Tube Amp Help/Problem


I have a new preamp. I notice when I turn the volume past 11:00 there is a very audible loud hiss.no hum. It increaes as I turn up the volume and at 11:00 is very audible from a listening position of about 7 feet away with no music playing. Is this a white noise issue? I tried switching the tubes to different positions (12AX7's) and no change/moving cables/interconnects away from power cords etc. This has a phono section built in which is exhibiting this issue. The other inputs do not hiss nearly as much or very little even with the volume cranked up which leads my to believe its not an impedence mismatch with my amp. I have read some of the posts that state they can hear hiss if they put thier ears next to the speaker. Mine is very audible 7 feet away. This is my first tube preamp so maybe this is normal.
autodexr

Showing 1 response by rodman99999

At what position is your control during normal listening/loudest volume? If this noise is present at normal volume control levels: As Newbee stated, you may be using noisy tubes or have a cartridge output/phono amp mis-match. Tubes purchased for pre-amp/phono gain stage use should be certified low-noise, or their noise will be amplified exponentially by the time it gets to your speakers. If you are cranking the control way above normal: chances are you have a very acceptable signal to noise ratio at listening levels.