The volume pot is one of the most important parts of the analog/digital preamp.
Very good point! ...Now we're into something.
Very good point! ...Now we're into something.
While it is true that many different DAC chips, well implemented, can sound pretty good, the implementation is very important...
In the case of a receiver, or any DAC which receives its digital audio from another box, my way of judging is simple :
- ESS with oscillator close : Best
- ASRC with oscillator located between ASRC and DAC : OK
- decent PLL (wolfson DIR, silabs, etc) : why not
- everything else : crap
- MCLK from CS84xx : sub-crap
If it's a CDP, asynch USB sound card or whatever that creates its own clock, then, it's a lot easier.
That's one among the list of things that are "eliminatory", if it fails on one of these points, then it cannot succeed... which is why it is so complicated, everything must be right...
Among other things on this list, in no particular order
- high-distortion volume controls
- deficient EMI countermeasures (zzzt-zzzzzz zzzz zzzzz hello cellphone)
- 3 MHz GBW opamps fed with high slew rate DAC outputs without filter
- no ground plane
- power supply decoupling fail (ie, WIMA plastic caps // ceramics or polymers, etc)
- etc
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Do we know what are the options for really good volume controls - for HT receivers they are never 'pots' but always electronic and often combined with some other functionality.
Who has good volume control chips ? - what do the OPPO units use ? or Anthem ? etc.
And Pioneer (and other Japanese/Chinese receivers) probably use some cheap digital volume control chips.
- And some of the flagship ones ($5,000+) might have a digitally controlled analog volume chip in them.
And yes, the Oppo 105 (not the 103) uses one of the ESS Sabre DAC for the headphone volume control (digital of course).
- The internal preamp's volume control; I don't know exactly.
- And some of the flagship ones ($5,000+) might have a digitally controlled analog volume chip in them.
And yes, the Oppo 105 (not the 103) uses one of the ESS Sabre DAC for the headphone volume control (digital of course).
- The internal preamp's volume control; I don't know exactly.
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It has no ESS Sabre DACs, but just a single 8-channel Cirrus Logic Crystal DAC, the CS4382.
So they run the volume control (in 1dB steps) through that chip: http://www.datasheets360.com/pdf/-6413476744246040275
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By the way, regarding weaknesses in receivers:
The Auto Room Calibration/Correction and EQ system; that's one of the big ones.
Most receivers with bad (poor quality) music and movie recordings sound awful! I mean real bad; to the point of extreme irritation!
Engage a good EQ system and it brings life to not only them bad recordings but also to them bad speakers and subwoofers. ...And to them bad rooms too.
With good quality music and movie recordings; it's the exact same.
To prove this, just try Trinnov, or Audyssey MultEQ XT (& XT32), or ARC from Anthem.
...Disengaged first, then engaged (presuming you did a god job with the mic positioning and measurement's process).
The Auto Room Calibration/Correction and EQ system; that's one of the big ones.
Most receivers with bad (poor quality) music and movie recordings sound awful! I mean real bad; to the point of extreme irritation!
Engage a good EQ system and it brings life to not only them bad recordings but also to them bad speakers and subwoofers. ...And to them bad rooms too.
With good quality music and movie recordings; it's the exact same.
To prove this, just try Trinnov, or Audyssey MultEQ XT (& XT32), or ARC from Anthem.
...Disengaged first, then engaged (presuming you did a god job with the mic positioning and measurement's process).
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...And the beauty about separates: You can mix and match separate pre/pros or SSPs with separate multi-channel amps to your heart's contentment.
Tomorrow, just buy a new pre/pro (more updated with the latest streaming features and compatible with more portable devices), and keep your already magnificent multi-channel power amplifier with brute force power and gorgeous audio replication.
And when you get that new pre/pro (SSP) there is a chance that it could be a very bad match with your amp. But don't despair; just buy a new amp from the same manufacturer as your pre/pro. That's the beauty of separates; you can mix pre/pros and amps just the way you prefer (not necessary the best match).
Or, just to make sure the match is fine; simply get a one-box solution, a receiver.
That way the amp is matched to the preamp section, and you save space in your audio rack.
Sound quality? I bet that a receiver with a good Auto Room Correction and EQ system sounds better than good separates without one, or one that is inferior.
...Not always but perhaps more often that what we truly believe, or what they want us to believe.
And of course the more money we spend the less certain we can bet on.
Tomorrow, just buy a new pre/pro (more updated with the latest streaming features and compatible with more portable devices), and keep your already magnificent multi-channel power amplifier with brute force power and gorgeous audio replication.
And when you get that new pre/pro (SSP) there is a chance that it could be a very bad match with your amp. But don't despair; just buy a new amp from the same manufacturer as your pre/pro. That's the beauty of separates; you can mix pre/pros and amps just the way you prefer (not necessary the best match).
Or, just to make sure the match is fine; simply get a one-box solution, a receiver.
That way the amp is matched to the preamp section, and you save space in your audio rack.
Sound quality? I bet that a receiver with a good Auto Room Correction and EQ system sounds better than good separates without one, or one that is inferior.
...Not always but perhaps more often that what we truly believe, or what they want us to believe.
And of course the more money we spend the less certain we can bet on.
I suspect the worst commonly used commodity chip tracks more accurately than all but the highest-precision analog pots.
I agree there, except for disliking Audyssey for neutering the bass and imposing a crappy speakers compensation notch in the midrange. ARC and Trinnov are both very good. Trinnov IME surprisingly so, given that it only measures at four very close-together points. Also, with ARC there's the huge advantage of Quick Measure, a built-in calibrated measurement system that can be used to optimize speaker placement.
