cave dweller very noisy

[trustybs]

Hello, i have finished a cave dweller delay, my second madbean pedal after a mudbunny.

Everything seems to work fine as the 3 pots do what they should and the delayed notes are very smooth and nice.

BUT there is a lot of noise coming with the delayed signal.  I have read the previous topics and understand that the more the time is increased the more it can be noisy.  But with my pedal you can hear noise when the time is on minimum no matter where i set the dwell and echo.

From what i read on the other posts I can check another chip or change the value of the time pot.  I tried to put another regulator with no success.

Any other idea would be much appreciated.

Thanks alot

BrunO

[stecykmi]

check your ground connections, sometimes a poor solder joint can cause noise.

[midwayfair]

Can you describe the noise?

Woosh = PT2399
Buzz = something else

Does the noise decrease as you turn down the Echo pot? That's the minimally filtered repeat and will be the noisiest.

Is it instead a motorboating noise (wub wub wub wub wub) that increases in frequency and pitch as you turn down the time knob? This is a problem with some PT2399s and could be solved by replacing the chip. I had to do this with one one of my Cave Dwellers just the other day. (I hope you used a socket unlike me! Getting the chip out if you didn't isn't fun.)

[trustybs]

Well, it is hard for me with my poor english to describe the noise but i will try.

It does not  seem to be motorboating because it does not change with the time knob.

it is more like a kind of white noise behind the delayed signal but loud enough to make the pedal unusable.

Yes the noise decrease a little with the echo pot down but it is still present.

As i socketed the chip and i have another i will try replacing it, and i will check my grounds again even if everything seems right.

Thanks for your inputs, i will post the results of my testings.
Bruno

[midwayfair]

it is more like a kind of white noise behind the delayed signal but loud enough to make the pedal unusable.

Yes the noise decrease a little with the echo pot down but it is still present.

This is in the PT2399 chip. Changing the chip will not make much difference.

You can increase C3, and/or simply turn the echo pot all the down all the time, but the noise will never fully disappear in this design. This is why Bean cautions that it's a "Medium-Fi" circuit. It takes a lot more circuitry to hide the noise.

[trustybs]

Hello, just to give some feedback.

I checked the ground connections and they were good.
I changed the chip without any difference.
So i unsoldered C3 and try higher values which canceled the noise but also the highs.  The smallest value i had was 10 nf and the change in tone of the guitar signal was way too big.

So i finally put a 4nf but just to try i put a ceramic cap instead of the panasonic i had put first, and MAGIC the noise is still there when the controls are turned to max or at high values but a lower settings (time or echo) there is almost no noise (at least way less than before).

I'm not sure why, may be because the ceramic is less precise than the panasonic but anyway i'm happy with my delay now.

Thank you very much for your advices as it was my first post.

Cheers

Bruno