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Hi All - hope everyone is doing well and staying safe.

I bought and build a LAZY SPROCKET from July 2021 and couldn't get the pedal to work properly.  I set it aside for a while and went back to trouble shooting it today.

Here are the symptoms:

It only "works" with the trimpot fully CCW - even then, the audio is scratchy.


I've gone through all the boards and tested voltages etc. 

JFET:
G-4.89V
S - 5.4V

741:
1 - 0v
2 - 4.71v
3 - 4.73v
4 - 0v
5 - 0v
6 - 4.73v
7- 9.18v
9 - 0v

The trim pot feels suspect. I couldn't get a good reading from the left leg
the right leg swings from 0 - 4.5kOhm
The left leg goes from 0 - infinity - wobbling in around 4.5kOhm

I have rechecked all components and reflowed all the joints. Before I did the measurements, I removed and reinstalled a few things, hence some of the slightly burned shielding on a couple of wires. I am not the world's best solderer, but this is my 7th pedal build and I've repaired/built several tube amps, and other electronics, so I know that my skills are up to the challenge of this build.

Pictures are attached, I would so appreciate if someone could take a look and double check my components and let me know if there are other tests I should do.







Thanks!!
Andy

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Andy Henry - mediocre with a soldering iron and the guitar.

You probably need a new JFET. Email sales@buildyourownclone.com and let them know. The good news is we have the same NOS 2SK30A FETs that were used in the original SG-1 in stock again, so we can send you one of those. Just keep in mind that the pin out is different from the 2N5457 you have in there now. You will need to utilize the extra D hole in the JFET space on the PCB. Keep the JFET oriented the same way, just shift it over to the right one hole so that the other D hole is empty.

And, yes. I realize I said D hole several times.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Thank you so much Keith. I just sent the email and will let you know if this solves the problem.

- Andy

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Andy Henry - mediocre with a soldering iron and the guitar.

Hi Keith,

I installed the new JFET but the pedal is still not functioning. There is a volume drop when the pedal is engaged but no swell no matter where I put the knobs or the trim pot. I had an extra TLC071CP laying around (long story) but that didn't work either - it sounded only briefly and then went silent.

The new JFET is getting me closer since now at least we have sound when not bypassed, but we are still not there. Would love any help anyone can offer.

--Andy

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Andy Henry - mediocre with a soldering iron and the guitar.

I know you said you reflowed your solder joints already, but in your pics you still have a number of questionable looking joints.

Try removing the op amp from its socket. Does the pedal work as just a unity gain buffer?

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

With the opamp removed, there is no sound when the pedal is engaged.

I can try to re-reflow the all the joints later today if you think that will help.

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Andy Henry - mediocre with a soldering iron and the guitar.

If the pic of your solder-side is post-reflow, then yes. I think you should reflow again. Add just a tiny touch of fresh solder as well.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Will do and will then retest.

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Andy Henry - mediocre with a soldering iron and the guitar.

As you reflow, I'd suggest that you carefully inspect solder joints that are very close together for the possibility of solder bridging between them. This is particularly important with the radial electrolytic caps (of which this pedal has twelve) because the + and - leads are so close together.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Well, we're almost there. Reflowing everything (again) must have done something because I now mostly have the effect. When I put it in it's housing though, there is volume loss, even when the pedal is bypassed. I will open it up and see if two connections are touching or something is accidentally grounding.

Thanks again for the help!

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Andy Henry - mediocre with a soldering iron and the guitar.

Thank you, yes, I'll take another look under the magnifying glass.

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Andy Henry - mediocre with a soldering iron and the guitar.

OKAY!!!! I had taken the pedal apart so many times that I knocked loose a wire on the foot switch.

All fixed and seems to be working.

Thank you!!!

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Andy Henry - mediocre with a soldering iron and the guitar.

Great news! Enjoy the new pedal!

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2