Cosmopolitan problem: Low sound [SOLVED]

[2tonewarrior]

Hi, I´ve built a Cosmopolitan and it does sound, but not very much. The bypass works but when you switch on the effect, the volume is barely the same (or even lowder) as when in bypass (with ALL knobs set to max.) It sounds a little fuzzier and cracked, and the sound is very muffled.

I´ve checked wiring, solder joints, Pot values,....

Tomorrow when i get my camera back i will post photos. I start this post today in case anyone has had the same problem and can help me

[k.rock!]

Check your transistor pinouts. Sometimes the base is not always in the middle pin. What transistors are you using? Maybe we can look for a datasheet.


-Kaleb

[2tonewarrior]

Check your transistor pinouts. Sometimes the base is not always in the middle pin. What transistors are you using? Maybe we can look for a datasheet.


-Kaleb

BS170, BC109B and AC127

I´ve double checked them. I´m a little newbie in electronics so it could be wrong but I think the pinouts are ok, I´ve take for reference this page http://www.kpsec.freeuk.com/components/tran.htm

The first time I connect the effect to the guitar the pinouts were back to front (I realized this later) Could I have burnt the transistors?

[mgwhit]

If it's not transistor pins (or the transistors themselves), check the values of R2, R3, R6 & R7 and confirm that they are Ohms and not Kilohms.  A Kilohm value in R2, R3 or R7 would result in significantly less gain/volume.  If that doesn't do it, yes, photos!  Good luck!

[pryde]

I had the EXACT same problem with my cosmo and the great folks here noticed I has the wrong capacitor value in C2. Triple-check ALL of your cap and resistor values. It sounds like you have a wrong value somewhere.


You are going to love this pedal when you get sorted!

[2tonewarrior]

If it's not transistor pins (or the transistors themselves), check the values of R2, R3, R6 & R7 and confirm that they are Ohms and not Kilohms.  A Kilohm value in R2, R3 or R7 would result in significantly less gain/volume.  If that doesn't do it, yes, photos!  Good luck!

All values are ok checked by code and multimeter.

I had the EXACT same problem with my cosmo and the great folks here noticed I has the wrong capacitor value in C2. Triple-check ALL of your cap and resistor values. It sounds like you have a wrong value somewhere.

You are going to love this pedal when you get sorted!

I´ve read you thread before posting this and double checked the values. Now triple checked it and all values seem to be correct. Maybe I am missing something because its true thats you problem is really similar.

EDIT: In my case the only pot that is working properly is volume. Gain rises the volume and a little gain in the last seventh of the turn. All the other pots seems to change slightly the sound.

Sorry for the poor english, I´m getting more crazy trying to explain my problem than trying to resolve it.

[2tonewarrior]

Photos!













Tell me if you need a photo of any specific part

[cjkbug]

It looks like you have a .001uf for c11 instead of.100uf that's the 1st thing I saw I'll keep looking. and can we get some closeups of the whole solder side?

[cjkbug]

c15 appears to be the same and c5 looks like a .022 instead of .220. I am gonna check the codes to be sure.

[2tonewarrior]

u1=0,1uF , isn´t it?

And can we get some closeups of the whole solder side?

Ok, i´ll try but it´s difficult with the mounted pots.

Thanks for reply

[2tonewarrior]

http://www.wima.de/EN/marking.htm

[cjkbug]

Also I've never seen a zener diode that looks like that the ones I usually get are the orange glass types.

The codes on your wimas  look to me like the values you used are off. I don't know how experianced you are so don't take it hard but I'm gonna see if I can find my conversion chart for pf nf uf.  I had a hard time understanding them at first.  basically 1000pf = 1nf = .001uf... it looks like your code 1k 63 would be 1k(1000) pf or 1n or .001uf with a maximum voltage rating of 63 volts.

Please someone weigh in if I am off track as I am not familiar with these particular codes. don't always assume the supplier put what you ordered in the little plastic bags. they screw up values all the time. it's pretty easily done.

[cjkbug]

u1=0,1uF , isn´t it?

And can we get some closeups of the whole solder side?

Ok, i´ll try but it´s difficult with the mounted pots.

Thanks for reply

1uf boxs caps are a lot bigger than that and would still be the wrong value

[2tonewarrior]

Also I've never seen a zener diode that looks like that the ones I usually get are the orange glass types.

The codes on your wimas  look to me like the values you used are off. I don't know how experianced you are so don't take it hard but I'm gonna see if I can find my conversion chart for pf nf uf.  I had a hard time understanding them at first.  basically 1000pf = 1nf = .001uf... it looks like your code 1k 63 would be 1k(1000) pf or 1n or .001uf with a maximum voltage rating of 63 volts.

Please someone weigh in if I am off track as I am not familiar with these particular codes. don't always assume the supplier put what you ordered in the little plastic bags. they screw up values all the time. it's pretty easily done.

This is my zener diode http://www.banzaimusic.com/9-1V-Zener-Diode-5W.html, as a noob I ordered the 5W version   but it should work well, shouldn´t it?

According to this web http://www.wima.de/EN/marking.htm:

u1k63 = 0,1uF - Tolerance=10%(k) - 63V

[mgwhit]

The codes on your wimas  look to me like the values you used are off. I don't know how experianced you are so don't take it hard but I'm gonna see if I can find my conversion chart for pf nf uf.  I had a hard time understanding them at first.  basically 1000pf = 1nf = .001uf... it looks like your code 1k 63 would be 1k(1000) pf or 1n or .001uf with a maximum voltage rating of 63 volts.

Please someone weigh in if I am off track as I am not familiar with these particular codes. don't always assume the supplier put what you ordered in the little plastic bags. they screw up values all the time. it's pretty easily done.

Sorry, but you're off with the capacitor codes.  u1 = 0.1uF, K = 10% tolerance, 63 = 63V.