Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
It's actually quite difficult to understand exactly what your test involves, but looking at your linked page, I get the impression that you are proposing this: 1. Take a file with a very low level signal (eg. -80dB). 2. Play it without digital attenuation, and increase the analogue gain until you can hear it. 3. Now apply some digital attenuation and increase the analogue gain to compensate (so the overall level is the same). 4. There will be an audible difference. Is that what you're saying? If it is, then my response is: hey, no sh*t, Sherlock! Now tell us something we don't already understand. And then try and justify how this extremely unrealistic scenario relates in any way to the normal listening experience. Presumably you tried this test with a signal at normal levels (ie. not artificially low) and failed to hear a difference? What does that tell you about the real world? mswlogo;538748 Wrote: Your ears, system, room, amp, dac etc. have a total fixed dynamic range and by using digital attenuation you are sliding the music out of that range. And when you use analogue attenuation you are sliding the music out of that range. -- cliveb Transporter - ATC SCM100A cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
It's actually quite difficult to understand exactly what your test involves, but looking at your linked page, I get the impression that you are proposing this: 1. Take a file with a very low level signal (eg. -80dB). 2. Play it without digital attenuation, and increase the analogue gain until you can hear it. 3. Now apply some digital attenuation and increase the analogue gain to compensate (so the overall level is the same). 4. There will be an audible difference. Is that what you're saying? If it is, then my response is: hey, no sh*t, Sherlock! Now tell us something we don't already understand. And then try and justify how this extremely unrealistic scenario relates in any way to the normal listening experience. Presumably you tried this test with a signal at normal levels (ie. not artificially low) and failed to hear a difference? What does that tell you about the real world? mswlogo;538748 Wrote: Your ears, system, room, amp, dac etc. have a total fixed dynamic range and by using digital attenuation you are sliding the music out of that range. And when you use analogue attenuation you are sliding the music out of that range. -- cliveb Transporter - ATC SCM100A cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
cliveb;538777 Wrote: It's actually quite difficult to understand exactly what your test involves, but looking at your linked page, I get the impression that you are proposing this: 1. Take a file with a very low level signal (eg. -80dB). 2. Play it without digital attenuation, and increase the analogue gain until you can hear it. 3. Now apply some digital attenuation and increase the analogue gain to compensate (so the overall level is the same). 4. There will be an audible difference. Is that what you're saying? If it is, then my response is: hey, no sh*t, Sherlock! Now tell us something we don't already understand. And then try and justify how this extremely unrealistic scenario relates in any way to the normal listening experience. Presumably you tried this test with a signal at normal levels (ie. not artificially low) and failed to hear a difference? What does that tell you about the real world? And when you use analogue attenuation you are sliding the music out of that range. What it tells you is the limit of your DAC even in the MOST EXTREME UNREALISTIC WORLD. Even with 6dB (1 bit of attenuation you can EASILY) hear a difference in these unrealistic test files. But if you can HEAR any difference I assure you it will effect fine level detail of a real recording too. Then if your crazy enough to use digital attenuation for volume and subract like 24dB you are just tossing some serious resolution. You're not pushing it down into lower bits and having your amp bring it back up if your DAC can't resolve those low level bits. Most DACs are no where near 24bit even though they may accept 24bit format. If DACs were perfect to 24bits then it would not be a big deal using digital attenuation. This helps show what your DAC can and CAN'T do. I found in my system that even 3dB attenuation (due to another problem which I finally found a work around for) had a huge difference in performance. I also found problems in another system thinking I was getting 24bit but I was only getting 16. You'd never know unless you ran a test like this. Another person found he had a noise problem with this test. Effectively you are finding the noise floor of your system with this. It's crude but it works. -- mswlogo XP Cat5 Transporter/DuetController SPDIF Meridian G68 DSP6000, DSP5500HC, DSP5000 XP Cat5 SB3 SPDIF Meridian DSP5000 XP Cat5 DuetReceiver SPDIF Meridian G91 DSP5000 'My Transporter Setup' (http://forums.slimdevices.com/showpost.php?p=350741postcount=45) 'Hitch Hikers Guide to Meridian' (http://www.meridianunplugged.com) mswlogo's Profile: http://forums.slimdevices.com/member.php?userid=9090 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
