New Dark Terror Hum with no signal
Posted: Fri Dec 07, 2018 3:56 pm
Greetings All,
I just bought a floor model, Dark Terror in a music store in Peru and living in Ecuador I have no warranty.
Long story short:
After getting back home to Ecuador and having the amp plugged into my Laney LH212H (8ohm) and playing for a short bit, I noticed that a hum developed even when there is nothing plugged in and all knobs are fully counter-clockwise. It is much louder than the typical hiss I'd expect from an amp. Switching the amp tp 15w, the hum changes a little and ever so slightly, louder. I can raise the volume while playing to drown out the hum and it sounds fine except for the low-level hum.
Things I checked:
Line Selector correctly set to 110v (originally it was set to 220V)
Cables - all my cables have been cross-checked
AC Power - relatively clean and none of my other audio equipment exhibits electrical noise.
Reseated all the tubes (valves) I noticed that the 12AT7 was a different manufacturer and not JJ as all the other tubes.
Regardless, since tubes are not readily available in my area, I ordered a complete set of JJs thru Amazon and I should get them late January.
Could it be a faulty line filtering Capacitor or a bad 12AT7...
Any thoughts would greatly be appreciated.
Thank you,
George
I just bought a floor model, Dark Terror in a music store in Peru and living in Ecuador I have no warranty.
Long story short:
After getting back home to Ecuador and having the amp plugged into my Laney LH212H (8ohm) and playing for a short bit, I noticed that a hum developed even when there is nothing plugged in and all knobs are fully counter-clockwise. It is much louder than the typical hiss I'd expect from an amp. Switching the amp tp 15w, the hum changes a little and ever so slightly, louder. I can raise the volume while playing to drown out the hum and it sounds fine except for the low-level hum.
Things I checked:
Line Selector correctly set to 110v (originally it was set to 220V)
Cables - all my cables have been cross-checked
AC Power - relatively clean and none of my other audio equipment exhibits electrical noise.
Reseated all the tubes (valves) I noticed that the 12AT7 was a different manufacturer and not JJ as all the other tubes.
Regardless, since tubes are not readily available in my area, I ordered a complete set of JJs thru Amazon and I should get them late January.
Could it be a faulty line filtering Capacitor or a bad 12AT7...
Any thoughts would greatly be appreciated.
Thank you,
George