I have an older DSL100. I just got it back from the local shop because it had a serious bias drift. The shop had it for almost 3 months. He repaired it (upgrading some resistors in the bias circuit) and told me he burned it in for 2 days and the bias is stable. I took the amp home and plugged it into my cab and it sounded fantastic. I was very happy.
For about 15 minutes that is. After 15 minutes of playing the volume fades out to silence. I can still hear the amp being on.. there is just no output. If I shut the amp completely off for 5 minutes and turn it back on its back to normal for about 15 minutes and then it does the same thing. The best way to describe what it sounds like when its fading is it sounds like the standby switch was switched on. Of course.. the amp has new tubes and none of them are glowing any different from each other. There is also no crackling or popping or excessive heat. Any ideas? I just spend $235.00 to get the bias fixed on the amp and now I have this problem.