[jandrews]

I just recently purchased a very nice, used Ultravalve from the original owner and purchaser and have been putting it to use for the last few days.  I’m trying too decide what preamp to use with it.
I have a Transcendence RB10 but it’s paired with my SET120 and in a different system in a different house.
Im currently using the preamp section on an old Yamaha CA-2010 integrated or using a single input Decware tube buffer with a volume pot on it.
I don’t think either are long term solutions… so seeking input on what others have successfully paired with their Ultravalve.
My source in this system is digital only so it’s a dac and it has a tubed output stage.  My speakers are Falcon la3/5a’s coming off the 16ohm taps on the Ultravalve.
Since my dac is tubed and the amp is a tube amp I’m thinking a solid state pre makes sense. 
I’d like to inject a touch more incisiveness , dynamics , resolution into the system. 
My gut instinct would be the solid state Vision RB pre from AVA.  There are also 2 used preamps on the AVA website including an early 1990’s Omega ii in a Pat cassis with a phono stage in it that could be a nice pairing .  I think I’m more attracted to discrete transistor stages rather than IC’s but i can be flexible. 
Also considering the new Schiit Kara.
Any suggestions ?
I’ve been advised by the amps previous owner that an Audible Illusions Modulus on the used market is a good pairing.
Having a volume remote would be nice but not necessary.
I also have considered the AVA digital preamp if I stay streaming only in this system.  This would eliminate my tubed dac.  Would use the single ended outputs on that piece obviously.
Thanks in advance

[opnly bafld]

Only thing I have for you is to suggest you try the 8 ohm taps and compare.

[jandrews]

I actually hadn’t thought of that
The Falcons are 15ohm speakers

[opnly bafld]

The Falcons are 15ohm speakers

Nominal
Have a look at Fig. 2 here:
https://www.stereophile.com/content/falcon-gold-badge-ls35a-loudspeaker-measurements

With tube amplifiers it's always a good idea to try different taps.

[jandrews]

Quick test

I’m detecting more fullness and even slam (for these tiny speakers) on the 16ohm hookup.  There’s more density and also presence from the lower register on the 16ohm.
Tested by listening to one speaker at a time and switching speaker output between 8 and 16

[mick wolfe]

In regard to a tube pre-amp for the Ultravalve, there are endless possibilities. I've run a Schiit Freya+ ( ANOS 6SN7's) for years with my VTA ST70. Excellent combination and the versatility of the Freya+ has been a real plus. I believe they offer a 15 day audition period as well. That said, lots of other options as well, especially if you're considering the used market. Audible Illusions, ( as already mentioned) Conrad Johnson, AR, Manley, Rogue, etc. The list is endless.

[jandrews]

Thank you
As mentioned I think I’m leaning towards a SS preamp

[TomBo]

Congratulations on finding an Ultravalve!  Go with your gut. Give AVA a call to confirm the pairing with the Vision RB. It took me a total of 5 minutes to hear how spectacular the Vision circuits perform on the SET 120 Control Amp and Vision Q+ Phono preamp... someone please correct me but I think AVA is using the Vision solid state phono preamp in their tube preamps as well?

Your other idea is also worthy of investigation/ comments and that is the DVA Digital Preamp...especially if you are all digital...

Curious to hear where you land!

[WGH]

I’d like to inject a touch more incisiveness , dynamics , resolution into the system. 

"incisiveness, dynamics, resolution" perfectly describes the AVA Fet Valve CFR preamp. Yes the CFR has 4 tubes but the sound is nothing like a traditional tube preamp. The CFR with my Vision SET 400 amp just sounds perfect, other preamps haven't sounded as perfect. I have used the Fet Valve Hybrid preamp and the sound was a little more clinical, the CFR is more true to life with better imaging, depth and bass. A friend brought over his DVA Digital preamp. The DVA is a clean sounding preamp and DAC, if you like it depends on if you prefer the sound of a standard DAC that does all the processing in the chip or a non-oversampling DAC like my HoloAudio May.

One of my tests when I hear a new piece of equipment is "do I have to have it" or "that was interesting". For me, the DVA Digital preamp falls into the "that was interesting" category. It's about synergy, the Fet Valve CFR preamp sounds great with the Salk HT2-TL speakers which can edge toward analytical if everything isn't right. The HoloAudio May KTE DAC is a true non-oversampling R2R DAC, it's sound is never sharp or digital unless the recording is. I also upsample all music to DSD256 using HQPlayer. I prefer the HoloAudio/HQPlayer sound to all the other DACs I have heard, not that the other DACs are bad, it's just what I like.

I also changed out the original JJ tubes in the Fet Valve CFR preamp to CV4024/12AT7 Mullard and Genalex Gold Lion B749/ECC82/12AU7 reissues. The tube change eliminated a vague sharpness that began to bug me. AVA electronics are so well designed that tube swaps barely make any difference but sometimes it's that last tweak that pulls everything together.
https://www.audiocircle.com/index.php?topic=180635.msg1898392#msg1898392

Actually the tube swap was probably the second to last tweak. The last tweak was to replace my USB cable and interconnects with Hapa cables, the improvement was bigger than the tube swap but all these little things are cumulative. I did put the JJs back in after a while with the Mullard/Genalex combo and immediately thought "nope." The JJs now hang out in my backup drawer.

[mick wolfe]

Thank you
As mentioned I think I’m leaning towards a SS preamp

Then the Schiit Kara you've mentioned might be worth a shot. FWIW, the Freya+ can also be run in passive or differential buffer mode taking the tubes out of play. Once again, I'm sure the 15 day audition/return policy applies.