Eliminated my preamp with amazing results

Could put in a transformer for volume control and diy.

I don't know if it matches your intentions, but if you need a switch with volume control, you could use a passive preamp (volume attenuator with input selector). Some high end brands are Goldpoint, Hattor, and Khozmo.

@charles7

The RME ADI-FS DAC has a volume control. It is a top-notch digital implementation; I believe the claim that the sound quality is the same no matter how low the volume setting.

1. I turned my preamp volume to near maximum, then raised the DAC volume control to my desired listening level.
2. Noted the dB level with a simple sound meter app in an Android device.
3. Removed the pre-amp and raised the DAC volume to match the dB level.

In my case, I preferred the sound with the Van Alstine Transcendence RB 10 pre-amp.

Thanks for sharing this. I just picked up an RME ADI-2 DAC FS. A friend has a bunch of big $$$ gear and was raving about it... talked about it replacing his expensive preamps. I first put it in with my Ayre KX-5 Twenty preamp and thought "Holy Cow... that thing IS pretty good". He said I hadn’t really heard it until I put it direct to my Ayre VX-5 Twenty amp. Well, I am now... and... well... I’m not sure it’s as good. It’s certainly not a "revelation" such that it makes the Ayre KX-5 Twenty obviously obsolete / redundant. (Which is a clue to me). I am going to go back and forth, but I have a hunch the "stuff" / dynamics... whatever, that the Ayre KX-5 Twenty does, is maybe just worth having / keeping...and in the end maybe I prefer it. Notwithstanding that, the RME ADI-2 DAC FS is really friggin’ cool. It’s a special piece and I won’t be selling it, unless they come up with a better widget to replace it with. I have the AKM4493 version.

It’s also occurred to be to be very cautious about selling a good preamp. You never know what new toy is going to come down the pike that "I wish I’d kept that preamp" to use. I suspect I am always going to want to own a great preamp. If I'm not mistaken, I believe Ariel Brown at Ayre has referred to the preamp as being THE most important piece in the chain... 

I can attest to the use a really good preamp or don’t use one at all approach. I moved up to a Ayre Acoustics KX-5 Twenty preamp and it’s revealing everything I’d been missing before. And here’s the deal, as I’m just getting back into this hobby I haven’t even added a DAC yet, using a old Yamaha CDC-845 CD player feeding to the Ayre preamp then the preamp feeding to Phillips FA950 integrated amplifier with the volume left at the pegged position for it to temporarily act as an amplifer. One component at a time, rebuilt the Kappa 9’s and picked up a good preamp, next up some good amps, then a good DAC. I think the preamp is the most important component, it can easily be the most expensive component if you want a really good one. Controlling the volume is a huge challenge and only the best preamps can do it without losing anything in the signal. It’s why we always compensate by turning the volume up, it ’sounds’ better, but with a good preamp it’s very dynamic across the spectrum at the lower volume settings and that’s where it can be magical, you don’t need to blast it for it to sound good.

@gfguillot 

Controlling the volume is a huge challenge and only the best preamps can do it without losing anything in the signal. 

With all due respect... that's not true. Audirvana has an excellent volume control. (Roon also). No preamp needed. It doesn't lose resolution as you turn it down so it sounds good at lower volume.

So the question is... what exactly is a preamp doing that makes it sound so good?? Adding gain. Colors the sound and, in the process, adds dynamics. Perhaps a bit of the Fletcher/Munson curve for better low level performance. Perhaps add tubes for some 2nd harmonic distortion.

Tests have shown that people, in general, clearly prefer this sound.

However, it seems a bit counter intuitive. We want to get the highest resolution music stream source and components with the lowest possible distortion levels. We seem to want the music as it was mixed from the studio but then add gain/distortion/color back via the preamp. Two steps forward and one step back!

Using Audirvana without a preamp, If so desired, I could add the Fletcher/Munson curve via EQ without adding any gain or distortion and achieve a much cleaner end result that sounds GREAT at low levels. The added dynamic "Magic" is there with no added distortion. Clean with added headroom.

To be clear... no signal should get gain/boosted in EQ. It's opposite. From zero gain line the 'Curve' is created by pulling DOWN the midrange frequencies. Nothing gets 'boosted' above that line. The bass and treble are in a more extended curve WITHOUT adding gain. IMO a much better way to introduce the Fletcher/Munson curve than boosting gain distortion with a preamp. 

Boost it up with a preamp (which the signal DOESN'T need), adding distortion, then try to clean it up the best you can. No wonder a good preamp is so expensive. 

You did say you were using Audirvana, so disregard, yes, I can see how adding a preamp wouldn’t improve anything. For those of us using non streaming sources, like CD’s, vinyl, tape etc, we need a good preamp. A good preamp keeps the voltage constant on the volume control, which in turn the benefit for the improvement. A regular poteniometer in just about everything below the very high end out there varies the voltage. I don’t know about the ’gain’ being added, which you’re saying adds distortion. All I know is my Ayre KX-5 Twenty preamp is a huge step up in improvement, detail, dynamics, sound stage and distortion levels. The high end market wouldn’t exist if it didn’t deliver and believe me it does, but it’s a pay to play hobby. No regrets getting a high end preamp for me.