Still in the process of troubleshooting a problem. My left channel drops out randomly, sometimes as long as 15 minute intervals but only with classical music coming from a digital source. Headphones play fine coming out of the amp, so it’s not the pre-amp or digital source.
Triggers that immediately precede the problem: extra-musical details such as bow noises and key pads on woodwind instruments, and in general, music with a diversity of timbres, i.e. an orchestra.
The problem doesn’t occur on analog and doesn’t occur on digital unless it’s complex orchestral music.
Ready to throw in the towel because thought I solved this problem already by taking CD player in to shop with the exact same issue, except it was definitely the CD player.
Is it the amp? Speaker crossover? Bad power?
Will be swapping speakers and cables but just so curious about the genre specific issue and if anybody has any interesting ideas about the source of the problem. Speculation allowed.
Since you are losing all of the sound if it were in the speaker it would need to be the main + and - paths based upon the design. I would methodically apply the channel switch technique in this order:
Speaker connections at speakers
Speaker connections at amp
Amp input connections
Preamp output connections
Proceed until it does not switch and you’ve found your fault. If it still switches after 4 it can be in the preamp as the output stage may not feed the headphone stage.