Preamp or not.

If you are getting the volume you need from your existing setup, then you don't need a preamp with any gain.  

The problem with controlling the volume from the DAC is that this is often done by reducing the number of bits going to the DAC, which reduces resolution.   An analog volume control doesn't do this.   Since you are using an external DAC with your Node 2i, the only way it can control the volume is to reduce it digitally before the DAC processes the signal.

I can recommend the Schiit Saga+ preamp. It is zero gain, and offers both a passive mode and tube buffer option. The volume is controlled by a stepped resistor network so the balance between channels is very precise. It also comes with a remote.  Cost is only $400 and they have a two week trial policy but do charge a 5% restocking fee if your return it.  If you need extra gain or want something fancier, the Schiit Freya+ preamp is $900. Both units are popular with lots of good reviews.

you do not need a preamp but a good one can improve the sound greatly.  
it is not so much about voltage but clean voltage and robust power supplies capable of fast changes and that greatly improve drive and dynamics.  
the analog section of DACs and digital players are what separate the good from the great and as so with the preamp feeding the power amp. 
look at the Rogue Audio RH-5 Linestage Headphone amp.  Review in Stereophile.   

https://forum.audiogon.com/discussions/high-end-stereo-preamps-worth-it?page=2

in particular, see mike lavigne’s post on second page... it covers well what is being asked

search bar above is always your friend... :)

If you can stretch a bit you could consider a Sachs pre that’d likely sound glorious with your wonderful amp.  Best of luck. 

I would consider a preamp with some tone control.that way you adjust some of the older recordings 

I finally understand the volume thing and explains "sounds better if it's turned up".  Much thanks @mlsstl .  I hope I wouldn't get too sensitive with the volume meaning small adjustments equal big volume swings.  The extra power supply might be a tradeoff for sensitivity.  Is that correct?  The speakers I have are about 100dB efficient(or higher)

Power and sensitivity should not be an issue for you. The Pass amp needs roughly 1.25 volts input for its full 25 watt output at 8 ohms. Your Topping, at 2 volts max out, has more than enough to drive the Pass, so with your efficient speakers, you’re going to need to be cutting volume quite a bit (unless you are a full tilt all-the-time head-banger.)

So, the question becomes, what is the best tool for controlling the input voltage to your amp? You don’t need any more gain, so that points to a totally passive or unity gain analog preamp. This would allow you to run the digital signal at 100% (no bit loss) but still control the volume to your liking.

Besides the Saga+ mentioned before, Schiit also has a totally passive volume control -- the Sys, for only $49. But, it has no remote. Others have suggested other excellent preamps, though you’d want to consider the gain issue in choosing one of them.

I have a ModWright LS36.5 that I recently pulled out of the system and running a RME ADI 2fs DAC with a Teddy Pardo supply direct to my Pass. It sounds great direct and I’m in no hurry to throw the MW back in anytime soon. The RME/Teddy is so clean and revealing and is not missing anything the MW offers, but the noise floor is much lower that the littlest of detail doesn’t get lost and the bottom end is on another level. Before I spent anything over $1,600 I’d consider the RME/Teddy combo if you’re not spinning vinyl, which I do so I will be keeper my ModWright for now. The ModWright is still a great preamp so if a must to get a preamp they’re highly recommended. Before my LS36.5 I had a SWL 9.0 SE and that too is a killer preamp... not as revealing as the LS37.5 but still outstanding.

The LTA headphone pre-amp combination sounds wonderful with the XA25 and it`s well under 2k. I have been using this combination for the last year. I have a Supratek DHT pre coming soon to pair with my XA25, DHT`s for me add more realism.

Check out Aric Audio. He makes a tube pre called the Unlimited. Talk to him he may be able to adjust gain to accommodate your needs. 

Been doing some digging after the group's guidance.  The links to other discussions was very helpful.  I see the Tubes4hifi pre amps are given to Don Sachs for his tweeks.  It looks like you can add a lot of options to the SP14.  It has 6SN7 tubes which many say is "the best" tube for pre amps!  Price is very reasonable.  I sent an email to Bob Latino and asked about gain.  I am assuming, so far, that the gain can be lowered or adjustable.  This would be a quite affordable version to try.  The passive Schiit was also intriguing.  I currently have a very "live" sounding setup.  It keeps getting better the more I play it.  Those who listen to more laid back setups might find my system not to their liking.  I think the tube preamp and eliminating the Bluesound volume(turning up all the way) would be a big change to my system.   The Topping and the Pass are both very quiet so it will be interesting. 

The Aric pre I mentioned can be configured for 6Sn7 tubes. Possibly variable gain. There is a thread on it here at AG. 

Thanks for the recommendations.  I am wondering about the difference in sound between the 12AU7, 6189W, 6SN7 vs 300B.  Bottlehead makes a preamp that uses a 300B which seems unique, but I am not a kit builder.  There are several choices in volume controls as well.  Is the main improvement more linear control or is there a better sound as well? 

Don Sachs here.  I see above that someone mistakenly things the tubes4hifi preamps are somehow given to me for tweaking.  Huh?   I get the bare board from Roy.  He has changed the board over the years with suggestions I have made.   That is it.  I choose every part.  I run the tubes at a different operating point.   I have modded the power supply and filament supplies, I use a much shorter signal path, I run the tubes on top and out in the open.  I use a 6BY5 rectifier, etc...   You can buy an sp14 kit and love it.  You can have Roy build you one and you will love it.  But it won't be my preamp.

