DEBUG HELP: big muff from tonepad has a thin / buzzy / de-focused sound

[blana]

Hello,

First of all, thanks to the creators of this forum for making such a useful knowledge base and learning center! Godbless!

I'm kind of new to the stomp-box building stuff so i decided to try with some simple projects. My latest one is a standard Big Muff with a schematic from tonepad. Here is the link:

http://www.tonepad.com/getFile.asp?id=94

Everyone on that site says it works from the first try, but...

As you expect, since i'm writing this topic, it does not work as expected. More precisely, it has a de-focused or buzzy sound, nothing like the sound of a stock big muff.

I used BC 549C transistors instead of the 2n5088 ones and 1n4148 diodes instead of the 1n914. I rotated the transistors as required since the BC 549C have reversed pins compared to the 2n5088 (I checked the spec sheets).

I triple checked all the parts positions and values, i triple checked the board for solder bridges.

I measured the power source, transistors and diodes, as required in the HOW-to debug section:

The source has 9.59 v.


Q1

E: 3.77 v
B: 0.67 v
C: 0.03 v

Q2:

E: 3.51
B: 0.64
C: 0.03

Q3:

E: 3.65 v
B: 0.63 v
C: 0.03 v

Q4:

E: 3.97 v
B: 1.84 v
C: 1.22 v

D1

k: 0.64 v
a: 0.55 v

D2

k: 0.57 v
a: 0.64

D3

k: 0.64 v
a: 0.6 v

D4

k: 0.6 v
a: 0.63 v


I didnt use a box or a bypass switch, i decided to test the circuit straightforward to avoid complications.


Anyone has any idea what can be the cause of the problem?

Thanks in advance.

[LucifersTrip]

I used BC 549C transistors instead of the 2n5088 ones and 1n4148 diodes instead of the 1n914. I rotated the transistors as required since the BC 549C have reversed pins compared to the 2n5088 (I checked the spec sheets).

it might not be reversed (b center, e & c flipped). according to this, some BC549C's have c in center
http://transistor-spravochnik.ru/description/bc549c/24750

Q1

E: 3.77 v
B: 0.67 v
C: 0.03 v

Q2:

E: 3.51
B: 0.64
C: 0.03

Q3:

E: 3.65 v
B: 0.63 v
C: 0.03 v

Q4:

E: 3.97 v
B: 1.84 v
C: 1.22 v

quadruple check pinouts...and re-check your readings. C's should be in the 4-5V range, not E's

[Kesh]

Looks like transistors in wrong. Collector and Emitter voltages are pretty much backward.

[blana]

Thanks a lot guys, that was it. The transistors were backward and i rotated them. Strange though, the sheets i checked were showing reverse pins...

Now its working, but unfortunately it  does not sound nearly as good as my stock muff.

Once again thank you for your time and help!