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Should I just replace the q1 again and see if that fixes the voltage discrepancy?


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Ok I checked the voltage of the 2n5457 drain as I turned the trim pot and it went as follows...
Trim pot all the way down = 1.66
Trim pot all the way up = 17.84

I did noticed the voltage would slowly drop then finally settle in.

I probed around with an audio probe and found the following....
The noise was on Q1 2n5088 collector
It was found on the Q2 2n5457 drain
It was found on Q3 bs170 gate


The noise is actually more than white noise, It has a slight squeal to it. I noticed as I turned the trim pot the sound changed pitch. All the way up created a really high squeal in the white noise/hiss.

I will check the trim pot and 5457 this evening.

I replaced the 5088 prior to taking the readings because I suspected it being bad. So unless my replacement was bad as well....?

I checked the pin out of the pn4302 and I did have it in backwards. I was able to get my hands on a 2n5457 and put it in place correctly.  After getting the 2n5457 in, I took new readings of all the voltages and have noted what each pin is.   Most voltages stayed the same after correcting the 2n5457.  I thoroughly looked over the board for any bridged solder joints, ect and could not find anything.  Getting frustrated with this one.

Q1 - 2n5088
Emitter Pin 1 -1.78
Base Pin 2-1.74
Collector Pin 3-9.13

Q2 - 2n5457
Gate-0
Source-1.46
Drain-3.76

Q3 - bs170
Drain Pin 1-0
Gate Pin 2-2.24
Source Pin 3-0.29

Pt2399
Pin 1-4.99v
Pin 2-2.50
Pin 3-0
Pin 4-0
Pin 5-2.44
Pin 6-2.45
Pin 7-1.13
Pin 8-1.18
Pin 9-2.50
Pin 10-2.51
Pin 11-2.51
Pin 12-2.50
Pin 13-2.50
Pin 14-2.50
Pin 15-2.50
Pin 16-2.50

No ideas?

Pictures of the board.




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I have a Hamlet + project that I have been having issues with for awhile and I can't seem to figure it out. The pedal creates white noise whether it is engaged or bypassed. The output is also rather quiet. I bought the board already populated but have since replaced the Q2 with a pn4302 because I cannot seem to find a 2n5457.  I thought that was the issue but it is still there after this replacement.  My voltages are as noted below.  Any ideas where the issues could be coming from?

Pt2399
Pin 1-4.99v
Pin 2-2.50
Pin 3-0
Pin 4-0
Pin 5-2.64
Pin 6-2.45
Pin 7-1.13
Pin 8-1.18
Pin 9-2.50
Pin 10-2.51
Pin 11-2.51
Pin 12-2.50
Pin 13-2.50
Pin 14-2.50
Pin 15-2.50
Pin 16-2.50

Taptation
Pin 1-4.99
Pin 2-3.55
Pin 3-3.71
Pin 4-4.39
Pin 5-4.98
Pin 6-2.27
Pin 7-4.81
Pin 8-4.99
Pin 9-0
Pin 10-0
Pin 11-4.81
Pin 12-1.19
Pin 13-0.21
Pin 14-0

Mcp41100
Pin 1-4.99
Pin 2-0
Pin 3-0
Pin 4-0
Pin 5-2.45
Pin 6-2.45
Pin 7-0.30
Pin 8-4.99

Lt1054
Pin 1-1.12
Pin 2-5.0
Pin 3-0
Pin 4-0
Pin 5-0.14
Pin 6-2.54
Pin 7-1.41
Pin 8-9.25

Q1 - 2n5088
Pin 1-1.78
Pin 2-1.74
Pin 3-9.13

Q2 - pn4302
Pin 1-16.29
Pin 2-0.18
Pin 3-0

Q3 - bs170
Pin 1-0
Pin 2-2.24
Pin 3-0.29

Reg - 78l05
Pin 1-4.99
Pin 2-0
Pin 3-9.22