Replacing capacitors for my ARC VS110

Just remember if you ever send it in to ARC, they will insist on stock caps or will NOT repair it otherwise.
For ARC fans, keeping it stock is a matter of faith.
If you really want to mod a tube preamp.. Go for a Counterpoint. Mods galore..

If you appreciate an uncolored/transparent presentation; V-caps are the hot ticket(http://www.v-cap.com/teflon-capacitors.php). auriCAPs are another excellent, less pricey, alternative(http://www.soniccraft.com/auricap.htm). There are a number of oil impregnated caps out there, if you like a warmer/softer presentation. Some VERY good things to know/observe, when installing capacitors: (http://www.audience-av.com/capacitors/a_applications.html) BTW- those notes apply to any film type cap. Most manufacturers can tell you how to discern which is their outer-foil lead. ie: (http://www.v-cap.com/installation-notes-2.php) Have you tried a non-stock power cord, and HI-FI Tuning fuses, yet?

The caps that are suitable for your amp are the ones Audio Research installed during manufacture. I have heard these so called upgraded Audio Research amps and preamps and I can assure you it is not an upgrade. It's hard to beat the engineers at ARC.

Thanks for the suggestions. I will keep this in mind and probably just leave things as it is.

If anything the output coupling caps will give you the most bang for the buck sonics wise. Dueland Alexandras are a good choice as they are paper in oil with a rich character.
I own two AR amps, an DR250 mk2 and Classic 60. Before you try caps try tubes. A nice pair of Telefunken or Mullard input tubes just may do the trick for you. Or if you use a tubed pramp the output tubes change will allow you to get a different flavor. Have fun trying.