amp footswitches

Progrockabuse · Post by **Progrockabuse** » Mon Nov 30, 2009 4:29 pm

as you all know, i use a fender blues deluxe. this comes with a foot switch for changing channels and turning reverb on and off.
i never ever use the channel changing side, as i only use the clean channel.
question is, how easy would be to make a small foot switch just to turn the reverb on and off?

i think i've read somewhere fender wire their foot switches a weird way, so you can only use official ones. plus i'd like a longer cable than the one you get supply with the official foot switch, maybe thicker guitar cable.

ideas? something in the case size of that mini switch of stewart has on is board.

Post by **Mike** » Mon Nov 30, 2009 4:31 pm

Do you has multimeter? We can figure out how it works if so and see if it's possible.

Progrockabuse · Post by **Progrockabuse** » Mon Nov 30, 2009 4:34 pm

don't think i do. might have to steal my dads. i know if you touch the jack when it's in the amp, you get a shock.

Post by **Mike** » Mon Nov 30, 2009 4:38 pm

WTF Fender.

That sounds properly barmy. What is the connection? Stereo Guitar lead? Does the footswitch have LEDs and no battery?

Progrockabuse · Post by **Progrockabuse** » Mon Nov 30, 2009 4:41 pm

stereo cable with leds on the switch and no battery.

think i've seen a HRD deluxe foot switch schem, same family of amps.

stewart · Post by **stewart** » Mon Nov 30, 2009 4:42 pm

funny, i was recently wondering if there was any way to mod my HRD to make the reverb footswitchable. the footswitch only has channel switching options, which are zero use to me, and the reverb can only be controlled with the knob, again, making it totally useless for my requirements.

robroe · Post by **robroe** » Mon Nov 30, 2009 4:48 pm

YOU GUYS NEED A COUGAR1000

REVERB SWITCH ON THE FLOOR MOTHERFUCKAAA

Progrockabuse · Post by **Progrockabuse** » Mon Nov 30, 2009 4:55 pm

does this help?

Post by **Mike** » Mon Nov 30, 2009 4:58 pm

Sort of. Confirms it is a Stereo TRS connection and that power is coming down somehow. I'm sort of a bit flummoxed as to what is going on there though.

robroe · Post by **robroe** » Mon Nov 30, 2009 6:07 pm

ill take mine apart hold on

chisa · Post by **chisa** » Mon Nov 30, 2009 6:18 pm

you could build one yourself. simple switch attach it to a stereo jack and see which connections work

robroe · Post by **robroe** » Mon Nov 30, 2009 6:21 pm

chisa · Post by **chisa** » Mon Nov 30, 2009 6:24 pm

Pens · Post by **Pens** » Mon Nov 30, 2009 6:53 pm

chisa wrote:

Can't be right. Ring and Tip can't be connected like that. Wait, maybe it is WTF is that?

The upper connection looks like it carries the 9V or whatever the voltage is for the LED and sends to the ground connection.

Only thing I can think is the switches cause the diodes to create a Voltage drop which is detected at the other end on the amp.

Sorry I can't help otherwise.

Bill Oakley · Post by **Bill Oakley** » Mon Nov 30, 2009 6:57 pm

Looks like a switching jack to me. Power is coming in through the ring of the cable and when inserted into the jack, it connects the ring to the tip, sending power to the little circuit. Positive voltage reaches the switches through the diodes and LED's which, through the switches, connects back to ground of the jack. When the switches are pressed into the "off" position, it breaks the positive connection.

Pens · Post by **Pens** » Mon Nov 30, 2009 7:56 pm

Bill Oakley wrote:Looks like a switching jack to me. Power is coming in through the ring of the cable and when inserted into the jack, it connects the ring to the tip, sending power to the little circuit. Positive voltage reaches the switches through the diodes and LED's which, through the switches, connects back to ground of the jack. When the switches are pressed into the "off" position, it breaks the positive connection.

Yeah this looks like what it is. Good call.

EDIT: The amp side of it probably uses some sort of flip-flop switching like most soft switches on Boss pedals and the like.

Post by **Mike** » Mon Nov 30, 2009 9:58 pm

Chisa's diagram is shite. Ignore it.

It seems odd to me that they'd use diodes to regulate the current, why not resistors. Must be to do with what's on the amp side (relays?)

Bill Oakley · Post by **Bill Oakley** » Tue Dec 01, 2009 12:52 am

Here's the Blues DLX footswitch section of the schematic:

This may help also:

Here is the footswitch schematic for the red knob "Evil" twin:

Post by **Mike** » Tue Dec 01, 2009 8:30 am

Wow. Cheers for all the info. Looks like it doesn't act like a normal "ground the tip or the ring to the sleeve" pedal at all, but that the amp is sensing the LEDs that are on via the tip connection.

I'm not afraid to admit I don't understand it.

Pens · Post by **Pens** » Tue Dec 01, 2009 5:22 pm

Mike wrote:Wow. Cheers for all the info. Looks like it doesn't act like a normal "ground the tip or the ring to the sleeve" pedal at all, but that the amp is sensing the LEDs that are on via the tip connection.

I'm not afraid to admit I don't understand it.

I'm not the expert but I believe it works by sensing the voltage drop from the diodes, like how diodes cause different clipping based on their voltage drop. The amp side senses the change of voltage with a flip flop, again if I follow those schems correctly.