That's just it, as is drawn, the 100K resistor is no longer passing feedback from the emitter of Q3 to the base of Q2. How can it be, it is connected directly to ground.
WhiteKeyHole wrote:That's just it, as is drawn, the 100K resistor is no longer passing feedback from the emitter of Q3 to the base of Q2. How can it be, it is connected directly to ground.
Yes, you are correct. I'll fix it later today. Thanks. It was late and I drew it up in about 5 minutes.
Actually, I first drew R5 correctly and then changed it to be wrong. I was looking back and forth between a couple screens (no printout).
looks about right once you fix the mistake. pretty simple circuit. I wonder if you could add an oscillation switch by switching in a filter cap from Vcc to Gr.
"You've converted me to Cubic thinking. Where do I sign up for the newsletter? I need to learn more about how I can break free from ONEism Death Math." - Soulsonic
Thanks cj, here's a quick layout if anyone wants to try it:
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP
I just checked it again and it certainly seems to match up with the schematic unless I've lost the plot. Did you put the hidden track cut in between the bottom leads of the 2M2 and 100n, and are you sure whatever transistors you've used are orientated CBE from top to bottom?
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP
yep, my track cuts are there and my 2n3904 are oriented the right way, at least they are like on the layout (straight side to the right). My offboard wiring is like this:
3pdt: 1-input
2-input jack tip
3-link with lug 6
4-output
5-ouput jack tip
7,8,9-nothing yet
battery snap: +9 to the board like the layout suggest
-9 to the sleeve on input jack
output jack: sleeve to the ground on vero board
Yes well the 2N3904 I have are orientated like that, so assuming there aren't variations from different manufacturers that should be ok. And you switch wiring sounds ok to me too assuming you're numbering the lugs like this:
1-4-7
2-5-8
3-6-9
If you check for continuity with a multimeter, are you seeing continuity between both socket sleeves and ground on the vero? You didn't mention whether or not you had the socket sleeves linked by wire and so I'm wondering whether there is a robust enough contact to ground through the case.
Is the switch passing the signal in the bypass position?
And if you didn't test it before soldering up the switch, while you've got the multimeter out, are you definitely getting the contacts switching over on the switch?
Failing all that can you take a front and back pic of the board just to see if anything jumps out.
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP
the grounding through the case is ok and yes I get a signal through bypass mode. When I touch the solder contacts and the transistors, there is some crackle but no wet signal. I took shots of it but wonder if its going to serve you!!
Nothing is jumping out as misplaced, are you sure those cuts are all the way through and you've not left a small bridge across any of them? If you've got a multimeter what voltages are you reading between Sag lug 1 and ground and Bias lug 3 and ground? I'm just thinking that if there is anything wrong with either of those pots then that would be a problem straight away as there may be nothing getting to the circuit. Assuming they're ok, what voltages are you reading between all the transistor pins and ground?
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP
fuzzmax wrote:sag lug 1= 3.93V (+9v connects direct to sag lug 3 and linked with lug 2 but I get no voltage when checking lug 2 to ground!!)
bias lug 3= 3.93V
Q1= no voltage!!
Q2= base .49V and nothing else
Q3= collector .63V, base 1.27V and emmitor 0.59V
the measurements are somewhat "non stable"?!?
could it be the solder??
Sounds very strange, you should be getting 9V (or whatever the battery voltage is) on Sag lugs 2 and 3. Are you sure the battery isn't duff? Bias lug 3 being the same as Sag lug 1 is what you would expect because they're physically linked, what voltage are you getting on Bias lug 1? Sag lug 2 should be reading exactly the same as lug 3 which suggests there could be a soldering issue with that link. Some of the soldering on the board looked like it didn't flow too well and that can certainly cause problems, but if you're getting these strange readings from the Sag pot then that at least looks like a likely cause for the problem, and is worth investigating first.
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP
when the sag pot is all the way clockwise, i get 9.3v on lug 3 and 2 and 3.89v on lug 1 (and bias lug 3 and 2).... bias 1 reads 1.27v.
when it is turned all the way counterclockwise, i get 9.27v on lug 3, 2 and 1 and bias lug 3 and 2. bias lug 1 reads 2.15v.
Well there's definitely something strange with the Sag pot. It should go all the way down to zero (or at least a lot closer than 3.87V) in one direction and up to the full battery voltage in the other.
I'll try and build it up later and see what I get.
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP
I have redone it with extra super duper careness and it worked!!!!!but i think something is wrong....sag and fuzz pot are working backwards.....minimum voltage with the pot fully clockwise and minimum fuzz same thing. It does really well the motorboating sound but a little difficult to get a good fuzz sound...I suspect some shitty components, even the pots!!!