# Woodpecker and Sea Machine issues



## Madallop (Jul 14, 2020)

Hey all, I have two pedals with two issues. Thanks in advance for any suggestions. 

Woodpecker has a drastic volume drop. Resistors, caps, and pots are correct.  PF5102 is replaced by a 2N5458 and 2N5089 is replaced by 2N3565.  Any ideas on what may need to be replaced or is out of whack? 

Woodpecker Guts 



https://imgur.com/a/IovRdTU


Sea Machine's LFO doesn't work but if I connect the rate pot's 1st and 2nd posts, the LFO works. Is this maybe a bad pot?  The pedal basically is just a delay pedal at this point. I switched out the LM324N with another chip and the same issue persists. 

Sea Machine Guts 



https://imgur.com/a/7NWoA7X


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## Chuck D. Bones (Jul 14, 2020)

Woodpecker: 
Those transistor subs are ok.  Measure the drain voltage on Q1 so we can see if it's biased correctly.  Did you recheck all of the resistor values?  

Your pics are not good enough for us to read the resistors, check solder joints, etc.


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## Madallop (Jul 14, 2020)

Chuck D. Bones said:


> Woodpecker:
> Those transistor subs are ok.  Measure the drain voltage on Q1 so we can see if it's biased correctly.  Did you recheck all of the resistor values?
> 
> Your pics are not good enough for us to read the resistors, check solder joints, etc.


Q1 measures at 0.33v.  Not sure what it needs to be.  The resistor values all check out fine besides the 22k which is a 22k resistor but seems to only measure around 9k so I'll desolder and check out of the circuit and report back.

And yes, my phone camera can't take close up photos and it's a Samsung S20. Bogus.  I will say that my soldering is pretty solid in terms of avoiding cold solder joints and bridges so I don't think that's much of my issue. I'll definitely work on getting some better photos!


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## Chuck D. Bones (Jul 14, 2020)

*No need to unsolder resistors!  *If you want to measure R3 or R4, just pull Q1 out of the socket.  

Now that I look at the circuit more carefully, it's a wonder that it works at all.  

Those _farging iceholes_ at EQD have done it again!  Who can spot the egregious design error?

Try a temporary jumper across C1, see if that fixes the Woodpecker problem.


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## Madallop (Jul 14, 2020)

Chuck D. Bones said:


> *No need to unsolder resistors!  *If you want to measure R3 or R4, just pull Q1 out of the socket.
> 
> Now that I look at the circuit more carefully, it's a wonder that it works at all.
> 
> ...


How would you place a temp jumper? Just something between C1's connections or R1 to R2?


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## Chuck D. Bones (Jul 14, 2020)

Not easy to do on the back side because the LEVEL pot is right under C1.  Just jumper from R1 to R2.  You want the side of R1 that doesn't go to ground and the side of R2 that doesn't go to Q1-G.


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## Madallop (Jul 14, 2020)

Chuck D. Bones said:


> Not easy to do on the back side because the LEVEL pot is right under C1.  Just jumper from R1 to R2.  You want the side of R1 that doesn't go to ground and the side of R2 that doesn't go to Q1-G.


Jumping R1 to R2 didn't help unfortunately.  I believe this circuit is supposed to boost with the level all the way up and depth down, right? When the effect is engaged with the depth level halfway up, it sounds like I'm rolling my volume knob down from 10 to 8 for a good description.


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## Chuck D. Bones (Jul 14, 2020)

Did Q1's drain voltage improve?  Should be up around 6 or 7V.  2N5458 has a huge range of Vp.  If Q1's Vp is too high, it will saturate and no gain happens.  Sometimes you have to hand-pick the right JFET.  Measure the drain and source voltages.  That last reading you got made no sense.  If Q1 is saturated, the drain and source voltages will both be about 3V.  If Q1 is cut-off (not likely), the the source voltage will be zero and the drain voltage will be 9V.  If Q1 is biased properly, the drain voltage will be somewhere between 3V and 9V, ideally close to 6V.


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## Madallop (Jul 14, 2020)

Chuck D. Bones said:


> Did Q1's drain voltage improve?  Should be up around 6 or 7V.  2N5458 has a huge range of Vp.  If Q1's Vp is too high, it will saturate and no gain happens.  Sometimes you have to hand-pick the right JFET.  Measure the drain and source voltages.  That last reading you got made no sense.  If Q1 is saturated, the drain and source voltages will both be about 3V.  If Q1 is cut-off (not likely), the the source voltage will be zero and the drain voltage will be 9V.  If Q1 is biased properly, the drain voltage will be somewhere between 3V and 9V, ideally close to 6V.


Yeah, I had my DMM on the wrong setting!  Q1 measures at 3.45v for drain, 2.45 at source, and 0 at gate.  Should it be higher for drain as a boost?


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