Hi Bruce,
I can't envision any way in which that might cause a problem. Inductive kickback occurs because the voltage across an inductance (in this case, inductance in the transformer) is proportional to the amount of inductance multiplied by the rate of change of current. A very abrupt change in the amount of current flowing through an inductance can result in a VERY large voltage spike, albeit a brief one, if the energy has nowhere to go. If that spike occurs in the transformer secondary, it can result in an even larger spike in the primary, due to multiplication by the turns ratio of the two windings. But without a signal being present, none of that would happen.
The one exception I can think of to that (which doesn't apply to your situation) might be if the amp were turned on or turned off without a load being present. In that situation an internally generated turn-on or turn-off transient might conceivably be large enough and fast enough to constitute a potentially damaging (or long-term reliability degrading) "signal." But even that would seem to be unlikely in most (but not all) cases. One situation I can envision in which it MIGHT be a problem is if the amp has a B+ relay which abruptly turns on plate voltages to the output tubes some seconds after turn-on. That would result in an abrupt change in the amount of DC current flowing in the transformer primary.
Best regards,
-- Al
I can't envision any way in which that might cause a problem. Inductive kickback occurs because the voltage across an inductance (in this case, inductance in the transformer) is proportional to the amount of inductance multiplied by the rate of change of current. A very abrupt change in the amount of current flowing through an inductance can result in a VERY large voltage spike, albeit a brief one, if the energy has nowhere to go. If that spike occurs in the transformer secondary, it can result in an even larger spike in the primary, due to multiplication by the turns ratio of the two windings. But without a signal being present, none of that would happen.
The one exception I can think of to that (which doesn't apply to your situation) might be if the amp were turned on or turned off without a load being present. In that situation an internally generated turn-on or turn-off transient might conceivably be large enough and fast enough to constitute a potentially damaging (or long-term reliability degrading) "signal." But even that would seem to be unlikely in most (but not all) cases. One situation I can envision in which it MIGHT be a problem is if the amp has a B+ relay which abruptly turns on plate voltages to the output tubes some seconds after turn-on. That would result in an abrupt change in the amount of DC current flowing in the transformer primary.
Best regards,
-- Al

