Reed relais good for bypassing?

[Zero the hero]

I have a bunch of reed relais that I bought while ago and I was wondering if they were reccomended for effect bypassing.

http://www.meder.com/it/index.php?page=720&prod=rre&prodnr=36

Each reed con be configured to form a SPDT and a with a couple of them a DPDT can be done.
A flip-flop like the Boss could be used to drive the coil and turn a led on when engaged.
Any reccomendation? I'm drawing a small board to accomodate all the components.
I was wondering why nobody uses it, they seem good for general switching purposes.

[The Tone God]

I think trying to use two relays together for bypassing is a bad idea because synchronizing the relays will be nearly impossible as they are mechanical devices and will vary from each unit. That difference will result in all kinds of problems.

I would advise against it.

Andrew

[Zero the hero]

Clear!
DOH! It's now time to think what do with 50 (YES, FIFTY) reed relays... 

[Shepherd]

synchronizing the relays will be nearly impossible as they are mechanical devices and will vary from each unit.

Reed Relay Matcher

[MKB]

I think trying to use two relays together for bypassing is a bad idea because synchronizing the relays will be nearly impossible as they are mechanical devices and will vary from each unit. That difference will result in all kinds of problems.

I would advise against it.

Andrew

What parameter would you have to match?  Activation current or voltage?  The differences in contact resistance and activation time between different units would be negligable.  If you drive them (in worst case) with individual drivers, I can't imagine why they wouldn't be dependable and repeatable, even using multiple ones in a DPDT arrangement.  In fact, you could use them as SPST's in a topology similar to the flip-flop footswitch circuit in Boss and Ibanez pedals, the relay contact would replace the jfet switching transistors in the circuit.

[RaceDriver205]

Using more than one relay doesn't seem that bad an idea. Yes there will be inconsistencies, but ive used reed relays, and I doub't they will cause you switching issues. I would recommend CMOS switching, but I still think multiple relays would work fine.

[The Tone God]

I haven't put much thought into it but my initial concern would be the contact switching time difference between the two relays. Mind you it depends on the circuit too. Some circuits may not mind the input and output not being switch exactly at the same time.

One could use a buffer then wire a single relay like SPDT switch. It is more circuitry but that would eliminate the need for both relays.

Just a thought.

Andrew

[jrc4558]

Well, you can always go for switching only of the output of the effect (1PDT), thus avoiduing having to match the relays...

[RaceDriver205]

I think thats what tone god meant

[Zero the hero]

OOOOOOOOK, I'll give these relays a shot, then!
Thanks.

[Zero the hero]

This thread slided down to page six, sorry for resurrecting it.

Code Select Expand

http://topopiccione.atspace.com/temp/boing.gif

This is a draft schematic for controlling a couple of reed relays. The reed I have are double SPST which are both normally open when the reed coil is off.
Actually, R5 and R6 are 0 ohm resistor (jumpers), and the bicolour led has been replaced by 2x 1N4148 small signal diode. IC1a and IC1b form a pushbutton operated flip-flip (there is an additional resistor and capacitor not shown in the schematic for avoiding button debouncing), which alternatively drives Q1 OR Q2.
Status leds are not shown since I have not yet decided how to connect them: should I use the remaining CMOS ports or should I try to connect the leds directly to the Q1 and Q2 bases (for example)? Which solution is better? Using other ports will increase power consumption, but allows status led not to interfere with the rest of circuit.

Everything works, but it's noisy and all the mods I listed reduced partially the BUMP I hear on the loudspaker of my amp. Now the switching noise is tollerable, but it's still audible. I also tried to bias both input and output with +4.5V, and to add capacitor on input and outputs of the whole circuit, but it did nothing against noise.
Also, 1M and 470k resistors to ground on both ins and outs doesn't do anything at all!
Also, different transistors and different ratings for R3 and R4 do almost nothing.
As always, I'm too naive to catch what I'm missing: I suppose the noise is generated into the reed relays, but this controller seems to be good enough for this purpose... was Andrew right?

EDIT: Link forgotten...