Ted,


Larry Cochrane has given me permission to post his seismic
amplifier/circuit, which is a well designed and proven to work well.


http://jclahr.com/science/psn/cochrane/

The easiest route is to purchase one from Larry: 

http://psn.quake.net/eqamp.html


A simpler design is posted here:


http://jclahr.com/science/psn/amp_filt/


John


At 06:20 PM 9/26/2006, you wrote:

Hi Stephen, 
Thanks for this recommended site...I could not enlarge the PSN Preamp and
PSN filter Amp by Pete Rowe, to see the values on the drawings.  I
searched the net but could not find any other site for them.  Do you
know where I might be abe to find these, large enough to print? 
Thanks, Ted