vintageHIWATTconvention.com

No matter what, I can't get a 1k resistor to work in the bias supply. It just causes a short (only get a spotty sound when I play hard). I always see a 1k in there whether it's an old one or a DIY. I had to use a 4.7k and 10k with 25k trim pot. (Instead of 1k and 47k). The amp doesn't seem as loud a...

Never mind. I was getting confused with a filament center tap verses a B+ center tap (or whatever it's called). Mercury put a warning label on the filament center tap so I assumed the worst. Never mind, nothing to see here.

I'm at a loss here. No matter how I hook it up, it doesn't work. I've used various bias ckts and it doesn't work. Like this one: http://hiwatt.org/DIY/bias.gif And this one: http://hiwatt.org/Layouts/DR103bias.png With the the 1k resistor, the amp only farts bits of guitar signal out. With 4.7k and ...

quick update... I was emailing Mark for his help (thanks again Mark!). I finally had time to work on this amp. The MM Hiwatt PT has a 72v bias tap. I had to change the 1k bias supply resistor to 15k. With the 1k, the amp sounded broken... kinda like a distortion pedal with a near dead battery. The 1...

Hi all, this is my first post. Has anyone here used the Mercury Hiwatt/Partridge transformers? I just got their 100w PT (HI100-P) to replace a blown PT in a friend's '72 DR103. I'd like to know your thoughts on them... I'm in the middle of installing it now. My one complaint so far is that even thou...