ODS 101-HRM Relay Wiring

[benoit]

I'm building the ODS-101-HRM schematic with the addition of OD/PAB relays.

Here's how the schematic shows they should be wired (correct me if I'm wrong)

Diode across the coil on both relays, 12v on one side, footswitch on the other. I'm fairly sure on that point. Now for the switches.

OD:

Com1 - OD entrance (47pF in parallel with 470k)
NC1 - coupling cap after 2nd clean stage/clean master leg(not the grounded one)
NO1 - Ground

Com2 - Preamp Out
NC2 - OD master wiper
NO2 - Clean Master Wiper

Now, this seems like it'd work OK but checking against pics of HRMs they don't seem to be wired that way. If it's not going to make a difference I can do it this way but regardless I'd like to know how the real thing is wired.

Now, I'm especially confused about the clean master wiring. Does one wire run from the .047pF cap to the relay and from there to one leg of the pot? Or do you run two leads from that cap, one to pot one to relay? Or is it first to the master then to the relay from the master?

On a side note - the deep swtich: Why was it included in the ODS-101-HRM schematic and the jazz/rock excluded. Every ODS or clone I've seen pics of has jazz/rock and NOT deep. Very confused.

[ic-racer]

checking against pics of HRMs they don't seem to be wired that way.

I see what you are talking about. I DO see two wires coming off Gil's relay board (so I know how he would answer the question ). In the 'real deal' pictures I only see one wire (perhaps the other comes off below the relay board??)

In terms of the J/R switch on ODS 101, I personally think that schematic could use an update or show some alternate hookups. The HRM schematic i'm slowly, slowly working on has Mid boost, J/R and bright with 'standard' PAB (not mega).

[heisthl]

Od relay state: Decide what mode you want to be in if your relay or relay power supply fails. I used to think clean should be the default, now I'd rather be stuck in OD, with no PAB. Not that it would ever happen....

[benoit]

Thanks gents, That about answers that for me.

Now as for the PAB side of things, again, according to ODS-101...

1. Yet another thing I forgot to order: 22Meg resistors. Struck out trying to get any locally. How critical is this value.. or how much can I get away with? If I have to I'll just place a mouser order and throw on some stuff for my next build (which is still quite a ways off).

2. Where to put said 22M resistors. I was thinking it'd be simplest for my non-PCB relay boards to mount one resistor on the relay board and the other from one leg of the bass pot to the wiper. Is that cool?

[heisthl]

1. you can use any value but it needs to be 4M7 or above to be somewhat transparent.
2. Those resistors can be mounted anywhere

You don't need to use the resistors at all, they just keep it from popping when switched.

[HiGain]

In terms of the J/R switch on ODS 101, I personally think that schematic could use an update or show some alternate hookups. The HRM schematic i'm slowly, slowly working on has Mid boost, J/R and bright with 'standard' PAB (not mega).

I essentially have time for lurking these days... If you want to take these schematics over and update them that would be great! Use the latest versions that are uploaded now.

Best,
Jake

[ic-racer]

In terms of the J/R switch on ODS 101, I personally think that schematic could use an update or show some alternate hookups. The HRM schematic i'm slowly, slowly working on has Mid boost, J/R and bright with 'standard' PAB (not mega).

I essentially have time for lurking these days... If you want to take these schematics over and update them that would be great! Use the latest versions that are uploaded now.

Best,
Jake

First off, excellent work on those schematics. I'm slowly working on a Marshall Iron/EL34 HRM and a BluesMaster. Maybe I'll call them 102 when I get done. Either way, they would not be possible without all the work you put in to the 101 schematics.

[ic-racer]

2. Where to put said 22M resistors. I was thinking it'd be simplest for my non-PCB relay boards to mount one resistor on the relay board and the other from one leg of the bass pot to the wiper. Is that cool?

You could put them both on the PAB relay board, using the same eyelets for the exiting and entering wires.

[benoit]

2. Where to put said 22M resistors. I was thinking it'd be simplest for my non-PCB relay boards to mount one resistor on the relay board and the other from one leg of the bass pot to the wiper. Is that cool?

You could put them both on the PAB relay board, using the same eyelets for the exiting and entering wires.

Could, except I decided to mount one of the deep switch 270k resistors on the PAB relay.

[HiGain]

First off, excellent work on those schematics. I'm slowly working on a Marshall Iron/EL34 HRM and a BluesMaster. Maybe I'll call them 102 when I get done. Either way, they would not be possible without all the work you put in to the 101 schematics.

Cool. You've done amazing stuff with layouts and schematics... Take it away!

BluesMaster is in the future for me too. Looking forward to your experiences.

Jake

[ic-racer]

I had posted a hand drawn board (I thought it was on this thread) but, this drawing is much more accurate and explains where all the wires go.