High Voltage Non-HRM 100W Build Started

[ToneMerc]

MM style high voltage power, high plate skyliner, FS mid boost and 6V regulated relay supply.

TM

[odourboy]

PEC pots?

Looks NICE!

[Structo]

Lookin good!

So no FET?
Is the relay on the right sidewall for the mid boost?

Hey, I just noticed something, you only have six of the radial filter caps verses eight on most amps.
Can you explain that?

[ampdork]

I see another blank board on the sidewall...I'm guessing switchable FET boost...

[ToneMerc]

Lookin good!

So no FET?
Is the relay on the right sidewall for the mid boost?

Hey, I just noticed something, you only have six of the radial filter caps verses eight on most amps.
Can you explain that?

Tom, I have so much going on I really haven't had time to tweak those PCB files for dual inline relays or order the FET pcb board. Thus I ended up making those boards via G10. I was going to use a pcb FET, but when I looked at the Ceriatone layout yesterday I said I can make an FET board real quick.

I tell you this pcb boards are the way to go, even using a respirator the G10 dust is nasty.

Yes, the small relay board is the mid boost relay and the plan is to mount the FET board at the right rear of the chassis.

The MM topology taps off the screen voltage between the first two big caps. Since I'm feeding my screens directly via a bigger choke, I really don't need to you use four radial banks.

The first board that I punched two weeks ago had 4 radial banks as I was thinking about running all nodes through a bank. So when I drilled the board mounting holes the chassis was mocked up and clearanced with Alpha pots. Well when I installed the PEC pots the power board butted almost right up to the deeper PEC pot. Thus, time for more G10 dust

Basic MM power plant

B1: 700 volts, first cap
B2: 350 volts, betweeen big caps, feeds screens (i'm also using a choke inline here)
B3: output of 25K 10W resistor
B4: post 15K resistor
B5: post 10K resistor

I did add a resistor post the 25K so that I could tweak the preamp string without having use the 10W as the adjuster resistor.

Mike

[ToneMerc]

Made a bit more progress, the power section is wired minus the heaters, standby switch and screen resistors.

[Drumslinger]

that's looking pretty sweet TM.

[Structo]

What layout did you end up using for the big filter board?

[ToneMerc]

It passed the smoke test

Unloaded voltages @ 123.6 VAC

B1 = 767 VDC
B2 = 383 VDC
Htr = 7.02 VAC
Relay PS = 6.03 VDC
Bias sweep @ wiper leg = -34.8 to -43.2

[Drumslinger]

have you slept any TM? Looks like your putting in some overtime on that amp.

[Teleguy61]

Looks good.
Keep 'em coming.

[ToneMerc]

have you slept any TM? Looks like your putting in some overtime on that amp.

Sleep is way overrated and besides, I'll have plenty of time to sleep when I'm on the other side of the dirt and my toes are pointed up!

Actually, I worked on it just little bit this evening after dinner. I only wired up the standby, turned a diode around and swapped two lead locations. I still have v1 thru v6 heaters and screens to finish up the power section.

The act of seeing 700+ volts was eating at me all day and I couldn't wait, I had to power it up.

Mike

[ToneMerc]

My version of MusicMan 100W iron showed up today from Heyboer and I've finally finished the preamp board.

Plates: 150/120 & 220/150,
Cathode caps: Sprague TE 5uf
Cathode resistors: Dale CCF60
Signal resistors: Speer & Electra/Mepco CF
Orange drops: combination of 225P, 6PS, 418 & 220P

TM

[Structo]

What is the huge cap on OD1?

[ToneMerc]

What is the huge cap on OD1?

.015 16PS