madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: Cyrial on July 19, 2020, 06:26:35 AM

Title: Solved: Bearhug super noisy
Post by: Cyrial on July 19, 2020, 06:26:35 AM
My bearhug seems to work except that it is very very noisy - which I think it is not supposed to be. Before I boxed it it was clean, then I added a little decay mod (3t switch with a 100k resistor in series on third throw) and soldered in the dc jack. Now it is not good.

Q1
D 5.05v
S 1.862v
G 2.269v

Q2
C 8.22v
B 0.586v
D 0v

Q3
Zeroes
G -1v on signal

C9
-.7v on signal

Across Q3
~300ohm, peaks up to (upward of?) 30k on signal, settles to ~1-2kohm
Title: Re: Bearhug super noisy
Post by: midwayfair on July 19, 2020, 10:22:35 PM
Pictures please.

It would be best if you can remove it again from the box (with all the wires intact) to check for noise.

At the very least check your ground wires on your jacks.
Title: Re: Bearhug super noisy
Post by: Cyrial on July 19, 2020, 11:50:07 PM
Reflowed everything, unboxed still noisy. The entire ground path seems fine. The noise reduces if I touch both the strings and the 1/4" plug (metal exterior), which leads me to think it is a grounding issue. The noise is present on both power supply and battery. Weirdly, if it's on battery and I touch the sleeve of the dc jack plugged into the same outlet as the amp, it buzzes more.

(https://i.imgur.com/mIV4uf4.jpg)
(https://i.imgur.com/c1iEBrg.jpg)
(https://i.imgur.com/cBnaUGn.jpg)

Here is a diagram of the delay mod I added. I didn't know how to draw a multiple-throw switch, so that's what the weird thing in the middle is.

(https://i.imgur.com/QdL1haD.jpg)
Title: Re: Bearhug super noisy
Post by: midwayfair on July 20, 2020, 01:52:55 AM
I'm kinda confused by your jacks. It looks like you soldered the input and output together.

Plug in your cables. Do you have continuity from the sleeve of one to the sleeve of the other?
Title: Re: Bearhug super noisy
Post by: Cyrial on July 20, 2020, 03:02:17 AM
I was under the impression that tip is ground - there  is continuity only tip to tip.
Title: Re: Bearhug super noisy
Post by: somnif on July 20, 2020, 03:11:14 AM
Quote from: Cyrial on July 20, 2020, 03:02:17 AM
I was under the impression that tip is ground - there  is continuity only tip to tip.

I'm afraid you have it backwards: Tip is signal, sleeve is ground. 
Title: Re: Bearhug super noisy
Post by: Cyrial on July 20, 2020, 11:55:23 PM
Newbie mistake - it sounds perfect now! Thanks somnif for the obvious solution, and thanks midwayfair for everything!