Differences in sound: DAC vs. DAC + Pre-amplifier

[bodiebill]

Just got this passive preamp and I love it:

https://www.ecdesigns.nl/en/blog/svc24

Shunt based and no need for a power supply!

 

The SVC24 sounds very similar (i.e. seems not to add its own sound signature) as the DIY Stereo Coffee LDR passive preamp it replaces, but is a tad more relaxed/quieter.

 

 

[xamastrok]

On 1/23/2020 at 10:53 PM, Blake said:

Although logic says this should not be the case, I have found that in some cases, but not all, a separate preamp can improve sound quality, namely, sound staging and layering (relatively more 3-dimensional). I am a sound staging nut, so I've gone in the direction of separate preamps.  The key is, balancing the sound staging improvements with possible losses in transparency.  There are preamps I've tried though that suffer extremely little audible loss in transparency, if any at all.  However, not all preamps I've tried improve sound quality.  Some made things worse.

 

Feel free to take this video with a grain of salt as PS Audio now sells a preamp, and it is just one data point, but I've come to the same conclusion:

 

This is an interesting topic for me. Here is my personal experience.

I had the following:

1. Self-made Music PC + Kingrex Linear PSU

2. Qute Ex DAC + Kingrex Linear PSU

3. Rcam rHead headphone amplifier

4. Meridian G02 (preamp)

5. G57 (power amp)

 

I then bought TEAC NT-505 to replace 1-4 with one box and obtain superior sound quality at the same time. I have been almost successful, sound quality is much better now, I replaced 1-3 (5 boxes in total), but I have not been successful in replacing the pre-amplifier.

 

I have tried several times to play music with the TEAC acting as the digital preamp directly connected to the power amplifier, but the sound is evidently poorer. But using the TEAC as a streamer-DAC only and the G02/G57 combo the sound is fuller, sweeter, and you get 3D sound-staging, you can hear sounds from the far right/left or from the back of the stage. We're not talking about subtle differences here, there's no comparison.

 

Is it because a 1300€ machine cannot do everything right and the digital preamp department lags behind? Is it because G02/G57 are designed to work at their best as a pair? Is it because that's the way it is as the PS audio owner described in his video in the first page of the topic?

 

I'm not an expert to say why. It's a pity because it's so much more convenient to simplify and control the volume from an app. On the other hand, I am getting excellent sound :)

 

Thanks.

 

 

 

 

 

[audiobomber]

26 minutes ago, xamastrok said:

Is it because a 1300€ machine cannot do everything right and the digital preamp department lags behind?

A DAC/preamp needs a superior analog output stage to drive a power amp properly. 

 

I'm using my exaSound e32 DAC connected directly to my power amps, as recommended by the manufacturer. I would not go back to using a preamp, because the cost to buy a pre that would beat the output stage of the e32 is way beyond what I am willing to spend. 

[GUTB]

Sometimes people should just LISTEN to ME for a change. No, your DAC's digital volume control isn't good. No, your DAC's little volume control IC isn't good. It's NOT. Wishing it were, pretending it were, doesn't make it so. What you SHOULD be doing is STOP playing around, give up and buy a good tubed preamp. The brand is irrelevant, get the best you can afford. Then you're going to roll in a set of the best NOS tubes you can afford.

 

B-but the SNR and distortion is worse! WHO CARES, the trade off is always worth it. There's high-end SS pre stages, I'm not denigrating those. You guys know who you are. But for the average listener on here who is just looking for economical solutions for best audio out of piecemeal systems, then you should NEVER use the DAC's volume control -- with few exceptions, and of course you all know who you are already. If you want best sound, you're putting a tube pre in front, THE END.

 

I know ASR (internet cult) is telling you that noise and distortion are everything, and everything appears on an easy-to-read chart. It's not true. Your cult leader is LYING to you. LISTEN to those of us with EXPERIENCE.

[Kal Rubinson]

1 hour ago, GUTB said:

Sometimes people should just LISTEN to ME for a change.

Hard not to when you shout. 🙉

[57gold]

Heard the shout, but ignoring the message.

 

Sold my preamp more than a decade ago, a two box unit with ten 6922s and two 6U8As, all NOS matched Siemens 6922s, after plugging the Wadia 861i with balanced interconnects into the DNA-500 and hearing more of the recording, no loss in dynamics or swing...good riddance to a $5K box, happy to get 75% of my $s back when sold.

