3stage + CF options

[Smokebreak]

dime the normal master and the amp should remain cleanish on bright until about 4 on the dial with no bright cap at all.. ish.

Totally. With normal master dimed it's stays clean with no fizz with gain up to 6, even. It's capable of being really loud and cleanish, and sounding great, but nastiness comes on past 6 on gain dial, regardless where the master is. I stuck 12at7 in PI to see if that was the problem area but it just reduced gain a little...fizz stayed the same.

[Reeltarded]

it should be doing that lol congrats

[Smokebreak]

Haha I know, I know. None of my other marshally CF circuits fizz out so much though. Ah shucks.

[Colossal]

Smokebreak,

I'm wondering if you're getting the dreaded crossover distortion fizzies in the power section. You might consider dropping the tail resistor on the PI from 10k to 22k.

[gktamps]

Have you measured and recorded voltages? If so, do you want to post them?
Cheers,
Greg

[Smokebreak]

Smokebreak,

I'm wondering if you're getting the dreaded crossover distortion fizzies in the power section. You might consider dropping the tail resistor on the PI from 10k to 22k.

I wish I knew what it is, I'm just blindly kinda stabbing at it, without a scope, at this point. i put the tail at 22K but that didn't affect any change. It seems like I'm missing some gain, with the gain dial all of the way up, in 1987 mode too. It's not as crunchy as other circuits like this I've built. i keep thinking that's a clue

Have you measured and recorded voltages? If so, do you want to post them?
Cheers,
Greg

Yea Greg here are my voltages. They seem to fall in line with Mark Huss', though it's been documented that there were some errors in his original readings, I believe, in the PI

v1 160 plates, 1.5 cathodes
v2 136, 232 plates 745mv,135 cathodes
v3 167,169 plates, 17 grids, 28 cathode
v4,5 421 plates, 373 screens, 24Ma,20mA bias

Im gonna go to work on the 6V6 grids

[Smokebreak]

Something I mentioned early on but haven't addressed, my heaters are 7VAC...

[Colossal]

Something I mentioned early on but haven't addressed, my heaters are 7VAC...

You can throw 0.1R/5W on each secondary leg if you want to knock back the heater voltage a little.

[gktamps]

Does it seem to you like your screen voltage is low, relative to your plate voltage? In my 1987X type build, they are about 15V apart. I wonder if your fizz is related to that?

[Smokebreak]

Thanks Colossal, I'll get some on my next mouser run.

GKT, the screens are definitely lower than normal, with respect to plate voltage. Huss has a 5K5W in series with the choke for the screen supply. I'm not really sure why that decision was made, though, other than maybe tube life, as otherwise he would have had ~440V on the screens. I've ran it with and without that series resistance, and even chopstick switched it, and thought that I liked it better without the droppage, but once I put it back in I really couldn't hear a difference.

[Smokebreak]

Yeah! No more fizz. The high mid sizzle is sitting right where I wanted it now. I decided there was just too much going on with all the switches and crap flying everywhere. I wired it straight 3stage+CF,non switchable stages, but kept the clippers, of course. 1st stage with the pot as the only division to grid. I took out the term strips and cleaned up the lead dress big time. Clipper comes off 100n>10K, but no CF master only normal master. No cathode cap on 3rd stage. It's kinda funny that the best sounding amp ended up being the simplest lesson learned. Thanks again!

[Reeltarded]

Rock'n! I don't always use the CF master in mods with the clipper either. Glad to hear ya got it kicking!

[Smokebreak]

As discussed earlier here, 4 gain knobs was just too much, for me. I ended up confusing myself trying to play it. What I *thought* I wanted with the 2stg switched out I'm getting in spades that clean crunch that's fun. Who really needs cleans below that for rocknroll

[Reeltarded]

my dirty amps don't do cleans at all none aint there forget about it

[Smokebreak]

Little crunch through phone mic, both gains backed down considerably and living room volume https://soundcloud.com/jeremyslemenda/s ... ay-evening