What would you change?

I have a system consisting of an EAD Ultradisc as transport, a Benchmark DAC, an ARC LS-15 preamp, Gamut D200 amp and VR4jr speakers, and find I am hearing some "grunge", for a lack of a better word, in the leading edge of vocals. There seems to be an edge to the sound, not a sweetnes , and I am seeking some ideas of what I might change to rid the system of the sound.
I realize the description is a bit week, but all comments will be appreciated.
Specifically, it what I'm hearing related to the amp/preamp somehow, or something else. Hope this is posted in the appropriate category.
I notice that you also have a analog source. Does the "grunge" you described also appear when you play LP?
Change pre-amp tubes...
There is nothing in the gamuts sound that I would remotely call grunge. Look elsewhere assuming the amp is functioning properly.
That is a very cool system. I think you have "outgrown" the nordost interconnect. Empirical Audio Holographic interconnect has really made a nice change in my system, getting rid of that leading edge digititus( for lack of a better word) without loosing the musical transients.
I would suggest power conditioning, your present system is not the cause of the glare and/or edge.
Try moving the speaker position here and there an inch or less at a time. Also try changing toe angle. You didn't mention your room and if there's any treatment but treatment can help alot, especially with first reflections. I've found the first reflections can cause what you are describing.
If you haven't already done it try putting your gear on a dedicated AC circuit - 20 amp breaker, dedicated wiring to a hospital grade outlet and proper grounding. Removing all non-audio loads from the line cleans up the incoming AC and you will be amazed at what that simple upgrade does to improve sound quality. If you're in a condo or can't run the circuit you may want to try one of PS Audio's Power Stations. I highly recommend the P-500.
As mentioned, a dedicated line and some power conditioning should help. A balanced power piece or a sine wave generator, like from Exact Power. Also, I would consider changing all of the wires and power cables, before replacing any equipment. Might be just the tune up you need.
Try cleaning all connections. The difference it can make is like investing in the multi-buck wires that most of us object to. Also the wires can develop an electrical field that may degrade your sound. Try wiping with some cleaning product like Pledge lemon or other appropriate electrical wire cleaning agent available at the electronic supply house.
Clean all connections.

As stated earlier, check your tubes.
I've a LS-15 and put in some Ediswan tubes. Real smooth.
Thanks for the suggestions. I'll try a good cleaning of all connections, and the tube sockets. Time for the ProGold treatment!and the Nordost.
I've got a dedicated 20 circuit, actually two of them ,but power conditioning might help. I'm in an rural area and have no interferance from condo-type problems, or neighboring buildings, but other than that I may still have power probs and not know it.First a good cleaning. Thanks for all the helpful advice.
Stop re-using that Q-tip you got at the beginning of the year. Splurge for a box! They're cheap!

LOL.Ya mean I need to bust the budget again this year???...Damn!!..No Ferrari again this year!!
So, did you get rid of the grunge by replacing the Benchmark with GNSC Opus21?
loose the benchmark it is not up to snuff with the rest of your gear
As a matter of fact, I did get the GNS Opus, and am pleased as punch!!

I owned a GamuT D200, imho it is bright, edgy and only works fine on very easy to drive speakers.