Why not route all power through the 3PDT switch?

[Kesh]

It occurred to me you could put all power through the LED's pole of the foot switch, then you wouldn't have batteries dying when the input jack was in and the LED was off so you forget.

Is there any reason this can't be done?

[trjones1]

It takes a bit of time for caps to charge when the power is first turned on, so there would be a slight delay after you hit the switch before you'd get any sound.  Also it could open you up to popping and other unwanted noises.

[frequencycentral]

Ker-thunk!!

[pinkjimiphoton]

the eki fuzz switched the power on with the switch as drawn... you'd hear a slight woosh and a loud POP when you turned it on.

for a kit that wasn't meant to really be much other than a simple electronic example, not a bad fuzz once wired right....for 9.95?

[armdnrdy]

Sounds about as useful as connecting the ignition switch to your accelerator pedal!! 

[Seljer]

Hmm, has anyone experimented with using an electronic circuit to turn off just the audio circuit (like a PNP transistor on the positive supply just after the filter capacitors) to save battery life? possibly combined with electronic switching that has just enough delay to silence the thump of any (de)coupling capacitors charging up?

[Mike Burgundy]

I think you might find more merit in trying to design low-consumption circuits, with the added bonus of being able to use it normally.
If you need to switch off while not playing so there's no power drain while you're doing something else, either incorporate a specific switch for each pedal (Not a footswitch and not to be used as one) or unplug the input jacks using the power-switching stereo jack trick.
Either that or use a centralized supply (one switch), whether that's adapter or battery-based.

[Pollinator95]

Hmm, has anyone experimented with using an electronic circuit to turn off just the audio circuit (like a PNP transistor on the positive supply just after the filter capacitors) to save battery life? possibly combined with electronic switching that has just enough delay to silence the thump of any (de)coupling capacitors charging up?

I'm guessing that again, there's a moment where there's no sound coming through, something I wouldn't want in the middle of a song.

[cloudscapes]

It would pretty much guarantee a loud POP

[R.G.]

One manufacturer of autos, desperate to meet the CAFE  rules, came up  with the scheme to make the motor die when stopped at idle, but auto-restart when the accelerator was pressed to go, thinking that fuel economy got better if all the time spent sitting at stop lights was zero fuel cost.

Test drivers simply hated it. There was a period of chugging as the starter restarted. The motor died if you momentarily stopped for just a fraction too long when doing things like parking. Not to mention the other drivers around you in traffic thinking you were an idiot to turn your motor off at a stop light. And that's if everything worked perfectly.

Some technologies need the prime mover to be all warmed up, running and ready.

[Earthscum]

When I was a mechanic there were a couple guys I heard about privately working on odd projects, one that did just as R.G. mentioned, but he used an electric motor to provide the initial go from the start. I'm not sure if he sold that idea, or just coincidence, but several years later the first Hybrids came out that use that same idea. The brakes generate power that is stored remotely just for that initial "push" on acceleration while the systems swap over from idle to go, even if the car's batteries are dead and in charge mode (engine running).

If you design right, there ARE certain things you could cut power to to save, most notably the item we actually control with the switch, the LED. One thing I've actually tried is cutting power to a phase shift oscillator. When I'd switch in, it would slowly ramp up the way they do, and actually seemed to work well at the time. No pops from it (I actually used a jfet with the oscillator section under it's Source, MBP style). As long as the ramp up isn't too slow, IMO it would work well to have something that doesn't have an instant "swoosh" to it as soon as you kick in on.

[R.G.]

If you design right, there ARE certain things you could cut power to to save, most notably the item we actually control with the switch, the LED. One thing I've actually tried is cutting power to a phase shift oscillator. When I'd switch in, it would slowly ramp up the way they do, and actually seemed to work well at the time.

That's the essence of the Vibra-Magic mod to the EH Tremolo; well, kinda. The oscillator was let run, but killed with the first signal detected, so the oscillations would ramp up.

But yes, things that come on slowly and don't cause pops anyway can be powered on by a footswitch. However, this still leaves you only able to apply things that you want to fade in slowly.

[armdnrdy]

I just had this brainstorm!!!!

Now this is just hypothetical mind you but.....what if you bought or built a power supply for your effect pedals? You wouldn't have to worry about batteries going dead, finding batteries in a remote location, making the band wait for you while you go get batteries, etc, etc!

I'll be honest, I know that many of you people still build effects powered by batteries but, I just don't see the waste of space in the enclosure, the hassle of batteries that I outlined above, and the cost of batteries!

This is 2012, soon to be 2013!! We have the technology!

Now unless you want to go jogging while you're playing guitar and don't own a long enough extension cord, I'd suggest getting an on board power supply. Batteries....Baaah 

[Kesh]

I just had this brainstorm!!!!

Now this is just hypothetical mind you but.....what if you bought or built a power supply for your effect pedals? You wouldn't have to worry about batteries going dead, finding batteries in a remote location, making the band wait for you while you go get batteries, etc, etc!

I'll be honest, I know that many of you people still build effects powered by batteries but, I just don't see the waste of space in the enclosure, the hassle of batteries that I outlined above, and the cost of batteries!

This is 2012, soon to be 2013!! We have the technology!

Now unless you want to go jogging while you're playing guitar and don't own a long enough extension cord, I'd suggest getting an on board power supply. Batteries....Baaah 

some old circuits hate power supplies. even negative ground fuzz face will find the slightest amount of noise in your power supply and ramp it up

[rousejeremy]

I did this once to get rid of the LFO ticking on an FSH-1. The popping sound made it unusable in a live situation.

[armdnrdy]

some old circuits hate power supplies. even negative ground fuzz face will find the slightest amount of noise in your power supply and ramp it up

Proper grounding techniques, keeping supply and signal lines separate, and supply filtering using "BOF" capacitors all do wonders in keeping the noise down.

On the subject of LFO ticking, there is very sound advice available on this site which includes a few localized components around the LFO op amp as well as trying a low power op amp such as a TL022 or LM358.

Or.....you can keep paying $3.00+ a pop for 9 volt batteries

[Kesh]

some old circuits hate power supplies. even negative ground fuzz face will find the slightest amount of noise in your power supply and ramp it up

Proper grounding techniques, keeping supply and signal lines separate, and supply filtering using "BOF" capacitors all do wonders in keeping the noise down.

Or.....you can keep paying $3.00+ a pop for 9 volt batteries

the fuzz face circuit, whether npn or pnp, relies on the low AC impedance of its power source. that's why they sound best with non-alkaline batteries, and noisy with ac power, nothing to do with isolating the supply line, it's an intgegral part of the circuit.

i use rechargables for those type of circuits.