ARC tubes

Hi,I want know what is the major symptom when tubes of preamp are old.I am not happy with the sound of my system.
Cal cd player,ARC ls-16,Arc V-70 amp,Martin Logan Ascent.I have a doubt it`s my preamp(the sound is a little fuzzy and thin.Sorry for my bad english. Thank you, Jack
Jack- Usually, old tubes become noisey and their sound can become dull and closed-in. However, I've had 12AX7 tubes that went thin and edgy as well as noisey. Tube rolling can be a great way to improve the sound of any system, and depending on the type and quantity of tubes needed, it might not be very expensive. You might want to check with someone like Kevin at Upscale Audio about tube recommendations and available/cost for your equipment. There are other dealers as well, but Kevin is very knowledgable, and usually very responsive. I'd have trouble recommending going to ARC for replacement tubes as they tend to be very expensive. Good luck.
Jack; I would check with fellow audiogoner [ fletchj ] he is great one of the best he knows his tubes and has very good prices ships fast has great feedback . I have delt with him many times and have been very happy with his ideas. He can find any tube you want new old stock or used , used may be a way to try a few till you find one type you like or ask James what he thinks Marc aka lake513
I just re-tubed my ARC LS-15 with tubes from Upscale. They seem like nice enough people. They charge a little less than the factory. Good luck
The 6922's in your LS-16 are prone to getting noisy. Iv'e had good luck buying tubes from Audio Research, Leonard is a lot of help with problems with thier amps.Call him, see what he says about your problem .
I bought a set of Sovtek 6922 tubes from ARC two months ago and although they are reasonably decent, my ARC LS16 still doesn't sound as good as I would like. As more experienced tube users have suggested, my next step will be to try some NOS tubes, probably from Kevin Deal at If I'm still not satisfied, I'll sell the LS16 and not use a preamp at all!