A few weeks ago, I discovered that the left speaker leads became disconnected while the system was running. The time duration that this occurred was at least thirty seconds, maybe as much as one minute. The system was running at low volume, and upon discovery was shut down.
Since then I have begun to notice some low frequency noise. I do not think that it was there before, or maybe not as pronounced, as the amp was very quiet when I first completed. The noise, or hum, presents at soft passages, and is hidden completely by nearly all music played at low to moderate volume. It is not a 60-cycle hum.
Did I do any damage, if so, what?
Speakers are Heresy II's, with recently replaced Crites caps. The completed kit ST70 has been running on the supplied power tubes since completion 18 months ago +/-. I use it often, so the tubes may be aging (?)
Thanks to all, Paul