DAC DIRECT IN TO AMPLIFIER OR TO PREAMPLIFIER

I have flopped back and forth and always got back to pre in chain. 

^Available bits of DAC to control volume without diminishing resolution, output voltage of the DAC to input sensitivity of the amp.

++1 @markalarsen @ghdprentice I had a similar experience recently, and it completely converted me from the ’no preamp is the best preamp’ camp to being a preamp believer. People often attribute it to synergy, but I really wish someone could explain exactly which elements, components or interactions in the gears contribute to better synergy.  Impedance matching is just a necessary condition but not a sufficient condition.

System dependent.

@markalarsen 

+1 

Yes… Logic says no… listening overwhelmingly says yes… the better the preamp the better the sound.

I have been a DAC to amp guy for a decade. There does not seem to be any logical explanation as to why a preamp would improve a signal. To the contrary, it seems that adding more circuitry to make the signal pass through would cause it to deteriorate.

So I decided to buy a tube preamp. It caused an amazing improvement. I cannot explain it. My wife noticed it immediately one floor above the system and referred to it as ethereal. It was an immediate improvement. All of my friends agree.

I will add that if funds were available to experiment, I would be tempted to try out the Conrad Johnson tube control amplifier in my den. It has gotten rave reviews. I realize I am vacillating here, but this control amplifier intrigues me, and it might tame the at times stringent highs I get with the AVA solid state SET 120. 

@tomic601 

Thank you for including me in this discussion. I know you are a Vandersteen fan as well.  Yes, for the reduced footprint in my smallish den (12 x 14’), the AVA SET 120 control amplifier paired with the Naim Uniti Atom headphone edition pre/DAC/streamer and my Vandersteen VLR CT standmounts (which can be placed within 6 inches of the rear wall) is quite good. I think I stretched a little bit before when I said it was sublime. This space does not have room treatments, and so I need to work on that before passing judgment… but I have to say that without treatments I was happier with the Belles Aria Signature integrated with Vandersteen Sub3 and high pass filters in my system.  The straight gain of the control amp was initially exciting, but after time I have found it to be fatiguing. I had an Audio Research Ref3 preamp that I regret selling, and will be investing in a tube preamp for my main system. I am in the camp now where a good (tube) preamp is beneficial. And I am going back to the Belles integrated and Sub3 in my den 

I would never run my system without a GOOD preamp.

To me it's like the secret ingredient that ties everything together, like corn starch in a sauce. 

But, you need a very good preamp and to me it makes sense if you have to budgetise to have a preamplifier that costs more than the power amp(s). It has even more impact on the sound (provided the amps have enough current and power to drive the speakers).

@dcevans you running signal thru the preamplifier AND the ( purposefully vague on the specifics ) unique NAIM analog / digital volume control. i use it in a similar way w outboard power amp and agree for the $, footprint and streamer/DAC function hard to beat.

in my reference system, i come down on the side of preamp in chain wins…but i have heard a few where that was not the case… sadly, extended listening is imo the only way to know….

I have the Grimm MU1 streamer feeding into a Mola Mola Tambaqui.  I have tried running it direct to my Pass Labs XA30.8 amp versus through my Aesthetix Calypso Eclipse ...and there is a definite improvement going via the preamp.  Don't get me wrong, the sound quality direct to amp is very good....something I thought I could live with...but when you have the chance to compare with a good preamp in the chain, you can't go back!  I originally had the standard Calypso, and the upgrade to the Eclipse is worth the expenditure.  I am considering moving to an integrated amp, but I'm not sure I can get the sound quality I'm getting through my current Calypso Eclipse/Pass Labs pairing.  

I tried both ways, my Esoteric DAC straight and no preamp vs. into my CAT preamp. The difference was very easy to hear. The DAC comes alive into the preamp, not at all direct, there really was no comparison. IOW, IME if you have a decent preamp, go DAC to preamp. 

Preamp.  I tried direct with PS Audio, Bricasti M3 (loved the volume control) and a few others. Currently running a Bricasti M1 SII through a Cary SLP-05 and love it.  Tried direct and as good as the Bricasti is adding the Cary back into the path added a little soul back into the sound.  Might be mental or just really like the Cary but I think the pre is a good addition.  

