All big muff builders I need a little help Please

[whomeno]

I built a nyc big muff on vero board. I have signal in regions q1 and q2 but loose it. Not sure where to look next. Checked for bridges and cold solder joints. looked for and grounding issues like I had before(pots) I used a probe and had it in q1 and q2 but can not find where it gose to q3 and 4. here are some pics.

diodes

q1
e  0
c  .84
b  5.21

q2
e 9.31
c  10.21
b  9.32

q3
e  .24
c  1.17
b  .25

q4
e  0
c  1.07
b 1.72
these don't seem right.

Thanks

[Marcos - Munky]

First off all, you should have noticed the schematic and layout you've posted doesn't match each other. Well, same parts and connections, but different values. For example, you have 120r emitter resistors on the layout and 390r resistors on the schematic. Not that it will not work, just will produce a somewhat different sound.

Your voltages are a little bit strange. All emitter voltages should be at 0V or near 0V, so Q2 is off. Check your R10 value, on the layout it's the 120r resistor in the middle of the two jumpers and right above one cut. Your collector voltage for all the transistors seems too low, so check the resistors that goes from collector to V+ (the 10K ones on the layout). It's an common mistake to use wrong resistor values, I just did it today with a Green Ringer I built and spending almost 2 hours debugging it before I noticed a resistor with the wrong value.

[MaxPower]

I dislike vero because it's difficult to tell what is connected to what.

The circuit stages of Q2 and Q3 are the same so they should have similar voltage readings.

[Kipper4]

^ has a point.
And similarly all collector resistors are 10k. so ?
All bases of the Q's have almost identical resistances too. ?
They must have had a run of 100k R's. 

as do the emmtter resistances, nearly. ?

Those voltages look funky.

The Q's in the schematic number backwards to the vero.

[Marcos - Munky]

I dislike vero because it's difficult to tell what is connected to what.

Some people seems to like vero. I'm not one of them . Can't understand what's happening on a vero board.

[whomeno]

ok checked r10 it is 120r  checked 10ks they are good. rechecked voltage
q1
e 5.19
b .84
c  .06
q2
e9.42
b  10.33
c  9.41

q3
e  .26
b  1.17
c  .24

q4
e  6.07
b  1.74
c  1.10
I'm not sure where to look to find out where i'm looseing the power

the schmatic is not the one the borad was made from he did not post it. i didn't know how to find the right one
here is where I got the design. http://tagboardeffects.blogspot.com/2014/10/ehx-nyc-big-muff.html
I can read a little schmatic but not much still trying to learn.
been looking for a place that I can learn to read them better
I'm thankfull for this site, and all the help that is given

[MaxPower]

There probably isn't much difference in voltages between the various BMP versions and these are the voltages I have from a (working) violet bmp on my breadboard:

Q1:
C: 4.nn V
B: 0.68 V
E: 0.nn V

Q2 and Q3:
C: 4.nn V
B: 0.68 V
E: 0.nn V

Q4:
C: 5.nn V
B: 1.4n V
E: 0.8n V 

Where n= didn't bother writing the exact values down as they aren't too important.

Note that the emitter is around 0.6 V to 0.7V smaller than the base. That is usually the case with most npn transistor circuits you'll come across so something to keep in mind.

There is a schematic on that link you provided. Maybe they added it after you were there. The first three stages use the same resistor values so the voltages around Q1, Q2, Q3 should all be similar.

All your transistor voltages look bad. Q1 and Q4 look like they are backwards, Make sure you have them oriented the right way (The collector voltages should be much higher than the emitter voltages).

I don't know what to say. Check for shorts/solder bridges, missed cuts, the usual gang of suspects.

[Kipper4]

Also a case in point where the op should have tested the circuit works before boxing it up.

The solder looks very blobby.

The way it's stuck in the enclosure doesnt look to clever either although its hard to see.

Are you (op) reading the pinouts right anyway.

