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Will an external DAC sound better/different than my AVR DAC?

heboil

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Hi everyone.

The thread's subject is almost clickbaity as I expect responses of "there is no difference" as I have read on numerous posts here. However, I am asking more from a theoretical perspective. Most responses I have read are similar to the following: the DAC conversion in the external will be re-digitized feeding back into the AVR chain with the active DSP, thereby negating any sonic differences using an external DAC vs the internal AVR DAC. I get the logic here. Nuances etc amongst the DACs are likely close, feeding it back into the AVR and then the room correction... no sonic differences.

But, my real question is, why won't it make a difference? Here I am using my analog chain into my AVR as what is driving this question. I had a Denon X3600H for my AVR running Audyssey XT32, a Technics SL-1210M5G turntable connected to a Rotel RQ970BX phono stage which was feeding back into my AVR. Once it was input into my AVR, it was digitized and room corrected to send to my speakers (JM Lab Cobalt 816). So that is what would happen with an external DAC. Same logic applies, except that the TT was analog converting to digital where the DAC is digital to analog and then back to digital. When I upgraded my phono stage to an iFi Zen phono stage, my vinyl world took a huge leap forward (huge... pun intended with the massive growth of the soundstage). So following the logic in the first paragraph (of which I have read in many posts), the phono stage shouldn't make a difference because either analog signal is getting fed into my AVR, getting digitized and cleansed with DSP.

So why would a phono stage change in my system make a huge impact, but a DAC change not make an impact? I get bits are bits, but I have tried different USB dongle DACs with my phone and they often sound worlds apart different. A bit is still a bit in my phone with my headphones. So why won't it make a difference in an HT or dedicated 2-channel system? If I am missing something, please let me know. I am eager to understand what I am missing.

Thanks!
 
most of AVRs are low power amplifier. Just use DAC from the AVR.
 
So why would a phono stage change in my system make a huge impact, but a DAC change not make an impact
Because cartridges are extremely inconsistent in terms of frequency response, separation, distortion etc. The signals are low-level and subject to noise. Amplifiers operating in these domains (especially MC) are getting close to noise limits. Records are variable across equalisation and cutting angle etc. The amplifier designer faces conflicting choices regarding equalisation curves, headroom and what to do with the grunge below 30Hz. Handling high frequency resonance requires options through resistance and capacitance as does predicting the phono cable characteristics. There is therefore no "correct" way that is universally correct.

None of that happens in the digital domain and line level signals.
 
Yes, it will make a huge difference. Especially if your AVR has the ability to shut down all internal circuits related to digital music reproduction and replay an external analog signal with only the pre and power amp sections active. Don’t believe me? Try it.

kn
 
 
Yes, it will make a huge difference. Especially if your AVR has the ability to shut down all internal circuits related to digital music reproduction and replay an external analog signal with only the pre and power amp sections active. Don’t believe me? Try it.

kn
Prove it. With measurements.
 
This was posted by someone else on another forum:
I did an informal test with the local audiophile club (several vinylphiles).
TT > dual output phono preamp >output1> amp input 1, output2> ADC/DAC loop > amp input 2. Instant, noiseless switching between amp in 1& 2. The biggest issue by far, was matching V levels > amp, using a test LP with tones. I would not submit to AES, nor guarantee it was matched at 0.1V precision. Single blind at best.
No one could tell the difference. The very last sequence, a vinylphile, disbelieving he could not tell difference, swore the last play was vinyl. I got up, walked away from setup without touching, had him sit in tester chair to see what he though 100% sure was vinyl....was actually "digital". Funny stuff.

Once it was input into my AVR, it was digitized and room corrected to send to my speakers
Of course, room correction changes the sound. ;) "Bits are bits" but you've changed them.

When I upgraded my phono stage to an iFi Zen phono stage, my vinyl world took a huge leap forward (huge... pun intended with the massive growth of the soundstage).
It shouldn't affect soundstage. There are likely differences in gain (translated to differences in loudness) and there might be differences in RIAA equalization and background noise.

Soundstage mostly comes from the recording, your speakers, room acoustics, and since it's an illusion, your brain is involved.

I get bits are bits, but I have tried different USB dongle DACs with my phone and they often sound worlds apart different.
A proper listening test should be level matched, blind, and statistically repeatable. What is a blind ABX test?
 
Pure direct with the external Dac could sound better depending on the dac, I've tried a tiny hiby 3 and it sounds amazing for £30
 
Look at Amir’s tests of the Arcam AVR 390 with only the amp section and compare it to other AVRs in his test using the internal DACs. AVRs in general are terribly noisy, but some at least have respectable amp sections when other electronics are disabled. Look at the measurements of the Arcam AVR400 in “Sound and Vision” for example: https://www.soundandvision.com/content/arcam-avr400-av-receiver-ht-labs-measures
Thing is, that the OP needs the DAC in the AVR to digitize the analog input(s) and apply room correction / DSP, so anything "pure direct" is out of the equation...
I wonder why, then, he's even using an external DAC, he could just enter the AVR directly... the DAC quality would be that of the AVR's anyway, even if you pass by a Chord D.A.V.E. (no pun intended... we all know how it measures, so...)
 