I'm using my DAC direct to amps right now.  I like the sound both through my preamp and direct to amps.  The direct route seems to be just a bit more lively to me plus it is 140 watts less power and time on tubes not using my tube preamp.  This DAC/preamp also uses tubes and even has analog inputs available.  It has a very good and quiet output stage.  I'm planning to try my phono preamp into the DAC/preamp to see how the sound compares to my regular preamp.  But this whole thing is a lot of change and I'm not liking change as much as I used to.  Funny how old age affects us.  Maybe in a few years I won't remember how the DAC sounds direct or through a preamp.  I've gotten used to using Roon instead of spinning CDs or Vinyl.  I keep thinking I could eliminate a lot of components but on the other hand that would be change...

Only a tad over six minutes long, watch it with an open mind:https://www.youtube.com/watch?v=Dh27E7YKN9s

@webking185 , I understand that it is counterintuitive to think that adding a whole bunch of circuitry into the line between the DAC and amp would sound better, but all I can say is that with my setup, which I don’t think is any slouchy setup, there is a definite and satisfying improvement in all aspects. It doesn’t make a lot of sense to me, but there it is. As @mofojo pointed out, an integrated just has the pre built in with less separation of the components, which I personally think is not as good as isolating the pre and amp. Finally an amp with an iPod? Just because you can do something, doesn’t mean that you should. You can use coat hangers for speaker wire . . . Doesn’t mean that it is a great idea. You might be able to power a small amp with a bicycle. Then you can eliminate any dirty power issues and get exercise at the same time. Doesn’t mean that you should.

An integrated has a preamp built in. 

I'm a fan of less is better, for less distortion, plug a DAC directly to the amp.  No need for anything else.  Get and integrated and your set.  Many people feel.a pre amp is needed, but I feel for its purity, I'll let the amp do the talking. Some people use a amp with a 1st gen ipod.

@moto_man 

😊👍

@ghdprentice, absolutely.  I have heard great things about the XP-32, but as usual, there are those that like the REF 6 over the XP-32 and those who love the XP-32 over the REF 6.  One thing that I have learned is that there are no reliable ways to predict how something sounds in your system other than putting it in there.  So unless I spring for an XP-32 just to see which I prefer and sell the other, or my local Wilson dealer gets one in on trade or something, I am probably sticking with the REF 6, although I may experiment with some room treatments or something to see what that does in my tiny (11x11) dedicated listening room!

@moto_man

Thanks for your excellent contribution. Just a caution, which it sounds like you would do anyway. If you choose to move to the Pass XP-32… audition before you buy. From what you have said, I would bet you loose the magic you get with the REF6 in your system. The Pass are a bit less warm and more analytical. That small difference could be an important one.

I an MSB Discrete DAC with Premier Power base, an ARC Ref 6, Pass Labs 250.8 and Wilson Sabrina X's.  Although MSB's National Sales manager thought that I should definitely run the DAC direct to amp, I experimented first with a loaner ARC LS 28SE, then a Renaissance Mark V, and finally, the ARC REF 6. Don't get me wrong, DAC direct to amp sounded good.  I found that the LS28SE was a very small improvement and definitely not worth it.  I found the Mark V somewhat better, but still not worth it.  However, the REF 6 was a noticeable and positive improvement in my system.  I just liked the way it sounded, and I thought it improved all aspects of the music, including the soundstage.  So I am very happy that I was able to add the right preamp to it.  As I said in another thread, I have flirted with the idea of putting in a Pass Labs XP-32 preamp instead of the ARC only to get away from the need to replace tubes and the potential unreliability years down the road of the availability of replacement tubes, but I already have a backup full replacement set, so I am definitely good for a few years.  I haven't yet made that leap to the XP-32 yet and not sure that I will, since I think that it is probably safe to assume that with all of the tube equipment out there, there will be a continuing supply of tubes, but who knows?

+1 it depends on your unique situation.  Some chains sound better with a preamp, other without. It’s not easily predictable, best to try in your own audio chain.

