No More upgrades to ARC LS25 Mk.1?

sell your Mk1 and buy a used Mk2, it will be way cheaper... they are built using two diffent tube set designs...6922 versus super tubes..

Edwyun: So now are you asking now which is better Mk1 or Mk2?
There are tons of threads on this...
Mk1 Warmer top, and a more classic ARC sound

Mk2 Better Bass, more solid state sounding compared to the Mk1 but also slightly more detailed, but some feel it's missing some of the magic of the MK1

Then you will have the third group that feels the ARC LS5 MIII it the best of both worlds...

My feeling is which one is going to have the best synergy with your system. Determining what you feel is lacking and what you want to improve or change will be the real question.

Search the archives for tons of comparisons.

I have been dissappointed (value and quality of tubes) in upscales tubes in the past... there are plenty of threads suggesting other tube sources.

I would keep your Mk1 to tame the tweeter, buy a JL Audio Fathom Sub F113/F112 since your 802's don't do 20hz bass anyway...) and dial in the bass, speaker placement and finally some room treatment(which will make a bigger difference than the more transparent Mk2)... oh yeah are you using balanced cables since your threshold is fully balanced? and do you have dedicated 20amp circuits to feed the threshold's!

Once again what do you want to improve about your system???? what do you not like?

You can buy a Mk2 and if you don't like it turn it for what you paid or a little less.... otherwise if you like the ARC sound, get an LS26