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Orban 8200 analog/aes ebu output seems de-emphasized? mpx out = ok

F

fugazi

Guest
Hi all,

I have a small issue. My 8200 has good spectral balanced sound via the MPX output.
The analog and AES/EBU output however seem to have 3dB/octave ( from 3 khz ) de-emphasis.
I checked this with a noise sweep. In IO setup, the analog outputs are marked as "flat"
The mpx output does not have this de-emphasis problem and is set to 50uS pre-emphasis.

Is there a jumper i may have missed, or a setting?

Regards,

Evert
 
If you have your outputs set to "flat" then they are de-emphasized. It's the same signal that goes into the processor's signal generator (and later out on your MPX output). It's only kept in the L-R domain and de-emphasized to provide flat frequency response. You can set your analog/digital outputs to "pre-emphasized" which will turn the de-emphasis off and you can "enjoy" the pre-emphasized audio, if you want...

MPX output is always pre-emphasized because the complementary de-emphasis happens in the receiver.


Regards,
Goran Tomas
 
I understand your reply, but i have an extra amount of rollof above 3khz. De-emphasis after pre-emphasis should mean flat response!
But it's not, noise swept it rolls off after 3kc with 3dB/oct. So it's not transparrent compared to the mpx output ( heard/measured after de-emph/reception ).

So the "flat output" of the analog out and the aes/ebu is NOT flat after de-emphasis ( flat mode ).
 
Goran Tomas said:
Are you measuring this with the processor in proof (bypass) mode?


Regards,
Goran Tomas
Click to expand...

I was wondering the same thing...

R
 
Test was done with several presets. So, not in bypass mode ( no proof , but live presets ).
I have no clue what is wrong, since the mpx's frequency response output is as flat as can be ( after demod & de-emph ).
Whatever preset i chose, i will see a 3dB/octave rolloff from 3k. This is clearly a de-emph, but i have no clue why this is.
 
IIRC the proof mode is in a separate menu, not a pre-set. If that's the case, you'll get the same sound regardless of pre-set, as proof mode overrides them all.

R
 
fugazi said:
Test was done with several presets. So, not in bypass mode ( no proof , but live presets ).
I have no clue what is wrong, since the mpx's frequency response output is as flat as can be ( after demod & de-emph ).
Whatever preset i chose, i will see a 3dB/octave rolloff from 3k. This is clearly a de-emph, but i have no clue why this is.
Click to expand...

It's not clearly a de-emphasis. I don't think the 8200 even HAS a de-emphasis circuit. It either adds pre-emphasis or not.

And why are you running 50 u sec pre-emphasis? THAT will give you less highs than you are supposed to have. Why don't you switch it to the USA standard of 75 u sec?
 
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