On the topic of tube hiss. I have all-tube cj gear: hiss evident at idle, although not loud enough to spoil my enjoyment of music. Replace factory-supplied tubes with some NOS Westinghouse and GE pre-amp and amp input tubes (not power output - couldn't afford that) from Vintage Tube Services. System now dead quiet at idle. Based on my experience, tube equipment can be quiet - all depends on the tubes, and the equipment of course.

Low hiss, can you hear it from your seat? If not… not a problem. Even if does, does it go away at low volume? Tube stuff is never gonna be DEAD quiet IME.

A low hiss is not normal from a good quality or better tube preamp. Deed quiet is the mark.

Update:

In my case the pre-amplifier made a noticeable improvement in sound quality- more than I thought it would. The Lumin volume control was fine, but adding a preamp confirmed my suspicion that I was missing out on something. This made the difference I needed from my system. I’m satisfied with my gear now and will be focusing on room treatment moving forward. I only listened to streaming and my NAS. I haven’t rewired the turntable for XLR yet, but will in the next couple days. I can imagine that results for a preamp will depend on the preamplifier being used. This might be where the "your results may vary" and "system dependent" comments come from. There’s no going back for me. If I had to describe the difference between running direct from the Lumin S1 compared to running through the preamp: with the preamp- more depth, better separation of instruments, more full sound, and better focused center image. The only downside I’ve noticed is it does make a little hiss with volume all the way down from the speakers, but it’s minor. I’m thinking this is normal since it’s a tube preamp. It’s still less noise than my old tube amp made though. I hope you find this information helpful.

Paul; Here is my most recent experience on topic:

I used an Audio Research SP15 as my preamp, an entry level DAC (Suncoz) to smooth my CD and hard drive inputs. I was dissatisfied.

I bought a PS Audio Perfect Wave DAC/streamer which is also a fine quality preamp. In fact Paul McGowan touts it as a substitute for the necessity of a preamp in some of his daily videos. I was excited about the front end of my system being a state of the art source / DAC and preamp. One less component, 3 fewer tubes, a lit less heat, etc. 

The CD sound was fantastic- truly revolutionary. The streaming sound was meh most of the time but wonderful when the material was well mixed and of a high quality uncompressed nature. I had achieved the impossible- tube sound with an all in one front end. I was ecstatic..until:. 

Poor volume control.  The PS Audio preamp just couldn't give a strong enough signal to my amps to make a loud DB presentation. Full volume was about the same as loud talking. It sounded fantastic but I couldn't push it to the level my speakers and amps would support- and some music needs to be played LOUD!

Given my particular components my conclusion is this: With a high end preamp a  first quality DAC is improved- not sonically per se but in overall control of the sound. 

I had Canary Audio 300B Mono amps with a Canary 1800 Dual Preamp.  I had a Lampizator Pacific  DAC.  People kept telling me I should try the Pacific direct to the 300B's but I wouldn't.  Then one day, just for the hell of it I did try going DAC to Amps.  I was astonished.  I thought the sound direct was better.  I immediately sold my Preamp and for the next year was a happy camper.  Then I sold the Pacific and replaced it with the Lampi Horizon, which has an even better Pre.  There have been many debates on WBF with Lampi regarding pre or not to pre.  I would say it is 75% Pre to 25% direct to the amp.  

I am still running my system without a Pre but I now have Aries Cerat Ianus Essentia mono amps.  Although my music sounds great in my opinion, I decided to order an Aries Cerat Ianus Ageto Pre.  I am still not convinced my sound will be that much better, but I hope to be proven wrong when I do get the Ageto.  

I am going to get the Dream DAC (not from OCD Guy). This is my last item to get. I will not use the DAC direct to amp. I will use it with the $2500 Benchmark LA4 preamp.

I can actually test the quality of the Dream direct to amp if it has RCA outputs. My CODA #16 amp has a nice toggle button on the front for RCA and XLR switching. After adjusting for the gain differences, I will be able compare with the LA4 preamp. Though I already know the answer.

