[DSK]

...Darren, I must visit very soon.....  thank you for your input.  Are your new speakers that much better than the ribbons?  That surprised me!!...

Yes indeed! It didn't surprise me that they are more dynamic and coherent than the Ambiences, but they also pass more inner detail and deliver a more refined, transparent, complete and natural presentation (in the same way that the LifeForce does compared to the AKSA N+).

The Ambience is a lovely speaker and does most things very well, but it has a mid hall presentation that (in comparison to the SSR) you 'listen to' but are not as 'immersed in'. It doesn't really bloom forward of the speakers or reach out and grab the listener (when the recording requires it) like dynamic cone speakers do. It is a more laid back presentation. This is less of an issue on orchestral and some jazz music, but moreso on rock and more intimate, close miked performances (blues, folk, acoustic, small jazz etc).

Hugh, you are always welcome to drop in for a listen (and a coffee and chat)! You might just gain a newfound respect for just how good your GK-1 and LF really are!  aa

[RonR]

I've recently migrated from a 55N+ to a LifeForce55. It has around 50 Hours on it so far, so I think it's time to give some feedback:

Like others have said here, the bass region is where first impressions grabbed me. The bass is articulate and tuneful, and it gives the impression of going an octave or so lower than that of the 55N+. Resolution is excellent, the rendition of cymbals seems to be especially good in my system. The Sound stage is also more accurate than the 55N+, pin-pointing instruments is easier with the LF. These improvements are evident even at low listening levels.

When I first got interested in HiFi all those years ago, The dealer asked me what I wanted from a system. "I want to hear EVERYTHING" was my naive but optimistic reply. I feel that I'm a big step closer to that ideal with the LifeForce.

Note for GK-1 Users: After 20 Hours or so running in, I was aware of a slight lack of "warmth" when compared to the 55N+. Then it hit me . I had used a pair of NOS Siemens E188CC valves in my GK-1, which although excellent sounding, are "fixed mu". The H2 that is ordinarily supplied by the GK-1 was not there. This wasn't noticed when the GK-1 was partnered to the 55N+ because the 55 introduces H2 of it's own.  Swapping to a pair of Siemens "variable mu" ECC189s brought back that warmth. It looks like I have some more tube rolling to do to see what valve is best for the GK-1 when partnered with the LifeForce!

Cheers,

Ron.

[Joules]

In the Hall of the Lifeforce King.
 
I’ve been listening to Hugh’s new amp for a wile now. I use a pair of Lf 55's to power a pair of Raven R2 ribbon tweeters. A pair of Lf 100 to power 2 Accuton C90-T6 ceramic mids.
The detail, the low level detail in nothing short of amazing. The end of my room completely disappears and is replaced with an utterly believable sonic image of the recording venue.
There are details in instruments that surprise me, “ I never noticed that before”. I have listened to a lot of amps that I thought came close to this but in the end  no cigar, not even close.
These amp are every thing every body is saying about them.

The rest of the audio world better look out !!

    

[PT914]

Just installed Lifeforce 55 for my tweeter and midrange amps with Lifeforce 100 for the woofer amps on my Orion system.  I now have 25 hours of burn in time and they are amazing.  Like previous reviews detail is paramount.  I hear detail and accuracy in high, mid and bass.  This sounds strangely familiar like a previous improvement when I switched to Hugh’s new power supply for my ASP board.  Hugh, you have probably cured my desire to tweak things.  All my tweaking has improved mainly the tweeter segment at the expense of making the highs stand out.  Your Lifeforce not only improved the highs but also has improved the whole range so that the blend or the mix is perfect.  Vocals to background music have a good blend.  Bass is so detail and strong, I just gave up on my subwoofers, I don’t need them now, besides they can’t match the speed and accuracy of your amps.  Previous amps were 25 N+, 55 N+ and 100 N+ with lots of tweaking.  Lifeforce was a major investment but well worth the music.

