[sdiy] ISD voice recorder IC is NOISY!!

peter edwards synth at casperelectronics.com
Sat Nov 8 01:16:00 CET 2008

Has anyone here worked with the ISD voice recorder ICs??
  They seem like they could be super useful in synth building but  
yowza the one I'm working with is noisy!!
I have a handful of ISD1000 20 second voice recorder chips that I've  
been planning to build some modules with. I just bought a complete  
kit from velleman to get the ball rolling.
This one uses the ISD1420. The kit is Velleman K8030. Here's the link  
to the official velleman page for this kit.

It's a good kit but the one BIG problem that I can't figure out is  
how noisy it is. There's a substantial humming over the recorded  
message AND you can hear the internal clock.
It also makes a loud click when the message ends. I disconnected the  
mic and the noise in the recorded signal was just as loud. I've  
looked through the whole board for loose connections but can't find  
anything. ANy advice?

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