Audio Research SP9 MKII to MKIII Upgrade

Try listening to the amp with 7308 tubes instead of the stock 6DJ8. I'm using Gold Aero Platinum Grade Gold Pin on my Mk II.

One cheap mod that makes a big difference is using fast recovery diodes in the power supply.

I had the MKIII upgrade done a year ago. There is a noticable improvement in sound quality, that I believe was worth the $800 cost. While the advice to sell your MKII and buy a MKIII on Audiogon is economically sound, I should mention that ARC included a really nice screwdriver when they returned my upgraded SP-9!!!

There is an audio research sp-9 MKI for sale and would like an mkII or an MKIII , however is starting out with

a sp-9 mk 1 to a mkII worth it or go out and buy a mkII directly or sn MKIII?

First time here so Hello to everyone.