DAC DIRECT IN TO AMPLIFIER OR TO PREAMPLIFIER

Good call @worldwidewholesales. It might be worth digging into why this is with a little more explanation, and others like @bigkidz may be able to better articulate. 

Inside a DAC, there is of course an analog conversion and output stage. In most cases, the job of that is to output a signal at line level with a specific voltage and impedance. Many amplifiers benefit from not just a higher gain coming from the source or preamp, but both a quality signal preamplified with quality voltage and current and matching impedance. When this is done well in a DAC and an amplifier is matched with it, there is a chance for magic to happen, but the chances of that are very slim. 

While many people who are in the “DAC to Amp” camp believe in the “less is more” philosophy, that a preamp is a straight wire that doesn’t inhibit anything, or doesn’t believe in a preamp at all, they are potentially depriving themselves of the benefits of a properly preamplified signal as well as a quality attenuator that does not add noise to the chain. In my opinion, I would always opt for the properly preamplified signal and accommodate a light level of noise (mostly inaudible) vs risking the mismatch or subpar signal delivery to attain a lower noise floor.

Only correct answer:  "It depends"

Many fallacies on resolution between digital and analog volume, pot, vs. stepped resister vs. optical vs. transformer.  Too much "religion" on all sides.   Listen for yourself.  My personal belief is implementation matters more. From an engineering standpoint, the answer is driven primarily by the resolution of the source. 

Well, can't resist.   Logic may say dropping bits is less resolution, but did those bits contain data?    Redbook, 16 bits, but a remastered tape with less than 80 dB DR, you drop one bit. Did you lose anything?  Fancy 24 bit stream. Is it really 24 bits of resolution anyway?  Analog volume.  Did you lose anything or is it below the noise floor?  Digital can be more accurate but does that matter? Pots add noise, but is it audible?  Do you hold to a believe from poor or obsolete equipment where it did make a difference? Any method, reducing the level is reducing the audible dynamic range. It depends. 

Some DAC combo line drivers are not the best.  But, are they any different from a DAC only line driver?   Some are, some are not.  A lot of combo units it is the same, just one mode fixes the volume by whatever internal method it uses.  It depends.

Do you want to add any distortion?  Tone controls, balance, maybe sub sonic or sub filtering?  Differing harmonic distortion from  tubes or other methods? There is a reason tube buffers have a following, just as some want the most perfect squeaky clean.   Your choice, so it depends.

Do you need additional input selection? Conversion between balanced and single ended? Remote controls?  Maybe a built in headphone amp? It depends. 

Budget ( like my DX3pro+ all in one spec chasing wonder) to excellent ( Ares maybe, HOLO?) to stratospheric, ( take your pick) you get fewer features which pushes you to DAC, preamp, headphones amp and you expect them to pay the careful implementation of their chosen technology.  After all, they want to sell you another billet case and external power supply so why add $20 worth of parts when they can sell you an $5000 box?  😁 But then you are adding in all those magic cables that destroy the world.   Can't win for losing. 

Some advocate passive volume controls of various technologies.  Less is more. SINAD perfect.  But, it depends.  Does the source have the current to drive a low impedance load?  How does the following unit handle a variable impedance feed? Super long cables that need low Z output and high current to drive the cable reactance?    I tried one, and with my stuff at the time, I was not impressed. 

So it depends. What are your needs? Can you hear a difference, or are you looking for some undefined magic that can't be measured based on a You-Tube made up way to sell adds or products?    Your choice.    You can always try a Freya+ and get tube, passive and ss buffer all in one.  Decent I believe, but not prestige level. On my desktop, I need more than unity gain because I reduce the player output by 3dB ( yes digitally) to prevent filter clipping in my DAC. HUGE difference for the good.  With my giant 2W amp and a all-in-one DAC/pre with only gain of 1, I did not have sufficient listening level for some sources so I have an active preamp with a gain of 4. My main stereo with a higher gain amp, I never get close to a  0dB output, only negative so I don't need another gain stage.    I see some "prestige" preamps that are actually analog in, A2D, digital volume, then another DAC. Go figure.  

  It depends.  IF I change DACs and IF it does not have remote volume, then I would be looking at Denafrips, Musician, and Schiit preamps.  Decent, not esoteric. I can only afford to pay for sonic improvements. Not magic. 

I recently made a change in my system. I purchased a Schiit Kara preamp. It’s specs are excellent and it’s as transparent as anything I’ve heard. You can switch between passive and active. In passive mode only the relay controlled resister ladder volume control is the only thing in the path. 

With balanced connections my DAC has enough output for the amp. I’ve listened in both passive and active and there’s no obvious difference other than volume control setting. But it’s new and I’m still listening. 

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

As a general rule, adding a preamp I’d better, giving you better sound quality and better control. However, if a streamer or a CD transport are your only input, you might have a setup that doesn’t need a preamp.