Parentheses mini fuzz side no sound

[Pyry]

I have a typical problem with the Parentheses mini. Boost is working normal but the fuzz is silent. Have I made an obvious mistake with the diode orientation, soldering etc. or should I look it trough with an audio probe? Please help!

 

[Mcknib]

If those are D9K germaniums the double white band is the anode + side (D2 and 3)
From Steve at Smallbears description which would make yours the wrong way round

Product Description

V fwd .25 to .3 V on my DVM, .35 to .45 on the PEAK DCA. The double white band is the anode on these.

http://smallbear-electronics.mybigcommerce.com/germanium-diode-russian-d9k/

Not 100% sure but it also looks like R17 may be a 220R (red, red, black, black, brown) instead of a 2K2 (red, red, black, brown, brown)

 

[Nostradoomus]

Can you measure the voltages on your PF5102?

 

[zgrav]

Use your DMM to check voltages on the transistors and ICs. An audio probe may help you find the problem quicker.

 

[Pyry]

Thanks!
I measured the R17 and it was 2K2. I’ll try turning the D9K’s around first and see if it solves the issue.

 

[zgrav]

2K2 is a measure of resistance, not voltage. Don't turn anything around just yet. If you don't know how to use your multimeter to check voltages, do a couple of google searches.

do you already have an audio probe? if not, they are easy to make. another good thing to search for in google.

 

[Pyry]

I measured the resistance of R17 because Mcknib suspected it might have been 220R instead of 2K2.
I will come back with the voltages when I have done enough Google searching. Thanks!

 

[Mcknib]

I measured the resistance of R17 because Mcknib suspected it might have been 220R instead of 2K2.
I will come back with the voltages when I have done enough Google searching. Thanks!

I couldn't see it clearly so it was just for you to check with the colour bandings given

As zgrav says don't remove or change anything until you know it's a problem

Are your ge diodes D9K?

Voltages will give an indication of problem areas

For the transistors look up each types pinout so we know which pin is which same for the LM308

To take voltages if you don't have an auto ranging meter set your meter to 20V DC place your black probe in the COM port red one in V for voltage port

Power your circuit put your black probe on any ground point and red on each transistor / IC pin then list your voltage readings by pin name - drain, source, gate for the PF5102 and collector, base, emitter for the 2N5089 and 5087

The LM308 pins 1 to 8 like this

 

[Pyry]

Thanks for helping out. I've never done these voltage measurements before so hopefully I got them right.

The IC is OP07 which came with the kit from Musikding. Here are the measurement I got:
1. 9.18
2. 4.61
3. 4.18
4. 0.00
5. 0.00
6. 4.61
7. 9.24
8. 9.18

And here is what I got from the transistors:

Q1:
d: 9.24
s: 0.36
g: 0.08

Q2:
e: 3.96
b: 4.24
c: 9.24

Q3:
e: 7.15
b: 6.53
c: 2.06

Q4:
e: 0.26
b: 0.81
c: 6.53

Q5:
d: 9.24
s: 0.38
g: 0.04

Q6:
d: 4.69
g: 2.32
s: 0.20

The germanium diodes are D9K. I noticed from another build report here that the GE diodes are the other way around. Those look like D9K's.

 

[Mcknib]

Reading through troubleshoots for this circuit there seems to have been a few where the pinout on the PF5102 has been the problem, people that have gotten their PF5102s from musikding say the S and G pins are reversed so as a quick check you could try swapping the S and G pins around obviously making sure they don't touch, use a piece of stripped wire insulation to insulate one of the pins

Your IC voltages look good at least power, ground, in's and out pins 7 and 4, 2,3 and 6
Q voltages I've no idea aside from pins with VCC the 2 fets look to me like buffers with the output at the source, they're job is to grab as much signal as possible to and from stages by setting input / output impedance but whether they're conducting correctly between D and S I don't know from the voltages

How did you decide which side of your D9Ks was anode and cathode

 

[Nostradoomus]

If you have any 2n5458 kicking around, try those in place of your PF5102. They always work in the rat circuits I’ve built, PF5102 not so much.

Can you take a measurement of the empty jfet sockets? Those source voltages are too low. If I recall from mine they were somewhere between 1.5 and 2v, will double check when I get home later.

 

[Pyry]

Hi!

I swapped the PF5102 S and G pins around and I got some life in the fuzz side. Octave works really nice, so does the amplitude and filter. The distortion sounds softer as I presumed. When I turn it fully clockwise in the OpAmp clipping it gives a nice full distortion but at 12 its very "on the edge" especially with the Symm and Asymm clipping. I'm not sure if this is a fault or a feature.

 

[Mcknib]

Just for info it appears from this post here your GE's will give an octave effect regardless of orientation

Parenthesis octave issue

I've built two parentheses circuits and they both have the same problem: with the octave engaged, the volume drops as you turn up the octave blend (with no noticeable octave effect). This sounds like the same issue that was covered in this thread...

forum.pedalpcb.com

I was comparing that part of the circuit to the green ringer and noticed the diodes where the opposite way around and wondered if it mattered it looks like it doesn't

With regard to the rat distortion the op amp clipping would be louder I think if that's what you mean

I've built rats with clipping options but not this pedal maybe somebody that's built it can let you know how the clipping switch affects the sound

Anyway good to hear your getting distortion through

 

[Pyry]

Thanks a lot for the help this far!