 

Currently, Mytek Brooklyn + is used as intended to great effect.  Stout output capabilities to drive amp, high quality analog volume control.  IMO, the world has gone CA and any DAC produced without a well-engineered output stage capable for driving amps and quality attenuation capabilities is a faulty, half-baked product.

 

Theta had it right with its DsPre back in 1988 (DAC with analog preamp), they were just too early as back then folks had turntables, cassette decks, FM tuners...and needed the switching and volume controls for the various sources.

 

[The Computer Audiophile]

18 minutes ago, 57gold said:

IMO, the world has gone CA and any DAC produced without a well-engineered output stage capable for driving amps and quality attenuation capabilities is a faulty, half-baked product.

I wish it was that easy, I really do. Some good DACs enable one to change the output voltage in addition to using volume control. This makes a huge difference with many amps. For example, my Constellation amps have an input that bypasses a gain stage. Using a DAC with 6 volt output is fantastic on this input. Most DACs however don’t have this type of output and I have to use the standard XLR input on my amps. A preamp can solve all these issues but may introduce others. 

[AudioDoctor]

Just my opinion, but it depends greatly on the DAC...

[sandyk]

3 hours ago, GUTB said:

If you want best sound, you're putting a tube pre in front, THE END.

 Sorry, but to put it bluntly :

B******T !!!

 

 Both WELL ENGINEERED SS and Hollow State can sound almost identical in most respects, however the vast majority of Tube Preamps are chosen mainly for one reason, which is to "improve"  cold and clinical sounding Digital sources, which these days do not have to sound that way.

 It's poorly implemented Digital technology that causes this.

 

It's laughable that so many will spend 10 or more times on the Vinyl side than on the digital side and then  rave about how much better analogue sounds .

[The Computer Audiophile]

9 minutes ago, sandyk said:

It's laughable that so many will spend 10 or more times on the Vinyl side than on the digital side and then  rave about how much better analogue sounds .

Many people do this, that’s for sure. 

[Allan F]

1 hour ago, sandyk said:

It's laughable that so many will spend 10 or more times on the Vinyl side than on the digital side and then  rave about how much better analogue sounds .

 

The equivalent can be said of those who extol the virtues of digital with their high-end five figure DACs and music servers.

[sandyk]

18 minutes ago, Allan F said:

 

The equivalent can be said of those who extol the virtues of digital with their high-end five figure DACs and music servers.

Perhaps, but most don't boast about how much better they sound than Vinyl.

[AudioDoctor]

29 minutes ago, Allan F said:

 

The equivalent can be said of those who extol the virtues of digital with their high-end five figure DACs and music servers.

 

I have often wanted to play a needle drop on my digital system to someone who doesn't know which of the two is playing to see if they can tell the difference...

 

I have some very high quality needle drop recordings, some in DSD, and IMO they sound like the vinyl record is playing.

[fas42]

6 hours ago, xamastrok said:

 

Is it because a 1300€ machine cannot do everything right and the digital preamp department lags behind? Is it because G02/G57 are designed to work at their best as a pair? Is it because that's the way it is as the PS audio owner described in his video in the first page of the topic?

 

I'm not an expert to say why. It's a pity because it's so much more convenient to simplify and control the volume from an app. On the other hand, I am getting excellent sound :)

 

Thanks.

 

 

A low priced machine can do everything well - but the engineering has to be done, exactly right. Most of the audio world refuses to understand what is the most important factor - which is, how well the overall integrity of the chain has been sorted, in its raw state. Most people get excited at the thought of adding an ultra expensive 'bit' to the rig, which will 'transform' the sound ... ummm, no - that's not how it works, 😉. I'm thinking here of going to a good restaurant - and the audiophile customer brings a whole bag of fancy condiments, and spends the whole time adding various combinations of them to bits of the meal - to "improve the experience" 🤪.

 

Well executed engineering has to have some thought put into it - it's not a "tick the boxes" process. So, a bit of gear that gets it right may be found anywhere - it could be a unit in the middle of the range of a large company; a single product from a mom and dad garage shed outfit; or an ultra expensive model from a highly regarded high end company - currently, there are largely no rules that dictate what makes something really excellent at producing good sound.

