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XXHighEnd > Ultimate Audio Playback > XXHighEnd Support > How much digital attenuation?
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Author Topic: How much digital attenuation?  (Read 5836 times)
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fralippo
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« on: June 18, 2016, 06:41:47 pm »
I use XXhe with a diy non-oversampling multibit dac directly connected to my tube power amps, no preamps. Volume control is only performed via software, my hardware was developed in a way that I hardly need to attenuate any album by more than 10db or so.
Recently I had to attenuate more (for a test in a different system) and SQ was much compromized.
I now wonder if I'd better to change strategy and add a "normal" attenuator somewhere...
What's maximum digital attenuation level suggested for best possible quality?
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PeterSt
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« Reply #1 on: June 18, 2016, 06:48:26 pm »
Hi Fralippo,

I myself would easily go to -27dBFS without being aware of compromises (and it measures good enough as well).

In the end this is not easy to judge for me, because I never play at -10dBFS or so. Maximum would be -15dBFS.

Technically (for a 24 bits DAC !) it should be OK up to -48dBFS. This is software wise. What your DAC makes of that I can not know ...

Are you sure it is not some other source causing the degratation ?

Quote
I now wonder if I'd better to change strategy and add a "normal" attenuator somewhere...

If you think it sounds good after trying.
But personally I would not even try.

Regards,
Peter
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fralippo
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« Reply #2 on: June 18, 2016, 07:06:20 pm »
Hi Peter,

thanks for lightning fast reply!
DAC ICs are PCM1704K chips bought by a safe source, they're directly connected to the JLsounds I2SoverUSB board that's bit perfect and has LJ24 output (via software). I don't think this "simple" and straight hardware should be connected to SQ issues.
Anyway soon I will repeat this test on a new DAC I'm completing - much similar but much more sophisticated and with different boards - and will check if digital attenuation "problems" will still be there. I will let you know.
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