My trimpot won't trim....

[Buzz]

Hi Chromesphere.

Maybe I should get it hooked up on the breadboard while I'm waiting for my socket pins.

I'll see if get the same problem there, if so I'll just keep upping the resistance and see if I can pull down the 8.9v.

At the moment I've got the transistor tester on the BB, so I might go through a stash of Ge trannies Brett kindly sent my way and get them sorted for projects.

The FF trannies are in the range of acceptable gains and leaks, I really think there was a fault in my build causing the problem.

[duck_arse]

here's a question: your diagram does not show a marked connection for "F1". you do have your fuzz pot connected to ground, yes?

[PRR]

> you do have your fuzz pot connected to ground, yes?

> Q1   
> E: 0v
> B -105mV
> C -356mV
> Q2
> E -367mV
> B -358mV
> C -8.75v

I'll be dinged. That _could_ explain it.

[Buzz]

Hi Guys.

The Fuzz pot ground is connected to the volume pot ground.

The full layout is here.

http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_pnp.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

Both lugs have zero resistance with the board ground.

That lead me though, to find a possible culprit.

The ground wire connecting the board to the output jack looked a bit dodgy at the board end. Wiggled it... snap.

It was just hanging on by a couple of threads.

It is possible this could have been caused by my lifting the board in and out so many times. Another possibility is that during the build I have re-flowed the solder while attaching one of the other grounds, causing this one to slip out a bit, leaving me with an insufficient ground connection.

That would explain the weak spluttery fuzz while the effect was engaged. It would also fit that the bypassed signal was unaffected, as the input and output jacks have a wire connecting their ground lugs.

But would that cause any problems with the bias trimpot?

[Buzz]

This also lead me to find another fault in this build, which also applies to my last four builds.

Lately I have been using input/output jacks like these:



They look neat outside and inside, and I like that they are fully enclosed.

They are, however, electrically isolated from the enclosure. I had assumed that the enclosure would be grounded by the stompswitch, which I tested by checking continuity between the stompswitch and the enclosure 

After finding the enclosure on this pedal was not grounded, I checked back over my other builds and they, too, have non-grounded enclosures.

Oddly enough they are quiet pedals.

I'm thinking the solution to this would be to solder a wire between one of the pot bodies and it's ground lug, as one would on a shielded scratchplate in a guitar.

Would that be the best solution?

[duck_arse]

it would be a solution. have you any fuzz sounds yet?

those ^ jacks bother me, the way the nut works as a screw and has so little to spanner. and I've been caught not paying attention to the way the switching contacts work, too.

[Buzz]

Yeah duck, the way the nut threads bothers me a bit too.

No problems yet, but early days, I haven't been using them for long.

As for the solder lugs, I didn't like that setup too much either. Solved it though, I snap off all the lugs on the Switching side ( the ones that get taken out of circuit when you insert the Jack )

I leave the other three lugs intact for the input jack. They work in a nice logical order, Sleeve closest to enclosure, then ring in the middle and tip on the inside. The same order they appear in on the male 1/4 jack.

Then for the output jack socket I also snap off the middle ring lug, as it won't be needed.

I just wiggle the lugs with some needlenose pliers til they break off, then file them flush  with the plastic enclosure. They end up looking very neat.

So what I end up with is an obvious input and output jack, with lugs in logical order. Makes wiring a breeze.

The only positive thing I can say about the nuts is that, because the external nut is metal and the female thread is nylon ( or whatever plastic it is ) is that if you put the right amount of torque into tightening them, they bite like a nylock nut and wont come loose. It would be nice if the metal threaded nut was a bit longer. I have no idea about the longevity of the items, I really haven't made any of these pedals do any hard yards.

A big question here is the grounding of the boxes. I haven't had any RF noise problems with these pedals. How important is it really to ground the enclosure ( and make a faraday cage... is that the right term? ) Or if I don't ground them am I really gonna regret it when one day I play in a room with banks of flouro lights?

I haven't gone any further with this pedal yet, still waiting for my IC socket strips.

I don't want to solder or de-solder those AC125's again. Don't want to bake them.

[duck_arse]

you shoulda said. not only have I got a shirtload of ic sockets here I've never used, but I also bought some (20) of these from rockby recently.



turns out they aren't "the thing" that I need to make all my pedals easy to design/wire/construct after all.

as for grounding cases, mine are pretty haphazard, but they don't get out much. if you make sure all yr metal parts like switches and pots make good electric connection to yr metal case, and return one of them to your board earth, you're most of the way there. using those insulated jacks means one less/one more problem: they won't cause loops, but they will both need earth wires.

I've been running all my wires from wherever, to my mill2 mounted on the footswitch. makes my wiring neater, and hasn't caused any probs. yet.