[matt99eo]

There is a ringing noise coming from my CHIME DAC (pre-built).  I turned off all other amps and can still here the ringing coming from the chime tubes NOT over speakers but from the actual amp.  what is it and should I be worried????

[dnewman]

There is a ringing noise coming from my CHIME DAC (pre-built).  I turned off all other amps and can still here the ringing coming from the chime tubes NOT over speakers but from the actual amp.  what is it and should I be worried????

Ahh, your tubes are singing to you!  Just how loud is it and is it following the
music itself?  Put differently, with some tubes you can when standing nearby
hear the higher frequencies of your music.  From my own personal experience,
it's always been fairly quiet and definitely dimished after 10 - 20 hours
on the tubes, in most cases going away entirely.  I've always figured it was part
of the break-in process as the getter finishes its job, collecting stray atoms left
over from the manufacturing process.  If you're not 95% positive it's the tubes
ringing, another likely suspect are one of the caps and would indicate a bad
capacitor.   While a faulty (or overloaded) transformer can ring, it would be
usually be a 120Hz or lower noise -- more of a buzz or hum then a ring.

In summary, if it's from the tubes, I wouldn't worry until you had > 50 hours
on them (or were approaching the return-to-merchant-for-refund date).
And even then, only if it was louder than a soft whisper.  On both of my Chimes,
all of the (NOS) tubes sang to me initially, quickly diminishing after a few
days to silence.

Dan

[matt99eo]

amp is one year old!  >>50hours on it.  Note this noise is not coming from speakers but from tubes themselves.

Buzz might be more of a correct word.... how  could I truly tell if it is coming from the transformer?

[dnewman]

amp is one year old!  >>50hours on it.  Note this noise is not coming from speakers but from tubes themselves.

Buzz might be more of a correct word.... how  could I truly tell if it is coming from the transformer?

While I won't swear to it, I suspect that it's okay to power up without any of the tubes in place.
There'll be very little current draw in that case but if you do hear the noise it will tell you that
it isn't the tubes.  If you power up with the tubes, then to locate the sound source you could
use tricks that auto mechanics use: a bell stethoscope or a piece of tubing held close to the
ear.  Failing that, you could briefly "muffle" the tubes with an oven mitt or something that can
withstand some heat for 30 seconds or so.  (You don't want the tubes to overheat either -- they
do need to dissipate their heat after all.)  You might want to only muffle one tube at a time.

And, if it is buzzing, it may be the rectifier tube or the transformer or both.  Hopefully, it's not
a component about to fail.  (The good news is that Jim has an amazing 10 year warranty!)

Dan

[hagtech]

It could also be dc on the ac line.  Sometimes this happens in unbalance household circuits.  A bit of dc voltage can shift the operating point on the transformer core such that it saturates in one direction.  At saturation, inductance drops and current goes way up.  This can cause the tranny itself to act like a speaker.

You might try outlets elsewhere in the house (different branches) to see if it makes a difference.

jh