YMI's 12xxxx build - feedback please

[YMI5150?]

ha, you're too funny!

5 hours in and its still holding at 196 VDC across the 100k resistor. stubborn cap??

the preamp tubes are in. is that slowing things down?

[ValveStorm]

forgot to remove PT centr tap?

[YMI5150?]

No. See yellow wire w heat shrink over end on second pick I posted this morning.

[ValveStorm]

If you want to try it wo the tubes dn't go all the way up to 120 right off the bat. Know and watch the voltage of you coupling caps.. and remeber, as the voltage across the res goes down, V everywhere else will go up!

[ValveStorm]

Sorry, I will not giv a sh#$ about typos... Im at 34000 feet! I have lousy laptop skilss!

[YMI5150?]

Sort of feels like the 21st century with wife on the plane. Think I'll try pulling the tubes. It is dropping about a volt every few minutes now. At 192 volts now, 6 hours in.

Edit: tubes pulled, ramped up to 120 vac and now measuring 95 vdc across the 100k and 265 across the couplers and dropping/rising. All seems good now.

[YMI5150?]

Alright. Got down to 25 vdc and preamp filter approached 350 so I dropped the variac down to about 98vac. Current reading is 12vdc across the resistor and 340 at the preamp filter.
Should I try to creep back up to 120vac if the filter allows or leave it alone?

[Strat78]

OK, now things are shaping up. The Erie 100uf PI cap will not hold things up, its that 16/16uf NOS erie cap that will take a bit longer. The one I put in Ben's amp last week was from the same batch as the 16/16 you have (last formed in 1976), it will slow things down for maybe another 40 hours. I got it down to 5.56v which is not bad for an old crusty cap like that.

[YMI5150?]

Yeah it's coming. I had to variac down to 90 to keep the 16/16 in spec. Resistor voltage is about 10.

[ValveStorm]

340 is HI at the preamp filter... The PI caap is probably well over its rated 350??? Remeber the big tubes are not there to grab voltage... in the real world the preamp wuld be below 300...

[YMI5150?]

Freaked me out. Just checked both preamp and PI filters. Both are at 332, 10 vdc at the resistor variaced to 95 volts.

[ValveStorm]

OK, so the PI is where it should be even wo the tube, the pre is runninghigh wo th tubes. Double check all the couplers 5 or 6 of them, including the tone stack, that there is not more than their rated 400v... then I would back it down to 325 and let it run over nite

Flyin thru MOntana now... just me and the pigmy pony! Gonna become a dental floss tycoon!

[Strat78]

Robert, I'll bet that pigmy pony is stinking up the place after eating all those cocktail nuts. Dental floss was my daughters favorite play thing, so I would market it to kids. Oh the many hours I bought for working on my amp by just handing her a little pack of floss to unravel.
Kevin, get out of bed and tell us the vdc!

OK, so the PI is where it should be even wo the tube, the pre is runninghigh wo th tubes. Double check all the couplers 5 or 6 of them, including the tone stack, that there is not more than their rated 400v... then I would back it down to 325 and let it run over nite

Flyin thru MOntana now... just me and the pigmy pony! Gonna become a dental floss tycoon!

[YMI5150?]

morning fellas,

3.5vdc, 343vdc across the preamp and PI cans, at 90VAC. I'll let it sit here while I go to work today unless you think its complete.

looking forward to experiencing the new mojo!

[ValveStorm]

Its done! Turn everything off, and discharge the caps for when you get home