The Sherwood Newcastle R-972 A/V receiver has Trinnov inside and cost only $599 (brand new)!
ARC is great too and you can manually tweak it to your preference, and only where it counts the most (audio band spectrum).
Audyssey; it is so bad that it sounds magnificent!
Perfection is imperfection. ...Measurements and listening are two distinctive equilateral quantum.
Physical dedication and love and commitment (mic positioning and all that jazz) are the recipe for a good life's listening experience.
And that, it can come from various systems. ...A system is only as good as its user.
The preferred measurements are not always synonymous of the preferred auditions.
There is another equation on the overall equilibrium; our brain.
ARC is great too and you can manually tweak it to your preference, and only where it counts the most (audio band spectrum).
Audyssey; it is so bad that it sounds magnificent!
Perfection is imperfection. ...Measurements and listening are two distinctive equilateral quantum.
Physical dedication and love and commitment (mic positioning and all that jazz) are the recipe for a good life's listening experience.
And that, it can come from various systems. ...A system is only as good as its user.
The preferred measurements are not always synonymous of the preferred auditions.
There is another equation on the overall equilibrium; our brain.
And yes I agree; the volume control chips they just amplify the noise or the audio signal purity of the chain gang.
BUT! It's nice to have something like 0.25dB gradations in it.
And most of them don't!
BUT! It's nice to have something like 0.25dB gradations in it.
And most of them don't!
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I'm more concerned about their impact on distortion - tracking accuracy doesn't seem to be an issue in real-life with any multi-channel receiver I've heard. The question is, once you accept that most of the DACs are good (if implemented properly) then the next item faced by the signal is the volume/mux chip.
Perhaps the amplifier is still the weakest link but you sure want to know that going with separate high quality amps will not leave you at the mercy of a cheap LSI volume control.
This is interesting because the more we explore all the weaknesses the more we are building ultra hi-end products where compromises and money almost don't quasi exist and coexist.
Still, keep it simple with the less parts possible is a sound logic philosophy.
...And it not only applies to sound but to everything else as well.
Still, keep it simple with the less parts possible is a sound logic philosophy.
...And it not only applies to sound but to everything else as well.
So today I opened the Onlyo for some tests...
The DAC board has no ground plane. Wherever I probed there was always like 20-50mV of RF noise, everywhere, mostly 12MHz from the bitclock. All power supplies are full of crap.
The PCM1796 outputs directly assault a NE5532. The poor thing is drowned in RF. The output of the IV has RF noise on it visible on the scope without even zooming. Just a sinewave signal being played, occupying half the screen, about 1Vpp, gives a fuzzy trace... there is another filter afterwards to clean the mess up...
The DAC GND is connected to the analog (opamps) GND through... some ceramic capacitors ! So the IV return current to the DAC has nowhere to go except through the cap... it probably has to loop through the chassis at some point...
And... I kept the worst for last... the I2S comes from the DSP board, but the DSP GND and the DAC GND are only connected through a capacitor !... The digital ground return currents have to run through a cable, to another board with rectifiers and reservoir caps, and back.
Of course the DAC and DSP are supplied from the same +9V through cheap linear regs without serious filtering.
The DAC board has no ground plane. Wherever I probed there was always like 20-50mV of RF noise, everywhere, mostly 12MHz from the bitclock. All power supplies are full of crap.
The PCM1796 outputs directly assault a NE5532. The poor thing is drowned in RF. The output of the IV has RF noise on it visible on the scope without even zooming. Just a sinewave signal being played, occupying half the screen, about 1Vpp, gives a fuzzy trace... there is another filter afterwards to clean the mess up...
The DAC GND is connected to the analog (opamps) GND through... some ceramic capacitors ! So the IV return current to the DAC has nowhere to go except through the cap... it probably has to loop through the chassis at some point...
And... I kept the worst for last... the I2S comes from the DSP board, but the DSP GND and the DAC GND are only connected through a capacitor !... The digital ground return currents have to run through a cable, to another board with rectifiers and reservoir caps, and back.
Of course the DAC and DSP are supplied from the same +9V through cheap linear regs without serious filtering.
So, that's inside your Onkyo TX-NR905 A/V receiver! That is a total piece of crap then! Why did you buy it!
{By the way that was a $2,099 receiver - USD - MSRP}
* Are you shopping for a newer/better receiver to replace your old/bad cancer?
Check this one out: http://www.hometheaterhifi.com/receivers/receivers-reviews/anthem-mrx-710-a-v-receiver.html
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Probably because so much processing, and still cheaper than separates.
Except now the Emotiva pair looks really interesting.
At last, some tough bench tests on a receiver!
BUT BUT BUT…why oh why no power output tests?
My comment to the OP was going to be that every receiver I have ever seen droops severely in power output as more channels are driven. In other words, a receiver clipping at 2x100 watts might clip at like 5x60W or such. That indicates that, as noted earlier in the thread, the power supplies are weak.
I get very puzzled by reviewers who just gloss that over saying that "well all the channels don't peak at once, so that's not a big deal in real life…blah blah…"
- Um, baloney, they DO all peak at once, haven't you ever seen a crash scence? (and let me quote the guy who mixed Insane Clown Posse on DVD-A: they wanted "as much bass as possible in every channel [all at once]"
- I often see reviews where the unit doesn't meet its own spec.
- These same magazines would have a conniption if some 5-channel power amp from Bryston or something drooped like that, let alone not meet spec.
So why are receivers so popular? You can get SO much stuff for like $300-500. And, they are the default. It would never occur to many people to buy separates.
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There aren't that may choices if you want room correction for reasonable $. What are the choices for separates with room correction ?
Oppo doesn't have it right ?
Oppo doesn't have it right ?
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