Hi Jan thanks for chiming in.
I confirmed this on my very good setup at home. To confirm it I changed the output stage gain, to give me the same listening levels for both 48 and 64 digital domain volume settings.
These guys in this 6 Moons interview/review also comment on "Bit Stripping" 2nd page at the start
http://www.6moons.com/audioreviews/sotm2/1.html
Cheers George
I confirmed this on my very good setup at home. To confirm it I changed the output stage gain, to give me the same listening levels for both 48 and 64 digital domain volume settings.
These guys in this 6 Moons interview/review also comment on "Bit Stripping" 2nd page at the start
http://www.6moons.com/audioreviews/sotm2/1.html
Cheers George
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That assumes that the digital volume control operates on the incoming 16 bit data. Not always the case.
Here is something DEQX also says.
"Difference between HDP-4.0 and HDP-Express MKii
The HDP-4.0 uses an Analog Preamp stage, the HDP-Express uses a Digital volume control. The volume is controled in the digital domain of the DSP Processor, not the post DAC analog volume like the HDP-4.0. One thing that should be noted is while the volume is digital bit stripping, it only occurs below about –20dB on the volume slider. If the six analog output gain jumpers are set on the main board you can balance the output level to keep the volume above –20dB and avoid bit stripping."
Cheers George
"Difference between HDP-4.0 and HDP-Express MKii
The HDP-4.0 uses an Analog Preamp stage, the HDP-Express uses a Digital volume control. The volume is controled in the digital domain of the DSP Processor, not the post DAC analog volume like the HDP-4.0. One thing that should be noted is while the volume is digital bit stripping, it only occurs below about –20dB on the volume slider. If the six analog output gain jumpers are set on the main board you can balance the output level to keep the volume above –20dB and avoid bit stripping."
Cheers George
Also from Bricasti, on their new dac, they want you to use their digital domain VC at the top part of it's level, and give you analogue pot set screws on the output so you can match it to the poweramp/s
"Unusually for consumer gear and more prevalent in the pro area,
each XLR output features a small back-lit set-screw receptacle
which allows fine-tuning of the output voltage gain from +8 to
+22dBm. This has obvious benefits when matching gain to a
power amplifier — using the M1 on its higher output levels avoids
bit-stripping."
Cheers George
"Unusually for consumer gear and more prevalent in the pro area,
each XLR output features a small back-lit set-screw receptacle
which allows fine-tuning of the output voltage gain from +8 to
+22dBm. This has obvious benefits when matching gain to a
power amplifier — using the M1 on its higher output levels avoids
bit-stripping."
Cheers George
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Do please set out an alternative case where the DAC's not being given no signal in the 4 MSBs, I'm all ears.
Working with 16 bit media file, processing in something like 32 or 64 bit float or 40bit fixed, dither and truncate to 24 bit and feeding that data to a modern 24 bit DAC does not produce any kinds of problems as discussed in this thread.
The only time all 16 bits are used ever is when you have information at 0dBFS.. is that what you want? I want dynamics and that means most of the music will live in 8 bit, 10 bit, 12 bit or whatever. It does not matter as long as the dither or analog noise from the DAC is inaudible.
If audible effects exists of the kind as explained by OP the math is impemented with flaws.
Low level sounds does not need to be played back with the same wordlength as higher level sounds.
In fact, a well implemented digital level adjustment will have higher dynamic range/lower noise floor than all or most analog alternatives. Analog also means addition of noise, but more than you get with digital. Also more distortion is added allthough a SOTA analog solution can have insignificant distortion.
The only time all 16 bits are used ever is when you have information at 0dBFS.. is that what you want? I want dynamics and that means most of the music will live in 8 bit, 10 bit, 12 bit or whatever. It does not matter as long as the dither or analog noise from the DAC is inaudible.
If audible effects exists of the kind as explained by OP the math is impemented with flaws.
Low level sounds does not need to be played back with the same wordlength as higher level sounds.
