Powering pedal from Footswitch

Started by antonis, September 12, 2014, 08:32:56 AM

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antonis

Hellow and greetings fron Greece... :icon_biggrin:

I have designed a custom made pedal board with 12 (or 14) effects for my son, divided in 5 effect categories (Overdrive/distortion/fuzz, Tremolo, Octave, Delay, Vibrato) and i've a question about thw way of powering ALL the pedals..

The easiest (and more curent consumable) way is to power on all of them simultaneously from a power sufficient PSU and selactong the effect by true bypass cabling 3PDT foot switches..

I'm thinking of powering EACH pedal from its own footswitch when the specific pedal in ON the loop (not bypassed), to reduce total current consumption and "working time" of the "off-line" pedals, by disconnecting its own  ground AND connecting the input of the circuit to the main ground loop..

Do you think it's a good idea powering-on the circuit and put it on-line simultaneously or it will cause pops, beeps, vzzzz  :icon_evil: or anything else..??
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

Mark Hammer

#1
You won't like it.

Why?  Because it takes a little while for the power-smoothing capacitors in the pedal to charge up.  So cutting the power, when in bypass, and then restoring the power, when you engage the pedal, will produce a short delay (not the good kind) before the pedal starts to work.  If the circuit is a modulation effect (tremolo, vibrato, chorus, phaser, flanger, etc.), the modulation may not start immediately.  You will find it disruptive.

Your idea comes up here about once a year, and the answer is always the same....unfortunately.

Now, what I will say is that there has never been any discussion about anything we might call "standby power".  That is, perhaps there is a way to cut back on current, when in bypass, such that engaging the effect and applying full current does NOT result in the expected disruption.

On the other hand, it is so easy and inexpensive these days to have power supplies with more than enough current to power everything, I don't think the effort would be worth it, evenif it were possible to do.

R.G.

Hello and greetings from Texas!

Quote from: antonis on September 12, 2014, 08:32:56 AM
Do you think it's a good idea powering-on the circuit and put it on-line simultaneously or it will cause pops, beeps, vzzzz  :icon_evil: or anything else..??
Sorry, it's a bad idea. Unless the pedal circuits are especially designed ( and this is the same as saying "more complex" ) they will pop or thump when they come on.

Trying to reduce the "on time" of each pedal is generally not a good objective, as most pedals will far outlive their original owner's interest in guitar pedals. And it increases the wear on each pedals, as there is some stress from each on/off cycle. So it's not a good objective from the point of view of longer pedal life - it probably makes no difference.

Hi, Mark - we're simul-posting again.
Go with the simpler and cheaper option of one power supply for them all.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

antonis

 :icon_biggrin:
Thank you both guys...!!!
(I can't find a beer emoticon.. :icon_sad:)

One more question:

Is there any need for grounding the signal inlet capacitor when the pedal is "off-line"..???

(meaning that it helps preventing "pop" better although there is a pull down resistor..??)
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

antonis

Quote from: Mark Hammer on September 12, 2014, 08:49:53 AM
Your idea comes up here about once a year, and the answer is always the same....unfortunately.
Sorry but the "search button" didn't work properly.. :icon_razz:

Quote from: Mark Hammer on September 12, 2014, 08:49:53 AM
Now, what I will say is that there has never been any discussion about anything we might call "standby power".  That is, perhaps there is a way to cut back on current, when in bypass, such that engaging the effect and applying full current does NOT result in the expected disruption.
Hmmmm... :icon_wink:

Something like a limited current draw, capable to keep the power supply capacitors allways charged..??
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

duck_arse

I'd just like to say hello from australia. I've never said hello to greece.

grounding the input of a bypassed pedal will mean the front end isn't being fed/picking-up stray noise and hum, so it can't amplify it. which may be a good thing, stability wise.
don't make me draw another line.

antonis

Quote from: duck_arse on September 12, 2014, 10:51:22 AM
grounding the input of a bypassed pedal will mean the front end isn't being fed/picking-up stray noise and hum, so it can't amplify it. which may be a good thing, stability wise.
I agree with you but (just for shake of theory.. :icon_lol:) does it matter as long as the pedal is completly bypassed..??

Or you mean that it would be a "wireless" amplified source of noise/hum..??

P.S.
Excuse me for my English but it was "retired" for long time..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

duck_arse

if it is bypassed of signal, but still commoned via power supply, an oscillating/junk amplifying/radio station pedal may well be a problem for other pedals.

your english is at least as good as mine, and I been usin' it evry day! I've forgotten how to spell.
don't make me draw another line.

karbomusic

QuoteBecause it takes a little while for the power-smoothing capacitors in the pedal to charge up.

Greetings from NC USA.  :icon_cool:

I was about to say the exact same thing. I figured this out when I started measuring current draw from my pedals and couldn't understand why I was drawing so much current with all the pedals "off". The it dawned on me, they aren't off, they are bypassed. If they were off, I'd have to deal with start up time which would be horrible sounding.