Do long wire runs on components change tone?

[tomer629]

I want to build an external mod testing box that can plug in to my overdrives to test a wide range of values.

I hate constantly picking up the pedal to change diodes or caps or whatever out to test different values. So I want to make an external box I can just plug in when I want to test stuff. Some people might think Im doing this ass backwards and should build a test station where I test my pedals and mod values before boxing them. Maybe I am ... But I think this will be a fun project. Could even leave it on my pedalboard for ultimate flexibility. I could plug into any of my pedals and instantly have access to tons of mod combinations.


I plan to install a female jack in my pedals that will have leads going to the sockets on the board where I want to switch different values. Diodes, resistors, caps. And then have the male end coming from the external mod box.


All that said... My question is: Will having long leads, (thinking around 12-18 inches) , affect the tone Im getting. In other words, if I test components in this external box, are they going to sound different when I put them directly on the pcb, due to no longer having 18 inches of wire to travel through? 


Maybe this is a dumb question, but if having long leads is gonna alter the tone, it kinda makes this whole thing pointless.

[Ben Lyman]

Have you checked out the Small Bear Idea Box? I got ideas from that for my own home made portable test station.
btw, I have noticed my clipping diodes give a LOT less distortion when I run them thru long snakes of jumpers... could be my imagination though, I dunno

[garcho]

I want to make an external box I can just plug in when I want to test stuff.

that's called a breadboard.

I have noticed my clipping diodes give a LOT less distortion when I run them thru long snakes of jumpers... could be my imagination though, I dunno

why do diodes "give" distortion? because they clip the round, organic, curvy, complicated, ultra-detailed musical AC signal at a certain voltage threshold, resulting in a wave that is forced into something more like a square wave, which to our ears sounds like what we call distortion. It has to do with harmonics and timbre. the hotter the signal, the more clipping happens, the more distortion sounds. so why would jumper wires prevent distortion from happening? if less of the signal is being clipped by the diodes, less square-ing happens, so less distortion sounds. that definitely shouldn't happen due to the inherent resistance of your jumper wires, unless your breadboard is a mile long. there's all sorts of problems that come from unshielded rat's nests of wire, but it's probably from some other connectivity problem, like broken wire or short somewhere within the breadboard buses.

[R.G.]

I want to build an external mod testing box that can plug in to my overdrives to test a wide range of values.

I hate constantly picking up the pedal to change diodes or caps or whatever out to test different values. So I want to make an external box I can just plug in when I want to test stuff. Some people might think Im doing this ass backwards and should build a test station where I test my pedals and mod values before boxing them. Maybe I am ... But I think this will be a fun project. Could even leave it on my pedalboard for ultimate flexibility. I could plug into any of my pedals and instantly have access to tons of mod combinations.


I plan to install a female jack in my pedals that will have leads going to the sockets on the board where I want to switch different values. Diodes, resistors, caps. And then have the male end coming from the external mod box.

There are several versions of this. The one I liked is here:
http://www.geofex.com/FX_images/protofx5.gif
http://www.geofex.com/FX_images/protofx6.gif
Those are from 1998, about seventeen years ago. Note the ready places for pots to be installed and the two jacks. Later versions of this idea enclosed this whole "wrapper" in an entire box. So the breadboard/test board can simply be the effect.

All that said... My question is: Will having long leads, (thinking around 12-18 inches) , affect the tone Im getting. In other words, if I test components in this external box, are they going to sound different when I put them directly on the pcb, due to no longer having 18 inches of wire to travel through? 

Yes and no. Don't you hate that answer, especially when it comes up so often?

It depends on which components you "outboard" and what the connect to back in the effect - and how well and solidly they're connected back in the effect. The wires themselves have no discernible effect on the sound, but the fact that they're off the board and way out in the RF and hum-filled aether, and that long wires make conductive loops that act like inductors and have parasitic capacitances and bum contacts where they touch things can very well make the circuit sound wonky.

