# Adding Battery to Amp Footswitch???



## studiodog (Sep 10, 2010)

hi folks -I had originally posted this in the pedals section, but am getting no response. Hopefully better results here! 

I'd like to mod my Apex AFS3 footswitch with an onboard 9V battery or 9Vdc power input (so I can use my pedalboard power supply) to light the LEDs when each switch is engaged. 

I use this switch with my Roland JC-90 amp to switch on/off the built in Distortion/Reverb/Chorus. Each of the three SPDT switches is wired like this:








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As you can see, there is already a stock LED and resistor in palce. If I touch a 9V lead to the pos/neg terminals, the LEDs light up, so that works ok. My question is: Can I simply add power leads to each switch from the battery like this?








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If I wire like Pic 2, do I risk any damage to the amp or sound quality issues due to voltage feeding back to the amp? 

Thanks in advance for your input!


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## Jims (May 29, 2007)

I'm no expert on roland amps, but I would've expected the amp to supply the voltage to turn the LED on when the footswitch is activated. I'll try to dig up a schematic, but I'd be concerned that the DC voltage from the battery might interfere with the operation of the relay that actually changes the channel in the amp's circuit. But, being unfamiliar with the actual circuit involved, I can't say with certainty what may or may not happen.


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## studiodog (Sep 10, 2010)

Hi jims,

I'm fairly certain that the JC amps do not supply voltage for footswitch LEDs, as the original JC footswitches were/are simply SPST switches without LEDs. I don't have a schematic to check, however, so if anyone can confirm this I'd appreciate it. 

I suspect that if I really want the LEDs to light up, I'll end up swapping the SPDT switches in my footswitch with DPDT switches. Then the LEDs can be wired to the battery on one side of the switch, separate from the amp cpnnections.....


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## Jims (May 29, 2007)

By "supply the voltage for the LEDs" I really meant that I expected the footswitch to use the control voltage that is actually being switched ON/OFF by the footswitch to light the LED; so it wouldn't require anything specical from the amp; however, since the LED only conducts on-way, the footswitch would have to be compatible with the amp.

Your diagrams look like the LED and resistor are in parallel with the switch, whereas I would've expected to see them in series, and that seems a little counter-intuitive to me. It's a moot point though if you go with DPDT switches, and have the LED's totally separate from the control voltage; then there should be no problem, provided the resistor is an appropriate value for the battery you want to add.

It still seems like an inefficient way of doing things to me, but's it's hard to diagnose these things sight-unseen with no proper schematic, and I think what you're suggesting would work.


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## studiodog (Sep 10, 2010)

Hey Jims.

Yes the LEDs are currently wired in parallel with the switches. Maybe I'll play around with one later and see if a series configuration will do the trick!


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## greco (Jul 15, 2007)

studiodog said:


> I suspect that if I really want the LEDs to light up, I'll end up swapping the SPDT switches in my footswitch with DPDT switches. Then the LEDs can be wired to the battery on one side of the switch, separate from the amp connections.....


I have been following this thread and I think this is the best solution....IMHO

Curious....If the JC amps didn't supply the voltage for the LED's..then where did they get the voltage required ?????

BTW..I might soon have an amp to donate to the school music program. I'll PM you.

Cheers

Dave


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## studiodog (Sep 10, 2010)

Well, I tried wiring the LED in parallel, but no dice. Either the JC's don't use the control voltage for footswitch LEDs or perhaps my LED resistors are the wrong value. They work fine with a 9v battery, but I have no idea what the internal voltage on the foot switches may be -maybe I'll bust out the ol' VOM and see if I can get a reading.....


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## greco (Jul 15, 2007)

Studiodog:

I have an Ibanez IFS4X switch (with LED's) with the cable if you want it....let me know










I bought it thinking ("assuming" is a more accurate word) that it would have 3P3T switches that I could use in projects.
Wrong ...it has SPST switches.

Cheers

Dave


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## studiodog (Sep 10, 2010)

Just by way of an update, I decided to swap out the SPDT switches for DPDT - wired the amp connections to one side of each switch, with the LED's and 9v battery power on the other side. Works like a charm and gives me groovy red lights when my effects are on! Yay - no more guesswork in loud venues! 

Anyway, it was an easy and relatively cheap upgrade - found the DPDT switches locally at $6CAD each.


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## greco (Jul 15, 2007)

Congrats on getting this sorted out. 

Where did you find the switches locally? 
Any 3PDT switches at the same place?

Cheers

Dave


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## studiodog (Sep 10, 2010)

greco said:


> Congrats on getting this sorted out.
> 
> Where did you find the switches locally?
> Any 3PDT switches at the same place?
> ...


Hey Dave. Found the switches at Orion Electronics on Lancaster (just N of Victoria). Didn't notice ant 3PDT's, though it couldn't hurt to ask!


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## islandman (Aug 14, 2015)

V


studiodog said:


> Just by way of an update, I decided to swap out the SPDT switches for DPDT - wired the amp connections to one side of each switch, with the LED's and 9v battery power on the other side. Works like a charm and gives me groovy red lights when my effects are on! Yay - no more guesswork in loud venues!
> 
> Anyway, it was an easy and relatively cheap upgrade - found the DPDT switches locally at $6CAD each.


Hello everyone...first time here! I realize this is a very old thread, but I also purchased the APEX AFS3 like studiodog. For 23.00 bucks it's an incredible deal for this military grade foot switch. My Boogie Simul-Class 2:90 does not have voltage to power the LEDs. I am not electronics savy, but I can follow directions well. Does anyone know, step by step, how to wire the battery to the DPDT switches to power the LEDs? I realize that studiodog switched the SPDT for DPDT, but how, and where on the switches is the battery wired to the 3 switches. Any help would be much appreciated!

Devlon


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## greco (Jul 15, 2007)

islandman said:


> V
> 
> Hello everyone...first time here! I realize this is a very old thread, but I also purchased the APEX AFS3 like studiodog. For 23.00 bucks it's an incredible deal for this military grade foot switch. My Boogie Simul-Class 2:90 does not have voltage to power the LEDs. I am not electronics savy, but I can follow directions well. Does anyone know, step by step, how to wire the battery to the DPDT switches to power the LEDs? I realize that studiodog switched the SPDT for DPDT, but how, and where on the switches is the battery wired to the 3 switches. Any help would be much appreciated!
> 
> Devlon


Welcome to the forum Devlon!

Is this any help?










Depending on the brightness of the LED you want, you will need to increase the value of the dropping resistor...larger value = less bright.

Here is an old thread that might also be very helpful:

http://www.guitarscanada.com/showthread.php?61459-Some-DIY-fun-last-night

Cheers

Dave


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