Wrong way to bypass

[guidoilieff]

Hi. "I have a friend" that made this circuitry on a diy fuzztone to see if he could bypass somehow the effect without using a 3pdt switch because they are damn expensive in his country and to see what happens.


It worked for a bit and the the effect stopped working even with the switch removed.


My question is: what could have broken/burned by doing this?
Thanks!

fuzztone schem:
http://www.generalguitargadgets.com/pdf/ggg_fz1s_lo.pdf[/font][/font][/font]

[antonis]

So "your friend" have made some repeated short circuits between C1 (which doesn't mind for instant polarity) and C5 (which DOES mind..)

Interesting experiment, indeed...

[duck_arse]

guido - what type switches can "your friend" get/has/afford? and can this "friend" find any cheap low volt relays near where "he (or she)" is?

[R.G.]

Hi. "I have a friend" that made this circuitry on a diy fuzztone to see if he could bypass somehow the effect without using a 3pdt switch because they are damn expensive in his country and to see what happens.

Have your "friend" go read geofex.com. In particular, the articles on The Technology of Bypassing and The Millenium Bypass. The Millenium Bypass gives you (1) true bypass and (2) a lighted indicator using only a DPDT.

The article on bypassing will also give your "friend" many ideas about bypassing with and assortment of switches.

[guidoilieff]

guido - what type switches can "your friend" get/has/afford? and can this "friend" find any cheap low volt relays near where "he (or she)" is?

Yeah, I guess so. Never worked with relays before.

[Elijah-Baley]

Hi!
If your friend would like to use 3pdt maybe could do a large order of those switch on e-bay or somewhere. Looking for some good deal on internet. On tayda electronics there are these switch, cheap and good enough.
I think there are many people who order components on line.

[antonis]

And a final recomendation for "your friend"...

"He - She" should use a DPST toggle switch instead of a SPST one (at the same price) wired at "reverse active" direction...
(one pair ON and other pair OFF and vice versa - maybe with some popping problems but with happy caps and an audible ON-OFF sign..)

[guidoilieff]

So "your friend" have made some repeated short circuits between C1 (which doesn't mind for instant polarity) and C5 (which DOES mind..)

Interesting experiment, indeed...

I replaced C1 and C5. It works for a second when I unplug the power making a fade out, till some capacitor runs out of power i guess.


I don't care much about popping

[antonis]

I replaced C1 and C5. It works for a second when I unplug the power making a fade out, till some capacitor runs out of power i guess.

I guess that it happens because of the power supply capacitor's value in relation with circuit's current consumption..
(if there isn't such a capacitor then your 1μF OUT cap is a workaholic type......)

[guidoilieff]

I replaced C1 and C5. It works for a second when I unplug the power making a fade out, till some capacitor runs out of power i guess.

I guess that it happens because of the power supply capacitor's value in relation with circuit's current consumption..
(if there isn't such a capacitor then your 1μF OUT cap is a workaholic type......)

I don't get it...

I tried probing and the dry signal from my bass doesn't make it trough C1 when I plug it to 9v. If its not plugged to the 9v it can make it to the first transistor.

[samhay]

Do you have a single throw (2 lugs) or double throw (3 lugs) switch?
If it is double throw, you can bypass by leaving the input always connected and then switching the output - the "simple SPDT bypass" at geofex: http://www.geofex.com/article_folders/bypass/bypass.htm

[Denio]

Wait,isn't a relay going to make a shit load of noise?

[R.G.]

Wait,isn't a relay going to make a shit load of noise?

If poorly done, yes.

If well done, no.

The relays doing bypass in the pedals for my "day job" are not audible in the signal.

Hmmm... it's also possible that "shit load" is "a negligible amount". I've never seen anyone measure one of those and convert to any other unit of measure. 

[MrStab]

The average weight of stools of 115 individuals is 123.6 Gm., with a standard deviation of 40.2 and a standard error of 3.74.

[R.G.]

Hmmm.
(1) individuals of what species are counted in a load?
(2) is the species reported there the same species that is contributing to the "load"
(3) what is being loaded? Earthmover? Dump truck? Pickup? Wheelbarrow? Backpack? Measuring cup? Lab scales? Mass spectrometer? Gas chromatograph?

[MrStab]

you've caught me out with the specifics, but i'm just glad my post wasn't met with an awkward silence. lol

...surely a dump truck, though.

[R.G.]

... and don't call me Shirley.

[guidoilieff]

... and don't call me Shirley.

So.... how you do it to not get a whatever amount of noise with a relay?

[R.G.]

Keep DC off the switching contacts, and carefully control the dv/dt and di/dt on the relay coil to keep switching noise from coupling in.

There are some shielded relays that make this easier, but they're quite expensive.

[samhay]

>So.... how you do it to not get a whatever amount of noise with a relay?

Personally, I've never had a problem with relay switching noise except for contact bounce, which is a problem with any mechanical switch.