Wires have very tiny, even by electronic standards, inductance and capacitance for each unit of length, as will as a very tiny resistance. If a 30 milli-ohm wire is in series with a 1k resistor, the wire's resistance can't be told from the tolerance of the resistor. If the wire is in series with a 0.1uF cap, the wire's sub-10pf self capacitance can't make a difference. Nor can the wire's nano-henries of inductance.

But if the wire feeds a 10M resistor paralleled with a 10pF cap and tuned with a 10nH inductance, it could well pick up VHF aircraft-band radio, and the circuit could heterodyne that back down into audio. Especially if what's being fed by the wired components is a MOSFET input. So the wires don't matter - except that their side effects can matter so much that the wires are immaterial. And what the wires connect to back in the circuit matters a LOT. Most circuits, no. Some circuits, huge difference. There's no way to say which it will be without knowing what the circuits do.

Maybe this is a dumb question, but if having long leads is gonna alter the tone, it kinda makes this whole thing pointless.

Here's a good question for you: what is "tone"?

[tomer629]

Thank you for the thorough answer R.G. After thinking about this more I think I should only need a few inches of cable between the pedal and this box anyway, they will just have to sit side by side while I'm testing. Also I plan to have the components inside a 1590BB, not in a breadboard on top like the pictures. Hoping that will cut down on the interference.

Another question. Should I run a ground wire from my pedal along my input and output wires to this box? So 3 wires in the cable: in, out, ground.

Here's a good question for you: what is "tone"?

Tone is life

[garcho]

i hope this isn't offensive, but have you ever noodled with these DIY pedals before? why would an "in, out" be necessary? if you want to swap say, filter caps, or clipping diodes, why would an "in, out" be useful? how would you actually swap the component out? the original component will still be in the circuit you want to mod, no? you'd have to have a wire for EVERY JUNCTION in the circuit, along with individual switches to toggle when you're using the "in-circuit" components and when you're using the "mod" components. that makes no sense in terms of usability. and you'll definitely have "tone" problems with that rat's nest, besides having an enormous monster of a proto-box with a huge snake cable and a thousand switches. also, you'd have to do that for EVERY PEDAL you'd like to use this box with. honestly, i can't understand how this could ever be pragmatic, when all you have to do to achieve the same result is to breadboard, like the rest of us

I hate constantly picking up the pedal to change diodes or caps or whatever out to test different values.

isn't that exactly what you'd be doing with the external box? find the components you want to swap and socket them, if you must have the ability to "mod on the fly". why would you want that anyway? just make the pedal the way you want it and keep it that way.

[tomer629]

I Think people are misunderstanding what I'm trying to do here. Yes I have noodled with these circuits. Most of my pedals have a switch or two for different mods. All I'm doing here is putting some of these components in another pedal. I said "in" and "out" leads for lack of a better term. When I have a switch for two different values, I wire it to the 2 pads on the pcb. I always socket components I think I might like to change.  I will not be running wires off every component in the circuit, just one or two.

Basically I'll have a switch with 2 positions on the actual overdrive pedal. One position will select the stock value component, the other position will send the lead for this component out to my testing box where I can play with many different values.

[deadastronaut]

testing box=breadboard.

nice and simple..

[PRR]

> constantly picking up the pedal to change diodes or...

So don't put it on the floor, put it on the bench.

Yes, "stomp" needs a limber leg (or an elbow), but all the plugs and knobs work fine at bench level, and also for part-swapping.

Yes, wah-pedals are hard to work on the bench.

> Do long wire runs on components change tone?

Different slant on what R.G. was saying....

Do long ropes on a vehicle steering wheel change handling?

Don't laugh. Many early farm tractors were steered from behind through ropes. The existing plows and mowers expected a man to ride them to work the adjusters. Also rope-steering was old-hat-- that's how you steer plow horses (well, ideally they are mostly voice-control).

But try that on a 1980 Chevy with the Saganaw POWER steering, or a MX-5 Miata with the micro-steering. These controls are SO sensitive that rope-steering would land you in the ditch.

So "yes and no". You need to know your machine.