I know a lot of folks do not care for this guy or his musings, but he has a point if you are digital only. https://youtu.be/81RQLo0tLHE?si=t9BKS9t34O0bESV2

Dealer OCD Mike peddles a 22k Playback Designs DAC that voids all preamps apparently on most of his videos. This video is no surprise. It is very doubtful that the dude's dac does endless miracles with every amp on earth..

It is not that much a mystery that amp manufacturers will design a pristine sounding  poweramp and pretty much try to lock you into a pristine sounding $$$$ preamp they specifically designed for it (atleast in the high end). All the DACs and the preamps from other manufacturers can sound less optimal thereafter with that poweramp (Not always though and there are enough exceptions, of course)..

@mitch2 I believe it was related to the size of the coupling caps used.

I concur. After conducting some research, we could apply the general guideline of a 3dB cut-off frequency at 2Hz to calculate the desired load input impedance (RL) in ohms using the formula RL = 0.5 / (π * f * C), where f is the cut-off frequency (2Hz in this case) and C is the capacitance in Farads.  For a better understanding of why 2Hz is suggested, you can refer to [https://www.v-cap.com/coupling-capacitor-calculator.php].

The Aesthetix Calypso Standard (Saturn) series employs 2uF output coupling capacitors. Therefore, the desired RL is calculated as RL = 0.5 / (3.1416 * 2 * (2x10^-6)) = 40k ohms. This calculation aligns with JA’s measurements in the lab.

Now, if the load input impedance at the amplifier doesn’t match the desired 40k ohms, one possible solution is to replace or upgrade the 2uF caps with the 4uF Dynamicaps used in the Signature series. This would reduce the desired RL to 20k ohms, resulting in benefits such as improved bass extension, resolution, dynamics, and reduced grain. According to the manufacturer’s website, the existing Saturn units can be factory upgraded to Signature specification. Alternatively, you could consider purchasing the Signature edition. In the used market, the Signature edition typically costs around $3,800, compared to the sub $2,500 price tag for the standard version.

@lanx0003 

Although the average output impedance (OI) is rated at 300 and 600 ohms for SE and XLR line outputs, JA (Sterophile) pointed out that both SE and XLR OI can rise to 3150 and 3900 ohms at 20Hz. This necessitates an amplifier with at least a 40k input impedance to avoid bass sounding lean.

The case of output impedance rising in the lower frequencies was not unusual amongst tubed preamplifiers.  I believe it was related to the size of the coupling caps used.

With almost any tubed amplifier, and with most SS amplifiers, the rising output impedance wasn't a problem but there are some SS amps like my SMc modified monoblocks that have input impedance of only 10K ohms, or some of the earlier Pass Labs amps that had input impedances of 20K or 22K ohms, where a high'ish output impedance from a tubed preamplifier might roll off the bass early.  The rule of thumb was to have an input impedance of at least 10x the output impedance, but I have always preferred to see at least 20x.

My experience goes back so many years it might not be useful in discussing modern equipment. Many years ago I ran an old Phillips CD with variable output directly into my amp. I thought it sounded pretty good. Then purchased a Conrad Johnson PV9a preamp and added it to the system. It was a noticeable improvement to me. 

Separately, I found this Bascomb King interview on the subject interesting. 

https://youtu.be/HHl8F9amyY4?si=HhNsdbI1xXADABk9

After acquiring a preamp primarily for analog attenuation, I've become convinced that a separate high-quality active preamp can significantly enhance sound reproduction and elevate the overall listening experience in almost every aspect. The key lies in the preamp's ability to establish good 'synergy,' including impedance matching, not only with the DAC but also with the amplifier. The specific elements contributing to this 'synergy' might be challenging to define, but you'll know when you find the right one.

The Aesthetix Calypso receives rave reviews as a remarkable piece of equipment. However, it appears that no one has mentioned a potential issue related to its impedance matching with your amplifier. Although the average output impedance (OI) is rated at 300 and 600 ohms for SE and XLR line outputs, JA (Sterophile) pointed out that both SE and XLR OI can rise to 3150 and 3900 ohms at 20Hz. This necessitates an amplifier with at least a 40k input impedance to avoid bass sounding lean.