[Allan F]

57 minutes ago, sandyk said:

Perhaps, but most don't boast about how much better they sound than Vinyl.

 

Most or some? I don't know that there is any objective data to support one or the other. 🙂 However, vinyl lovers are probably more enthusiastic in their support of their preferred format.

[ecwl]

Forgive me for not having read all 18 pages here. But I did a quick search for some keywords and didn’t see them so I presume (and was surprised) this wasn’t discussed. Although I think @barrows sort of touched on this a little

 

I have always thought that one of the reasons why digital volume can sometimes sound inferior to an analog preamp is because a lot of DACs don’t have great low-level linearity. This is measurable except I only see Hi Fi News and Audio Science Review measure this.

 

Randomly I selected one DAC with good linearity and one with poor linearity from both sites:

https://www.audio “science” review/forum/index.php?threads/topping-d90-balanced-usb-dac-review.10519/

https://www.audio “science” review/forum/index.php?threads/measurements-of-musician-pegasus-r2r-dac.18786/

 

https://www.hifinews.com/content/simaudio-moon-780d-v2-network-attached-dac-lab-report

https://www.hifinews.com/content/ps-audio-stellar-gain-cell-dac-stellar-m700-dacpreampmonoblocks-lab-report

 

So you can imagine as you reduce the digital volume, even if mathematically your digital audio signal is accurately reduced, the DAC simply cannot accurately recreate the low-level analog signals because of the poor linearity. Of course, playing the DAC at full power and then using a good analog preamp to lower the volume level would mask the low-level nonlinearity issue.

 

And of course, there are other reasons why people prefer analog preamps.

 

 

[AudioDoctor]

1 hour ago, ecwl said:

Forgive me for not having read all 18 pages here. But I did a quick search for some keywords and didn’t see them so I presume (and was surprised) this wasn’t discussed. Although I think @barrows sort of touched on this a little

 

I have always thought that one of the reasons why digital volume can sometimes sound inferior to an analog preamp is because a lot of DACs don’t have great low-level linearity. This is measurable except I only see Hi Fi News and Audio Science Review measure this.

 

Randomly I selected one DAC with good linearity and one with poor linearity from both sites:

https://www.audio “science” review/forum/index.php?threads/topping-d90-balanced-usb-dac-review.10519/

https://www.audio “science” review/forum/index.php?threads/measurements-of-musician-pegasus-r2r-dac.18786/

 

https://www.hifinews.com/content/simaudio-moon-780d-v2-network-attached-dac-lab-report

https://www.hifinews.com/content/ps-audio-stellar-gain-cell-dac-stellar-m700-dacpreampmonoblocks-lab-report

 

So you can imagine as you reduce the digital volume, even if mathematically your digital audio signal is accurately reduced, the DAC simply cannot accurately recreate the low-level analog signals because of the poor linearity. Of course, playing the DAC at full power and then using a good analog preamp to lower the volume level would mask the low-level nonlinearity issue.

 

And of course, there are other reasons why people prefer analog preamps.

 

 

 

I think this gets to why HQPlayer has, in my opinion, a great software volume control. Perfect, or near as mathematically possible, linearity and as the volume control can be done in conjunction with upsampling, no resolution is lost in the process.

[sandyk]

1 hour ago, ecwl said:

So you can imagine as you reduce the digital volume, even if mathematically your digital audio signal is accurately reduced, the DAC simply cannot accurately recreate the low-level analog signals because of the poor linearity. Of course, playing the DAC at full power and then using a good analog preamp to lower the volume level would mask the low-level nonlinearity issue.

Nevertheless, it still comes down to how electrically quiet the source device is, and this will also apply  with conversions to DSD.

If you doubt this, and are using a Desktop PC try doing what one and a half (Gary) is recommending here.

https://audiophilestyle.com/forums/topic/60381-hdd-to-case-bonding-uptick-in-sq/?tab=comments#comment-1084599

 It won't cost much at all to at least try it.😉

 

[ecwl]

45 minutes ago, AudioDoctor said:

 

I think this gets to why HQPlayer has, in my opinion, a great software volume control. Perfect, or near as mathematically possible, linearity and as the volume control can be done in conjunction with upsampling, no resolution is lost in the process.