mswlogo;538905 Wrote: What it tells you is the limit of your DAC even in the MOST EXTREME UNREALISTIC WORLD. And pray tell why I should care about these EXTREME UNREALISTIC circumstances? mswlogo;538905 Wrote: Even with 6dB (1 bit of attenuation) you can EASILY hear a difference in these unrealistic test files. Of course you can. So what? mswlogo;538905 Wrote: But if you can HEAR any difference I assure you it will effect fine level detail of a real recording too. Rght... I routinely accept the assurances of strangers, of course. Heaven forbid that, having compared my Transporter via a preamp versus direct (using appropriate passive attenuation, of course) and discovered that the direct connection sounds better, I should trust my own experimental results. mswlogo;538905 Wrote: If you are perfect then just ignore it. No need to be jerk about it. I will admit to being pretty aggressive in my first reply, which is fairly out of character for me. That's because your opening statements included calling people like me fools. Now you've called me a jerk, so you'll understand why I've maintained my impolite attitude. -- cliveb Transporter - ATC SCM100A cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
I have a Duet and a high-quality external DAC going into my preamp. My kids use the SB Receiver volume control and are perfectly happy with it. However, I always turn the SB volume up to 100 and use my preamp. A few times, I noticed the system isn't really sounding very good. Invariably, it ends up being because I forgot to turn the Squeezebox volume back up to 100, which very audibly corrected the problem immediately. I can't assign this to listener bias because I didn't have a clue that was the problem. It is certainly settled to me that the digital volume control on the SB receiver degrades sound quality. However, I believe it is outputting 16 bits, so it doesn't prove whether the digital volume control can be used with 20/24 bits. My DAC literature claims 24 bit resolution, so maybe it will work if I ever upgrade to a Touch. -- mps mps's Profile: http://forums.slimdevices.com/member.php?userid=36351 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
mps;538936 Wrote: I have a Duet and a high-quality external DAC going into my preamp. My kids use the SB Receiver volume control and are perfectly happy with it. However, I always turn the SB volume up to 100 and use my preamp. A few times, I noticed the system isn't really sounding very good. Invariably, it ends up being because I forgot to turn the Squeezebox volume back up to 100, which very audibly corrected the problem immediately. I can't assign this to listener bias because I didn't have a clue that was the problem. It is certainly settled to me that the digital volume control on the SB receiver degrades sound quality. However, I believe it is outputting 16 bits, so it doesn't prove whether the digital volume control can be used with 20/24 bits. My DAC literature claims 24 bit resolution, so maybe it will work if I ever upgrade to a Touch. All SqueezeBoxes are 24bit you don't need a touch to get to 24bit. It gives you 96Khz. -- mswlogo XP Cat5 Transporter/DuetController SPDIF Meridian G68 DSP6000, DSP5500HC, DSP5000 XP Cat5 SB3 SPDIF Meridian DSP5000 XP Cat5 DuetReceiver SPDIF Meridian G91 DSP5000 'My Transporter Setup' (http://forums.slimdevices.com/showpost.php?p=350741postcount=45) 'Hitch Hikers Guide to Meridian' (http://www.meridianunplugged.com) mswlogo's Profile: http://forums.slimdevices.com/member.php?userid=9090 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
I never use digital attenuation, because, in my system, as I listen to relatively low levels, there is an audible difference with an analog one. I did the test several times, I prefer a good analog preamp. Those who don't hear any difference do as they like. ;) -- Themis SB3 - North Star dac 192 - Croft 25Pre and Series 7 power - Sonus Faber Grand Piano Domus Themis's Profile: http://forums.slimdevices.com/member.php?userid=14700 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
cliveb;538926 Wrote: And pray tell why I should care about these EXTREME UNREALISTIC circumstances? Of course you can. So what? Rght... I routinely accept the assurances of strangers, of course. Heaven forbid that, having compared my Transporter via a preamp versus direct (using appropriate passive attenuation, of course) and discovered that the direct connection sounds better, I should trust my own experimental results. I will admit to being pretty aggressive in my first reply, which is fairly out of character for me. That's because your opening statements included calling people like me fools. Now you've called me a jerk, so you'll understand why I've maintained my impolite attitude. Sorry about that. You are right. I fixed my opening post. If you adjust the Gain on the Transporter such that you are close to 100 on the volume scale for normal listing you would be ok. But if you attenuate even as little as 3dB you are losing clarity that you CAN hear. My test just shows that it's possible and why it's not 24bit to start. You have to start with what your DAC can do first then go from there. -- mswlogo XP Cat5 Transporter/DuetController SPDIF Meridian G68 DSP6000, DSP5500HC, DSP5000 XP Cat5 SB3 SPDIF Meridian DSP5000 XP Cat5 DuetReceiver SPDIF Meridian G91 DSP5000 'My Transporter Setup' (http://forums.slimdevices.com/showpost.php?p=350741postcount=45) 'Hitch Hikers Guide to Meridian' (http://www.meridianunplugged.com) mswlogo's Profile: http://forums.slimdevices.com/member.php?userid=9090 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
