andrewsrea
Well-known member
The two shortcomings are: 1.) 'Is it on or off,' and 2.) 'Why does it suck my tone when it is off?'
This was precipitated by a client who loves his wahs. Each one he gets, he immediately asks me to put an 'on' indicator LED, which some models I can get away with replacing the DPST stomp switch with DP3T, providing true-bypass to boot. His latest love is a Vox 847, which has a longer that usual stomp switch threaded shaft, making the standard solution require build-ups on the treadle and preventing it from being able to cock the treadle to a specific frequency, due to the build-up unbalancing the treadle.
Accordingly, I created a relay-based solution, which utilizes the internal pedal power, fits in the unusual wah pedal real estate and uses the existing stomp switch. It works flawlessly!
Cost under $7 in parts and adds about 57ma to the 1ma effect, for a total of 58ma supply requirement (when 'on').
My client has big feet which hide the LEDs and on this last one, he said he needs another one that can be seen beyond his feet. We talked about where in the playing position the LED would be best located (see pic) and I used a Jumbo 10mm Green LED (frosted to afford seeing it from more than head-on). The finished terro board fit perfectly upside down between the instrument and amplify jacks.
Parts:
- About a 1-inch square terro board (PM me for schematic and layout, if interested).
- (1) 9.1R 1/4w resistor (Isolates 9v power to mitigate any crosstalk between the effect and the LED / relay power supply)
- (1) LM7805 5vDC regulator
- (1) HK 19F 8P-5V DPDT relay
- (2) 47uF / 25v electrolytic filter caps (on each side of the voltage regulator to filter out any ripple or RF, preventing relay chatter)
- (2) 1M8 1/4w resistors (signal to ground, one each for the 'instrument' and 'amplifier' common to ensure silent relay switching)
- (1) 30R 1/4w LED current-limiting resistor (ensures the required 2.4v
This was precipitated by a client who loves his wahs. Each one he gets, he immediately asks me to put an 'on' indicator LED, which some models I can get away with replacing the DPST stomp switch with DP3T, providing true-bypass to boot. His latest love is a Vox 847, which has a longer that usual stomp switch threaded shaft, making the standard solution require build-ups on the treadle and preventing it from being able to cock the treadle to a specific frequency, due to the build-up unbalancing the treadle.
Accordingly, I created a relay-based solution, which utilizes the internal pedal power, fits in the unusual wah pedal real estate and uses the existing stomp switch. It works flawlessly!
Cost under $7 in parts and adds about 57ma to the 1ma effect, for a total of 58ma supply requirement (when 'on').
My client has big feet which hide the LEDs and on this last one, he said he needs another one that can be seen beyond his feet. We talked about where in the playing position the LED would be best located (see pic) and I used a Jumbo 10mm Green LED (frosted to afford seeing it from more than head-on). The finished terro board fit perfectly upside down between the instrument and amplify jacks.
Parts:
- About a 1-inch square terro board (PM me for schematic and layout, if interested).
- (1) 9.1R 1/4w resistor (Isolates 9v power to mitigate any crosstalk between the effect and the LED / relay power supply)
- (1) LM7805 5vDC regulator
- (1) HK 19F 8P-5V DPDT relay
- (2) 47uF / 25v electrolytic filter caps (on each side of the voltage regulator to filter out any ripple or RF, preventing relay chatter)
- (2) 1M8 1/4w resistors (signal to ground, one each for the 'instrument' and 'amplifier' common to ensure silent relay switching)
- (1) 30R 1/4w LED current-limiting resistor (ensures the required 2.4v