I apologize for that, Don.  I do not understand what it takes to build equipment and should be more careful when posting. 

A DHT pre would use 300B tubes. Some like DHT tubes in a pre while others do not. I have heard DHT pre amps that give the illusion of being at the performance with a spooky realism. For this reason i have ordered the Supratek DHT/6SN7 pre amp it gives the ability to use 6SN7 or you can switch to a DHT tube the best of both worlds.

I went w/o a preamp for a few years but added one back in (Jeff Rowland Criterion) and won't look back.  Its ALL in the midrange.  I really believe the only way to get that depth of midrange, woodsy tone on the wood winds and reeds, thick gooey gushy music coming from between the speakers is with a really good preamp.  The volume in the digital domain is incredibly difficult to do w/o compressing the sound.  When its done properly, there is really just one optimum setting and that's where you hear the awesome clean detail and low noise floor but you will notice there's no emotion in a vocal, no depth & feel to the music.  

OP here. I worked with Roy atTubes4hifi and he helped me come up with a great solution, a passive with a tube buffer.  We are using the SP12 with option for volume only and adding tubes if desired later for active.  Otherwise the passive vs active argument was going on in my mind. 

passive is nothing more than a switchbox for sources.
active is the way to go if you value dynamics.  10 db gain or so would not cause volume control fine tuning issues.  

Otherwise the passive vs active argument was going on in my mind.

Active preamps cannot make more dynamics than what’s on the music source to start with, if anything they can only reduce and add distortions/colouration. (they are not dynamic range expanders) thank god, as they are rubbish.

When a passive is matched into the system "they cannot" reduced dynamics or add distortion, it is the most transparent and dynamic way of getting the music source signal to the poweramp.

The only thing that’s better is direct connection to the poweramp, if the source has a digital domain volume control, and you go direct to poweramp, that’s used in the top 1/3 of full volume (otherwise below that it could "bit strip" if below 1/3 of full) if below then a $49 Schiit Sys passive can be used as volume preset so then the digital domain volume control can then be used in the top 1/3 of full volume.

Cheers George

@georgehifi   
active preamps can certainly add significant dynamics to the overall sound if a passive or inadequate active is not delivering what is on the recording.  
this is especially true for micro dynamics and quick transitions.  
haven't you ever heard this?  
similar to differences heard with various phono preamps.  the good ones deliver much more.  

not always, but in my experience as a practical matter, more often than not, active pre’s do add to the sense of drive in a high quality, resolving system

active preamps can certainly add significant dynamics

Absolutely impossible for them to give more dynamics or detail than what’s from the source.!! unless they have a dbx inside, and as I said they sound crap.

They "can" add a colouration/distortion edge to the music making you "think" they are more dynamic.

Cheers George

Consider a EVS Ultimate attenuater. Do a google search for pics.Of course you will loose some dynamic range of a preamp, But can eliminate a set of cables ect, Works very nice. I have mine in use for a Bi-amp sitaution and use the EVS for level matching between amps, so its on my tube mono blocks with virtually no sound degrade.  . 

Absolutely impossible for them to give more dynamics... than what’s from the source.!!

They sure can, if they have more gain.

They sure can, if they have more gain.

The gain is from the source, "if it’s enough" to get to the loudness you need, any more is not going to be used used no matter where it comes from or is added as it will just be turned back down to where you want it!!!!!

Remember what Nelson Pass says about passive preamps

"What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.
And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp."

Cheers George

I don' t think there is one answer to this passive vs active debate.  It depends on your system.  If 2V SE or 4V BAL from a DAC is enough to drive your speakers and your amp is right sized, passive should be fine.  If you have demanding speakers and demanding music then an active might be right.  I don't see how an active preamp would make up for an undersized amp or hard to drive speakers.  All the parts add up to the whole.  An active preamp could add a sound signature that is appealing to some ears.  The preamp I am buying will let me try a tube buffer, passive with no buffer, or with a little modification, it could have tubes added.  Once again, I learn plenty on this forum.  Thank you all.

@daledeee

I don’ t think there is one answer to this passive vs active debate. It depends on your system. If 2V SE or 4V BAL from a DAC is enough to drive your speakers and your amp is right sized, passive should be fine. If you have demanding speakers and demanding music then an active might be right. I don’t see how an active preamp would make up for an undersized amp or hard to drive speakers. All the parts add up to the whole. An active preamp could add a sound signature that is appealing to some ears.

well summarized

i find passives are highly system dependent, even down to the cabling

i use a sonnet morpheus dac with a lossless volume control to drive any new amp i get with short cables (<1 m) - thus removes the preamp from the chain for the clearest sense of the sound of the amp

when i have a fix on what the amp sounds like, i then may elect to inject the pre/linestage into the chain to get input switching and whatever sonic benefits are needed (e.g. ayre for additional bass drive, cj tube unit to soften up the treble a touch and expand/deepen imaging, or i will use an old but lovely carver lightstar reference passive unit to gain input switching and volume control without adding any sonic drive - actually at a tiny of loss of drive...)

I received my VTA/tubes4hifi preamp and it was a total problem solver. I am running it as a passive pre amp with a tube buffer. Yes, I was definitely losing resolution at lower volumes. Very nice sounding. And it was affordable.   Definitely got plenty of power and gain without any pre amp gain.