Audio Research SP9 MKII to MKIII Upgrade

The jump in quality from MKII to MK III is substantial, and well worth the cost. However, it's cheaper to do what I did-- sell my Mk II on Audiogon and buy a used Mk III. I probably paid $150 for a mod that would have cost $800 if I'd sent my unit back to the factory.

If you're seriously considering moding your SP9, you might want to chat with Steve Huntley at Great Northern Sound about it. I had him mod my SP9 MKII to their Reference level which I have been extremely happy with. While not cheap, there are a number of things Steve can do that I suspect would easily beat out the MkII to III upgrade. Contact info can be found at http://www.greatnorthernsound.com. Definitely worth an email or phone call!

There is a Mark3 for sale here at $900. there are two Mark2's for sale at $635, so it seems that you may want to consider Swklein's advice.