*updated pic and ideas* Help debugging my lofo?

[343 Salty Beans]

Turns out I reversed the strip with the hole in it...

Built this late last night, but it didn't end up working. The original layout is
http://aronnelson.com/gallery/album20/LofoMofo_Vero...

Here's my modification listing the voltage readings at each given strip of the board (i did two measurings on the strip with the hole, one for each side).



I made no substitutions for any parts. I did, however, use the 3PDT switch to make a LED (green ) to note whether or not it's on.

If you need any more info, say so and I will measure it out.

My thoughts...

Bad transistor? The top pin (on the layout) reads 4.5v, the middle pin reads .54...butthe bottom reads 0. however, doesn't this make sense, since that third strip up is ground? But when I look at other distortion circuits, the lead doesn't go to ground.

My second guess is a bad 220pF resistor...it's reading .54v on the top pin, 0v on the bottom pin. Anyone want to confirm this for me?

My last thought is something to do with transistor voltage. I'm not too knowledged in these, but I'm pretty sure that those voltages are wrong.

Thanks in advance.

[343 Salty Beans]

okay, note the transistor pinout right here http://www.nteinc.com/specs/100to199/pdf/nte123a.pdf...but then, look at the vero layout up top.

The way that transistor is laid on the vero, I shouldn't have just slid it right in, (2N2222s are the kind that have a metal cap and a triangular pinout already), right? Instead, according to the schematic symbol on top of the transistor in the layout, the emitter should go on the BOTTOM...even though if you just slide it right in, it goes on the TOP. Am I right to assume that since I slid it right in, the pinout is incorrect, and that I should reverse the bottom and top pins so that the emitter is pointing downwards?

[343 Salty Beans]

The second time you repost on your own thread, you feel like a retard.

I redid the transistor, and sure enough, that was the problem...sort of. The next problem is that it sounds like I'm missing a connection, because the volume output is lower than the bypassed output. However, I am playing a bass, through a bass amp, and the small input and output caps pretty much assure that almost all the bass is entirely cut...given that, I think it's fixed. It's for our guitarist, so i don't think I need to worry about that volume problem, right?

[Connoisseur of Distortion]

your voltages from the first post look good. ground should be zero volts, you know... and the voltage divider will give 4.5 volts to the collector of the tranny.

the cap does not appear to be a problem.

i would check wiring around your pot, and check the pot itself for problems.

what exactly is it doing?

[343 Salty Beans]

well, at first it was giving nothing. No sound, just the typical hiss of a tangled mess of wires outside it's box...one time when I moved it around on accident while someone was playing my bass through it, it made a VERY quiet noise every time a string was plucked.

So I checked with the multimeter and decided I may have had the transistor pins switched. So I switched the top and bottom (before it was top-emitter, bottom-collector, now it's vice versa) and I replaced the 220pf, since it's voltages were being stupid. Now it works fine, except that it's quieter than bypassed mode. I know I'm playing through a bass, and a bass amp, but even when I had treb and mid rolled all the way up on my EQ and the bass rolled all the way down, even on my highest fret (20th on the G), it still is a little quieter than the bypassed signal...even with the volume all the way up.

I don't think this could result from transistor pinout. But could it? I think it's more of a 'something is touching something it shouldn't be" deal.

Another note is that the 500k grit pot seems off...as in the first half of the turn is entirely clean. Then it starts to get slightly gritty, and at the end there's a big clippiness. I know it's a logarithmic taper, but still...you'd think that the first part would do SOMETHING.

[coitmusic]

I haven't even bothered to read all the posts in this thread completely, but the first thing I notice about your layout pict is that you have the tips (signals) of the jacks connected  and the sleves (ground) going to the DPDT switch. Bypassed this would sound normal, but you'd get nothing when switched on. I'd check this first.

Good luck,
Chester

[RLBJR65]

It's probably working OK. I just tried mine with a bass which I had never tried before and it sounds pretty much like you described. Kills most of the Bass and Mids but thats what it was designed to do.

Take a look at Tim's schematic and build notes. (about half way down the page)  http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html