02-07-2014, 05:23 PM
Most times the high voltage caps are across the primary of the output transformer where they can see inductive transients. When you have a push pull transformer the audio peak voltages can be twice the B+ supply.
If the output tubes are overdriven into cutoff, the inductive spike can reach very high voltages. This is one of the purposes of the cap as it forms a RLC circuit which effectively damps the resulting transient.
If the output tubes are overdriven into cutoff, the inductive spike can reach very high voltages. This is one of the purposes of the cap as it forms a RLC circuit which effectively damps the resulting transient.