I've improved my Noisey Cricket mkII

[brett]

Hi
I just built a noisey cricket mkII (beavisaudio.com). I was suspicious of the small size of the cap between the JFET buffer and the volume pot, which is only 10k.  The suggested cap is only 47nF, which gives a roll-off frequency of 340 Hz.  That's high!  So I used a 0.1uF cap (it's C2 I'm talking about).  According to my scope, the actual roll-off frequency is now about 160 Hz, which makes a lot more sense.

The other two changes I made were just for "safety".  I put a 0.1uF film cap in parallel with the big filter cap, which I upgraded from 220uF to 470uF.

I was able to get 0.5W (8V p-p into an 8 ohm load) of clean power out of it, but the IC was getting quite hot.  I might organise some sort of heatsink. I'm running it at 12V from a wall-wart.

It sounds quite good.
cheers

[ambulancevoice]

use some of that thermally conductive double sided adhesive stuff and a 220 heatsink
adhere one side to the ic and the other side to the 220 heatsink
bang! instant ic heatsink

unless someone knows otherwise (someone always does...)

[arawn]

You could also pickup some of those ram heatsinks that have the thermally conductive adhesive on them already i got some pretty cheap awhile back, I think $5.00 qamerican for a whole big set.