Great conversations and recommendations.  I am in all of your debt!!

I called and spoke with the manufacturers at Berkeley DAC and Aesthetix.  Berkeley's Technical director thought though direct in would be just fine and nothing would be lost in the signal.  Aesthetix manufacturer though that the loss of fidelity in adding additional cables would be less than a percentage or two.  All things being equal (As far as input output ratios Etc.) The key would be the quality of the preamplifier in the DAC versus the quality of the preamplifier...very close to my current hypothesis.

Now to test out the theory...I will let you all know the result.  My assumption is that the Aesthetix Calypso is a superior preamp - and therefore should yield superior sound.  We will see :)

@lak Im waiting for an Atma-Sphere MP-3 preamp. 😁

I would throw out another option. DAC/preamp into control amplifier. I have Naim Unit Atom Headphone edition DAC/streamer/preamp paired with AVA SET 120 control amplifier (integrated without active pre). Volume control from the Naim remote. This is a truly great pairing. I’m not sure whether the preamp is activated, but sublime regardless. I have paired with Vandersteen VLR CT speakers in den system, along with Bryston CD-1 player. 

Into a good pre, which has always been better to my ear.

@veerossi out of curiosity which preamp are you expecting?

I'm in the opposite situation as you, I have preamps (tube and SS) but no DAC with volume control.

I have tried many preamps including Audio Research Ref 6se and Pass Labs XP 22.   My MSB Analog DAC sounds better direct to my Pass Labs XA 100.8.   Speakers are Wilson Sasha.                     Preamp adds coloration every time. DAC direct is more natural , has more detail and is definitely coherent across the frequency range 

I’m glad I came this one in my Agon weekly recap email. I started a thread recently with pretty much the same situation/question. I’m also have a Lumin direct XLR into class D monoblocks. My Lumin S1 (superseded by the X1) also has the LeedH volume control. I think it’s sounds nice, but I had to take the plunge to find out since I don’t have any friends that are into audio that I could borrow one from. I have a tube preamplifier arriving next week. I can’t wait to hear the difference- either way. Or, maybe it’ll sound the same? No matter what, at least I can finally hook-up and listen to my turntable again.

I have a Mola Mola Tambaqui DAC and A Mola Mola Makua preamp. I conferred with the master US importer to confirm my long held belief and he did not equivocate AT ALL. It is ALWAYS better to have a qualify preamplflier in the chain. Always. I have never NOT used a preamplifier with my other DACS. 

Interesting approaches to digital level control.    Great to see innovation. Looks like these ideas could be very inexpensive and trickle down to commodity products. 

So the correct answer remains: it depends. 

We can have words and concepts learned by minimal acoustic experiments in our room..

Then we "dont know what we dont know" but we can guess it by listening our speakers/room ...

There must be a balance between all acoustic factors for exemple for a brass orchestra timbre of trumpets ,french cor , tuba, trombone, to be experienced rightfully with clear distict timbre tone playing in a spatial clear distibutions and transients and dynamic and the "rise-duration-decay time " and all the spatial distribution and extent qualities in 3-D...And we must learn how to control these acoustics factors in our room...

Then " i dont know what i dont know " it is true but i did not have so much ignorance as 12 years ago when i did not understood and perceived yet the contribution of each acoustic concepts ... But i learned them by experiments and how to control in some degree and act on them for better and worse...

then you are right :

Let your ears determine what sounds best after you run thru the many different configurations.

But i know even if i never listen to it yet what could be my best upgrade and why and how...there is a minimal acoustic satisfaction threshold and i reach it at low cost and i am more than happy... It takes lot of hard work and years of experimenting to reach it... Most people dont do that...They then catch upgraditis...And they, in an opposite way to me, suggest branded name of gear they own for upgrade not acoustic and electrical and mechanical embeddings as more fundamentals with the necessary gear synergy as i do ...

For sure we must learn and buy and make mistakes... I did for years ... But my point is that we will makes more mistakes and create more unsatisfaction if we dont learn basic embeddings controls... Acoustics being the most important... Dac upgrade is half the time unnecassary.. People do it because they dont know how to reach synergy and they dont learn any acoustics concepts by EXPERIMENTING...

