[aurelius]

Damn you Darren... you taunt me further.  That you have heard and compare the LF favourably to the glass harmony drives me nuts!  For me, the glass harmony is 20%-30% better in many aspects than the N+... its sence of space and utter lack of mid-range congestion sends tingles down my spine.  A listening session at Hugh's (ironically, I guess) inspired me on to the PassLabs forum where I too could play with Class A single ended MOSFET output stages. (My study system that I am building now will be a single stage common source pre-amp [Bride of Zen] driving a single stage source follower [Seven Watt Amplifier - SEWA] into a set of Decware High Definition Towers mkII... no global feedback in sight!).

If the Life Force has similar sound-staging and resolution capabilities as the Glass Harmony, with the musicality, top-to-bottom integration and pace of the N+, well, it will simply be unmissable. 

Hugh, I'm afraid I will have to take you up on an offer for a listen.  Damn you all!

[AKSA]

Mark,

A thousand sorrows, Effendi.....      it is galling indeed - it is my private obsession, and I just have to keep moving forward, but I do admit I was astonished that this particular topology worked so well.   It took bloody years to find it.....   

Which all goes to show a huge part of innovation is simply blind good luck, serendipity by another name.....   

Actually, for bass resolution/heft, and midrange slam, the LF amps are both better than the GH, and I think the spatiality/soundfield (I say field, not stage, because it is imbued with height as well) rivals it.

You are welcome to visit any time, Mark, I have a 55LF here right now;  the 100LF is out on audition in Martin's system.

Cheers,

Hugh

[SuperMart]

Hi all,

LF100 auditioner here. Hugh, you will have to arm wrestle me to get this thing back and into Darren's system. I've just re-read Darren's excellent posts and I found myself nodding in agreement all the way through. I think the best way that I can describe the LF100's performance is exactly the way it struck me the first time I heard it. All the attributes of the LF55 are there plus the familiar drive and weight of the 100N+ but there is also an increased sense of presence and soundstage which somehow translates into an even more detailed yet natural presentation.My wife sat down on the couch next to me last night and said "It sounds very real, doesn't it."Over the past few days I've put a great variety of discs and DVD's through it - yes, I'm one of those weirdos that runs DVD's in 2 channel through my DAC - and concerts like "Bruce Springsteen and The E Street Band" and the wonderful "Concert For George" take on a truly thrilling "almost there" sensation.

Contrast that with Jorge Bolet playing Liszt's Annees de pelerinage which the missus greeted with the comment "That sounds lovely." Both Lifeforces reproduce very real sounding piano. Switch to some old Atlantic Soul recordings- Otis Reading, The Drifters, Aretha et al and the LF100 produces them in all their original glory - recordings which have been lying on my shelves unplayed for ages because I used to find them thin/bright/grainy. Bung on a $7 CD cheapie lable like Belaart and hey there was a good performance waiting to get out all along. Busy complex recordings are a joy to listen to because the LF100 presents all the strands of music so that arrangements are easy to follow and appreciate.

I'm looking forward to Darren's listening impressions in due course - you are in for an audio treat, cobber! For me, it's all about the music, the emotion and the joy whether it be hard rock or The Lark Ascending. I think the LF100 is a stunning achievement - there I've said it. Please see my previous posts for the usual disclaimers about my friendship with Hugh and my previous purchases of Aksa products. Now all I have to work out is how I go from a LF55 to a LF100 without robbing a bank?

Cheers,   

[AKSA]

Thanks Marty,

Great wrap up.  It clearly describes the strengths of the LF and I think most audiophiles would relate well to your comments.

Mark,

The GH is not a simple source follower;  intrinsic output stage distortion with local feedback only PSpices to 0.05% at full power, which is around 15 times less than a standard source follower without feedback (other than the usual 100% local normally attributed).  Consequently, a source follower without feedback (though I think NP put in a bit of interstage/global, didn't he?) would have much higher H2/H3, and this reflects in a higher level of the very quality of congestion you mention.

I guess I'm saying that the GH is a bit odd;  it has a local feedback factor (estimated) around 100K (100dB) and this gives incredibly low distortion at moderate power.  But it can't go loud;  max output is only 28W, and that for 150W heat dissipation per channel.  It is this horrific inefficiency - around the same as a gasoline engine - which is so transmogrifying, and which prompted me to produce something a little kinder to the environment.  The Lifeforce is the result, and there are moments of hubris where I suspect this will be my life's best design.

