Noisy Cricket 2 doesn't sound right.

Started by diskett, March 08, 2012, 04:07:02 PM

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diskett

Hi!
I'm not expecting you to explain everything to me, just a few tips would be nice, so i could get my amp working.
Problem is that if i connect my amp to guitar, i get this humming noise and if i turn the volume up, it's gonna start whistling(or if i switch grit on).
Most parts are like it's recommended in the NCM2 DIY page ( http://www.beavisaudio.com/projects/NoisyCricket/DIY/NoisyCricket_Mark2_BuildGuide.pdf ), except:
47uF capacitors are ceramic discs, not poly film.
Volume pot is 5k, not 1k (still linear though).
I used 1/2W resistors, except 10R one, which is 1/4W.
Wires are standard 22AWG, should i use thicker ones ?
I connected all ground wires into same joint, might that be the problem ?
Speaker is 8 ohm 5W 2.5 inch.

I think my soldering is pretty good, so i don't think that is the problem.

Much obliged if you go give me some tips :).

texstrat

Some pictures would be helpful. You have to upload the pictures to a service like Photobucket to post on this site.

Also, read this http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Good luck.


texstrat

#3
Quote from: diskett on March 08, 2012, 05:26:35 PM
Imageshack maybe ? http://imageshack.us/g/835/imag0387m.jpg/

Yep, that will work.

What are you using to provide power? If you are using a non-regulated power supply, wall wart, then that is the problem(s).

Edit - I see you are using a 9V battery. Also, you might want to check your soldering for cold solder joints. Looking at the backside of PCB I noticed that some of the solder is not completely on the pads and that will create problems.

Edit 2 - The schematic you used is version 1.02, this one is version 1.2 and uses a pre-fabbed radio shack pcb. I don't know what you skill/build level is, but using this board my simplify the process.

diskett

Resoldered all the joint, same. Changed some of the wired, nothing.
I'm gonna try this one http://www.beavisaudio.com/projects/NoisyCricket/MarkII/NoisyCricketMarkII_RadioShack_Rev2.pdf , pretty much the same.

So problem can't be that i used wrong resistors or capacitors ? If not, i'm going to use same parts and hope that i made a simple soldering mistake that i couldn't find this time.

texstrat

Quote from: diskett on March 09, 2012, 08:36:53 AM
Resoldered all the joint, same. Changed some of the wired, nothing.
I'm gonna try this one http://www.beavisaudio.com/projects/NoisyCricket/MarkII/NoisyCricketMarkII_RadioShack_Rev2.pdf , pretty much the same.

So problem can't be that i used wrong resistors or capacitors ? If not, i'm going to use same parts and hope that i made a simple soldering mistake that i couldn't find this time.

Just be sure to double check your resistor values, in fact test them using your DMM. There are only two electrolytic caps that you have to worry about polarity. Take your time, check off the items as you populate the board and get good solder joints.  :icon_lol:

diskett

After a couple of hours of resoldering and testing ended up taking everything apart. Next week i'm gonna buy a new soldering set, a bit bigger circuit board and try again.
Thanks to everyone who bothered to help :)

diskett

#7
Okay, new build, sort of the same problem. This time i made a video, rustling sound is bit louder than what you hear in the video.
http://www.youtube.com/watch?v=vyDQqm70Zd0

BF245 that i used the first time is replaced with 2N3819, and all resistors are 1/4W.
47nF caps are still ceramic.
Used this schematic:
http://www.beavisaudio.com/projects/NoisyCricket/MarkII/NoisyCricketMarkII_RadioShack_Rev2.pdf

Any help ?

diskett

#8
And yesterday, it worked allright for a couple of minutes, now it's gone again, rustling sound's back. Did nothing to it, works randomly, why ?

Would it make any difference, if i used shielded wire or made wires shorter. Right now every wire is 10cm long or so.