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In the Forum: Off Air Audio
In the Thread: Tuners and digital noise from DAW, A/D and D/A
Post Subject: Lavry DA-924 + Sansui TU-X1 ~ Noise and interferencePosted by peter foster on: 7/21/2008
Dear Romy,

I performed the following tests:

Test 1.

Digital CD source OFF;
Digital Domain DD-2 processor OFF;
Lavry DA-924 OFF;
Sansui TU-X1 ON and set to FM output;
Custom tube amplifier ON volume HIGH;
ESL-57 speaker arrays ON;
Result: no interference and no noise detectable at 99.9 MHz or at 88-96MHz.

Test 2.

Digital CD source ON;
Digital Domain DD-2 processor ON;
Lavry DA-924 ON;
Sansui TU-X1 ON and set to FM output;
Custom tube amplifier ON volume HIGH;
ESL-57 speaker arrays ON;
Result: no interference and no noise detectable at 99.9 MHz.
Result: interference and noise detectable at 95.9 MHz but not at other frequencies between 88-96MHz.
Signal source: the interference and noise detectable appears to be an AM frequency.

Test 3.

With the interference and noise detectable during Test 2 then switch OFF the Lavry DA-924 and the interference and noise immediately disappears.

Notes:

I have high quality, directional FM and AM antenna system that allowed me to identify the interference and noise as an AM broadcast, even though the Sansui TU-X1 is set to FM output.

Is it possible that you do not have a high quality AM antenna system and that is masking the interference and noise making it difficult to identify as an AM broadcast?

Either way, one would hope that such noise and interference did not happen.

Test 4.

With the interference and noise detectable during Test 2 switch OFF the digital CD source so that the Lavry DA-924 begins its cycle to locate a digital source and interference and noise becomes immediately audible not from an AM broadcast but instead matching the cycling of the Lavry DA-924 trying to identify a digital source.

In summary, this is the first time I have run such tests.  When all components are switched ON and the Sansui TU-X1 tuned in to a FM signal with FM output or tuned into an AM signal with AM output there is no interference or noise.

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