Took a chance... MM content.. package arrived

[FUCHSAUDIO]

Okay, thats' the one with the switched primary. The secondary voltages are fine to make a high voltage 65 watt D-style no problem. The bias voltage you will need will be low, so that winding would be fine. It could also run your relays (it has the current), and you can tap the HV for your bias as well, if you like. Let me know if you need anything.

[talbany]

Bob
Looks like you may be able to use it give you about 675 under load on the HV ..

Good Score!!

Revised..

Tony

[Bob-I]

Okay, thats' the one with the switched primary. The secondary voltages are fine to make a high voltage 65 watt D-style no problem.

Excellent news. Now, what do you mean by "switched primary" and which schematic should I use for the HV?

The bias voltage you will need will be low, so that winding would be fine. It could also run your relays (it has the current), and you can tap the HV for your bias as well, if you like. Let me know if you need anything.

The only thing throwing me is I can't find a schematic that shows the bias without a CT, but I'm sure this will work out find for the bias.

Thx Andy.

[ToneMerc]

[quote="Bob-I]The only thing throwing me is I can't find a schematic that shows the bias without a CT, but I'm sure this will work out find for the bias.
[/quote]


Check your PM

Mike

[Bob-I]

Bob
Looks like you may be able to use it give you about 675 under load on the HV ..

Close, I'm reading 651 unloaded. Close enough for rock n roll.

[FUCHSAUDIO]

Okay, thats' the one with the switched primary. The secondary voltages are fine to make a high voltage 65 watt D-style no problem.

Excellent news. Now, what do you mean by "switched primary" and which schematic should I use for the HV?

The bias voltage you will need will be low, so that winding would be fine. It could also run your relays (it has the current), and you can tap the HV for your bias as well, if you like. Let me know if you need anything.

The only thing throwing me is I can't find a schematic that shows the bias without a CT, but I'm sure this will work out find for the bias.

Thx Andy.

High voltage should be the standard MM voltage doubler, then feed the screens from the middle of the two supply caps through a resistor (See MM schemos for value) and to a second cap for the screen supply. I use 1-K per EL-34 screen, and I believe we used 1-K 5-W for the screen limiter resistor. I use 180-V 400 V surplus caps on the mods, which work great.

Use a bridge or a single diode to make the bias supply from the 33 V winding.

Add a transformer to run the relays and stick with the MM windings for everything running the amp.

The primary had a lead (I think it was red/black) that fed the pilot lamp, so when you switched from high to low power the lamp stayed lit properly....The diagram you show should allow you to find the proper leads to feed the primary from 120 V.

[Bob-I]

Thx Andy. Wiring that up I got 651VDC, should work out well

[talbany]

Bob according to my math the PI dropping resistor (650v) should be roughly 36K 10w WW and a 820K (@PI node) bleeder for the RC..then 2.2 & 2.2

Hope This Helps!!

Tony

[Bob-I]

The rest of the parts arrived yesterday. The ebayer forgot to post that the chassis had been cut down by 4" and the end welded back on.

I sent him a message. I gave him 2 choices, refund half my money and I'd return everything but the iron, or refund all and I'd return everything. He said forget returning the screwed up parts, he'd refund half. So I got the iron and some new 50/50uF 500V mallory cans for $65. I have a chassis I can use.

The model is 2475-65-UL. No serial number, that was on the cut off part of the chassis.