When to go on "standby?"


Please tell me more. I looked through the manual and I did not see anything about a 45 minute waiting time.


Sec ?


Yes second. I edited the post.

David said

Bascom, or anyone,

Do the filaments come on instantly or do they ramp up to full voltage slowly? I assume that they ramp up slowly, no sudden surges. My experience is that tubes usually fail when turned on, without the ramp-up. Thanks the heater voltage is applied abruptly. Seems to work OK and I haven’t heard yet of anybody’s tubes not lighting.

The tube heater voltage is applied full on. I haven’t heard yet of anybody’s tubes going bad with open heaters.


stevem2 said

The BHK Pre by default goes through a warm-up that takes something like 45 second before becoming active. Not sure what all goes on during that period.

The time delay allows the tube heaters to come up fully AND the plate voltages to stabilize. The delay also gives the coupling capacitors that feed the solid state output stages to fully charge up as their outputs are shorted to ground during the time delay. Then, the coupling capacitor outputs are unshorted and the units can play. This is true of both the preamp and the power amps.


Thanks Bascom! Good to know what’s going on behind those blinking logos.


I usually listen to music daily (if it is OK with the wife) and leave my BHK250 in standby mode most of the time. If I am going to be away for an extended period, I will turn off the power switch. Am I shorting the tube life any significant amount doing it this way? When I am ready to listen, I will take the amp out of standby. Since I am one of those vinyl people it will take me at least 5 min. to begin listening to music. From what I read from Mr. King that should be adequate warm up time with further improvement as more time passes.


That approach should be fine.