I have a 1997 HRD which initially had the thermal fuse blown on the PT. New Fender PT and tubes installed and resoldered tube socket connections on tube PCB. Filter capacitors checked out okay and with the bias set the amplifier appears to work as it should. I have noticed that the PT gets warm to hot when the amp is pushed hard though I haven't actually measure the temp with the IR thermometer. I'm not too familar with the HRD and wonder if I still have an issue? Do the PT run hot on these models? Dumb question(s) but what can make the PT run hot (assume that that you aren't trying to source a dead short or there is no ventilation in the room) or what temperature would be normal if the amp is played hard for 20-30min in a room which is at 68-70F?
The customer also believes that this amp has more 120Hz hum when they use the drive channel. This may just be a cable/guitar pick up design issue and the gain of the amp is pretty high in the "more drive" mode? I'm treating this as a separate issue from above. I'm going to get another HRD to compare the hum level between the two amps. Is there a way to objectively answer the hum question? The amp does not have any AC hum present without a cable in the input and yes moving the guitar does make a difference though it doesn't drop enough to make the customer happy.
The customer also believes that this amp has more 120Hz hum when they use the drive channel. This may just be a cable/guitar pick up design issue and the gain of the amp is pretty high in the "more drive" mode? I'm treating this as a separate issue from above. I'm going to get another HRD to compare the hum level between the two amps. Is there a way to objectively answer the hum question? The amp does not have any AC hum present without a cable in the input and yes moving the guitar does make a difference though it doesn't drop enough to make the customer happy.
Comment