Need help w/ Audible Illusions M3A


First off I'll say that I'm new to owning tube gear and appreciate any advice Audiogoner's can give. I own an Audible Illusions M3A and it has developed some "hiss" in the right channel. It's loud enough to hear when the system is idling from 12 feet away, and therefore fairly annoying. It doesn't sound as though the performance is comprimised any other way though. Time for new tubes? If so, any suggestions?

Thanks in advance,

Scott

associated equipment:

Audio Research D-200
Theta Data basic
California Audio Labs Sigma II
Vandersteen 2CE
Synergistic/XLO cables
Tice Solo
trailrunner1
I'm running a L-1 with a 4-ch Theta Dreadnaught biamping a pair of Vandersteen 3A Sigs. I use a Meridian 508-24 for CD sources.
Trailrunner:

You can pick up low noise Reflector 6h23/EB's from ATSI Tube for aprrox. $45-$50/matched pair (not certain of the current price). They are dead quiet and work quite well in the 3A.

I tubed my friends 3A with ATSI's in the line stage and Siemens 7dj8/PCC88's in the phono stage, over a year and a half ago (both pairs are still going strong).

I no longer have a source for the 7dj8's, but two matched pairs of the ATSI 6h23/EB's will also work.
yes the gain switches are in the preamp. I am running amperex bugle boys. You will need to make sure that you are flipping the correct switches because there are 4 switches two for the gain and two that are for by-passing the capacitors.
Well I think you got bad info on the bugle boys because mine have been in my M3A for 2mos. and still sound as good as the day I put them in. I do use a set of pearl tube coolers, also I leave the pre-amp on at all times. I also have had success with telefunken tubes, but I thought that the bugle boys sounded better. just MO
I guess I should list my system
SONY X779ES - CD
AI MOD 3A Pre
MCINTOSH 2100 Amp
Montana DPS Speakers
Stealth Audio Solid Silver interconnects
Magic Power Cord
Panamax Line Conditioner