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corsair
19-05-2018, 06:16 AM
... that I've been given doesn't have a footswitch, so I built one. It doesn't work correctly in that I have to stomp twice to effect any change. So, I tried momentary switches: Uh-uh, nope. Back to latching switches...
This is a double switch with a TRS out on the amps back panel marked "Tip-Channel, Ring-FX".
The exact same switch I built for an older Crate works beautifully, complete with LEDs so what the hell is this Behringers deal?!? Info on the web is sketchy and I cannot find a schematic, so I'm asking everyone I know who might have some idea - you guys are first call!!

Anyone got anything?!

Cheers, chaps!

Simon Barden
19-05-2018, 05:10 PM
Strange that a momentary switch doesn't work, as stomping twice on a latching switch does seem to, and that should give the same result. Are these straight switches with no LEDs?

What model of amp is it?

corsair
19-05-2018, 05:51 PM
I went back to this, fresh and non-irritated, and have indeed figured out that they should be - and now are - momentary switches, thanks, Simon! However, it would appear that I can only have one switch working correctly; I cannot have the two working in the enclosure and that seems to be an earthing problem... with everything connected correctly, nothing works but disconnect one earth/common and the other switch then works beautifully!
I've added LEDs in series, with resistors...
The amp is a Behringer V-Tone 1200, and seems ....OK so far...

Simon Barden
19-05-2018, 06:54 PM
That sounds strange, as the switch contacts should be isolated from the switch casing. Might be worth checking that none of the switch contacts are connected to its casing, so that the switches get connected to together through the casing.
Or it may be that there simply isn't enough voltage or power available to drive LEDs (and with momentary switches they may simply not work). Have you measured the voltage coming out from the amp to the footswitch? On many amps, the common isn't 0V but at the circuit voltage, and the switch feeds the voltage to flip-flop circuits in the amp. I don't think the Behringer footswitches have LEDs.

corsair
19-05-2018, 07:07 PM
Yep... there's 4.7V on both ring and tip. I've had nothing to do with momentary switches so this is all new to me....

Simon Barden
19-05-2018, 11:03 PM
I'd try the switches without the LEDs across them. I doubt that Behringer would over-complicate the switches.

corsair
20-05-2018, 04:17 AM
Yep, I have; doesn't make a difference.

DrNomis_44
20-05-2018, 01:07 PM
Sounds a bit like the footswitch for my Marshall amp, it uses two latching footswitches and two leds too, I think I had a schematic for it on my PC's HDD somewhere, I'll see if I can find it and make a hand-drawn version of it that I can post in this thread.

corsair
20-05-2018, 02:55 PM
Thanks, Doc! This one is definately momentary switches, but there's something else going on that I haven't co-coed to yet; I made a standard triple footswitch with latching switches & LEDs for the old Crate I got at the same time and it works perfectly...

Simon Barden
20-05-2018, 05:10 PM
Unless you can find a schematic of the Behringer footswitch, and as the Behringer stuff isn't expensive, you may be better off buying one. I've done a couple of web searches and couldn't find anything useful.

corsair
20-05-2018, 09:24 PM
Unless you can find a schematic of the Behringer footswitch, and as the Behringer stuff isn't expensive, you may be better off buying one. I've done a couple of web searches and couldn't find anything useful.

Thanks, bloke - yeah; not much out there, is there?! :-) I'd love to find the schematic for it, or for someone to open up theirs and photograph it as the switches new here are A$70+ so until that happens, I'll just box on with the channel changing switch as I don't use the onboard fx anyway.... it's just one of those itches you can't scratch, eh!

stan
21-05-2018, 08:20 AM
Have you tried the switcher for the Crate on the Behringer?

corsair
21-05-2018, 03:51 PM
Yep; the Crate uses latching switches and the Behringer uses momentary, so a fundamental difference there; that means I had to stomp twice quickly in succession to make changes but the same problem raised its' head....

Simon Barden
21-05-2018, 05:11 PM
Weird, as presumably the switches you've got are normally open, make when pressed? I could envisage some possible issues (depending on the circuit if the switches were normally closed, and break when pressed.

Normally open switches shouldn't have any effect on the other channel, whereas normally closed switches could.

I'd check them out with a multimeter.