Vox Royal Guardsman 1131 problem

[52 Bill]

I'm also solving the issue with breakage of the multi-stack power switch, as shown. Same function, same knob, done with mini-relays on one PCB under the switch.

So you're using one relay for the speaker line and the other relay for the higher current ac components?

What did you end up doing about the channel rocker switches?

[R.G.]

So you're using one relay for the speaker line and the other relay for the higher current ac components?

Yep. I found relays for $3 each that have 120Vac coils and 15A contact ratings. It turns out that same-looking (close enough for a chimera, anyway) indicator lights are available in 120V neon, which will work directly from one section of a low current rotary switch.

What did you end up doing about the channel rocker switches?

I found black plastic rockers that mount by pressing through a rectangular hole. Their body was smaller than the rectangular cutout on the panel, so I made up a small metal plate that mounted under the panel with the existing screw holes, and the small rocker mounts in that. I think that with some flat black paint it will be passable.

It's still being built. Slowly.

[drewl]

Wow RG, you made up new boards?

For some reason the wiring in these doesn't bother me, I usually group them and tie wrap the wires to keep them from breaking.

Another thing, I've found those wafer switches that are used for the Power/Standby.
I found a bunch of computer A/B Data boxes for switching between two computers/terminals that have the large wafer switches inside FWIW.

[52 Bill]

I found a bunch of computer A/B Data boxes for switching between two computers/terminals that have the large wafer switches inside FWIW.

My concern would be how much current the contacts could handle. Probably okay for the light show, but not enough for the speaker output.

[R.G.]

Yeah, that's the real issue. The outputs on a Beatle can put 12A peak through those switch contacts if you load them with resistors. If you're driving speakers, it can double or triple that. I've tried to look up the kind of rotary wafer switches they used, but I've never found one with a current rating over a few amps. What probably saves the originals is that they are wiping contacts that get wiped every on/off cycle.

I found a Grayhill rotary that can do 6A-8A, so theoretically with two sections paralleled, they might work. But the PCB relays are rated for the load. And if that doesn't do it, this relay can pull in the coil on an AC contactor...

Yeah, I made new boards. There's almost no limit to what a nut - er, enthusiast - will do when he sets off. I hate running long wires, and I hate stripping, soldering and bundling cables. With the majority of the wires going from PCB to pots and switches, and the pots and switches all kind of local to one place on the control panel, it just seemed reasonable to put the electronics that runs the pots and switches as close to the pots and switches as possible. No fewer wires, but the ones that are there are mostly only an inch or two long, and don't wind up tying the PCB down like Gulliver in Lilliput. It seemed like a good idea at the time.

As much as anything else, I hate to see these amps dumped into the garbage. With a typical tech bill for recapping them running to multiple hundreds of dollars and many techs simply refusing to work on them, it made an interesting exercise in whether I could just replace the insides with the same electronic circuits, but much easier to work on. Eventually, I suppose I could get a run of the PCBs made to make rebuilding these things easy.

... if I can get these to run by fixing my own dumb mistakes.

[drewl]

I'll have to take pix, but the wafer switches I've found look beefier than the originals.

[R.G.]

That's good. Beefier is better. Those speaker contacts carry a lot of current.