Cheers,

Hugh

[aurelius]

Hugh, this is way off topic, so I will brief... I never meant to imply that a source follower would emulate the GH... only that it was a simple and (relatively) cheap way to determine how much of what I heard with GH was attributable to Class-A MOSFET.  SEWA is not a NP design (as far as I can see, NP mostly uses common source with CCS or output-modulated CS).  As for your life's best design, I'm pretty impressed with your Feedforward regulator as well... its application, if and when you chose to unveil the IP, is amazingly broad.  Might drop around Wednesday evening if you are available.

[AKSA]

Mark,

Hey - I know you implied nothing!!  It ain't important!   

Wednesday would be great, any time, come for tea!   

Hugh

[PSP]

Quoting Hugh:

...Which all goes to show a huge part of innovation is simply blind good luck, serendipity by another name.....   

True, but IMO the really huge elements of innovation are (1) having vision and (2) having the drive to keep going when you are tired, afraid, alone, and getting closer and closer to that dreaded discussion with your banker.  Those who are smart and lucky sometimes find paydirt before their resources are exhausted.  Congratulations on this stunning accomplishment.   

Peter

[Seano]

Just to come wombling back on topic.....kind of.

I've not heard either of the LF.........yet. Hint......Hugh.....BIG hint.

BuT my 100 started life as a Nirvana before hitting the heights of a N+.

And you know.....I'd be loath to put any sort of rating on either of them.

The main distinction?  The N+ was better than the plain N in ways that aren't entirely clear these days.  But (and it's a big but) the N+ cost more.  And I was never able to directly compare the N to the N+.

Personally I find most magazine reviews of product very misleading or just plain confusing (but I still read them).  The ones that are most useful are the ones that provide a comparison with similar product in the same price bracket. The ones that are least useful are those that provide a product rating as a score or star.....which means most mags. And even e-zines.

So the solution may be to organise a comparo against multiple power amps in the same retail price point (but not necessarily power rating) as one of the LFs, all hooked into the same reference system (source, pre, speakers) and have more than three or four reviewers......not sure how many mags/zines/suppliers would be keen on this since the audio industry (unlike the car industry) seems rampantly pathological in its avoidance of direct comparison with its competitors.......and gee I wonder why

[aurelius]

I figure its about time I actually got on topic.

Last night I had the pleasure of a visit to the home of AKSA and was given the privilege of hearing both the LF100 and the LF55.

Before I talk about the amps, let me qualify the discussion by stating that I now consider my Orions at least a class or two above any of the speakers Hugh had available for demonstration.  This is not to denegrate Hugh's set-up, but rather to highlight that there may be many strengths of the amp that I under-empasize, due to speaker differences.

In regard to the following aspects, the LF amps are clearly superior (LF + Hugh's speakers beats 55N+ plus Orion):

Preservation of decay: this is truely awesome.  Sounds fade from their peak to nothingness in perfectly textured natural decay.  As a result, environmental cues are much more realistic and the presentation of space is astonishing.

Sound Field: The aural image is substantially deeper, wider and higher.  Wall-to-wall, floor-to-ceiling; it's pretty magic stuff.

Mid-range tonal fidelity: I find voices a very difficult reference from which to judge tonal fidelity. Unless you intimately know the person singing (a la Dick Olsher's Leslie test), you can't possibly make a judgement; however, acoustic guitar is another matter entirely.  If one was well versed in these things, one could determine the wood of the sound board.  Whist no so practiced and estute myself, it was certainly a very engaging experience.

With regard to Mid range smoothness and effortlessness , the session gave me reason to believe that the LF is better than the N+, but speaker differences make it impossible to say for certain.

Specifically, one minor disadvantage of the N+ is the slightest propensity to make any midrange distortion in the original material stand out like dogs' balls.  Johnny Cash's version of Trent Reznor's "Hurt" off "Ring of Fire" is a fair exapmle.  The LF seemed to have relaxed the midrange without taking away any of it's dynamicism or musicality.

The area that most listners have noted to date is the bass slam.  I must confess that Hugh's speakers (with or without the Lifeforce) are a poor match for 2 x 10" Peerless XLS dipole woofers, equalised to 20Hz, 0.5Q, driven by 2 x 55N+. I can only go by what others have said.

As for the LF55 versus the 100, I will go against the tide and state a strong preference for the 55 for two reasons. 1) The sound field on the 100 sounded a little stretched for my taste... hard to explain, but it felt as though it were forced wide... some times it was as if I were wearing headphones... never experienced that with the LF55 which flowed effortlessly into its space. 2) Just a little more tonal elegance.  Swimmer or ballet dancer?  In a fight, you'd take the swimmer, but when beauty and grace rock your world, there is no comparison.

