Since I bought my s/h HRD iii last November there's been a bit of intermittent noise from one or more of the valves in the clean channel (I don't use the dirty channel). Sounds like a quiet scurrying windy, hissy, rumble. Nothing serious but I thought I'd locate it and swap out a valve or two.
Plugging the guitar into the return socket ("power amp in") eliminates the noise, so I concluded it's not an output valve.
Swapping out the 12AX7 in v3 and the noise is still there. Swapping out v2 and, touch wood, the noise is gone. But how can this be? I thought v2 was for the dirty channel?
Thoughts?
Comments
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
The other main problems a preamp valve can have are microphonics - usually whistling or 'ringing', but sometimes lower frequencies - caused by the internal parts having come loose and effectively amplifying physically vibration - and hum, which is usually caused by breakdown of the insulation between the filament and the cathode.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein