09-21-06: Bartokfan
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.
You agree? Because you have also compared the sound after having improved the power supply and after having changed the capacitors, or because this has made the most significant difference of the other tweaks you have tried thus far?
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.
This is a tweak. Not a mod. You asked about mods.
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.
I'm suspect of your tech guy's expertise. Changing caps generally results in a lower noise floor and better resolution. This is not simply a flavor change, although it certainly results in a change in the sound of the player by reducing noise. Perhaps he's offering lowest cost alternatives at your request.
4) I guess power cord. Though I'm not much a believer in cord differences.
Yet another tweak. Not a mod.
If you want info about tweaks, then ask about tweaks. You asked about mods.
Regarding the info in this thread, which has been consistent, I would suggest you do some thorough research by carefully reading the level of modifications offered by Modwright, Empirical Audio, Reference Audio Mods, and others. All these providers begin with power supply upgrades and move on from there.
On the other hand, if you're intersted primarily in tweaks, then there's a boatload of info in the threads on this topic.