Ampdog
R.I.P. 23 June 2022
Perhaps the following statistics might accentuate one of many more misconceptions regarding valve amplifier run-in period. There are almost as many diverse subjective views on this as on cables, and ingrained views will not be altered; still.
I recently tested a stache of 50 x 6L6GCs, most new, some somewhat used. The test conditions were anode and screen voltage: 400V, Grid 1 bias: -33V. Specified value of anode current then: 70 mA. Voltage sources were stabilised, heater voltage not.
I noted the time taken to get to about 90% of the maintained anode current value fom cold, and the stabilised value after some 10 minutes.
All valves reachd the 90% mark within some 40 seconds, reaching stable current after about 60 sec. (The stable current was the value after some 10 minutes. This was not taken for all valves, otherwise I would still be busy.)
Brands were mostly Tung-Sol STR, with also several Electro Harmonix, G.E. and RCA.
Allied to this is the matter of 'burn-in time needed' for valve amps. Due to their nature such should take no more than a matter of minutes, as the power valves represent the greatest factor of possible change with time.
This as a simple observation, not as an invitation to elicit subsequent heated or otherwise exchange of subjective experiences.
I recently tested a stache of 50 x 6L6GCs, most new, some somewhat used. The test conditions were anode and screen voltage: 400V, Grid 1 bias: -33V. Specified value of anode current then: 70 mA. Voltage sources were stabilised, heater voltage not.
I noted the time taken to get to about 90% of the maintained anode current value fom cold, and the stabilised value after some 10 minutes.
All valves reachd the 90% mark within some 40 seconds, reaching stable current after about 60 sec. (The stable current was the value after some 10 minutes. This was not taken for all valves, otherwise I would still be busy.)
Brands were mostly Tung-Sol STR, with also several Electro Harmonix, G.E. and RCA.
Allied to this is the matter of 'burn-in time needed' for valve amps. Due to their nature such should take no more than a matter of minutes, as the power valves represent the greatest factor of possible change with time.
This as a simple observation, not as an invitation to elicit subsequent heated or otherwise exchange of subjective experiences.