In fact, a well implemented digital level adjustment will have higher dynamic range/lower noise floor than all or most analog alternatives. Analog also means addition of noise, but more than you get with digital. Also more distortion is added allthough a SOTA analog solution can have insignificant distortion.
The 4 MSB's per se is not what I am questioning. It is the assumption that it is always 4 out of 16.
It's even better... in favour of a digital solution..
1) Feed a signal out from a DAC and measure noise and distortion.
2) Reduce level with 20dB or so and measure noise and distortion again.
If you compare the two, the noise floor will be basically the same (dominated by DAC analog noise) at some inaudible level but distortion will be lower. Often significantly lower.
Harmonic distortion may be reduced by 20dB. Using a fully analog level control will increase distortion, not reduce.
I don't know if anyone suggested this earlier in the thread but here's a test to see if your CD-player or DAC is ok regarding the implementation of the digital volume/level control.
Use a good audio editor to reduce level with the same amount as you experienced problems with the integrated volume control. Render to 24bit with dither and compare (16bit obviously if you have a CD-player with no digital in).
Bring both files into some editor to check gain to make sure you compare level matched files.
I have experienced digital volume controls that sound bad (flat, loss of dynamics, muddy) and those that are audibly transparent (to me).
1) Feed a signal out from a DAC and measure noise and distortion.
2) Reduce level with 20dB or so and measure noise and distortion again.
If you compare the two, the noise floor will be basically the same (dominated by DAC analog noise) at some inaudible level but distortion will be lower. Often significantly lower.
Harmonic distortion may be reduced by 20dB. Using a fully analog level control will increase distortion, not reduce.
I don't know if anyone suggested this earlier in the thread but here's a test to see if your CD-player or DAC is ok regarding the implementation of the digital volume/level control.
Use a good audio editor to reduce level with the same amount as you experienced problems with the integrated volume control. Render to 24bit with dither and compare (16bit obviously if you have a CD-player with no digital in).
Bring both files into some editor to check gain to make sure you compare level matched files.
I have experienced digital volume controls that sound bad (flat, loss of dynamics, muddy) and those that are audibly transparent (to me).
I asked over at the other place also about "bit stripping" with digoital domain VC's.
And Thorsten Losech of AMR has quickly answered.
"Turn down the volume even the tiniest bit using the digital volume control and the sound quality to a massive hit."
DIYHiFi.org • View topic - Digital Domain Volume Controls and "Bit Stripping"???
Cheers George
And Thorsten Losech of AMR has quickly answered.
"Turn down the volume even the tiniest bit using the digital volume control and the sound quality to a massive hit."
DIYHiFi.org • View topic - Digital Domain Volume Controls and "Bit Stripping"???
Cheers George
I am always very weary about these all-encompassing general statements. I have yet to find one that is true as it is presented. No value.
Jan
That line screams ignorance miles and miles.
Did you do the test I outlined?
Did you read my post and did you understand them?
Do you only want square waves and brick wall limited music?
Do you hate Ravels Bolero?
Bit stripping is nonsense from people not understanding half of the technology relevant to the discussion.
I was thinking of this:
Pan said:
Audacity and Reaper can be used for this. If you can detect the processing of these softwares one option is to export a 32bit file and do the dithering and truncation with something like SoX or iZotope.
What I meant is that all music will exercise the smallest bits (LSB and up) but not necesarily the biggest (MSB). Only when something is full trottle at 0dBFS we will actually use all 16bit or 24bit of the PCM format. This means that the supposedly horrible results of coding a signal at say 12bits (or reducing to that approximate level with digital VC) and below should give the same results for anything in a recording that is not FFF.
Me too!
It's pretty dynamic usually. Crest of 20dB or more. This means that the average level is around -20dBFS = less than 13 bits if we are talking redbook. A significant time the music will live in even less than 13 bits. This still sounds good on a good recording... which gives?- Status
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