Help preamp problem: overload?
OK, so I bring home my brand spanking new Bryston BCD-1 and hook it up (Audioquest Emerald balanced) to my Sonic Frontiers Line Stage 3.
I cue up the last movement of Sibelius's 5th, and sit back to bask in the glow.
So far so good, until the last minute or so of the piece, where it reaches its glorious, rousing climax. At this stage, I've got the preamp up pretty loud (72 on its numeric scale), but still within limits. Suddenly, the preamp starts going into standby and muting for 2-3 seconds on the loudest chords, then turning back on automatically and continuing until the next very loud chord. Did it three times in the last minute of music.
(You can tell when it goes into Standby, because the volume numbers disappear and are replaced by six dashes, and you hear a relay clicking.)
I repeated the experience exactly, to make sure it wasn't random dips in the power supply, but no, it went into standby at exactly the same points in the music again.
Then I backed the volume on the preamp down to 67 (a good average everyday listening volume for this recording), and it played through to the end without a hiccup.
So my question is: what was going on?
Was I driving the preamp into overload, and if so, should it be overloading at that kind of volume?
Was that a protection circuit cutting in and putting it into standby/mute? (I trawled through the owner's manual and it makes no mention of such a circuit or safety feature.)
Is there some sort of less-than-ideal synergy between the Bryston and the Sonic Frontiers (you'd have thought not, both being Canadian and all...)?
Does this mean that the tubes (all? some?) are aging (remember: there are lots of them, in the head unit and in the separate power supply). I put my ear to both channels of the loudspeakers with no music playing, and couldn't hear anything anomalous--no crackling, hissing, etc.
Suggestions, expert advice, consolation please. This has certainly taken away from some of that high associated with installing a new component...