[Early B.]

My buddy has a nice system consisting of a tube amp, tube preamp, DAC, and transport. Recently, he has been experiencing loud popping sounds after a few minutes of powering up. It sounds like intermittent popcorn static. This sound comes through the right speaker. To troubleshoot, we swapped the left & right tubes on the amp and preamp, but the sound remains on the right side. It occurs when no music is playing, as well. The weird thing is that the popping sound doesn't occur until the system is warmed up.

How should we proceed with troubleshooting?

Thanks.

[FullRangeMan]

My buddy has a nice system consisting of a tube amp, tube preamp, DAC, and transport. Recently, he has been experiencing loud popping sounds after a few minutes of powering up. It sounds like intermittent popcorn static. This sound comes through the right speaker. To troubleshoot, we swapped the left & right tubes on the amp and preamp, but the sound remains on the right side. It occurs when no music is playing, as well. The weird thing is that the popping sound doesn't occur until the system is warmed up.

How should we proceed with troubleshooting?

Thanks.

In the late 1980s I had a similar prob it was a pop that danced according the music in the tweeter, it was a defective diode in the pre-amp.

[richidoo]

This happened to me once in a preamp on an AC demo tour. Everybody was raving about it, but when it arrived to me it was making loud intermittent static and crackling noises. I returned it to the mfg/tour host who determined that it was a tube cathode resistor that had cracked (shipping?) but it looked fine externally. He said it was rare but he had seen it before.

[Doublej]

Swap the Left and Right interconnect between the preamp and amp. If the static switches sides the problem is either in the preamp or upstream (transport or DAC). If the static stays in the right channel it's either in the amp downstream (speakers).

Go connection by connection until you have identified the faulty component.