Question about power supplies to pedal boards

[motterpaul]

I was thinking about this as I pondered "true bypass" pedals... the one thing they do not "bypass" when turned off is the 9v power still powering the circuit. The 3pDT switch takes the signal directly from tip in to tip out on the guitar jacks - but the circuit itself is still getting its 9V power from the power source - it just isn't in the signal chain.

It now seems to me that unless you have a pretty powerful power source (depending on what kind of effects you are running, of course), that you could be using up a fair amount of your available power if you have 12 circuits or so.

On my board I now have

1) optical wah
2) tuner
3) diamond compressor
4) maxon 808
5) PT2399 - chorus w/ BMP LPB1 (2 circuits)
6) Brunetti Mercury
7) AMT B1
8) Boss Waza Delay
9) Ibanez noise buster
10 one-knob noise gate

Now - all I have is 1 One-Spot (1700 ma) running the whole deal - all daisy chained. It works great but you definitely hear a difference if you take off just one pedal and plug it straight in with a separate power supply.

I assume buffers would a be a logical answer some people might offer, but I also wonder if I would benefit more from getting a more sophisticated power source for my pedals.

I know that PedalTrain uses transformers to isolate the power for each pedal - reducing ground loops, but do they offer more or cleaner power to drive more pedals?

[motterpaul]

Also - another question - assuming a buffer will help (and I think it probably will) would you put it at the beginning of the pedal chain, after, or both?

[nocentelli]

motterpaul wrote

Now - all I have is 1 One-Spot (1700 ma) running the whole deal - all daisy chained. It works great but you definitely hear a difference if you take off just one pedal and plug it straight in...

The difference in sound is more likely to be caused by the extra length of cable capacitance between the extra pedals than by the current draw of the extra pedals. A buffer at the front of the chain will help reduce this. If you have a very long cable from the last pedal to the amp, a buffer at the end of the chain could help (you can always measure the total current draw from the daisychain with a multimeter, but I doubt it will be anything approaching the 2 amp limit of the onespot unless you have a dozen current hungry digital delays etc).

[Neil mcNasty]

A buffer will not do anything regarding pedal supply noise!
You do not want a pedal to have it's power cut when bypassed!

This one often helps with noise issues: http://guitar-fx-layouts.42897.x6.nabble.com/Weird-quot-hum-quot-from-a-couple-of-pedals-td20501.html#a20590
It is a simple power decoupler with a half wave bridge rectifier for additional ripple filtering.
As you can tell, it is quite simple to build/understand and can be expanded to as many outputs as you like...
A great circuit for making a splitter/decoupler box for your one-spot supply...!

[Muadzin]

Neil mcNasty wrote

You do not want a pedal to have it's power cut when bypassed!

Aye.

I like to build effects into some of my guitars. The usual trick to save battery life is to disconnect the ground when no plug is inserted. But this only saves power when the guitar is not in use. It doesn't save power when you play the guitar but not use the effect. At first I used a SPDT switch to simply cut the power to the effect in addition to the effect bypass switch, usually a DPDT. Which means I first have to hit two switches to activate the effect. Not so ergonomic when playing guitar. Then a built a few guitars with a 3PDT switch wired in such a way that when the effect is in bypass, the power will be cut as well. Simplest solution, one flick only. But as I discovered when you activate the circuit and also restore power there will be a huge pop. And no amount of pull down resistors can fix that.

Long story short, do not cut power to effects when bypassed. And if you do, first restore power before hitting that bypass switch.

[motterpaul]

Thanks for replies....

As I thought about it I realized I probably was not pushing my One-Spot that hard. I only have 3 commercial pedals, a TC Tuner and a Boss WAZA Digital delay - those probably have the most digital circuitry. I also have a Morley Wah (optical) which I opened up and saw that it is all analog - and that it actually does have an inductor for tone (like any decent wah) - the optical part just replaces the pot most wahs have.

I put a Cornish buffer in front of the Wah - but I don't think I like what it does - the overall sound seems dull now. I also have Ge transistor based fuzz (which also supposedly also do not like buffers).

So, right now I have my pedalboard as I listed in top message, but I think I will put the fuzz right after the wah (or tuner) - and then add the buffer to the limiter which would come next.

So - my question is this - I do not think I want to add any more gain to my rig since I seem to have most of my clean pedals just barely below breakup (like my chorus), but I do want to preserve that great tone I get when I have just one pedal direct - so the question is...

What is the best buffer? Or is it more a matter of location?

By the way - I am just reading how to read MilliAmps on a DMM now - have never done it.

[motterpaul]

THE RESULTS:

I put a Cornish buffer (because it was already built) inside my Briggs Diamante limiter, ahead of the limiter circuit. So I have Wah, then tuner and Tonebender Fuzz - then limiter with buffer.

The whole board does sound better, except for the fuzz which sounded better with the limiter pushing it, so even with the buffer, I think I will move it back there.

But yeah, a good buffer can make a big difference. As I recall, most standard TubeScreamers are not true bypass - so the buffer in them would explain why many classic rock guitarists still use them in their boards. Same with the Klon and the EP3 if I recall correctly; both have buffers.

[Muadzin]

You gotta have at least one buffer on your board, unless you plug in directly into an amp. And Pete knows how to make a good buffer. It's shame his boards are all butt fugly.