PT914

[AKSA]

Darren, Ron, David and Phil,

Many thanks for your collective inputs - greatly appreciated, you have all nailed the salient features of the amps pretty well.      The preternatural detail, the sense of 'being there', the power of the bass and clarity of the mids and highs is apparently affirmed by all of you.  I'm convinced it's this detail which is at the heart of the surreal imaging;  it's caused a rethink on my part and I believe that imaging is about detail, mostly the almost subliminal detail of the recording environment.

Ron, I believe your comments about the ECC189 are absolutely spot on - there is no doubt that the major step up in detail of the LF over the AKSA mandates use of the 189 tube because it adds just a smidgin of warmth.  There is absolutely no distortion in the Lifeforce at all;  it's incredibly low, around 0.01% at close to full power, at least five times lower than the AKSA.  Only a tube knows precisely how much distortion to add, too, it's extraordinarily difficult to engineer H2/H3 into a global feedback SS amp though it can be done.

I'm absolutely delighted with results and sales to date - this amp is my absolute best, superior to the Glass Harmony, and I would hope to be selling it in the years to come just as I have the AKSA to this point.  I do believe that after all these years I've finally found the critical areas of amp design, after serving my dues it's all come together.  Sam and I are getting pretty slick at making them too, and we can each build eight modules all at once and test/bias/lacquer them for despatch in reasonable time.

The Squeezebox power supply and the Transmission Line speaker (the VSonics) are coming along too.  I'm really pleased to say that these projects just seem to be getting better and better.  I've been away interstate for some time, attending to my Mother after cardiac surgery, but she's turned the corner and doing very well.  Last Sunday we drove almost 700 miles - that took a while to recover!!   

Many thanks to all AKSAphiles who have contributed to this thread - but please keep these reports coming, they are invaluable for others trying to figure out exactly what these LF modules do......

Cheers,

Hugh

[AKSA]

Fajimr/Jim,

My apologies, your post was fiddled and lost, so here it is again:

O.K. .. it's about time I chimed in with my impressions.  I've had the LF55 running for about 3 weeks now and have more than 150 hrs in it so it should be pretty well settled in.... not really sure where to begin as I really haven't done these reviews before. 

I think it is easiest first to simply agree with what all the others have said- the LF55 is a definite improvement over an already excellent 55N+.  The detail is remarkable as is the soundstage that is reproduced.  In my system this is most apparent and striking in the cymbals and actually hearing the guitarist's fingers sliding on the strings- really remarkable!!!  The bass is definitely tighter and more pronounced but I don't think as much as others have noted- not sure if this is because I have Ellis 1801b monitors or possibly an artifact of running pure silver INPUT wires from the RCA to the LF board (anyone want to comment on this?  I almost posted this question in the IC discussion, wondering if the two silver wires with cotton sleeving should be twisted- they are not in my setup).

What strikes me most about the LF is that the music has more of a "dimensionality"- not in the sense that it is fuller but actually "rounder" if one may use that description.  It almost feels like I can hear the music in a third dimension. hmmm...... and here I have to pause as words can hardly describe the feeling but feeling is exactly what it is- the music has more feeling and more texture... really stunning!!!!

bravo to Hugh... I wasn't sure if the LF was worth the trouble and/or expense (actually dropping it in is no trouble at all)... but I am extremely happy I did.  I'm feeling quite happy with the sound now and have no interest in upgrading or changing... life is good.  Now to get a little time to get the GK1 together...

cheers all

jim

[Jens]

Hugh and everyone, please forgive the slight transgression into the realm of curiosity (about wiring)

So, instead of continuing along the wiring line (which is now in another thread), I'll post my Lifeforce 55 listening impressions:

First of all, I'd like to say that I entirely agree with Hugh's comment about this amp being "an entirely different beast". And beast it is, it's probably one of the best amps I've heard to date, and it obviously "beasted" the hell out of my superb 55N+, which I was very fond of. Shame on you, Hugh, what has that nice little amp done to deserve such treatment? (hope you received the returned 55N+ modules by now  ).

So, how does LF 55 sound like in my system? Well, just to put you all in the picture - in my system the LF55 only drives the treble and the mid, so obviously I cannot comment on its performance in the bass region.

