About two years ago, I made a post here about the Express Machining Heavyweight Counterweight. I bought this counterweight for my (then) Rega RB900, and I was amazed at how much improvement there was to the arm's performance. I commented then that I am generally very skeptical about "tweaks", but in this case I thought that the Express Machining counterweight was a "must buy" for anyone with a Rega tonearm. The counterweight can be purchased from The Audio Advisor, Music Direct, and directly from Express Machining.
If you want to read my original review of the counterweight, here's the link to the Audiogon archive:
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1003547794&openusid&zzSdcampbell&4&5#Sdcampbell
For more info, use this link to Express Machining:
http://www.expressimoaudio.com/weight/weight.html
If you want to read my original review of the counterweight, here's the link to the Audiogon archive:
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1003547794&openusid&zzSdcampbell&4&5#Sdcampbell
For more info, use this link to Express Machining:
http://www.expressimoaudio.com/weight/weight.html