The Amp Garage

How does it work, lower resistor on the plate side of the split, lower voltage out? Is 47k/47k half of the output?

I know the liverpool is a hi-gain amp but looking to clean one up a bit. I think I found my answer..just to make sure, lowering the resistor to ground in the cap/resistor combo going into the 3rd stage will lower the gain of the amp right? So if I have a 120k in there now and replace it with a 56k o...

Liverpool built in a old Acetone 1x12 combo. 2xEL84s. Just about done, need to do a couple more things. Did a quick power up to check voltages...looks good. its a bit higher than the standard Wreck plate voltage due to the Power tranny..about 375v..biased to about 11watts. If u look down in this for...

I'll try it and start with a 100pf.

Can I put a 100p cap across a Rocket's PI plate resistors to knock down some high end or does the Cut control pretty much do the same thing?

Anyone have the M75 in a open back? I can believe that this thing is close to 30w, its loud. SS recto. I did e-mail Scumback and told them what I am using and going for and they suggested the M75 65watt.

I'm guessing its no more than 20watt tops..and that's probably pushing it!

I built a loud 2xEL84 rocket. 385v on the plates due to the trannies I'm using. It sounds great! Right now I have a single 12" old Vox Silver bulldog with a TT hemp recone I play it through, also sounds wonderful but I think I need to get a little bit higher power rated speaker for this amp. I also ...

Want to look further into this topic. I also find the 50p in the treble cap a little mid cut when cranked. Thinking about putting a 100p or 200p on a switch ala boogie mid shift. Any thoughts. On the tone sack calculator it looks like raising the cap value to 250p u get a mid boost and the highs and...

This combo was a 60's Acetone Rockey, stripped other than transformers and used it for my Rocket build. Sounds wonderful! Still tweeking a bit. My PT puts 380v on the plates but after the screens, all my voltages match the Rocket files more or less. Its loud! Right now in the combo I have a old Cele...

or if someone can direct me to a thread about the PI values...

And do I want a Silver Mica for the 500pf cap after V1a or a .0005 like a 715p?

Thanks Sixstringer

I have a old Output transformer from a Acetone Amp. The amp has 2x EL84.
I would like to find out what the input impedance is. How do I go about measuring that? Thanks!!
The tranny is in my new Rocket build.

Found the problem!!! I had a .005 instead of a 500p (.0005) between V1a and the volume control. Fixed it and it sounds great! I have to go get a true 500p, right now just have 2 .001 in series. I still have the PI with 470ohm/22k bias and tail, what will I hear changing it to 1.2k/47k? More drive to...

Ok, update. I got the power supply as close as I can get it. Plates and screens are in the 385 range, bias 11.9watts but from the PI down I got my voltages almost exactly per the voltage chart. Amp is loud and top/mids are clear and sweet. The issue is low end. With the bass control anywhere over 1 ...