Who needs a Preamp??

Preamp has always been better in multiple systems for me. 

If your source has a high quality volume control (as with a few DACs that change volume by adjusting the reference voltage), you can achieve the impedance and power supply benefits mentioned earlier using a high quality, unity gain, buffer, which I believe is similar to what @grannyring‘s well-regarded The Truth preamp is doing, although The Truth provides the volume control too using photo cells.  Pass is correct about having sufficient gain in our sources but he also recognized the sonic benefits of an active stage, which is why he designed his B1 buffer.  SMc’s VRE-1 is another excellent unity gain line stage (with volume control).  Tortuga Audio’s tube preamp buffer is another buffer option (no volume control) at a lower price.

I've tried powering a Jolida JD100 tube CD and a Meridian 506 CD, both of which are respectable CD players, directly to my solid state amp that had volume controls for each channel. They both sounded flat to me. Uninvolving. After placing my Conrad Johnson PV5 preamp between the CD player and solid state amp, it made a world of difference IMHO, not just to my ears, but for every single person who listened to my system. It was just MUCH more musical and involving. I guess it depends on the equipment and maybe the music you listen to, since I've hooked both CD players up to a Conrad Johnson CAV-50 integrated and though that too sounds much better than the solid state without the CJ preamp, it doesn't quite have the same sound I prefer compared to the solid state mated to the CJ PV5. Definitely more slam and low end power with the latter. I've never had a truly high end solid state preamp, so I can not comment how that would influence the sound from the solid state amp connected to the CD player.    

a preamp can soften a digital source and make it listenable

This then is the fault of the source, and not the fault of going direct.

Better to fix the problem (get better source) and not just put a band-aid fix over it, by softening the problem with adding an expensive preamp.

Ivor Tiefenbrun, inventor of the Linn Sondek LP12, had a very good saying.
"It all starts with the source, get that right and your part the way there.
Don't get source right and it'll be a never ending struggle"

Cheers George

1. try tubes?

2. loudness compensation (progressive low volume boost of lows and highs) usually an on/off switch. When 'on' it automatically, and progressively, engages boost as you lower the volume below ...

Typically misunderstood because it is 'oppositely' named, it should have been called 'low vol compensation'.

https://en.wikipedia.org/wiki/Loudness_compensation

Note: the amp volume/preamp volume/low vol boost circuit work interactively, you need to find the combo that only engages it when the preamp vol is turned below ... Another reason it is either misunderstood, or, disliked because it gets engaged too soon at mid to high volume.

When you get it right, t is a wonderful thing to listen to Jazz at low volume and still hear/enjoy the bass player and brush work on cymbals at proper 'relative' levels.

3. balance/tone controls. remote volume from listening position, oh yeah!

some recordings benefit greatly by a very slight balance adjustment, and some recordings benefit from a bit of tone control

Add the fact that we lose our ability to hear high frequencies as we age. Of course you don't.

carpet is a tone control, acoustic treatments are tone controls, why the heck not use tone controls for certain recordings? bypass of controls is nice.
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give yourself a flexible/optional setup (I change my path often)

Three optional paths

1. direct into my tube integrated amp, Cayin A88t, which has remote volume and 4 inputs (one preamp in)

For sources that I know I will listen to fully attentively, at moderate to high volume, i.e. reel to reel, single cd player, never low volume when I would want low volume boost.

2. tube preamp/tuner via integrated amp's 'preamp in',

McIntosh mx110z for it's amazing tube FM and it's tube Phono EQ. When listening to FM at low volume, it automatically and progressively applies 'low volume boost'.

My TT has switch to bypass or use it's optional built-in phono preamp eq. I prefer the McIntosh tube phone eq. However, my prior McIntosh SS C28 preamp, I preferred the TT's preamp. Then, the TT goes to line, or direct to an amp or integrated amp. Sometimes I go straight to tube monoblocks.

3. Chase RLC Remote Line Controller. Primarily for it's remote balance control from listening position.

It's a remote controlled switch/volume/balance/tone control, and,



Primarily it is for CDs I know need a balance tweak, perhaps a single favorite track, or compilation CDs with many different engineers choices.

Also for a batch of CD's during a picnic/party ... 

And for memory lane a dual cassette deck and an 8 track thru it.

It has two sets of outputs if I want to easily compare amps, SS/Tube/....

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IOW, give yourself options that are practical: direct when best, preamp for it's advantages, low vol boost when desired ....