Requesting Help with a Retrograde

[strat68]

Been struggling with this for a while and just came back to it.
Build doc: http://madbeanpedals.com/projects/Retrograde/docs/Retrograde_2014.pdf
Basically there is no signal past the base of Q1 (using an audio probe).  I've checked cap orientations and resistor values.  Switched out all the transistors.  Turning off the power give me a straight guitar signa; out.  No visible shorts on the solder side.  I'm not sure exactly  if and when the transformer comes into play.  I've built dozens of pedals without issue but this one has me stumped.

Here are the voltages at the transistors:

Q1 2N5087
---------------
C  .02
B  2.71
E  4.30

Q2 2N4401
---------------
E  ~9
B .02
C 0

Q3  2N4401
----------------
E  8.91
B 0
C 0

Thanks for any help.
BD

[midwayfair]

All your pins are labeled backwards.

The base of your Q2 has no voltage, and neither does its emitter of Q2. Something has clearly gone very wrong, and you've either failed to solder something or have a very bad connection (perhaps in your socket) -- look at the schematic. Q2's base is connected directly to the collector of Q1, but you have different voltages on both. Q2 is a basic common emitter circuit; its emitter should be about 4V and the base should be about 4.5V (or 4.3V in your case).

[strat68]

Thanks, I wondered about the pin labeling.  I've suspected a missed connection somewhere.  But you've confirmed what I suspected about the Q1 -> Q2 connection.  I'm going to start with the socket and check for continuity from there.

Thanks again!

Note:  I went back I saw how I reversed the pinouts.  Ended up printing a complete diagram and schematic of both transistors.  The layout diagram is pretty good for seeing where everything is routed to.

[Cloverleaf]

Hey guys, I've got the same issue so I figured I'd revive this thread...

So my problem is pretty much the same as strat68's. The signal 'disappears' after the base of Q1 (tried audioprobing past Q1's base, no dice). I've reflowed some 'suspicious' solder joints, measured connectivity yet the problem persists. I'm pretty stumped as well 'cause I've had many more complex builds before this which worked right off the bat.

I measured the voltages of my sockets (with and without tranny's), could you guys mayhap take a look at it and point me in the right direction of where to look?
Thanks a whole lot in advance!


Sockets without tranny's:

Q1:

C 9.33v
B 3.62v
E 9.30v

Q2:

C 9.38v
B 9.33v
E 0.00v

Q3:

C 9.33v
B 0.00v
E 0.00v


Tranny's in their sockets:

Q1

C 3.44v
B 3.48v
E 3.44v

Q2

C 9.03v
B 3.44v
E 2.88v

Q3

C 3.44v
B 2.88v
E 2.21v

[strat68]

All your pins are labeled backwards.

The base of your Q2 has no voltage, and neither does its emitter of Q2. Something has clearly gone very wrong, and you've either failed to solder something or have a very bad connection (perhaps in your socket) -- look at the schematic. Q2's base is connected directly to the collector of Q1, but you have different voltages on both. Q2 is a basic common emitter circuit; its emitter should be about 4V and the base should be about 4.5V (or 4.3V in your case).

Just wanted to offer a huge thank you.  I re-traced the circuit and once I saw how it all connected I re-checked the resistor values.  I had a 220R for R5 which should have been a 220K.  Switched it out and it worked.   It's a tad noisy but it needs to get boxed yet.

[strat68]

Hey guys, I've got the same issue so I figured I'd revive this thread...

So my problem is pretty much the same as strat68's. The signal 'disappears' after the base of Q1 (tried audioprobing past Q1's base, no dice). I've reflowed some 'suspicious' solder joints, measured connectivity yet the problem persists. I'm pretty stumped as well 'cause I've had many more complex builds before this which worked right off the bat.

I measured the voltages of my sockets (with and without tranny's), could you guys mayhap take a look at it and point me in the right direction of where to look?
Thanks a whole lot in advance!


Sockets without tranny's:

Q1:

C 9.33v
B 3.62v
E 9.30v

Q2:

C 9.38v
B 9.33v
E 0.00v

Q3:

C 9.33v
B 0.00v
E 0.00v


Tranny's in their sockets:

Q1

C 3.44v
B 3.48v
E 3.44v

Q2

C 9.03v
B 3.44v
E 2.88v

Q3

C 3.44v
B 2.88v
E 2.21v

Check your resistor values.  That did it for me.

[Cloverleaf]

Just checked all connections again, plus my resistor values.
Found out I had a connection going from Q1's emitter to R11... that explains the strange voltage readings.

So, problem solved thanks for the nudge in the right direction!

[strat68]

That's what I needed as well.  Just point me somewhere.  Glad to hear it was something simple.