Klon rat's nest of hell Debug

[zipfool]

I've been building a Klon kit from General Guitar Gadgets, and I ran into a problem while attempting to set it up partially on a breadboard.

I want to be able to test different components in place of D2, D3, C7 and C14. For now, I'm just using the stock components. When I plug in, the pedal doesn't seem to be doing very much. Doesn't even sound like a boost with the gain turned all the way down. I get a little bit of breakup when I turn the gain up to about 4. Once I go past that and turn the gain up any more, I get a low frequency hum and no more guitar sound. The humm doesn't stop unless I turn the gain back down.

Before I reflow all the solder joints, can anyone suggest anything else I should try in order to troubleshoot?

Voltage readings:
Starting voltage: 9.08V
IC1

• 4.55
• 4.55
• 3.56
• .01
• 4.54
• 4.56
• 4.83
• 9.08

IC2

• 4.60
• 4.55
• 4.55
• -8.35
• 4.55
• 4.55
• 4.44
• 16.07

IC3

• 9.08
• 4.50
• .01
• -4.21
• -8.35
• 4.62
• 5.83
• 9.08

Pin 7 on IC3 is a bit further off than the other numbers.
If I turn the gain all the way up, I get pretty much the same voltages, with a few exceptions that are around .03V higher.

Here are some photos:

https://www.aronnelson.com/gallery/main.php/v/Schematics-etc/PXL_20210211_032115897.jpg.html?g2_imageViewsIndex=1

https://www.aronnelson.com/gallery/main.php/v/Schematics-etc/PXL_20210211_032142735.jpg.html?g2_imageViewsIndex=1

https://www.aronnelson.com/gallery/main.php/v/Schematics-etc/PXL_20210211_032231981.jpg.html?g2_imageViewsIndex=1

https://www.aronnelson.com/gallery/main.php/v/Schematics-etc/PXL_20210211_032131358.jpg.html?g2_imageViewsIndex=1

https://www.aronnelson.com/gallery/main.php/v/Schematics-etc/PXL_20210211_032201573.jpg.html?g2_imageViewsIndex=1

https://www.aronnelson.com/gallery/main.php/v/Schematics-etc/PXL_20210211_032131358.jpg.html?g2_imageViewsIndex=1

[iainpunk]

IC3 is the charge pump that turns the 9v in to +18v and -9v for more headroom.
those voltages don't seem weird to me, as a matter of fact, all voltages seem alright to me.

in general, 8 out of 10 similar problems turn out to be a bad solder connection somewhere, and the other two are wrong component values and the use of Vero board.

i suggest re-checking the component values, and if everything checks out, id re-flow the solder connections.

cheers, Iain

edit: FYI i can't open the picture links, which is probably on me, but i wrote this without visuals

[antonis]

FYI i can't open the picture links,

Good for you, Iain..
(pics are of about 12354854698541254778 X 5569741599321277 resolution..) 

[cab42]

edit: FYI i can't open the picture links, which is probably on me, but i wrote this without visuals

I had some problems accessing the gallery from my home wifi. It happened almost from one day to another late last year. It turned out to be the DNS of my internet provider (suggestion from the it guy at work). After changing  to Google's DNS , I could  see the the Gallery again.

[zipfool]

Thanks, I'll triple check the component values and reflow solder this weekend. I'll update when I've got something to report.

Funny how often it's just the simplest little thing I've done wrong.its just finding the needle in the haystack (rat's nest in my case).

If anyone else is having trouble seeing the photos, here's a different link to try: https://photos.app.goo.gl/tbX5Tsh5yGceUkxM6

[iainpunk]

Thanks, I'll triple check the component values and reflow solder this weekend. I'll update when I've got something to report.

Funny how often it's just the simplest little thing I've done wrong.its just finding the needle in the haystack (rat's nest in my case).

If anyone else is having trouble seeing the photos, here's a different link to try: https://photos.app.goo.gl/tbX5Tsh5yGceUkxM6

its probably nothing or just the lighting in the picture bu in the top right, some traces look sketchy, you might want to check them with the multi-meter.


cheers, Iain

[zipfool]

Not finished checking everything yet, but is there any reason why both r29 and r30 aren't giving me a stable resistance reading on my multimeter? The number counts up for about 30 seconds until it finally reaches the proper value (27k).

It levels out around 27k for both so I'm not sure it matters. But why would they do this?

[antonis]

Can't say for sure without a schematic but if they form Vbias voltage divider (or so) they shoud have a cap from their junction to GND..
Lift any of cap's leg and measure again..

[zipfool]

I fixed the problem. The gain works like it should now.
Not sure what was the silver bullet, but all my component values checked out. The pcb traces we're fine.

I reflowed all solder joints and secured a jumper on the gain pot that was questionable. Not sure which one fixed it, but I'm able to use the full range of the gain pot now.

Now I've got to figure out why the treble pot seems to be adding gain (and treble), and the output pot doesn't seem to do a damn thing unless I have it set to 10.

[iainpunk]

for the volume: is there a chance that its anti-log taper instead of log?

for treble control: the treble cut/boost is so broad that it feels way lower or higher gain, because it slightly cuts in to the midrange. its just a psycho-acoustic effect that just makes the gain feel different than it is through filtering.

cheers, Iain

[zipfool]

All of the pots are Linear (B). I'm realizing now that it might not be shunting to ground like it should.

I also have a nagging suspicion that, because I set this up on a Beavis Board, I'm not getting the proper Klon tone. For example, the Beavis Board used two mono jacks, but the Klon schematic has a stereo input and mono output.

I'm going to bypass the Beavis enclosure and stick true to the schematic and see where that gets me.

[zipfool]

My suspicion was right. Output wasn't shunting to ground until i used the stereo input. Still not sure why, but I'm glad I've got it working.

Thanks everyone for the help!