I haven't got time to get deeply into this a the moment but: 1) if you can only hear a very very quiet sound with your ear pressed against a driver I can absolutely guarantee you can't hear it at all at 1 metre/3 feet away. The inverse square rule sees to that. 2) any sound in the 3 least significant bits is going to be totally masked by other higher level sounds 99.9% of the time. This is partially why good MP3 can be VERY hard to detect... 3) The sound simply does not collapse into a catastrophically dynamic range limited, noisy mess if the digital volume is not at 100. You have to go way lower than that... Final thought. You are listening to a track. It starts to fade out. Does the sound quality collapse or does it just get quieter. You know how that fade was achieved? ...yes you've guessed... 4) I don't care if my DAC can only resolve to 20-bits since the best ADC's in the world struggle to get 20-bits of usable signal. The bottom 4 bits are always just noise... -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker Chord Interconnect cables Kitchen Boom, Outdoors: SB Radio Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
Phil Leigh;538958 Wrote: I haven't got time to get deeply into this a the moment but: 1) if you can only hear a very very quiet sound with your ear pressed against a driver I can absolutely guarantee you can't hear it at all at 1 metre/3 feet away. The inverse square rule sees to that. 2) any sound in the 3 least significant bits is going to be totally masked by other higher level sounds 99.9% of the time. This is partially why good MP3 can be VERY hard to detect... 3) The sound simply does not collapse into a catastrophically dynamic range limited, noisy mess if the digital volume is not at 100. You have to go way lower than that... Final thought. You are listening to a track. It starts to fade out. Does the sound quality collapse or does it just get quieter. You know how that fade was achieved? ...yes you've guessed... 4) I don't care if my DAC can only resolve to 20-bits since the best ADC's in the world struggle to get 20-bits of usable signal. The bottom 4 bits are always just noise... RE: 1) Your trying find the LIMIT of your DAC, not your ear or what you can hear normally. It's useful to know that limit. It's useful to prove your point in #4 to yourself. It also helps verify you system is truely passing 24bit to the DAC. And in one system where I thought I was, I'm not. RE: 2) Correct, the 4 most least signifcant bits are in audible. So why shift higher (audible) bits into the least significant bits that are inaudible and cannot be even amplified back if your DAC can't resolve that low. RE: 3) Don't assume attenuation is only achieved shifting things down digitally. You can have soft full scale data. Read up on Compression and Expansion. Even if Fading is done purely by digital amplitude why would you want to operate always Faded (attenuated digitally). RE: 4) I agree with #4. Folks keep saying but it's 24-Bit Volume so you won't lose anything audible (that's the mistake). NO, it's more like 20-Bit Volume (or less) and you will hear a difference. Because your DAC really runs at 20Bit-ish (at BEST with your EAR plastered to driver at full volume) and the extra 4 bits in 24bit volume are completely useless. That's why I did the test to see what the limit of the DAC is (in the best case). If the DAC came out 24bits that means with enough amplication you can get those real low level bits that were attenuated back into audible range. But if your DAC is really 20bit's then what your shifting out IS audible and can't be recovered (even by amplifying). -- mswlogo XP Cat5 Transporter/DuetController SPDIF Meridian G68 DSP6000, DSP5500HC, DSP5000 XP Cat5 SB3 SPDIF Meridian DSP5000 XP Cat5 DuetReceiver SPDIF Meridian G91 DSP5000 'My Transporter Setup' (http://forums.slimdevices.com/showpost.php?p=350741postcount=45) 'Hitch Hikers Guide to Meridian' (http://www.meridianunplugged.com) mswlogo's Profile: http://forums.slimdevices.com/member.php?userid=9090 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
I very quickly switched to 100% full volume @ Transporter and routed the signal through analog preamp. The difference in sound was astonishing. But this is written in both reviews in absolute sound and stereophile. I also exchanged some correspondence with Steven Stone from TAS to confirm my findings.. But ears everyone has are different as different are system. So, it all does not matter what I write.. -- michael123 michael123's Profile: http://forums.slimdevices.com/member.php?userid=23745 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
I very quickly switched to 100% full volume @ Transporter and routed the signal through analog preamp. The difference in sound was astonishing. But this is written in both reviews in absolute sound and stereophile. I also exchanged some correspondence with Steven Stone from TAS to confirm my findings.. But ears everyone has are different as different are system. So, it all does not matter what I write.. -- michael123 michael123's Profile: http://forums.slimdevices.com/member.php?userid=23745 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
Re: [SlimDevices: Audiophiles] DAC Resolution Test and Don't EVER use Digital Volume Control
michael123;539053 Wrote: I very quickly switched to 100% full volume @ Transporter and routed the signal through analog preamp. The difference in sound was astonishing.Huh? I'm not sure I understand the context...where are you coming from? -- audiomuze 'Cable break-in is real, and occurs between the ears of the listener - nowhere else (most certainly not in the cable).' (http://sound.westhost.com/cables.htm) '*last.fm*' (http://www.last.fm/user/audiomuze) audiomuze's Profile: http://forums.slimdevices.com/member.php?userid=33613 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 ___ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
