July 16th, 2012, 03:37 PM
I need help debugging a noisy cricket. Haha get it? Made it a week ago and it worked without a problem up until today. I haven't changed or done anything to it in that time. It even worked fine a few hours ago but now I just turned it on and it's a lot quieter than it was before, and it's also distorted (even with the grit switch off and the gain knob all the way down). When I turn the grit switch on and turn up the gain knob, it starts to self-oscillate at about the 75% point on the knob and the pitch changes when I turn the knob. I don't think I've done anything out of the ordinary to it; I used a wall wart to power it that said the output was 9.6V but that shouldn't be a problem because I thought I read you can use up to 12V. I went through and checked for solder bridges or see if anything came loose and didn't find anything. Tried a different power supply too and that didn't do anything. Could it be a bad component?
Any help is appreciated.
July 16th, 2012, 04:16 PM
The Ruby amp is less buggy than the Noisy Cricket, its like a little gem of an amp... Tip your bartender, I'll be here all week.
I regularly run my Radio Shack lm386 chip amp on a 12.1v wall wart but it hasn't died yet.
Never mind what is printed on the wall wart, they are often way off, you need to measure it.
What voltage do you read on pin 6?
Does another lm386 chip do the same thing?
July 16th, 2012, 05:07 PM
I haven't tried any new chips or anything. And (don't hurt me!) I don't have a meter or anything. I will order some extra parts next time I make a big order, which will be sooner than later. I can't stand the thought of paying radio shack 10 times more than I pay someplace else for the same part. In the meantime, if anyone has any other ideas... :)
July 17th, 2012, 01:04 PM
I went through and checked for solder bridges
If you LOOKED for solder bridges, you are a better man than I.
Go get yourself a cheap analog meter, you can upgrade to a nice DMM later. You need something and you can use it later for things where its just easier to see a needle bouncing around than digits.
Sometimes $15 at Radio Shack can keep me occupied for a weekend. Now that is cheap entertainment.
July 18th, 2012, 01:15 AM
Update: I can get the range and behavior of the self oscillation to change if I push the chip all the way into the socket or have it kind of half clicked in etc. Which leads me to believe it's a bad chip? Also in the process of cuddling around with it, I became initiated into the forum. I actually burned my fingers lol. Needless to say, this ended my futzing around with it for the night since I got mad at the chip for hurting me. is the chip supposed to get that hot? Part of me says yes cuz this unit is actually putting out power as opposed to a guitar pedal's chip, part of me says no just because.
July 18th, 2012, 12:28 PM
No, if it is that hot something is wrong.
July 18th, 2012, 05:43 PM
Hurray for it only being an $0.18 fix!