Prove it. With measurements.
“This is quite good! Turning off Direct mode activates digitization of input and performance goes to hell:” - amirm May 4, 2020


kn
 
Thing is, that the OP needs the DAC in the AVR to digitize the analog input(s) and apply room correction / DSP, so anything "pure direct" is out of the equation...
I wonder why, then, he's even using an external DAC, he could just enter the AVR directly... the DAC quality would be that of the AVR's anyway, even if you pass by a Chord D.A.V.E. (no pun intended... we all know how it measures, so...)
Not my experience. The bass sounds slightly better when two channel signal (digital) goes through AVR processing, but everything else sounds worse than analog in. I choose to use my external DAC which is currently a Chord Qutest with a Teddy Pardo power supply with my AVR set to “direct” when listening to two channel digital music. Using a sub allows some adjustments of bass response, and the overall effect is quite good to my ears.
 
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Thing is, that the OP needs the DAC in the AVR to digitize the analog input(s) and apply room correction / DSP, so anything "pure direct" is out of the equation...
I wonder why, then, he's even using an external DAC, he could just enter the AVR directly... the DAC quality would be that of the AVR's anyway, even if you pass by a Chord D.A.V.E. (no pun intended... we all know how it measures, so...)
Wouldn’t this require that the AVR has an ADC built-in to digitize the analog signal from the phono pre or an external DAC? I am not sure there are very many AVRs with this feature. There may be some processing of the analog signal in the Denon AVR to simulate multiple channels and application of Audyssey curves to the analog signal. I looked at Denon’s descriptions and specs for the AVR3600H online and could not find anything about ADC feature. The AVRs I have used certainly don’t have that.

That said, the amp section of the AVR3600H is quite good according to Amir’s measurements. I can see how that (in direct mode) combined with OP’s speakers could differentiate between different phono preamps and probably external DACs as well, at least between DACs that have significantly different performance envelopes.

kn
 
Wouldn’t this require that the AVR has an ADC built-in to digitize the analog signal from the phono pre or an external DAC?
Dunno. Just echoing what the OP stated in his first post... I know none of the gear mentioned here, put my reply based on the theory behind the question(s).
 
Not my experience. The bass sounds slightly better when two channel signal (digital) goes through AVR processing, but everything else sounds worse than analog in.
That would depend on the ADC performance of the AVR, wouldn't it?!? Hence my statement that the performance will be dictated by the ADC/DAC of the AVR, as it is the final (re)conversion. The efforts of your Chord would be rendered null in a similar scenario, am I wrong?
 
Wouldn’t this require that the AVR has an ADC built-in to digitize the analog signal from the phono pre or an external DAC? I am not sure there are very many AVRs with this feature.
Every Denon/Marantz AVR has this feature.
AVR set to “direct” when listening to two channel digital music. Using a sub allows some adjustments of bass response, and the overall effect is quite good to my ears.
How do you use a sub with the AVR in direct mode? Doesn't that bypass all DSP including sub/bass management?
 
“This is quite good! Turning off Direct mode activates digitization of input and performance goes to hell:” - amirm May 4, 2020


kn

That Arcam performance hit is hardly an across-the-board finding in Amir's tests of AVRs, nor does Amir determine if and when it is *audible*, which is what really matters.

Nor have you determined it. The differences you purport to hear with your great are easily within the usual realm of bias effects. Your claims are a huge generalization, and your reports of audible difference are quite the leap of faith.
 
Wouldn’t this require that the AVR has an ADC built-in to digitize the analog signal from the phono pre or an external DAC? I am not sure there are very many AVRs with this feature. There may be some processing of the analog signal in the Denon AVR to simulate multiple channels and application of Audyssey curves to the analog signal. I looked at Denon’s descriptions and specs for the AVR3600H online and could not find anything about ADC feature. The AVRs I have used certainly don’t have that.

