100w 2nd Gen. ODS build

[martin manning]

You are referring to this layout?
https://ampgarage.com/forum/viewtopic.p ... 80#p462380
If you bolt the reg to the chassis and solder the legs to a terminal strip (as in the later ODS layouts) you already have two grounds: the tab, and the center pin (via the terminal strip). In the linked diagram "RPS ground" is just a ground lug (if the reg is board-mounted), or it can be the grounded center lug of the terminal strip. The reg is grounded (twice!), so you just need to connect the lower capacitor negative and diode anode to the grounded lug. It's ok to have more than one ground if they are in that corner of the chassis and close together.

[DSull89]

Thanks again, Martin! You’ve been a big help! When my parts show up I’ll post some progress pics.
Thanks,
Dan

[DSull89]

A little more progress, but wanted to ask a couple questions before I went any further. On the 1Ω cathodes is it best to ground them in pairs, individually or am I over thinking and it doesn’t matter? Also, as far as the 100 Ω filament grounds, does it matter which sockets I run them off of? I was thinking of going off pin 2 of V5 and pin 7 of V6 to be neat unless there would be an issue I’m unaware of. Let me know and thanks again to all that have been taking the time to help. Much appreciated.
-Dan

[martin manning]

A little more progress, but wanted to ask a couple questions before I went any further. On the 1Ω cathodes is it best to ground them in pairs, individually or am I over thinking and it doesn’t matter? Also, as far as the 100 Ω filament grounds, does it matter which sockets I run them off of? I was thinking of going off pin 2 of V5 and pin 7 of V6 to be neat unless there would be an issue I’m unaware of. Let me know and thanks again to all that have been taking the time to help. Much appreciated. :)
-Dan

If you look at the #124 layout you can see that the heater and cathode grounds are grouped 3 and 1. Grounding in pairs or individually will be fine. Similarly you can do the 2x 100R off the same socket or from two adjacent ones. Here is how I did my ODS.

[DSull89]

Thank you, Martin! Just the clarification I needed. Very nice work, too! Which ODS variation did you build and how do you like it, if you don’t mind my asking?
Thanks,
Dan

[martin manning]

Which ODS variation did you build and how do you like it,…

That is a #124 with a few tweaks. It’s a great sounding amp IMO, and capable of producing a wide range of tones.

[DSull89]

It’s been a long while but I’m back to working on this thing. I have the regulator board almost wired up but have a quick question. So as far as grounding the cap negative and diode anode, is the blue wire I’ve run to the strip sufficient or do I need to also ground from the cap negative eyelet? I’m a little confused because I’m working from two layouts simultaneously. All help is greatly appreciated.

[DSull89]

I think my issue was I was actually combining the stock regulator layout with Martin’s modified layout, basically I just need to follow the regulator layout for 102 or 124, right? Also got V6 and V7 mostly wired up.

[dbharris]

Yes, there are some differences between the different layouts. With your relay transformer, you can go with either a FW or FWB. For FW you would use the CT and one of the outside leads, shrink wrap and float the other outside lead. For FWB you use both outside leads and float and shrink wrap the CT.

For your grounding question, I would need to see layout you are using to understand.

-Dan

[DSull89]

Thanks, Dan! I have the relay transformer wired for FW and the diagram I’m following is Martin’s modified version with the added regulator minus the 56R found here…

https://ampgarage.com/forum/viewtopic.p ... 1185911549

[dbharris]

Looks like you are good to go. As long as your grounds in the board tied together (as shown in Martin's drawing) you only need the one wire connecting to chassis ground. You should be fine the way you have it.

-Dan

[DSull89]

Great! Thanks, Dan! Will get back to work on it over the weekend!

[DSull89]

Hey Guys! I have the relay supply wired up but hit a snag with the DIN wiring. The plan is to have the FET be footswitch only. So would the wiring be as follows or would I have to wire this like 102 and 124 with the OD and FET switches on the back panel?

1 Manual/Pedal switch
4 OD relay
2 Ground
5 FET relay
3 Supply board

Also, can somebody help confirm that my supply board wiring coincides with Martin’s layout? I kinda ended up with a hodgepodge between that and the stock 2nd Gen. board layout and I’m not sure if everything is up to snuff. The relay coil connection is where I’m confused, the way I have it set up there is a green wire going to the regulator from the 1k connected to the cap positive and a separate wire going from the cap positive to the relay coils. I really appreciate all the help.
-Dan

[martin manning]

Should go like this for 6.3 VAC into voltage doubler.

[DSull89]

Thanks, Martin! So if I’m reading the schematic right I would just get rid of the orange wire I have running from the cap positive to the relay coils since I already have the green wire running from the 1k to leg 3 of the regulator? Then I could just connect the relay coils to the tag lug connected to leg 3 like in 102 and 124, right?