BS or Not BS?

[csmatt45]

Read an ebay description about a Tyco oct-up. Not an exact quote but something like this:

"Made on a circuit board (PCB) so it is not prone to oscillations and squealing like ones made on perf."

Doesn't seem possible to me that an electrical current would care if it's in a copper wire, or on a copper trace.

Anyone?

thanks,

Matt

[markm]

I don't disagree but, my experiences with perfboard is that noise is more of a possibilty than an etched PCB however, off board wiring can be an issue as far as oscillation goes especially in high-gain circuits.

[tcobretti]

I am nowhere close to an expert on this, but I remember reading an RG post where he said that all signal paths (IE pcb, perf, vero) color the sound, even if only very slightly.  Any conductor will have tiny amounts of resisitance, and I believe he was sayng that it will even have a small amount of capacitance.  So, current does always care what it is flowing thru.

[csmatt45]

but it seems like that would imply that a copper stranded wire or a naked resistor lead would be better.

right?

[markm]

better than......

[Dragonfly]

Just a guess, but i wouldn't think that much besides the *layout* itself would affect the circuit...

but i'll defer to the experts on this one...
AC

[markm]

Just a guess, but i wouldn't think that much besides the *layout* itself would affect the circuit...

but i'll defer to the experts on this one...
AC

I'm with you Andy.....
This may be of some interest to your original question csmatt
http://www.diystompboxes.com/smfforum/index.php?topic=49928.0

[Gilles C]

IMHO, it depends on who did what.

A good perf layout who duplicates a good etched pcb exactly can be as good as the pcb version. But a perf layout where the wires are flying all over the place will indeed be prone to oscillations and squealing.

And a badly designed pcb can also be prone to oscillations. It's the same if the wiring is not done correctly.

Some people say that an amp is better if wired point-to-point than if it uses a pcb. The same question can be asked, and the same answers will follow IMHO.

Gilles

[Alex C]

http://geofex.com/Article_Folders/pt-to-pt/pt-to-pt.htm

[tcobretti]

better than......

"Better" is relative.  For some circuits, one approach could produce a more pleasing sound.  Or, more likely, it will be impossible to hear the difference.  If by "better" you mean the circuit would function more efficiently or without oscillation, using a PCB instead of a perf to solve a problem is treating the symptom instead of the disease.  If the circuit oscillates, PCB vs perf won't have nearly the effect of swapping a few components. 

I don't think my previous post implies that pcb is inferior; signal is always affected by the path upon which it is conveyed, be it pcb or perf.  I wasn't at all trying to suggest the superiority of either.

Basically, my uneducated guess is that the ebay guy is full of it.

[tcobretti]

http://geofex.com/Article_Folders/pt-to-pt/pt-to-pt.htm

I've never seen that article.  It's amazing how stuff turns up from sites you've seen a zillion times.

[csmatt45]

I'm reminded of reading an article a while back that explained where to wire what, and layout placement, and wires to and from etc. It was all over my head then, probably still is. Later I opened up my TS9 to take a peak for something unrelated. Moving the circuit board out after removing the appropriate screws I was greeted by a spagettie-like tangle of wires. to put the thing back together you just smooshed the wires back in, and put the screws back. Hmmm, I thought, all that wire business must not be that important... FYI the pedal was stock, I was the only owner, so no one created the tangle. I know I'm over simplifing, but its a good point.

matt 

[Gilles C]

http://geofex.com/Article_Folders/pt-to-pt/pt-to-pt.htm

I've never seen that article.  It's amazing how stuff turns up from sites you've seen a zillion times.

The same for me. I went there many times, but never saw that article. Or at least I don't remember.

Thanks forposting it.

Gilles

[aron]

"Made on a circuit board (PCB) so it is not prone to oscillations and squealing like ones made on perf."

I don't care what that person says. I've built so many pedals on perf and it rocks!

Sure, sometimes when I have about 3 hi-gain stages being pushed by an op amp, sometimes I get oscillation, but it's the nature of the circuit. I've built several Tyco octavers and they work fine on perfboard.

Ebay is a lousy place to base opinions on.   

[Paul Perry (Frostwave)]

It's possible to make a perfectly good pedal using any technique at all. Even point to point.
Here's the thing though... if you are wanting to make exactly the same effect a hundred times, or wanting a hundred people to make one, and have them all sound exactly the same..... you are going to want the same layout & method, whatever it is.
When I make a batch of pedals, I try to design out all the 'loose' wire. That way, all the stray capacitances and any track resistances are the same, and there is no unpleasant suprise when you make the 37th one & it sounds a bit different. Or howls at the moon.
Nothing wrong with perf. Nothing wrong with vero. Nothing wrong with PCB.

[Doug_H]

In response to the original poster: BS.

i just read the ebay thing about the wah (from the lounge) that claims stuff like "silver solder means good tone" (paraphrased), yada, yada...

Don't look to Ebay for technical advice or info...

[csmatt45]

Darn, I was just about to buy a pedal called the "Hendrixicon". It's a pedal with one knob labeled "Jimi". You just plug it in and you're instantly as good as Hendrix. Theres a mod you can do that makes you even better than Hendrix, but that voids the warrenty.

matt

[petemoore]

  Theres a mod you can do that makes you even better than Hendrix, but that voids the warrenty.
  Gets my vote for pedal of the month/best pedal joke.
 

[csmatt45]

thanks man...

[MikeH]

And a badly designed pcb can also be prone to oscillations. It's the same if the wiring is not done correctly.

So what makes a PCB poorly designed and prone to oscillation?