Mods in Tube players: list in order

From what i'm gathering from the local tech guy here in Baton rouge, he feels
1) opamps: easy to change/pop out, low cost/$25 each, and make the most significant difference. I agree, it has made the most difference.

2)Tube roll. Not so easy, as each tube will offer noticable character. I'm working on locating a set right now. Can be costly as if you buy used and don't like them, your stuck. So this tweak is risky.

3) caps changed. Though the tech guy feels this is more of a "flavor" change than anything of significant. And its abit costly. Good caps/labor =$200. I'm hesitant here.

4) I guess power cord. Though I'm not much a believer in cord differences.

Thanks Tvad, I'll look at the 3 sites for mods.
Yes tweaks are another issue. The caps I was refering to are Mundorfs at $50 each. I may go with it.
I'll keep you guys posted on the mods I make.

Ken just changed out the other 4 opamps and ahs made another significant boost in this true balanced design.
First we changed 2 of the 6 opamps, and now the other 4.
I'm listening to Mississippi Blues cd, the vocals are super realistic, instruments are clearly separated. The bass has power to where i can now only turn the Jdais up just past 9 O'clock. Any more with rattle the dual 7 inch Seas mids in the Thors.
Somehow new higher grade opamps boost the fq's, allowing cleaner higher resolution.
I
'll find out the name of the opamps Ken used.
My next move may be to upgarde these Romlex commercial wires I bought at Lowes for $25. I'd like to look at some silver/copper combo, see if i can get some improvment in the upper hz's.

Well I had the other 4 opamps replced in the 17. That makesa total of 6 changed. My tech guy said the original are $2 opamps, and he used ones that were "la creme de la creme" costing $25/each.
I did notice a significant gain as the first 2 were changed, these were the 2 most important I believe. Now the 4 behind the 2 manis were changed and sure enough added benifits in the soundstage can be heard.
But as I say the complete 6 new opamps have made vocals seem cleaner, much more live like, bass is deeper. Power has been increased, as i play the Mississippi Blues cd, the drums now rattle the midwoofers and this just at 10 o clock vol.
At present the amp is the weak link in my system. The Thors have more potential, the Cayin has more potential.
My tech guy does not feel its necessary to change the caps to Mundorff, as the stock caps are already superior quality.
I will try a quad of sovteks to see if they beat the stocks.