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Vintage threads from the first ten years

Programmable FX switcher

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5/4/2000 3:12 PM

Programmable FX switcher

quote:
"it was going to be a surprisingly expensive project ...
We decided to get into it, when we have found a reasonable pricing parts supplier, or get them somewhere else.(relays from wrecked modems and so on)"

Yeah, that's the drawback. I'm slowly making one.

If you can do mail order surplus parts, you may be able to cut that down. B.G. Micro has one pole, ten position rotary switches for US$0.69 each right now, and SPST dip relays for the connection switches are often under US$1.00 from surplus places. However, I'm aware that mail order to some countries is subject to large tariffs and added costs.

You might consider making the CMOS switched one - it cuts the costs a lot. All you have to do then is find the rotary switches for programming, and in a pinch you can use dual-row pin strip and jumpers for that.

Good luck with it, and if I can offer technical advice, please don't hesitate to send email.

5/4/2000 2:41 PM

Re: Stomp box switches?

quote:
"I'm pursuing a slightly different tack. I think I've located some miniature latching DPDT relays."

What are your thoughts on using dpdt reed relays in stompboxes? They don't appear to be very popular. They are relatively inexpensive and easy enough to find - it seems to me that these would work well with an also easy-to-find SPST stomp switch.

quote:
"I don't think anyone's had the nerve to dig into my any-to-any programmable switcher yet - it's a big project to tackle."

I'm on it! I've been meaning to write you about this - I can't tell you how happy I was to discover that project on your site. I've been toying with that idea for about ten years now, and had gone so far as to sketch out the rough circuit a couple of years ago. The main difference in my setup was that it was loosely based on the channel switching circuit used in my old Carvin X60 head, and consisted of 1 spst on/off switch, 2 sections of 4049 hex inverter, 3 p-channel jfets, and one DIP switch per channel (plus the diodes, led's, etc...). The big drawback, and the reason I never built it was because I could never figure out how to incorporate momentary switches into the circuit so that activating one would cancel the previous selection (I can build and/or copy, just can't design).

Anyway, the switcher I'm working on now combines elements of yours and Randall Aiken's designs. I hope to have it ready by mid-june (big fat televised gig in VA - I'd like to NOT be tapdancing in front of the cameras

. I'll post the results when it's done.

Thanks,
=Bob

5/4/2000 3:18 PM

Programmable FX Switcher

quote:
"What are your thoughts on using dpdt reed relays in stompboxes? They don't appear to be very popular. They are relatively inexpensive and easy enough to find - it seems to me that these would work well with an also easy-to-find SPST stomp switch."

That's an OK option if you can stand the continuous power drain that the relay coil eats. If you're AC-adapter powered, this is not a problem, of course. Surplus DPDT reeds are great for this, but if you have to buy them new, they're $12-$20 each!
Dual SPDT's work, too. You just have to watch the whole balance of total cost, space in the pedal, and power used. It's a nice little engineering problem, actually. If I were still teaching EE labs, I'd assign that one for cost/benefit tradeoff analysis.

(on the programmable switcher)
Go for it! Yell if I can help.

5/4/2000 11:20 PM
PTJohn	RG: I hate to bring up THE DREADED NAME, but Radioshack.com store has DPDT reed relays for under $4 each. Would these be any good, and if not, other than the fact that RS sells them, why not? Thanks for the input. John.

5/4/2000 11:54 PM
R.G.	ACK! The dreaded "RS" word! Actually, some of the stuff in there is OK. It's just my last resort. I haven't seen the RS DPDT reeds. They might be just fine. I'm a firmly grounded pragmatist. In general, if it works and you can live with the side effects, do it.

5/4/2000 11:59 PM
PTJohn	Thanks, man. As always, I appreciate the reply. John.

5/5/2000 1:58 AM
J.Everman	IF you are looking for dip relays cheap, check out www.allelectronics.com They have a lot of stuff cheap. J.Everman

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