Pedal PCB Cleaver Not working right

[SirHugo]

Hello all,
So I bought and built the pedal PCB cleaver (Keeley katana Boost clone)
But it isn't working right.
Here's what works and what dosnt,
The guitar signal goes through when off no problem,
The LED lights when on, but I get no signal.
However when I hit the boost switch on the pedal I get very fait
Broken up signal, which is controllable with the volume know
so it seems to be working.

Here are my reads for the pedal via multi meter
R1 0.00 - 0.00
R2 2.16 - 0.00
R4 0.00 - 0.00
R5 2.15 - 0.00
R100 0.00 - 9.00

C1 2.15 - 0.00
C2 0.00
C3 2.16 - 0.00
C4 0.00 - 17.72
C5 0.00 - 2.15
C6 2.15 - 17.72
C7         - 0.00
C101 13.46 - 4.58
C102 17.76 - 0.00

Trim 1 all pads read 17.71
Trim 2 all pads read 17.72

T1 17.71
T2 17.72

LED 9.00 - 2.48

Dc jack 9.01 - 0.00

Vol. all pads read 0.00

IC 1 8.93  5 8.93
    2 4:58  6 5.48
    3 0.00  7 3.94
    4 0.12. 8 0.34

Switch up 1 0.00  4 0.00
               2 2.16  5 2.15
               3 2.16  6 2.15

Switch down 1 2.16  4 2.13
                   2 2.16  5 2.15
                   3 2.07  6 0.00

Build docs:
https://www.pedalpcb.com/docs/Cleaver.pdf

[PRR]

So your JFETs are sitting with 0V, 2.15V, and full 17.7V.

I wonder if your trim-pots are shorted?

There should be trim instructions. What changes when you do that?

[Slowpoke101]

I don't see any instructions for setting the bias trimpots in the build doco. Initially set the bias to 9V as measured between ground and TP1 - adjust TRIM1 for 9V. Then do the same for TP2 - measure between ground and TP2 and adjust TRIM2 for 9V.



That should get the booster to work, then you adjust TRIM1 and TRIM2 by ear for what you think sounds good.
If you cannot adjust for 9V, do as Paul suggested and make sure that the trimpots are not shorted.
If they are OK and you cannot see any other problems then remove the FETs and turn them around so that the flat side on the FET body faces away from the trimpot. Then try the bias adjustments again.
Sometimes you will encounter a transistor or FET that has different pin-outs to what the datasheet shows.

[SirHugo]

Thanks guys,
So the lowest I can drop the trim pots is 17.67, when I max it the opposite
Direction, it hits about 17.70, I tried flipping the FETs but it acted the
Same. How can I find out if my trim pots are shot?
This is my first forey into both having the charge pump and trim pots.
Thanks again for ya'lls help,
-Hugo
Also how can I avoid frying them if that is indeed the issue?

[Slowpoke101]

Check R2 and R5. They should be 680R (blue, grey, black, black, brown - for 1% resistors). Your picture has them in shadow so it is very difficult to see the colour code.

Make sure that the circuit is un-powered for the following tests;
To test the trimpots - remove both FETs, set your meter to measure resistance. Place the red test lead on cathode of D102 (end of diode closest to IC1 pin 8 ) and the black test lead on TP1. Vary TRIM1 - you should see the meter change from 0 at one end of the trimpot travel to 10K at the other end. Do the same for TRIM2 but place the black lead on TP2.
If the trimpots show those measurements then they should be OK.

[SirHugo]

Haven't done the tests yet but R2 and R5 are (blue grey black orange brown)
But isn't that 680 ?
Perhaps this is my issue?

[Slowpoke101]

Ahh.. You have 680K resistors.
Yes, this would be the problem.
Change them out for 680R and it should work.

[SirHugo]

Ok cool! Thanks so much! I'll have to order them but as soon as I can swap them
Out I will report back

[patrick398]

Ok cool! Thanks so much! I'll have to order them but as soon as I can swap them
Out I will report back

Do you have any resistors in the ballpark? I don't think it's critical. At least to see if you can get it firing try something under 1k if you have it

[SirHugo]

I unfortunately do not, I have to wait for shipping lol.
Lots of spare caps but I'm usally pretty good about my resistors
And as such don't have any extras.

[PRR]

> pretty good about my resistors

A "pretty good" plan for resistors is a bulk-pack of all values. $5-$15; saves much re-ordering+shipping.


500+ carbon film
500+ metal film
AS&S pack (good folk)
Elenco pack
Seeed Studio pack

[patrick398]

If you don't already, it's worth buying things like resistors form Tayda. Shipping can take a couple of weeks (to UK anyway) but you can get about 100 resistors for around £1.20. For about a tenner you can keep yourself stocked up on resistors for a pretty long time

[SirHugo]

That's a great idea thanks! I suppose I hadn't fully embraced this addiction,
But buying in bulk will certainly solidify it. Haha thanks again guys!
I will report back when in get my bits in!

[SirHugo]

Hey guys,
Ok, update. I replaced the two 680k resistors with the proper 680ohms and adjusted the
Trim pots to as close to 9v as I could get, and it works beautifully!! Thanks so much for all of your help!! I also have anouther lingering question, so now that it's working properly I can adjust the trim pots where ever sounds best right? Or will they reach a threshold where they'll cease to work like before I adjusted down to 9v?
Thanks again,
JHK

[Slowpoke101]

You got it working! That's good news 

Feel free to adjust the trim pots to where-ever you think it sounds the best. If you go too far either way with an adjustment the effect will stop working so you then turn the trim pot slowly in the other direction until the effect works again. Play with the adjustments, you can't damage anything by adjusting the trim pots.

Have fun.

[SirHugo]

Awesome!!
Thanks again Man!
I'm so happy with this build, thanks again for your time and knowledge!
-JHK