2. amps-preamps
  3. 1245249128

my tubes are hissing non - stop


just upgraded from a STEREO bat vk55 to a pair of bat vk55 mono blocks whereby am pairing with a bat vk32 pre amp.

initial 7 days of listening was almost hiss / noise free until recently where the hissing sound was audibily louder and as i turn the volume higher, i began to hear popping sound.

a few observations

1. the hissing sound remains same level regardless volume is high or low.

2. hissing sound comes on only after pre amp is turned on. if only power amp is on, no hissing sound...

3. tapping (even slightly harder) on power amps/tubes in the power amps did not bring about any change on the hissig sound. does this mean that the power amps is not teh culprit?

4. dun think its the quality of the current as the set up for the transformer/multiplugs did not change at all.

5. i have not inspected the tubes in the pre amps shld i and how?

this is suppose to be an upgrade but ....

am at a loss....is this a current issue or a tube issue and is it an issue in the pre/power ... looks v tricky to troubleshoot
art80342
mike_in_md
84 posts
 
Try replacing the tubes in the pre. Sounds like the place to start.
art80342 OP
65 posts
 
Generally - can't the a faulty tube in the power amps make such a hissing sound even before pre-amp is turned on?
cyclonicman
693 posts
 
This is a very common occurrence when tubes are on their way out. Sounds to me like your preamp tubes need to be replaced. Until the preamp is turned and there is a line level or phono signal, the power amp should be quiet. Since you just upgraded, you should contact the technician that serviced it and inform him of this situation anyway.
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