Would I part with the cash? If I had a simple stereo system, I wouldn't have walked out the door without slipping Hugh a lazy $750... as it is, I have a quad-amped system... do the math... it ain't pretty.  I suspect that I will upgrade one day any way... I'll just have to come up with more sophisticated marital cash laundering systems.

Cheers.

[AKSA]

Thank you Mark, and for coming all this way for the audition!

I think you've captured it fairly well;  your writing is very lucid.  The spatial qualities, the decay, the resolution and the bass slam are the standouts.  This is the first SS amp I've heard which does the image almost exactly like a well designed SE tube amp.

I must apologize for my crummy speakers.  We were reduced to my D'Appolito party speaks for most of the audition;  punchy, but not high resolution.  I think the Peerless two way was better, but bass was not as full.  During development of the LF I trashed a few drivers - mostly carelessness on my part as I probed the stability parameters - but I can promise this amp is more stable than any I've done to date.  The next test is electrostatics;  I suspect this will be a consummate performer with ESL989s.

Cheers,

Hugh

[Geoff-AU]

natural decay isn't something that gets brought up too often, but after upgrading from a 30 year old sansui integrated amp to my ESP pre-amp and AKSA55 I definitely noticed it.

I believe it speaks well of the speakers as well as the amp to be able to tightly control a peak excursion and be well damped yet still reveal the subtle decay effects.  It's not an easy task.

All this talk is making me keen to build new speakers, new amp, new pre... argh! I definitely need new music before any of that though

[stvnharr]

Mark,
I have speakers with 2 Seas W18E's per side in a 2.5 config.  I have only just received my new LF 55's and don't have really very much time with them, but I do have enough for a small comment.
The Seas Excels already do a fair bit of what the LF brings to the table, as far as resolution, etc.  However, the LF does help things on a fair bit more.  I think you might find the LF55 to go nicely with the W22's in your Orion.

I've been to Hugh's many a time, and listened to his various speakers.  I forget what was hooked up during my little LF prototype listen last March.  However, any speaker with Seas Excel Mags is, as you say, a couple steps up. 
I was impressed with my little March listen, as I heard WAY more resolution and precision out of Hugh's speakers of that day that I had heard previously.

Good luck with the marital cash flow laundering system!

Steve

[LM]

Some two weeks ago, I posted my first ‘wow’ impression of the LF55 after listening at AKSA HQ for an hour or so through Hugh’s backup speakers.  So I couldn’t wait to get it home and try it in my dedicated stereo system but by the time the opportunity came up this weekend, it was the LF100 that Hugh placed in my boot.

Having reread most of the previous posts about both the LF55 and latterly the LF100, I’ve realised that I have found what everyone else has already said to be true and that repeating the descriptive accolades would simply take up space.  So I will take a slightly different approach and apart from summarising my impressions at the end, I will rather describe what the LF100 (trial) has done for my system.

To set the background then, I have been deeply researching speakers over recent times as my taste is for accuracy and detail, but neutral.  After much listening, Vandersteen 2CE sigs headed my list but in the ‘saving up’ meantime, I had picked up some very old but pristine Vandy 1s.  Whilst they are bottom end of the range, I had found them very good but lacking a little something, dynamics I suspect, with the previous amplification I had heard them with.  Whilst lovely, they were perhaps a touch more laid back than I wanted.

So, enter the LF100 stage left, hook it up to the Vandy’s with a reasonable CD source and lets see how they go together.  Well my first reaction is that ‘wow’ simply doesn’t cut it as a descriptor any more.  This has been simply the most pleasantly, astonishing upgrade weekend that I have ever had.  Talk about coming alive.  The LF100 has been simply brilliant in bringing out the best in the speakers.  Base is now amazing for a 2 way system.  That lower octave I was missing over the bigger 2 series is of course still missing in an absolute sense but the drive and slam on what I do have, is excellent.  More importantly to me, the overall naturalness and musicality across the whole frequency spectrum is pretty much everything I have previously dreamed of.  And I can’t even imagine how much better the next model up might be.

I have thrown every sort of music I can at the system to see if it trips up anywhere, but not so far. I hope I am not going too far now but I prefer the LF100 overall to the Glass Harmony for the reasons above.  To me it is quite neutral and while it perhaps lacks that little bit of extra warmth and finesse in the midrange, it is so punchy and fast such that to my ears it is reproducing all of the musical detail in an extraordinary way.  I have one quality recording of a string quartet that I have listened to about three times now and I still find it hard to grasp just how realistic the timbre of the instruments is.  Imaging and soundstage were superb such that you are really part of the performance.