That said, the amp section of the AVR3600H is quite good according to Amir’s measurements. I can see how that (in direct mode) combined with OP’s speakers could differentiate between different phono preamps and probably external DACs as well, at least between DACs that have significantly different performance envelopes.

kn
I’m a new poster and a little confused with what is being discussed here. If the signal goes in via digital, then the AV amp’s DAC is being used. So we exclude that. If the external DAC is sending a line-level signal in, then the DAC (external) is doing its thing, and dependent on the AVR’s “direct mode” it will skip DSP. If the digital signal included a sub (I think it is called LFE) then in a direct mode that will also address the sub, but if it was simple two channel audio that would skip the sub. Unless the sub was wired in using both an LFE signal from the sub out as well as a neutrik cable attached to the L and R channel. At that point, the sub (being active) would be triggered by frequencies as per its own crossover settings. If direct mode is turned off, then the processing of the sound is not being done by the DAC but by whatever DSP settings occur within the amp, itself, if it is arriving as line-level (not digital) signals. It is inconceivable that a 2 channel turntable can address a sub in “direct” mode because turntables are generally two channel. So, either the OPs sub is connected using a neutrik connector to L and R, or DSP is throwing to the sub via LFE. BTW My old, but curiously lovely sounding Yamaha AVR (running through three active power amps into Linn speakers) does all sorts of weird crap to it, including inventing a centre channel and throwing stuff to the sub. I think the question around the sub would depend on how it is connected to the AVR. My sub is simply on an LFE channel, and is skipped in “direct” mode because my speakers are more than capable of handling all the music I throw at them. Anyway, long time lurker and first time poster and really do love these forums and Amir’s work.
 
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I’m a new poster and a little confused with what is being discussed here. If the signal goes in via digital, then the AV amp’s DAC is being used. So we exclude that. If the external DAC is sending a line-level signal in, then the DAC (external) is doing its thing, and dependent on the AVR’s “direct mode” it will skip DSP. If the digital signal included a sub (I think it is called LFE) then in a direct mode that will also address the sub, but if it was simple two channel audio that would skip the sub. Unless the sub was wired in using both an LFE signal from the sub out as well as a neutrik cable attached to the L and R channel. At that point, the sub (being active) would be triggered by frequencies as per its own crossover settings. If direct mode is turned off, then the processing of the sound is not being done by the DAC but by whatever DSP settings occur within the amp, itself, if it is arriving as line-level (not digital) signals. It is inconceivable that a 2 channel turntable can address a sub in “direct” mode because turntables are generally two channel. So, either the OPs sub is connected using a neutrik connector to L and R, or DSP is throwing to the sub via LFE. BTW My old, but curiously lovely sounding Yamaha AVR (running through three active power amps into Linn speakers) does all sorts of weird crap to it, including inventing a centre channel and throwing stuff to the sub. I think the question around the sub would depend on how it is connected to the AVR. My sub is simply on an LFE channel, and is skipped in “direct” mode because my speakers are more than capable of handling all the music I throw at them. Anyway, long time lurker and first time poster and really do love these forums and Amir’s work.

In an AVR, DSP is (obviously) done in the digital domain. So if you input an analogue signal and want to do ANY DSP (Including Crossover to sub which is done by the DSP), then the analogue signal is converted to digital, DSPd, and then converted back to analogue using the AVR DAC.

LFE are part of a digital signal stream - so can only be extracted in the digital processing, and sent to a SUB via the AVR DAC.

There is no DSP done in the amp section of an AVR. DSP is DIGITAL signal processing.
 
That would depend on the ADC performance of the AVR, wouldn't it?!? Hence my statement that the performance will be dictated by the ADC/DAC of the AVR, as it is the final (re)conversion. The efforts of your Chord would be rendered null in a similar scenario, am I wrong?
Yes, if AVRs actually have ADC capabilities for incoming analog signals, which may exist in some models, but I don’t think I’ve ever seen one advertised with that capability. I think but am not certain, that some processing of an analog two-channel signal occurs in the preamp to create false center and rear channel signals and sends lower frequencies to the sub, but I do not think the analog signal is digitized before processing.

Based in this thread, I decided to test this in my system where I use an AVR as the amp. Listening to a vinyl recording with analog into my receiver, if I engage signal processing, I get a number of options beyond “Stereo Direct”, including “Analogue Stereo” in which the subwoofer is only engaged via the high level speaker terminals. In “Analogue Stereo + Dolby Pro Logic”, “Analogue Stereo + Dolby PLII Movie”, “Dolby PLII Music”, “Analogue Stereo + Neo:6 Cinema”, and “Analogue Stereo + Neo:6 Music”, all are various “flavors” of spatial imaging in 5.1 with the sub operating via low level RCA output from the receiver. For some music, this might be enjoyable.

I would say the general character of my phono cartridge and preamp are preserved in “Analogue Stereo” versus “Stereo Direct”, but the the sound is several decibels lower at a given setting on the receiver, and I hear more a bit more noise in “Analogue Stereo” mode with nothing playing. I tried the same thing with analog out of my Chord DAC and got the same suite of options and results as with my vinyl front end.

I have honestly never even attempted this with an analog signal until reading and responding to this thread, but I have no reason to expect it is due to the entire analog signal from my phono pre or DAC being digitized and converted by the DAC in the receiver. If anyone knows better and would like to correct me, I am open to being educated.

kn
 
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