The Amp Garage

http://home.comcast.net/~stphkeri/magnatone_109.png Used signal from the screen of the first power tube to to the grid of the second. I built this power section into an amp once to cut down one tube. Just not enough volume, and the sound wasn't distinct enough to be cool for cool sake info here: htt...

For typical fender/marshall tonestack, i mount a three terminal standup strip centered at the mid control. plate/cathode to the bottom lug, slope R from bottom to top, caps from top to mid and bass, cap from bottom to treble. No circuit board, nothing extra.

There are symmetrical and non-symmetrical sources of interference that the heaters can introduce/pick up. The humdinger allows you to adjust the reference of the heaters to ground to help eliminate the non-symmetrical sources that a symmetrical center tap can't take care off. i just made an amp with...

martin manning wrote:Actually, I guess it has to be 60Hz since powering the filaments with a battery killed it. Schematic?

not true. 120hz from the HT diode transient can couple into the heater winding if they are on the same PT. That can then be amplified by the tubes.

Typically safer to run 100% higher than 100% lower I think. So an 8 into a 4 would decrease your load line towards higher voltage swing, away from higher current swing. Running a 4 into an 8 would push your load line in the direction of higher current swing. Since you're only at 450V you are probabl...

Don't know why it would be now, but try turning the tank 180 degrees so the return driver is now farther away from the PT?

I build high gain amps a lot, with AC heaters and hum is not an issue compared to hiss. It is possible to get even a high gain amp quiet with AC only. You need to be careful with how to route the heater wiring, how and where it's referenced to ground etc.. Post a gut shot of your amp and maybe we ca...

You're not going to be able to use a regulator with that supply unfortunately. They need to drop 2 or 2.5 volts, check the data sheets. You'll need at least a 8v transformer, full-wave rectified. You've also got to worry about heat dissipation, because all that "waste" voltage will get converted to...

The humdinger is a pot connected across the 6.3vac winding with the pot wiper going to ground (or an elevated voltage). Even if a heater winding has a CT it may not be balanced as well as possible. The Humdinger allows you to sweep the pot back and forth in order to find the most quiet position for ...

depending on the amp (high gain, low gain) you may get away with a big filter cap. I use a bridge followed by 22,000uF and only have issues with high gain amps. In those cases, its regulated with a LM1085. Poorly designed DC heaters can be noisier than AC heaters done right. You're introducing 120hz...

I use snap mounts almost exclusively. The pin spacing is just right to slide into two lugs on a terminal strip or into a turret board. I like to either lay them down sideways and solder the pins to a terminal strip. Or if i am using a turret board, the pins fit just right and I"ll stand them up into...

you are most likely overdriving the driver tube. voltage divide the signal going into the driver. After your 500pf put a 220k or 470k. Sharing the cathodes between stages can get wonky when you're talking massive signals of the same or opposite phases, but it is fine here since the reverberated sign...

Vietnam building peavey amps I believe