LTA Ultralinear vs SET amps

So, I guess I have the best of both worlds.  I am using the LTA mz 2 as my pre to a Welborne Labs Laurel (1995] which has been gone through an upgraded by a very competent tech.  Using Cantuck Audio lil audio 15s open baffle speakers.  It is in a small space.   Emission labs 300b tubes,  Sophia 274b rectifier….results are lovely.  

I also own the Elekit 300B integrated. I haven’t used it in a while but I remember it being very dynamic, especially once I changed out the small signal tubes to some nicer nos tubes. It’s not only dynamic but actually digs fairly deep too. Not deep like my old Pass Labs X-250 but deeper than my First Watt F3. I am using very efficient speakers. 

Like everything else, it depends on the match with the speakers.  That said, I agree with Lance that the LTA is not lean at all.  They all sound different though and for me, the Ultralinear didn't move me, while the Z40 Integrated did.  I also really liked the Z10i if you only need 12 WPC.  I own the Z40 (paired with Volti Rivals if that gives you a sense of my rig).

I think SETs are different animals but I used to have Joule Electra VZN-160s for many years, which I think is the working definition of "Lush Life" and while the LTAs are not as lush as the Joule Electra's there are several things they do better and have that same spooky transparency in the mids that I really have only heard with OTLs.

@bigwave1,


You should talk to Nicholas or Mark at LTA. My understanding is that they will do the same mods on the UL which is easy since there is only a 5% difference in the circuit between the UL and the ZOTL40.

I had to chuckle at the mention of Sonic Frontiers. I briefly owned a Power 2 and of the near 30 tube amps I’ve owned, it was the worst I’ve ever heard. You couldn’t give me another one.

Oz

I agree with Larry DHT's in a pushpull configuration can sound pretty special. I'm currently listening to a pushpull 2a3 amp with vintage Acrosound transformers and it sounds spectacular with 93db sensitive speakers.

The Atma-Sphere OTL are special. I lived and loved SET sound for decades. I got Atma M-60s on trial. After 5 minutes, I knew that I was done with 300B and 45s forever. The M-60s were as magical and musical combined with detail like a great SS amp.

All amps require proper matching with speakers to sound best. SET amp won't sound its best with speakers requiring high damping factor, limpid bass. Steep impedance curve not good, unbalanced sound, need easier to drive. And not all SET created equal, different power tubes, different manufacturers. Try 845SET with massive power supply, you want speed slam, here you go. Provided proper matching, SET does things no other amp topology can match. At the moment I rotate 845SET, 300B SET and push pull tube in system, all three have their special attributes.

Agree Medium_Grade, I also have the Elekit TU-8600 and it is a remarkable amplifier, slightly leaner than my SETs but with greater clarity overall.  

@lancelock,
LTA modded UL’s? Thanks 

I felt the same way about my former 300B monoblocks. Bought and built the Elekit TU-8600 with Lundahl transformers and that fixed it for me. It's an excellent amp And those transformers have such a vigorous and authoritative sound. Definitely not anemic, at least not to me. 

I had a friend who wrote an article called 'Color Me Perfect' meaning every amp has faults and you pick the one that has the combination of pluses and minuses that please you the most. That means that the most important factor in choosing audio gear is to learn to know yourself, a hard process. 

But single ended amps have certain characteristics. Due to high output impedance they have soft, bumped up bass and also often bumped up midrange. Due to low power output they are easy to run into overload unless you pick very efficient speakers. And due to non linearity they have high second harmonic distortion, a very rich but musically enticing sound.

All single ended amps are inherently non linear due to the circuit topology of single ended meaning there is no cure for it. They produce a non symmetrical output. They don't amplify the negative half of an input as much as the positive half. If you put a test sine wave in them the negative half of the test wave will not go down as far as the positive half will go up.

By the wave David Berning is a genius and his amplifier designs are special. A friend of mine who designed all sorts of unique tube amps over the years called me up when he saw what David did with his latest circuit and told me it was the first really new circuit concept in decades.

I’m listening to my LTA Ultralinear right now. Compared to my previous tube amps, not SET admittedly, the LTA has much more clarity, stronger and more articulate bass, and only the slightest touch less midrange magic which is a fair trade to get the other dynamics. 
I would expect the trade would be similar to a SET but man, it really combines the best of both worlds for my ears. 

You might try Whammerdyne...

The right ultralinear amp will, try a sonic frontiers amp, they will light up your 99db at a watt speakers like a christmas tree. You will not believe what your sensitive speakers have to offer until you hear a sonic frontiers amp with vintage nos tubes in it.

I agree with the lean assessment of the UL before the recent mods. My ZOTL40 is a different amp now and nothing lean about it. I believe they’re doing the same mods on the UL. This latest iteration must be heard.

mglik,

I agree with you that, generally speaking, SET amps are much richer than the LTA amp I heard and that SET amps are particularly magical at lower power.  That is not to say that all SET amps are warmer than all OTL amps (assuming that the LTA really qualifies as an OTL amp).  Some OTL amps are fairly rich sounding, such as some older Joule amps.  I've heard a non-commercial OTL amp that I would take over any other amp I've heard.

The SET sound is magical-the lower the power the more magic.

I have owned two Berning amps. Have recently replaced my Berning MicroZOTL with a Bakoon HP-1. LTA makes its version of the MZ and licensed the ZOTL circuit for all their amps.
A SET is much richer than an LTA. The latter may have more detail and punch but a SET is a very different animal. 

300B SET no inherent lack of dynamics, proper matching with speakers, quality of power supply and transformers all have role to play.

I have not made any kind of direct comparison, although I have heard the LTA amps that are based on the Berning circuit.  It is a quite dynamic sounding amp, similar in that sense to an OTL amp, but, it is voiced on the lean side.  If you are a fan of the 300b, 845 and 45 sound, my guess is that the LTA is not for you.  The 2a3 single ended amps I've heard (I own an Audio Note Kageki) are a bit leaner, and hence closer to the LTA than the other tube types mention, but, I still suspect that the LTA is leaner an more brittle sounding than most SET amps, including those utilizing the 2a3.

When properly executed, I think that pushpull amps utilizing the tubes you mentioned can deliver a lot of what SET amps can do, but with a little more punch and dynamics.  I would not leave out such designs from consideration, and I would add to the tube types to consider for pushpull amps to include the KT-66 and 6L6.  You could also look at different SET models.  There is quite a range of different sound based on specific models and manufacturers; SET sound is particularly dependent on the quality of the parts, particularly the output transformer, so really good SET amps are NOT low cost, even if the design appears to be simple.

Good luck on your search.