[tbuddha]

I have been burning-in an X-Cans v.3 amp for over 100 hours now. It is in my office rig, which I leave on overnight and on weekends with the same dynamic classical CD repeating at approximate listening levels. I should note that I am also burning-in new Senn HD-650s.

This morning I noted that I seem to have lost some of the gain from the amp. I have to turn the volume up a bit to get the same levels. Not a great amount, just about 15 percent or so. The quality of the sound seems just as good. Does anybody have any idea what might be going on?

 

[sacd lover]

I have noticed sometimes when you burn an amp in the sound smooths signifigantly. Then because the sound is not as raspy or bright the volume level seems lower. Once this occurs you have to turn up the volume a little to get the same subjective volume as before. My new mpx3 is doing this right now. Along with your amp, the tubes in your amp will break in too, and this may also be a factor. I think your amp is ok.

But I am not a big believer in leaving an amp on for extended periods. You want to break it in; not break it. IMO, much of the actual break in results from the repeated heating and subsequent cooling of the internal parts and tubes. I like to leave the tube amp on for 8-10 hours, then let it cool down, and then repeat this cycle over several days until the sound stabilizes. I dont like leaving components on for days at a time, and I never leave a tube amp on when I leave the house. Lots of people break in components just as you are doing, so this nothing unusual. But again, IMO, this is a bit risky; especially with a tube amp. Be safe first.

 

[gort]

It can't be that bad. I rarely go over 54 (about 1/4) on the dial on my X-Can V3 driving my HD600. Jazz and classical CDs goes to about 40 (1/3) max. Because I was busy trying out every CDs (they all have slightly different volume levels) I can get my hands on, gain loss you mentioned must of escaped me.

 

[tbuddha]

GORT - Thanks. When I started, I was listening at around 54 dB. Now I'm down (up?) to the vicinity of 40 dB on the dial for everything but the most dynamic classical material. Again, I am driving HD 650s, so I'm pretty sure the impedance is the same as yours.

SACD Lover - thanks for your reply also. The X-Cans is the first tube gear of any kind I have owned. I know there is a line of thinking that says that the real cause of wear and tear is the heating and cooling during the on-off process. It's logical that could also contribute to the positive effects of burn-in. What makes me wonder is the fact that it seems to me Musical Fidelity must have omitted a power switch for a reason.

 

[Harty]

I also noticed loss of gain when I burned in my replacement cable for my Sennheiser HD600's, my amp was properly burnt-in at the time.

Best wishes,

Paul.