No wet signal from Ungula Cleft Mod

[robertbmillet]

Hello! I have an older revision of the ungula (not sure which, not printed on the board) and it appears quite that some of the pads polarities are labelled opposite from the build guide, which confused me, so I went ahead and soldered negative to the square contacts on the board, which is standard practice but like i said, reversed from the build guide. the project is assembled, but I'm not getting any wet signal. true bypass is working, the main LED is working, and I'm getting 9 volts past D5, which I assume means that power is getting into the rest of the circuit, do i just need to reverse D1-D4?

 

[Feral Feline]

Here are those updated pics, I'm not sure what you mean about the transistors? as far as i can tell they appear to be what the mod calls for.

Sorry, I just wasn't paying attention; it says right in the title of the thread "Cleft Mod".

People often sub out components, and I couldn't tell what you have for Q2&Q3 from the first set of pictures.
Sometimes the pinout of different packages causes complications, however in this case 2N1308 TO-5 package and MPSA13 TO-92 are in the same order.








New pics are good, can't see anything untoward...

Wish I could've been more help.
Maybe there's a solder-bridge under the sockets, or a faulty 3PDT...
I think it's time to follow Locrian99's advice and audio-probe it.

 

[Erik S]

The parts list for the Cleft Mod says to omit C6.

Not sure what the impact of that is, but it looks like you populated that.

 

[Feral Feline]

Well spotted Erik S.
I think C6 is a matter of subjective taste, though, not something that will kill the wet-signal.

The Ungula's C6 is a feedback filter cap; including it cuts out some of the harsher high-end resulting from the clipping diodes.
Without it, there will be more treble content, that's all.

 

[Chuck D. Bones]

The voltages on Q1 & Q2 are definitely wrong. Q3 look good and Q4 is suspect. Q1-Q3 should have similar collector voltages. Visually verify resistor values and solder joints.

Don't take this the wrong way, but your soldering could be better. You're using too much in most places. Your tip temperature may be too cold. You have to clean the flux reside off of the board. All that flux makes inspection difficult and if it absorbs moisture on a humid day it becomes somewhat conductive.