circuit requiring hitting to work

[11-90-an]

i made a pedal with a couple of s9015 transistors, 1n4007s and LEDs for clipping. when i run the circuit on a breadboard, it either gives a 1.tiny bass fuzz, 2. no sound , or 3. very nice overdrive-y distortion. problem is, i need to somtimes repeatedly hit the wiring to get the distrtion sound. since i thought that the problem was with the wires, i put it on pcb. when i tested it, it just gave the tiny bass fuzz instead of the overdrive!!! pls help i really want a overdrive unit...

[stallik]

Welcome to the forum.

You haven't given us anything to work on here. We will need circuit diagram, BB layout and pictures to stand a chance but here are a couple of things to consider when using breadboards

Breadboards are not all made equal. Cheap ones can lead to poor connections. Likewise with patch wires
If you alter the effect of the circuit by moving the wires, you have connected, disconnected or shorted something. Trouble is, you don't know which one of the 3 has happened so you don't actually know the state of the circuit so sort that issue before continuing.

It's likely that the 'tiny bass fuzz' was the correctly working effect as you had it on the BB. Time to break out the breadboard again

[PRR]

> anything to work on here. We will need circuit diagram.... to stand a chance

"We may have had our break! This record is a manual of sorts. It provides some wiring blueprints Renfry has been able to identify with that cat's cradle of cords up there."
"Some wiring." Renfry's enthusiasm did not match Ashe's at that moment. "About one line in ten! This is like trying to put together a missile head when all your working instructions are written in code! Yeah—the red cord hits the plate there—but does it say anything about these white loop-de-loops to the left?"
Ashe squinted at the loops in question and consulted the record reader again. "Yes!"
Renfry was down on his knees in an instant to see for himself the diagram on the picture screen.
"Well—that's more like it!" Ross climbed the rest of the way into the cabin and stooped to look over Ashe's shoulder at the miniature screen.
"I'd say it's closer to the plans for a demon-inspired highway system," he commented judiciously.
― Andre Norton, Galactic Derelict

[11-90-an]

Welcome to the forum.

You haven't given us anything to work on here. We will need circuit diagram, BB layout and pictures to stand a chance but here are a couple of things to consider when using breadboards

well, here are the images of the circuit and such...

It's likely that the 'tiny bass fuzz' was the correctly working effect as you had it on the BB. Time to break out the breadboard again

if this is the case, why would there sometimes be a overdriven sound?

[willienillie]

Lotsa things going on here.  Biggest probably is that you need coupling caps after each transistor.  The soldering ain't so great, no offense.  It's not a good practice to solder to the eyelets on the pots.

[11-90-an]

The soldering ain't so great, no offense.  It's not a good practice to solder to the eyelets on the pots.

yeah i suck at soldering. thanks for the tip

[antonis]

Am I the only guy who thinks Q1 is not quiescent biased..??
(as it is, it only works during heavy negative signal waneform..)

P.S.
Is (+) on 9V a typo, or are we talking about reverse-active region..??

[willienillie]

MPS9015, I presume.  I can't find any info whether PNP or NPN.

[antonis]

S9015 (as clearly stated on schematic) is definately p-n-p ..

[11-90-an]

S9015 (as clearly stated on schematic) is definately p-n-p ..

well, for some reason, when i use my multimeter to test my transistors, the s9015s reacted like npns and my s9014(npn equivalent of s9015) reacts like pnps. i know for sure that my multimeter isnt broken of anything... and also my s9015s dont work if i make the circuit specifically for pnps...

P.S.
Is (+) on 9V a typo, or are we talking about reverse-active region..??

i just added +9v just to signify positive 9 volts.. sorry for confusion...

[antonis]

No need for apologies & no confusion alsor..

I mentioned (+) sign before 9V 'cause, in accordance with your drawing, Q1&2 are P-N-Ps so they should be fed from -9V..
(positive ground circuitry..)

[11-90-an]

ahh ok.. is it a good idea to desolder everything and go back to breadboard? also, the only time this thing overdrives is when the red led lights up according to the guitar signal. thats how i knew when it was working(back in the breadboard). i thought that it was just bcos the wiring was bad so i transferred everything to pcb. when i tried it, the led doest light up already. it isnt broken though.according to this, what do u guys think i shoud do now...?

[willienillie]

S9015 (as clearly stated on schematic) is definately p-n-p ..

Yes, you are right.  I just assumed "MP" was left off the marking, you know how they do that sometimes.  But searching "s9015" brings back plenty of info.  PNP it is.

is it a good idea to desolder everything and go back to breadboard?

Going back to the breadboard is a good plan for sure.  Desoldering everything might be more trouble than it's worth, unless those are the only parts you have.

[11-90-an]

Going back to the breadboard is a good plan for sure.  Desoldering everything might be more trouble than it's worth, unless those are the only parts you have.

well, I have really few parts, which is why I'm using less common s9015s instead of more common ones like 2n3904. I tried to buy some j201s before quarantine but my local electronics shop does not sell it. do you guys think any of these transistors could be of any use?
-s9014
-9018f
-s8550
-mpsa13

[aron]

Where did that schematic come from? At first I thought you had channeled the "Hilo, Hawaii" fix, which is to whack any piece of electronics to produce an immediate fix on the gig! :-)

[willienillie]

do you guys think any of these transistors could be of any use?

All working transistors can be useful somewhere.  The MPSA13 is a very high gain NPN darlington type, fairly common, great for buffer stages.  The rest in your list are unfamiliar to me, as the S9015 was, but you can google up the datasheets.  J201 is (was) a common n-channel JFET, maybe you know already.  Those are getting harder to find.

[antonis]

Where did that schematic come from?

Probably from : www.youcanthrowanythingyoulikeintoverifiednonworkingcircuits.com

@ 11-90-an: Are we now talking for suitability of whatever is inside your transistor drawer (from pnp BJTs up to npn Darlingtons, involving also some Fets..) to be placed into the very particular and "universal" bias circuit posted above..??

[11-90-an]

Where did that schematic come from? At first I thought you had channeled the "Hilo, Hawaii" fix, which is to whack any piece of electronics to produce an immediate fix on the gig! :-)

Well, i just made the schematic by myself after some research about diode distortion and stuff like that. Whacking the breadboard works but whacking pcbs dont

@ 11-90-an: Are we now talking for suitability of whatever is inside your transistor drawer (from pnp BJTs up to npn Darlingtons, involving also some Fets..) to be placed into the very particular and "universal" bias circuit posted above..??

Well, I just want to know if there are any type of pedals that i can make during this quarantine so that i may be satisfied that i might have achieved something. It would really be good though if one of theese transistors could really be an effective replacement for the s9015 transistors.

[antonis]

Well, i just made the schematic by myself after some research about diode distortion and stuff like that. Whacking the breadboard works but whacking pcbs dont

So you made a Mojo-Whack..

Don't get me wrong but try to make a more "sensible" schematic/circuit..
(e.g. decide of transistor type and try to make them working at forward-active region.. And a bias configuration should also be useful..)

[11-90-an]

Don't get me wrong but try to make a more "sensible" schematic/circuit..
(e.g. decide of transistor type and try to make them working at forward-active region.. And a bias configuration should also be useful..)

What do you mean by the bias configuration? I always see this in transistor  tutorials but i dont really understand it that much. Does it relate to the Ic=hfe * Ib? Im sorry i dont really understand these things...