100w 2nd Gen. ODS build

[DSull89]

Cool! Thanks! I have a 166J6 on hand, will that suffice?
-Dan

[martin manning]

Yes, that'll be fine.

[DSull89]

Not much, but a little more progress…

[DSull89]

Hey everybody, been a while since I’ve had time to work on this but I’m thinking I can get it sewn up over the next week. I’ve had to reacquaint myself with a lot of info and have a couple questions. As far as the 100w 2nd/3rd Gen’s are concerned, is the power tube wiring essentially the same as 102? I also plan to eliminate the half power switch, is there anything that needs to be omitted/adjusted for this other than the switch wiring itself?
Thanks,
Dan

[martin manning]

As far as the 100w 2nd/3rd Gen’s are concerned, is the power tube wiring essentially the same as 102?

Yes.

I also plan to eliminate the half power switch, is there anything that needs to be omitted/adjusted for this other than the switch wiring itself?

Lose the switch and the LED's, and add 1-ohm resistors the to power tube cathodes.

[DSull89]

Thanks, Martin! Really appreciate the help! So just to clarify, I’d need the 1Ω ‘s on pin 8 to ground on all four power tube sockets?
Thanks,
Dan

[martin manning]

Yes that’s the easiest and safest way to measure idle current for setting bias. Installing test jacks is even better.

[DSull89]

Thanks again, Martin! Much appreciated! Will order a few more parts and get soldering. Which test jacks do you prefer? Also, what size resistor do I need for the cathodes?
Thanks,
Dan

[DSull89]

Was just doing some research on the forum and came across norburybrook’s wonderland build using peavey transformers like mine. Apparently a fwbr is needed for these, all things considered will there be anything else I need to revise to allow for this? I noticed his diagram shows a 1 Ω instead of the 3k3 that I used according to the 2nd Gen diagram I followed. Any and all input is greatly appreciated.
Thanks,
Dan

[martin manning]

If you have a PT with no CT then you need to do the FWB. Do you know what the HT winding VAC is?

[DSull89]

Unfortunately I don’t. Can’t really find any info on these transformers, only thing I can find is the schematic for the Deuce which shows a fwb.

[erwin_ve]

Unfortunately I don’t. Can’t really find any info on these transformers, only thing I can find is the schematic for the Deuce which shows a fwb.

And you have the colors of the secondary wirings. The fwb is for the B+,
The secondaries with 1 diode is the bias circuit. You can use the standard ods bias circuit and adjust the resistors when the bias voltage is out of range.

I built a Ods with the same transformer. Check: https://ampgarage.com/forum/viewtopic.php?f=4&t=29721

Erwin

[DSull89]

Thanks, Erwin! Really nice build, by the way! Will modify my rectifier board today.
Thanks,
Dan

[DSull89]

Some good clips of a 2nd/3rd Gen. Now I really can’t wait until my parts order shows up. Lol

https://m.youtube.com/watch?v=655AC2zmG ... IDE5Nzc%3D

https://m.youtube.com/watch?v=jfuSnkqtS ... NzegBwE%3D

https://m.youtube.com/watch?v=C3B6iTBDZFc

[DSull89]

So I did some work modifying the rectifier board for the fwb and also decided to add the voltage regulator to the relay supply. I’m working off of Martin’s 2nd gen mod and was thinking I can just do it with a three lug center ground terminal strip rather than adding eyelets to the board. As far as the hookup for the rps ground, would I just wire the center regulator pin from the strip to the diode juncture and then from there ground it to the chassis? Or would this be an issue since it’s getting grounded at the strip before reaching the board?
Thanks,
Dan