any suggestions.