Metal Simplex questions and issue

[ConanB]

I've put this little ciruit together on the breadboard and played with it for a few hours trying to solve a little issue. Couldn't figure it out so did a forum search and no one seemed to have the same issue as me so I'm not quite sure what is going on.



The problem is that the volume control basically does nothing 
The signal basically comes through without any modification besides maybe a slight change, and max volume isn't loud at all, basically same volume as my bypassed clean signal.

I've checked over and over how I have the pieces arranged on the breadboard, and I'm certain they are right. The FX itself sounds good, and I like it. The only LED I had around was a 5mm red, and I've tried 2n3904 and 2n5088/9's, all of which sound decent enough. Gain control doesn't do too much past 20-30%ish, and I've added a 1k resistor to it so that 0 doesn't cut the volume as suggested in old forum threads. I've tried with and without the tone control, and both setups work, though currently I'm not using it.

I usually use trimpots on the breadboard and have tried a handful of 100k for the volume, each time checking that the in signal goes to lug 3, out is 2, ground is 1, like normal and all my other built pedals. But still nothing really changes, so it's not a faulty trimpot.

Any ideas as to why a volume pot wouldn't work when wired correctly?

As I said the FX works otherwise, just fairly hissy, which I'm almost thinking has something to do with it. Now I'm still an electronics newb, so only thing I could think of was RF noise, considering with gain down and amp volume up I could hear voices I also checked ground connections with the rest of the circuit and only things connected are the emitters of both transistors, as would be expected if there is no tone control.

Also another question: should I be aiming to get 4.5v at the collector of both transistors?

Any help would be great!

Cheers,
Conan.

[ConanB]

Ok eh, anyone ever have this issue then: breadboard jumper wires not working 

Turns out the volume pot didn't work simply because the jumper to ground wasn't letting anything through.

So anyway, problem solved. Glad it ended up being a faulty wire and not me failing to convert a schematic to the breadboard. Hooray I'm getting the hang of this

[drk]

troubleshooting is always a big problem ehe
congrats on finding it 

[earthtonesaudio]

Often I go "why is this not working?!" and spend several minutes looking around the breadboard, only to discover one of these as the answer:
Power not plugged in
Guitar not plugged in
Effect bypassed instead of engaged
Guitar volume at zero
Amp not plugged in

...you get the idea.  Sometimes you have to make the same mistake several times before it starts to sink in.  In a way, it's more helpful to have to de-bug something you've already soldered up, because you're more likely to remember not to do it again, than if it's just a two second breadboard fix.

Wisdom comes from experience,
Experience comes from a lack of wisdom.

[newfish]

Congrats on your new pedal.

The hiss on your Breadboard construction could well be due to the lack of shielding.

You've got all those wires looping round everywhere, acting as little aerials picking up RF and such.

You should find that once you've soldered up and put your Simplex in a steel / aluminium box, things should be much quieter.

[ConanB]

It just ended up being so annoying that I did have everything right, in all the right places, but a jumper for some reason doesn't let anything through at all 
Did a couple extra tests with that jumper and it doesn't do anything, litrally. Put it by itself with a LED/resistor and a battery and no voltage would go though it. Switch it with a different jumper and hey presto what do you know it works! 

I think I had rechecked the actual breadboard layout about 10 times against the schematic thinking I had something wrong. Grr 

Anyway, time to solder it up and add it to the collection. Sound isn't too bad, not as wild as my other distortions I've thrown together, but it's a good sound none the less.