[Mr. Big]

I think you will be happy with the LTA. The Ultralinear is supposed to have a bit more oomph than the Z40+ I had (in one review, the Ultralinear was able to drive Magnepan LRSs whereas the Z40+ couldn't other than low volume playback). I will be interested in your report. I thought the LTA Z40+ sounded quite good. There is a whole thread on that.

https://www.audiocircle.com/index.php?topic=183364.0

Not sure the Spatial board is dying. When Clayton got sick and Spatial kinda went dark things slowed down. Even now Spatial only has a couple of offerings but soon will be selling high end amplification stuff and they already (Cloud) are selling Don's Valhalla amp. But all of the boards are a bit slow other than the trading post section compared to Audiogon or others but those also have a lot of tension in them. I've found this board to be quite helpful and friendly for the most part.

Been so many posts here at some point it has to slow down, I think that everything that could be said by owners has been said. I am sure as new products hit the market and we start looking into them and owning them this site will kick back in.

[Tangram]

The LTA UL Integrated arrived a week early. Here are some thoughts regarding how it stacks up against my XA25/EAR868 pairing.

I was surprised by two things:

1) The LTA has more and fatter bass than the XA25.
2) I preferred listening to the LTA at lower volume than the XA25, which makes me wonder if the LTA’s frequency response is, well, more linear. I do need to push the LTA a bit though, volume was between 60 and 67 for the session, which tells me that the Spatials’ sensitivity, combined with the 4 ohm impedance, is borderline too low.

The XA25 is more dynamic but only by a hair. Both are very detailed but I was surprised by how detailed the LTA was given the tubes. Music seems to flow and pulse from the LTA, like it has a beating heart. The XA25 is more neutral, a tad less euphonic. LTA soundstage is wiiide, even bigger than the XA25, which is no slouch. Overall, the LTA envelopes you in sound, like being wrapped in a warm blanket!

Other observations: the LTA gets pretty hot! I guess that’s tube amps for you. I have it on a separate rack with nothing above it so all good. It’s so light. Lack of output transformers along with the switching power supply? And it is unbelievably quiet, which I stack up to good engineering along with the ZOTL topology. I’d love to try the amp with uber-sensitive speakers in the 8 ohm, 100 db range (i.e. horns.)

Is the XA25 leaving the stable? No. I won’t sell it since I don’t know what speakers are in my future and the amp could be the perfect fit for the right type of speakers. But the LTA is a revelation. As long as it stays comfortable with the volume at 60%, it’s all good. Admittedly I am wondering if the Z40 may be the better fit for the Spatials (because of the higher power output) but then I would probably lose some of the glorious detail and bass the UL seemingly magically pulls off.

Overall, I'm extremely impressed. That's a lot of performance packed into a smallish, light package.

[geerock]

I had the LTA reference 40 plus with the Don Sachs pre with my X5's and it was a very nice combo.  Then I got Don's 300b stereo version and it was really no comparison.  Stunning depth and resolution.  Huge soundstage.  It was really quite a revelation.  Cloud at Spatial was a big fan and still is for LTA amps, BUT upon hearing Don's prototype monos he posted  how overjoyed he was at that amp with Spatial speakers.  Steve (sjsfiveo) on this site in a current active thread is selling his 300b stereo version as we speak.  Maybe worth look8ng into.

[Tangram]

Thanks for that. I’m surprised a 300B based amp is enough to drive Spatials. Maybe there’s some secret sauce? I have had some more seat time with the LTA over the past couple of days as well as going back and forth with the XA25. I’ll be sticking with the LTA for the foreseeable future. It’s an amazing piece of kit - such good sound, so well sorted. It would be great to compare the LTA and Don Sachs amps side-by-side.

[geerock]

Thanks for that. I’m surprised a 300B based amp is enough to drive Spatials. Maybe there’s some secret sauce? I have had some more seat time with the LTA over the past couple of days as well as going back and forth with the XA25. I’ll be sticking with the LTA for the foreseeable future. It’s an amazing piece of kit - such good sound, so well sorted. It would be great to compare the LTA and Don Sachs amps side-by-side.

Not sure why you're surprised about the 300b driving Spatials.  X5's are 8 ohms with 98 sensitivity.  I've have flea watt amps hooked to these things with all kinds of head room.  Clayton himself used to show his speakers with the LTA 10.
All the best to you.

[Tangram]

Sorry. I was talking about my M3 Sapphires: 92 db, 4 ohm.

[RonN5]

I owned the M3 Sapphires (sold them).  I also own a X25 and a Wells Audio amp...the Wells gives you much of what the X25 gives you, but more midrange warmth and sound density....so, some of the sought after tube characteristics.  This amp looks to be a pretty good deal....

https://www.usaudiomart.com/details/650047875-wells-audio-innamorata-stereo-channel-power-amplifier/

Here is a review:

https://www.enjoythemusic.com/superioraudio/equipment/0513/wells_audio_innamorata_amplifier.htm

[dls123]

Sorry. I was talking about my M3 Sapphires: 92 db, 4 ohm.

Hi
The various prototypes of the 300b, and of course the final version that Spatial is now making will easily drive 88 dB.  They are very high current.  The M3 Sapphire is easy for it.   I know it will drive an 86 dB mini monitor in a smaller living room to screaming levels.   It has all the drive of a 60 watt/ch KT88 amp even though it specs at about 25 watts/ch.  As for how it compares to LTA gear.... well let's just say it inhabits a different universe entirely.  It should.  It costs a lot more.....

[Tyson]

With moderate to high efficiency speakers we are not even using a full watt the vast majority of the time.

[Tangram]

Hi
The various prototypes of the 300b, and of course the final version that Spatial is now making will easily drive 88 dB.  They are very high current.  The M3 Sapphire is easy for it.   I know it will drive an 86 dB mini monitor in a smaller living room to screaming levels.   It has all the drive of a 60 watt/ch KT88 amp even though it specs at about 25 watts/ch.  As for how it compares to LTA gear.... well let's just say it inhabits a different universe entirely.  It should.  It costs a lot more.....

Thanks for the clarification Don. The new amp sounds like an amazing design that will appeal to a wider reange of speaker owners. Will the new amps work just as effectively with 4 ohm speakers?

[opnly bafld]

Will the new amps work just as effectively with 4 ohm speakers?

8 and 4 ohm taps standard.
As always try both.

https://www.spatialaudiolab.com/revelation-300b-monoblocks

[dls123]

Thanks for the clarification Don. The new amp sounds like an amazing design that will appeal to a wider reange of speaker owners. Will the new amps work just as effectively with 4 ohm speakers?

Yes, they are quite happy to play into 4 ohm loads.  They have 4 and 8 ohm speaker taps and we have run them with 4 ohm 88-89 dB speakers with no problem and plenty of power.

[dls123]

Also, just a note that Spatial will be presenting their latest speaker(s) and the Revelation series preamp and amps at the SW Audio Fest in Dallas March 15-17.  I will be there as well on the Friday and Saturday and I believe Lynn Olson is planning to attend.

Maybe I will see some of you there.