WTB: abx switcher

[garlandstephens]

I'm looking to buy or commission an ABX switcher for long-term use. This is a simple build using, say, 12V DPDT relays and a wired remote using a push-on push-off switch. Preferably switching both line-level and power, 2-in and 2-out for both so 2 amps can be switched between 2 sources and 2 sets of speakers or dummy load. I just don't have time to pull it together.

Any takers?

[Spasticteapot]

I'll do it!

How much are you offering?

[garlandstephens]

How about $100 (5 hrs at $20/hr) + cost of parts (parts list to be agreed in avance)?

[Spasticteapot]

Originally posted by garlandstephens
How about $100 (5 hrs at $20/hr) + cost of parts (parts list to be agreed in avance)?

Sounds good to me.

What relays would you prefer? Would a wired remote be acceptable, or would you prefer an IR remote?

Also, what relays would you prefer? I have some NAIS AGN20009s that might fit the bill for the inputs, but you'd need something beefier on the outputs.

[garlandstephens]

Those are fine for signal, but too small for power, as you point out. I'd like to support 200W RMS on the power side.

If you can do IR, that would be great.

I'd like to set it up where I can switch without being able to tell which device is currently being used. i.e. push a button to switch, rather than separate buttons for A and B.

It would also be nice to have a simple way of starting in an unpredictable state. One thought I had for random/blind use is to use a rotary switch to spin. Positions would alternate between A and B. This is not strictly necessary, though, since a few fast pushes without counting would have the same effect.

On the signal side, RCA jacks for in and out will do, and on the power side, dual binding posts that accept paired banana plugs.

[Spasticteapot]

Originally posted by garlandstephens
Those are fine for signal, but too small for power, as you point out. I'd like to support 200W RMS on the power side.

If you can do IR, that would be great.

I'd like to set it up where I can switch without being able to tell which device is currently being used. i.e. push a button to switch, rather than separate buttons for A and B.

It would also be nice to have a simple way of starting in an unpredictable state. One thought I had for random/blind use is to use a rotary switch to spin. Positions would alternate between A and B. This is not strictly necessary, though, since a few fast pushes without counting would have the same effect.

On the signal side, RCA jacks for in and out will do, and on the power side, dual binding posts that accept paired banana plugs.

I think I can whip up something that will work well enough. The rotary switch is not a bad idea.

[garlandstephens]

Sounds like a plan. When you have it worked out, let me know what the ballpark parts costs are, then I can send you the money for that. When you're finished, I'll send the rest.

I'm flexible if you want to proceed differently.

[garlandstephens]

Just wondering where you are with this

[Spasticteapot]

Sorry for not getting back earlier!

I've finished the copper enclosure - it's riveted together, made out of a single piece of hammered copper, and nearly indestructible. I also have a wall-wart, and the signal input relays on a PCB, ready to go. It looks sweet.

I'm currently bribing someone better at programming than me to write the code for the microcontroller. This should cost about 5$ worth of chocolate - I'll cover it.

Still needed are the binding posts and input jacks, and the large relays for the speaker inputs. (2 DPDT relays are needed). Apexjr has excellent deals on input jacks on binding posts, and very likely has the type of relays you'd be looking for.

Total expenditure:

$4 - 2 super-mini relays (you can upgrade to gold-plated relays if you'd like - just ship 'em here!)

$5 - assorted bits of PCB and stripboard

~$10 - cost of PICmicro and voltage regulator to drive it. (Any IR remote can be used.)

$whatever you think is fair - copper enclosure with Lexan panel. It's not the world's best and I made it in only about an hour and a half, but I certify that if you accidentally push it off a table, no one will be the wiser (aside from the dent in the floor.)

I presume you'd like the controls as follows:

1. On startup, neither amplifier is on.
2. On an IR signal, either one of the amplifiers is randomly switched on.
3. On ensuing IR signals, it switches from one to the other.


Would you like a display of some sort? A single red-green bicolor LED will let you know if it's the first or second amplifier; two internal LEDs (not visible from the front) would tell you which amplifier is which. Or, I could do something else.

E-mail me at spasticteapot@gmail.com if you'd like pictures, and for more info or comments.