I say that because i did exactly this BEFORE experimenting and learning...

My post made sense ONLY for people with a limited budget and people who cannot afford to buy illimited dac pieces or gear pieces to try them... Experimenting may cost nothing, but it cost much in time and in reading, this is why few did it...This does not change the fact i spoke about :  audio is about synergy and especially embeddings controls not about costlier piece of gear... 😊

Mahgister- "you don't know what you don't  know". In this case, this doesn’t have anything to do with system synergy, IMO it has everything to do with the quality of the dac and the preamp.

A lot of dacs are noisy when using as a preamp so a preamp is a requirement. Some dacs like mine have attenuation to compensate if there is any noise going directly to the amp. 
 

Before ps audio came out with their BHK preamp, Paul’s recommendation was to go directly to the amp from their dac. I had a new $5000 preamp a few years ago that I used with my dac, and other sources. I took the preamp out and went directly to the amp, played with attenuation, and the sound quality was the same, so I sold the preamp. The BHK preamp might be better than the preamp I had, but when looking into making the dac sound best, most of the conversations I saw was to get the dac to perform best in its sweet zone, and this involved using or not using the attenuation feature. For example, some people claimed the sound with attenuation on sounded more smooth, while others claimed it was lifeless. Same goes for attenuation off. 
 

Let your ears determine what sounds best after you run thru the many different configurations.

@carlsbad2 + 1 

I do it another way:  I am good at buying and selling used equipment.  The key is never to buy junk.  So I buy a lot of equipment and resell the equipment that doesn't suit me. 

@ghdprentice Indeed, well said.  It would be hard to put together a system just by reading on the internet and that is what some people do.  Others try to do a lot of auditioning either in showrooms or using liberal return policies.  I do it another way:  I am good at buying and selling used equipment.  The key is never to buy junk.  So I buy a lot of equipment and resell the equipment that doesn't suit me. 

Jerry 

I also use a Lumin X1 directly into the Lumin AMP. SQ improved after removing an excellent Rogers High Fidelity KWM-88 integrated amplifier modified to use KT 170 tubes.

I tried many different connects from AMP to streamer and found that made an audible difference too. Not really news.

The Lumin(s) use Leedh Processing Volume Control. No lost bits.

Does this mean than some/all Lumin’s do not need a preamp? I’m not touching that one. Far more experienced than me forum members @blisshifi ​​​​@worldwidewholesales who have benefited from having listened to far more equipment and know their stuff should be heeded.

@ghdprentice 

You put together a system without one and you don’t know what you are missing. And this missing stuff is often the most important stuff…

Very true, both wrt to preamps and with other stuff too.  In my case it was dual subs, which I should have added years ago.

So, without a preamp you often get amazing detail but somewhat flat lifeless presentation. 

Not everyone has the same experience with loss of depth and dynamics, but it was mine with the 4 or 5 resistive passives I have tried in my system.  The internal volume control of the Metrum Adagio DAC was better sounding and certainly not flat or lifeless, but it leaned more toward a clean/detailed sound without providing the degree of body and rich tone I enjoy.  In addition to the Adagio, the only other passive solutions I have tried where that "somewhat flat lifeless presentation" didn't occur used Slagle autoformer volume controls (AVC) but those two units had their own sound that, while nice, I ultimately moved on from.

Regarding DAC volume controls and loss of bits, here is some reading material explaining how bits can be lost in some situations.  The article also includes a couple of illustrations by ESS showing how analog volume controls lower both the signal and the noise while digital volume controls can lower the signal while leaving the noise unaffected, which has the effect of reducing the S/N ratio.  

Not all DAC volume controls are the same.  The approach practiced by Cees Ruitenberg at Metrum and at Sonnet (now together under one roof!) involves changing the volume by varying the reference voltage of the converters, which, in conjunction with an algorithm they employ, preserves S/N.

In the end, as mentioned by others here, you really need to try things out for yourself and preferably in your own system with the music you listen to.