[Kipper4]

https://www.electrosmash.com/images/tech/bmp/big-muff-pi-v3-bias.png

[whomeno]

Kipper4,
I was learning a lot last night. as in the schematic you posted all caps form the c of the transisitor  to the b of the next are all coupling caps non polerized .in the vero board he used polerized elec. caps.
Am I right that this is wrong? and yes those are the points.
Thanks

[whomeno]

He has r12 before c13 . but i got it up to cap 13 and it dose not go through cap13.

[whomeno]

Kipper4,

i am not very good yet at schematics, but volts at transisters are

q4 b .8     c  5.33

q3  b 10.30  c  9.14

q2   b 1.19   c  .25

q1  b 1.15  c 6.16

I used the q order from the schematic

I do have parts coming to build a test box, so i can test them before putting them in a case.

This is the last vero board for me untill i understand schematics better.

[whomeno]

There probably isn't much difference in voltages between the various BMP versions and these are the voltages I have from a (working) violet bmp on my breadboard:

Q1:
C: 4.nn V
B: 0.68 V
E: 0.nn V

Q2 and Q3:
C: 4.nn V
B: 0.68 V
E: 0.nn V

Q4:
C: 5.nn V
B: 1.4n V
E: 0.8n V 

Where n= didn't bother writing the exact values down as they aren't too important.

Note that the emitter is around 0.6 V to 0.7V smaller than the base. That is usually the case with most npn transistor circuits you'll come across so something to keep in mind.

There is a schematic on that link you provided. Maybe they added it after you were there. The first three stages use the same resistor values so the voltages around Q1, Q2, Q3 should all be similar.

All your transistor voltages look bad. Q1 and Q4 look like they are backwards, Make sure you have them oriented the right way (The collector voltages should be much higher than the emitter voltages).

I don't know what to say. Check for shorts/solder bridges, missed cuts, the usual gang of suspects.

Looking at the diagram not the schematic my q2 is way high  e  9.5 b 10.3  c  9.4  I have no idea how it is so high checked for all shorts and solder bridges none to be found

[duck_arse]

with reference to THIS diagram:


on your board photo, I can see what appears to be a copper whisker across the cut two holes above the Q2 C. if this were shorting, your Q3 base would be pulled very, very close to ground. you need to go over ALL your track-cuts with a magnifying glass and a knife, to cut the little crescents from the holes.

there may be other problems. what transistors did you fit?

[MaxPower]

If you have extra parts you can try building one transistor stage for testing purposes. Don't use vero! Use a piece of cardboard and poke holes in it. Or you can do it without the cardboard if you want.

Since we're only interested in the DC voltages, you can leave out the capacitors.

Using the first stage,  connect  Q1, r14, r9, r13, r22 and connect a 9V battery  to it (+9v at the top of r13 and ground to the bottom of r14 and r22). Check the voltages around the transistor. They should be similar  to what we've posted.

[whomeno]

I reflowed  joints. Checked for shorts. Got right voltages now.
But now I lost bypass and still no sound. ( I did order a regular pcb  borad) but I still want to fix this one as a learning experience
Thanks for all the help so far.

[Marcos - Munky]

If you lost bypass, the problem is at your switch or jacks. Check them. For the bypass signal, it doesn't matter what's happening at the board (or even if there's a board), what matters are the jacks and the switch. Also, I think it's always better to test the board before wiring an switch.

[whomeno]

If you lost bypass, the problem is at your switch or jacks. Check them. For the bypass signal, it doesn't matter what's happening at the board (or even if there's a board), what matters are the jacks and the switch. Also, I think it's always better to test the board before wiring an switch.

.


I agree, But don't have a test box to test it. I am going to build one next. ok here is what I have at this pointif I pulg guitar in nothing in bypass or anything.
If I take guitat cable use jumper wires to an mp3 it all works. so now could be wrong now? I'm thinking ground some where.

[whomeno]

ok
NOW I am really confussed!!!!!!!!!!!!.   If I plug muff straight to amp. mp3 player into input, it all works great. then I pull mp3 player plugin guitar nothing!!!
I'm using a streo plug for the in put and mono for out.

[bloxstompboxes]

Sounds like your input jack is wired wrong.