On Mar 10, 8:46*pm, Robert Macy wrote:
Need a sound recorder for recording noise intrusion from an adjacent
tenant.

Using Sony ICD-SX700 did not achieve very good results.

What should I use?

As mentioned above, a tape deck is cheap and effective. A second hand
stereo one (be sure to get one with mic inputs) and a couple of good
mikes will knock the socks off any mp3 type device, for the same or
less money.
see
http://www.vintagecassette.com/
for specs.
-B