Behringer Echo Machine EM600 - Bypass not working any more

[nils]

Hi there.

I have a Behringer Echo Machine Delay. Yesterday I noticed that the bypass function is not working anymore. The delay is working fine, but I can't turn it off (it turns on automatically after powerup). Not really a problem, as I use it within a rack system with a  TB-Looper/Switcher; but: I've added an external control jack to the delay so I can use the tap tempo feature via the switcher's foot controller.

The pedal is built fairly complicated and it's all SMD (and double sided, too), so I don't really know where to look. Has anyone ever seen a schematic, parts list or layout for this pedal (or maybe the Line6 Echo Park, which I believe the Behringer is a clone of)? Any chance of repairing it?

Thanks!

[jefe]

This part:

but: I've added an external control jack to the delay so I can use the tap tempo feature via the switcher's foot controller.

... makes me wonder if you somehow altered how the bypass switching works. How did you implement this mod? What kind of TB-Looper/Switcher are you using? I'm a bit confused.

[nils]

... makes me wonder if you somehow altered how the bypass switching works. How did you implement this mod? What kind of TB-Looper/Switcher are you using? I'm a bit confused.

Not really. The pedal has a small soft switch that closes two contacts when pressed. I soldered two wires to these contacts and connected them to a 1/4"-jack. Been working for a year or so without problems, until yesterday. Happened after turning on the power.

[a bit OT]
About the Looper/Switcher: I built this thing myself. It's based on the idea iof a relay-controlled true bypass strip. I built what I like to call "loop chains" with 4 inserts (like: input - insert 1 - insert 2 - insert 3 - insert 4 - output). I put three of these chains (two pre-chains and one post-chain) in a 19"-Enclosure and added 6 switching outs. The foot controller is merely a bunch of DPDT-Switches that turn the voltage for the relays on or off. All my pedals (except the wah and my tuner, which are on my pedalboard) sit on rack drawers, each connected to one insert on the looper. I use the switching outs to control the speed setting of my Rotosphere, and a few of my pedals have remote control jacks - the delay for tap tempo, my Phase45 clone to select speed and phaser/vibrato mode, my foxx tone machine clone to turn octave on/off.
[/OT]

[jefe]

... makes me wonder if you somehow altered how the bypass switching works. How did you implement this mod? What kind of TB-Looper/Switcher are you using? I'm a bit confused.

Not really. The pedal has a small soft switch that closes two contacts when pressed. I soldered two wires to these contacts and connected them to a 1/4"-jack. Been working for a year or so without problems, until yesterday. Happened after turning on the power.

Ah, ok, sounds pretty simple - and it's been working fine for a year. This would lead me to suspect that the soft switch was getting worn out  - except you've mostly had it racked, and not using that switch so much... I dunno, I'm stumped! just thinking out loud here, hoping it'll give you some ideas.

[a bit OT]
About the Looper/Switcher: I built this thing myself. It's based on the idea iof a relay-controlled true bypass strip. I built what I like to call "loop chains" with 4 inserts (like: input - insert 1 - insert 2 - insert 3 - insert 4 - output). I put three of these chains (two pre-chains and one post-chain) in a 19"-Enclosure and added 6 switching outs. The foot controller is merely a bunch of DPDT-Switches that turn the voltage for the relays on or off. All my pedals (except the wah and my tuner, which are on my pedalboard) sit on rack drawers, each connected to one insert on the looper. I use the switching outs to control the speed setting of my Rotosphere, and a few of my pedals have remote control jacks - the delay for tap tempo, my Phase45 clone to select speed and phaser/vibrato mode, my foxx tone machine clone to turn octave on/off.
[/OT]

Sounds pretty cool... way more advanced than anything I've done so far, lol 

[nils]

The switch can't be worn out, because it's never been used  . Also, shorting the switch's contacts (precisely what the remote jack does) should do the job even if the switch has gone bad.... but please keep the ideas coming  . I'd hate to loose the tap tempo feature, plus I really liked this delay (DESPITE being a Behringer).

[continued OT]
I went to this system because I got sick of lugging around giant pedalboards (yeah right... lugging around a 10HE rack is MUCH easier... NOT) and tired of stepdancing and never hitting the pedals right (much easier on the foot controller now). Also, the pedal setup is much safer in a rack than it is on a pedalboard, on my pedalboard there were always patch cords broken or DC cords going bad, noise here, hiss there, you know the drill. And I use up less space in front of me, too.

Here's a picture of the rack and the foot controller. The rack is in an early stage (I've changed the pedal arrangement and added a patchbay for easier access) and you can't really see the looper (it's at the bottom where the red D-Sub plug connects), but anyway:





[/OT]

[anchovie]

The bypass switch is going to be connected to some sort of flip-flop, either in an IC or constructed from discrete components. See if the switch lugs lead to any logic chips or transistors.