While this is somewhat true, but even if you’re to use HQPlayer to send excellently upsampled and noise-shaped DSD512 signals to your DAC, your DAC hardware still has to be able to produce that low level of linearity. A simple thought experiment is that if your DSD DAC has lots and lots of jitter, it doesn’t matter how great the noise-shaping is for the DSD512 signal, the actually analog output would still have poor low-level linearity.

[ecwl]

11 minutes ago, sandyk said:

Nevertheless, it still comes down to how electrically quiet the source device is, and this will also apply  with conversions to DSD.

If you doubt this, and are using a Desktop PC try doing what one and a half (Gary) is recommending here.

https://audiophilestyle.com/forums/topic/60381-hdd-to-case-bonding-uptick-in-sq/?tab=comments#comment-1084599

 It won't cost much at all to at least try it.😉

 

I don’t think that’s totally true. Obviously, the ASR measurements are presumably done on the same PC’s and the Hi Fi News measurements are don’t on a different PC that is used for all the measurements.

But I don’t think introducing a high-end desktop PC with no noise injected into the DAC is going to suddenly make a DAC hardware with low poor low-level linearity into a DAC with great low-level linearity. By all means, anyone who is interested can send your favorite low-noise PC to ASR or Hi Fi News for them to use.
I think a lot of this is fundamental to the DAC’s hardware architecture. But of course, you can somewhat bypass that architecture if you use your PC to upsample and noise shape to DSD256/512/1024 but then you’re now reliant on the DAC’s DSD hardware architecture.

[sandyk]

27 minutes ago, ecwl said:

But I don’t think introducing a high-end desktop PC with no noise injected into the DAC is going to suddenly make a DAC hardware with low poor low-level linearity into a DAC with great low-level linearity.

 That is not what I said, or inferred  !

It doesn't matter which type of output you use, especially USB, but crap from the front end will still go along with the Binary Data signal.

How much affect it has depends on the noise rejection of the DAC itself. NO affordable DACs are perfect in this respect, or we wouldn't still need ISO Regens with low noise external power , or expensive aftermarket boutique USB cables, even though we may be converting to DSD .

John Swenson has even reported that motherboard PWM controlled fans cause a degree of SQ degradation, which is why he designed the linear controller for the Mac Mini

[AudioDoctor]

2 hours ago, ecwl said:

While this is somewhat true, but even if you’re to use HQPlayer to send excellently upsampled and noise-shaped DSD512 signals to your DAC, your DAC hardware still has to be able to produce that low level of linearity. A simple thought experiment is that if your DSD DAC has lots and lots of jitter, it doesn’t matter how great the noise-shaping is for the DSD512 signal, the actually analog output would still have poor low-level linearity.

 

Then get a better DAC???

[mevdinc]

There are quite a few very good all-in-one DACs out there with builtin pre and analog volume control. Some DACs even provide one analog input which is what I need.

I have been using such DACs with my active speaker system for a long time with satisfaction. 

[Reg19]

On 3/18/2020 at 3:15 PM, Miska said:

 

Preamp can only worsen the quality that comes out of the DAC, not improve it. Generally it increases noise and distortion, more or less.

 

Input impedance of a pre-amp shouldn't differ from input impedance of a power amp.

 

Pre-amp is of course useful when you want to switch between multiple inputs.

 

@Miska: given that one needs a preamp while using HQ Player Desktop with the RME ADI-2 DAC to upsample music to DSD256 with DSD direct enabled (no volume control in DAC), which one do you recommend?

[Miska]

2 hours ago, Reg19 said:

@Miska: given that one needs a preamp while using HQ Player Desktop with the RME ADI-2 DAC to upsample music to DSD256 with DSD direct enabled (no volume control in DAC), which one do you recommend?

 

It depends on what kind of features you'd like. At the moment I'm using Cambridge Audio Azur 851E (feeding 851W power amp over balanced) these two talk to each other over CA's serial bus. It fills my requirements of good technical performance, enough inputs (3 balanced and 5 unbalanced) and possibility to name each input.

 

But now for another setup I've been eyeing Schiit Freya+ in solidstate buffer mode or if budget allows Benchmark LA4 which has very nice performance although even more short of inputs.

 

But also largely depends on your budget... McIntosh has nice C53 with nice amount of inputs and C49 is not bad either. And Accuphase has number of very nice preamps: http://accuphase.com/pre_amp.html