Owner`s manual

Ringing or 'bell' sound when operating volume (microphonics): Usually the 12AU7
in the line stage is the most likely to cause this fault. The 12AT7s in the
phono section can do this too. If the MP3 is OK on AUX inputs, but rings on the
phono, then a 12AT7 is most likely at fault.
LED lit up continuously: Check the 6SN7 in the channel associated with the LED.
If only channel is lit, try swapping the left and right 6SN7s. The lit LED
should now be in the other channel. If the LED remains lit, replace the TLO82
opamp ICs beside the associated 6SN7. They are in sockets and the ICs are
available from Radio Shack or other electronic supply houses.
NEVER, EVER, USE TWEEK ON TUBE SOCKETS! Tweek is an organic compound and is
capable of forming resistance paths if it breaks down.
If none of these suggestions help, please contact your dealer or Atma-Sphere
Music Systems, Inc..
MORE TIPS AND TWEAKS
You can reduce the noise level beyond the specification by using low noise tubes. When
ordering from any source, specify tubes for a differential circuit (matched tube
sections). We have found that the 12AT7 at the input of the phonograph section, and
the 12AU7 at the input of the high-level section are perhaps the most audible.
We recommend line conditioning. The fifth harmonic of the powerline frequency has been
shown to be far more problematic for good sound then all other types of powerline
problems (RF, spikes, etc.) put together. Be sure that the conditioner you use can
filter line frequency harmonics, particularly the fifth (300 Hz on 60Hz line).
We have found that the power cord can have audible effects! A good cable is
recommended.
The Sound Anchors equipment stand is the finest we have seen. It is highly
recommended. Use it in conjunction with the Ultra Resolution Technologies vibration
damping platform. NavCom Silencers or other anti-vibration pads are also recommended.
Tube damping rings are highly recommended.
A cartridge with .3mv or more is recommended, unless you have the stepup transformer
option.
NOTES