Adding tube sound to my SS system

I don't have the space for a full tube preamp. But a tube buffer is another matter. In my big desktop system (SS headphone amp/preamp [Violectric V281], class D amps [Bel Canto 600Ms], speakers [Harbeth 30.1s] and sub [JLAudio e110], I use a DAC that combines old-school Philips chips + a tube output buffer: the MHDT Labs Orchid. I have the best NOS buffer tube plus adapter that I could find.

The results are subtle and all positive. There is obviously real synergy in this collection of components. When I switch in a "better," more expensive NOS DAC, the Metrum Onyx, the sound via speakers is not quite the same. Yet in a different, headphone-only system also using the Violectric V281, the Only easily betters the Orchid.

(synergy)

For just a touch of tube sound with SS amplification I’d stick with an Audio Research pre-amp. Just make sure the input impedance of the SS amp is a good match to avoid flabby bass and distortion in that most tube pre amps have higher output impedance than SS. . 60kohm SS amp input impedance with most tube pre amps is probably a safe bet but 100kohm or even higher won’t hurt. I’d go with a fully balanced XLR connection if possible.

A few years ago I had a Musical Fidelity tube buffer stage that you could put between pre amp and amp or into a tape loop, etc.  I personally did not care for it, but it or something similar may be an easy easy and inexpensive way to add a little tube sound into your current set up.  Got rid of my Mac tube amplifiers also.  Guess I'm a SS guy all the way.

Reporting back after a ton of research and experimenting. 

I've been demoing the LTA Aero and Mojo Mystique Y in my system this last week and thought I'd share my early impressions.  While waiting about a month for these to arrive, I also tried some other speaker cables.  Supra 3.4, Mogami w3104, Oyaide Tunami v2, and Neotech 3001.  I had some excessive brightness/harsh treble that made some tracks hard to listen to.  Speaker cables made a huge difference surprisingly and each of those upgrades provided noticeable improvements! 

System now is Roon Nuc - Ifi Zen Stream w/ elite LPS - DAC - Luxman l509x - Spendor D9.2.

I previously had a Lumin T2.  I don't think it synergized well with the spendor Ds and luxman.  It was too detailed and analytical for me for speakers which already lean a touch that direction for my tastes.  

Both of these DACs completely changed the system for me.  Albums I previously thought were poor recordings revealed by my revealing system are now enjoyable.  There is more weight, organic richness, tone and life to the music.  I could happily live with either one.  Its going to be difficult to decide.

I swapped tubes in the Aero to the Ray Tubes Reserve 6sn7.  That changed the character of the Aero and made me realize how tube rolling can influence the sound.  The 6sn7 toned down some of the incisive zippy nature of the Aero and gave more tonal richness, lifelike insight into the music.  I've also been trying a Cary SLP-05 tube preamp into the separates input on the luxman which is pure magic.  The Aero with stock tubes straight into the Luxman gave perhaps 30% of the tube magic vs including the Cary in the chain. The Ray Tubes Reserve 6sn7 gets me 70% of the tube magic while retaining more of the drive and solidity of the Luxman preamp.  The aero with the 6sn7s into the luxman I would describe as spacious, detailed, insightful, organic, rich, airy and alive.  The band sounds in my room vs listening to a great recording.  Acoustic and jazz shines.

The Mojo also sounds fantastic and swapping back and forth between the Aero and also including the Cary preamp it's difficult to nail down a clear winner.  The Mojo is smooth, dense, very composed and clear.  The soundstage is a touch narrower but more dense.  It is even handed.  It also has similar giddieup to the Aero with the 6sn7 tubes (although not as much as the stock tubes which want to boogie).  I seemed to like the Mojo best relative in comparison to the Aero with more produced music like Abbey Road or an Eryka Badu album. 

At this point I'm leaning towards the Aero with the upgraded tubes and sticking with the Luxman vs going tube pre / ss power amp.  It gives me some of the tube magic while keeping the setup simpler and it sounds fantastic.  Its a tough call though, the Mojo also is a lovely DAC.  The Cary is special.  I have more listening to do.  Thanks to all the folks on this forum sharing their experience.  Really happy with how things are sounding over here.

Wow. Thanks for the detailed report. really appreciated. Lots of work on your side! Good for you.

But a question… I know you are doing this in a really short time… is all this equipment fully broken in? … as having 150 - 200 hours of play time before analysis and comparison. Or, if used and already broken in, an additional 20 hours to settle down. New equipment tends to be trebly and thin and often a bit noisy… then settles down and becomes more relaxed and natural sounding when you are over 150 to 200 hours. My Audio Research gear needs 600 hours to fully open up… granted after 200 the difference is not night and day.

Cary is definitely special… and if not broken in fully will just sound better and better.