LTA Ultralinear Plus Integrated vs. Pass Labs XA25/EAR 868pl

I own both of these amps and can swap between them fairly quickly. I use them with Spatial Audio M3 Sapphire open baffle speakers (4 ohm impedance, 92 db sensitivity) in a 13’X16’ room. Source is 100% vinyl (Kuzma Stabi R/4Point11, Etsuru Urushi Cobalt Blue/Luxman EQ-500/Allnic AUT 2000 SUT). I listen mostly to rock, jazz and folk, and at a decent volume (85 db A-weighted peaks).

Since these are well-known pieces of kit, I will limit my comments to a  sound comparison. I’ve had the XA25 for a year, and prior to that, an XA30.5 for four years. I’ve only had the LTA a couple of months.

The LTA has a big sound with an expansive soundstage that seems to wrap around you whereas the XA25/EAR combo seems smaller but more nimble by comparison. The LTA’s big sound doesn’t come at the expense of detail. In fact, certain “decorative” sounds like bells, triangles and non-drum percussion seem to stand out more with the LTA. Same with vocals, which are quite forward in the mix and, possibly, not to everyone’s liking (personally I prefer it). The XA25 wins on dynamics. In fact, with the Spatials, for me, this is one of the best things about my system. But the LTA is entirely satisfactory in this department as well. Finally, to my surprise, the LTA has amazing, addictive bass that makes the Pass Labs (which until I heard the LTA, I thought produced more than adequate bass) seem anemic in the lower registers. I like the Pass Labs bass enough that I don’t use my subs. With the LTA I would say the bass I get might actually be too much for some ears. Subs are absolutely not needed.

I’ve had tubes in my phono pre and linestage for a long time but the LTA is my introduction to tube amps. The reason I own it and the Pass Labs at the same time is that I wasn’t convinced buying the LTA was going to be an improvement so I held onto both. It’s possible that the EAR is holding the XA25 back and/or the LTA preamp is superior to the EAR. The only way to find out would be to try another preamp with the XA25, which I may do. Honestly, the David Berning design of the LTA seems to provide the best attributes of both tubes and solid state, in an incredibly small, light package. Does magic exist in audio? I think so.


Glad to  hear you really like your LTA UL.  I had the opposite experience with an LTA Z40+ int.  Bass was weak and the amp was lifeless at low volume 50-70db (which I prefer to listen) even with nos Mullards. Soundstage and higher volumes sounded much better but still lacked tube warmth and meat.  My Raven Blackhawk sounded so much better in that regard.  Sold the LTA within a few weeks.  Just shows how everyone’s systems synergy and tastes dictate best sounding components.

@tksteingraber the reason I was LTA-curious was because Spatial often pairs their speakers with them at shows. What speakers were you driving the Z40+ with?

Yes, LTA mentioned they paired them with Spatials at shows.  I played the LTA z40+ amp through both Goldenear Tritan 2 towers and Fritz monitors.   I now have moved to a full tube set up with a Decware Torii Jr v2 amp with Supratek Cabernet pre rotating the GE’s with Ohm Walsh Tall 2000’s.  Amazing low volume combo.

LTA seems to provide the best attributes of both tubes and solid state, in an incredibly small, light package


@tksteingraber It just goes to show you that specs aren’t the whole story. With 50 w/ch the Z40+ should have had no problem with the Goldenear’s especially since they have a powered woofer. The UL is only 20 w/ch and probably would have failed even more miserably. I wonder if part of the difference in our experiences was listening volume, since I listen loud and you prefer lower volume? As an aside, I don’t feel the need to listen as loud with the LTA as I do with the Pass Labs, probably because of the fuller bass I get from the LTA.

I had a look at the Raven Blackhawk, which I wasn’t familiar with until you mentioned it. Lower power than your LTA, yet far more satisfying. Like I said, specs only get you so far.

how is the tone and timbre of the two amps.  I love the xa25 and found it to have a warm sound but with fast dynamics and resolution. It sounded like real instruments.  Is that your experience and does the LTA sound natural in tone and timbre?

Love this stuff.


i have both the pass xa25 as well as the lta zotl reference+ amp

i did have the spatial m3 sapphires but sold them before long as i found the treble aggressiveness unbearable (as much as i liked what the speaker did otherwise)

based on this experience, i would say that the xa25 will do a significantly better job managing the bass response of the dual woofers of the sapphires -- otherwise the tonality of the two amps will depend greatly on the choice of tubes used in the zotl amp

(the zotl could not sound any more different than your dad’s old rose-colored mushy sounding tube amp.... it is vibrant, even sharp, in its musical presentation but it simply does not have the damping factor of a well designed well built ss amp like the pass)

@johnah5 both amps do tone and timbre well.  I’d give the nod to the LTA for simple acoustic music and solo vocals. On albums like Lady Blackbird’s Black Acid Soul, the ever so slightly lusher sound of the LTA makes it shine. On more complex music where there’s a lot going on (for example YYZ by Rush) the XA25 gets my vote, maybe because it has a more power in reserve. 

@jjss49 hey there. Pretty sure I’ve seen you over at the Spatial Circle on Audiocircle. Really sorry you couldn’t sort your treble issues out. After three years of ownership the M3 Sapphires only sound harsh when it’s on the recording, for example some of Elvis Costello’s first records. I struggled with harsh treble when I first got the speakers but over the years, a combination of break-in, multiple changes in speaker and listening position, and a complete change in every other part of my system makes the treble a non-issue.

It’s interesting - when I post about LTA’s Ultralinear amp, most who have had LTA gear invariably say they own or owned the Z40, not the UL. Not sure why. Extra power? I would LOVE to compare both integrateds in my system because even though they are both David Berning designs, Z owners often have a completely different experience than I’ve had with my UL. When I bought the UL I thought the same as you with the bass but my experience is the exact opposite to yours when compared with the  XA25.


@tangramca I was wondering maybe my issue was the Z40+ had too much power and when I was driving them at lower volume they suffered.  The lower power models ,like your UL, when driven at a higher amp level might be the ticket to better bass and meat. The Z40 sounded great when driven at higher volumes which I can’t live with.  Just 🤔 


the m3 sapphires certainly did not work me, glad they are working for you

i have not had the smaller lta ultralinear amp, sorry, so i cannot comment directly on that... i have quite a store of old stock british and dutch el34 and kt77 tubes from the good ol days, so the zotl ref amp is a natural for me, not to mention the additional power output this upper model affords -- i am actually getting a second zotl ref so i can run them as monoblocks!

It’s interesting - when I post about LTA’s Ultralinear amp, most who have had LTA gear invariably say they own or owned the Z40, not the UL. Not sure why. Extra power?

I think the power rating explains this—people generally think more is better. But these two amps sound different. It’s not simply a matter of more of the same. LTA calls the UL “more refined” and it is—more detailed, nuanced, magical. If you don’t need the extra grunt then the UL is your boy.

@dodgealum interesting. I agree that the detail is there in spades. I don’t have much experience with tube power amps so I wasn’t really expecting this. How would you compare the bass of the two amps?

@tangramca  Like most low powered amps (but perhaps to a lesser degree) I think the bass response of both LTA amps is really system dependent. I don’t think either amp is for every setup. But if your speakers are reasonably efficient and present a fairly modest load they are among the best available, certainly at their price (and well beyond). The nice thing about working with LTA is the opportunity to try them out and see which you prefer and how they perform with your speakers in your listening room.