another master volume question

[funkmeblue]

is there any reason a "type 2 master volume" from the trainwreck pages can't be used on a liverpool or any other cathode biased amp? Also, what would happen if you left off the .1 uf caps on the "type 1 master volume"? Are they just there so you don't loose the high end? thanks

[solderstain]

I've used the modified Type II MV (from the Metro pages) on three cathode-biased amps so far - my '63 AC30, and two smaller 18w-style EL84 amps. I think the modified Type II MV works better in a cathode-biased amp with no NFB than it does in a fixed-bias amp, in my humble experience.

[Structo]

On the little cathode biased 6v6 amp I built I experimented quite a bit with different master volumes.

The type 2 was ok but pretty touchy at low volume.

Tried most of Fishers MV's, tried the crossline MV.

I found I liked the Bootstrapped MV best of all on my amp.

Seems to have a good range and keeps the tone more consistent than the others I tried.

Someone here reported that they just used a single 1M in the input of the PI.

I used a dual gang 1M like this drawing shows.

Of course this is a pre PI MV but on my 2 x 6V6 amp it seemed to work the best.

BTW Funk,

The caps are used to keep the DC voltage off of the pot, so it doesn't go scratchy.

[funkmeblue]

right on, looks like I'll have to try them all! I built a 10 watt ultralinear "liverpool" and have been tweaking it for a couple of months now......really sounds good, good enough a friend of mine wants it.....if it had a master.......I don't want to sell it, but I want to build another amp and funds are low. Something with a cothodyne PI. Any reason I can't use a type 2 master after a split load inverter?

[Markusv]

right on, looks like I'll have to try them all! I built a 10 watt ultralinear "liverpool" and have been tweaking it for a couple of months now......really sounds good, good enough a friend of mine wants it.....if it had a master.......I don't want to sell it, but I want to build another amp and funds are low. Something with a cothodyne PI. Any reason I can't use a type 2 master after a split load inverter?

Funk

Could I ask you wat you experiences are with the ultralinear Liverpool?
What would you say is the benefit of the u/l configuration? Tone- wise?
And how do you hook it up? just the u/l taps directly to the screens? no resistors as in hi- fi, I guess?
I have never used that configuration but I have a u/l tranny (25 watt) staring at me on the bench.

Also, what output tubes? I have had success with 10'ish watt builds with 6GW8/ ECL 86's, using the triodes as PI. These tubes deliver great sound and with the right component values can sound huge for their size

I would value your help please.

Markus V

[funkmeblue]

I used el84's at about 300 volts. Just hooked the taps right up to the screens. Really can't explain the sound. Tried it both ways and liked the ul taps better, the high end had more "sugar" on it and not as brite. This amp also uses a 5y3 rectifier with a choke and puts out 10 watts. I also used seperate cathode resistors and bypass caps when I switched to UL.