Things I have particularly noticed were the handling of decay; brilliant.  Echo and reverberation detail are such as I have never heard before and as well, there is a totally natural instrument separation and an almost holographic soundstage.  My overall impression was of effortless rather than absolute power giving great dynamic range, transients, tonal purity and superb openness and imaging.  The dynamics gave me a huge sense of the performance, particularly during dynamic orchestral passages, that was very, very impressive.  There was no congestion, distortion or harshness that I could detect.  Strings, wind and vocals are remarkably lifelike.  String plucks are clean and all the stages of a drumbeat detectable.

I hope everyone reading this realises that I am neither a true audiophile nor a professional reviewer, just an enthusiast.  I haven’t listed any negative points as I have not noticed any.  I am sure, on rereading the above, that my description may sound a little enthusiastic for essentially budget speakers and source, but that’s how much the LF100 has enhanced my system to my ears.  In the end, I virtually dragged Hugh around to my place to have a quick listen to the amazing synergy between amp and speakers in a customer system.  I hope it was worthwhile Hugh.  My only problem now is being able to hang on after returning the demonstrator amp till Hugh can supply my order.

[Felipe]

Nice review Lyn 

Just 1 thing missing, you say it was an amp upgrade but didnt mention what you had (or have) before ! Is it the AKSA55 ?
Nevertehless...thank you for posting !

Felipe

[AKSA]

Felipe,

Lyn is not an AKSA owner, so he will be buying a complete, assembled amp from me.

He presently owns an ARCAM HT amp.

A clever man, he's a highly trained Hercules and Chopper pilot, a retired senior officer from the Oz Air Force.  He now works for an IT company which sells Air Traffic Control software around the world.

Like me, he's a petrol head, and owns a pristine 1972 Aston Martin DBS!!  His wife Robyn LOVES bikes, and recently had a suburban ride with me on the Kawasaki ZRX1200.

Lyn, I hope all this is OK with you!!

Thanks for the great review.  Very measured, perceptive comments.

Cheers,

Hugh

[andyr]

Felipe,

Lyn is not an AKSA owner, so he will be buying a complete, assembled amp from me.

He presently owns an ARCAM HT amp.

A clever man, he's a highly trained Hercules and Chopper pilot, a retired senior officer from the Oz Air Force.  He now works for an IT company which sells Air Traffic Control software around the world.

Like me, he's a petrol head, and owns a pristine 1972 Aston Martin DBS!!  His wife Robyn LOVES bikes, and recently had a suburban ride with me on the Kawasaki ZRX1200.

Lyn, I hope all this is OK with you!!

Thanks for the great review.  Very measured, perceptive comments.

Cheers,

Hugh

Hi Hugh,

"He now works for an IT company which sells Air Traffic Control software around the world." ... is that The Preston Group or Adacel??   

Wow, a '72 Aston Martin!  WOT a niiice car!   

Regards,

Andy

[AKSA]

Andy,

Ocean Software.......

Yes, a great car, with a hugely impressive lineage, archetypal British sports car, with the 325 bhp Vantage motor.

Cheers,

Hugh

[LM]

Hugh, Andy and Felipe,

No I don’t mind Hugh except it takes the focus off your astonishing amp and Andy, it’s flying management rather than ATC software.  We try to stay below the radar rather than on it.   Also Hugh not really a clever man, bit of a slow learner actually; otherwise I would have bought an AKSA or GH years ago.

Felipe, I had a stereo amp and speakers in place when I first heard Hugh’s GH but I retired them to a second room and pursued the holy grail of surround sound for a while.  Lost my way so to speak.  Ultimately after some failures, ended up with Arcam gear for HT and it was the top stereo performance of this kit that reawakened my interest in 2 channel from which I no longer had to cringe.  I won’t admit to what the speakers and amp were in the second room  but both had to go and you now know what their current replacements are (or will be).

[fred]

The next test is electrostatics;  I suspect this will be a consummate performer with ESL989s.

If I recall correctly, the AKSA is incompatible with electrostatics.  From your above comment, may I assume the Lifefore does not have this restriction?

[DSK]

The next test is electrostatics;  I suspect this will be a consummate performer with ESL989s.

If I recall correctly, the AKSA is incompatible with electrostatics.  From your above comment, may I assume the Lifefore does not have this restriction?

See http://www.audiocircle.com/index.php?topic=29033.0