However, even when leaving out its bass performance (which others have commented very favourably on), what it does is horrific. The very first impression I had "out of the box" was that of utter clarity and cleanness, paired with exceptional control and tightness. In my book, there is no comparison to the 55N+ at all. The 55N+ is a seriously good amp, but the Lifeforce 55 is one hell of an amp!

There has been a few comments that the LF could seem a bit cold. I do not agree. I think the LF plays every bit as much music as the 55N+, it just does it in an entirely different fashion and much better. You get detail and separation and soundstage to die for, paired with that clean, tight sound - but it still plays music. I have also noticed that there is less tendency to compression. Not that the 55N+ had a problem with this, but again the Lifeforce just does it better. Everything sounds more free and unconstrained. Even the dialogue in movies is much clearer and is easier to understand.

Another thing: when you've listened to this amp for a while, you just know instinctively that it sounds "right". I don't know exactly how to explain how I know this - I just know. Perhaps it's based at some intuitive level on many hours of listening to live music (especially classical) or other similar experiences - but it's a gut feeling: this amp does it right.

And for those who might be tempted to change the "rolled" tubes in their GK-1 to add extra warmth: I'm using Siemens Gold Pins (7308) in my GK-1R, and it's never ever sounded so sweet! No need to change anything.

To sum it all up: The Lifeforce is much more than just one step up from the 55N+, it's more like a leap up  Hugh, you did a really great job on this one 

Friends, Romans, and fellow Aksaphiles - don't miss out on this great amp!

[AKSA]

Thank you Jens,

This is a very good review, appreciated.  You touch on all the important points, well expressed and succinct.

I have another to follow, just now posted by Darren (DSK) on Critics Circle.  Here it is in full:

Foreword:
I have previously shared most of this content with fellow AKSA owners in the Aspen Amplifiers forum on Audio Circle. However, I continue to be so impressed by this amplifier that I thought I’d tidy them up into a more formal review for the interest of enthusiasts who haven’t heard the new AKSA Life Force amps and may not have heard of Aspen Amplifiers, the company. The number of times I’ve been moved to do this, during the many years that this obsessive hobby has had its boney fingers gripped tightly around my neck, could be counted on one hand. But, if I can help someone else onto the right path to achieve their audio nirvana I will be happy that I have given something back. I am grateful to the people who have helped me along my own path. Be aware that I am not a professional reviewer (a fact that will no doubt become evident as you read on) and that my ears may or may not be any more golden than yours. So, feel free to take this review with a large pinch of salt.

Intro:

Until about two and a half years ago, I was using the Plinius SA100 mk3 power amp. This was purchased after listening to a variety of amps from Audio Aero, Consonance, Melody, Electrocompaniet, Perreaux, Musical Fidelity, Arcam, Rotel, NAD, Elektra, ME, RedGum etc. The Plinius, rated ‘Class A’ by Stereophile, was a nice amp and I used it for several years. However, two years ago I had the opportunity to audition the AKSA Nirvana Plus amp in my system and compare it to the Plinius. Despite reviews praising the Plinius’ bass, the AKSA amp had more articulate bass, better transient attack and seemed a little more extended on top. Overall it was a more transparent amp than the Plinius, which sounded a little soft, veiled and ‘blowsy’ or romanticised in comparison. I also auditioned the Bel Canto EVO2 in my system and, although very clean sounding, it lacked emotion and life. So, I upgraded to the AKSA Nirvana Plus and used it happily for two years, until…

In July 2006 I had the opportunity to audition the new AKSA LifeForce 55 in Hugh Dean's system (which I have come to know quite well) for a few hours, then in my own system for a few days. Shortly after, the LifeForce 100 (subject of this review) was released and I eagerly snapped it up. The LifeForce 100 (100wpc) is simply a more powerful version of the LifeForce 55 (55wpc) and I’ve had it in my system for several months now. All marketed AKSA power amps are solid state designs.

Test System:

Sources: Sony SCD-XA777ES SACD player; Bolder modded SqueezeBox2 with Bolder linear power supply.
Pre-amp: AKSA GK-1 tube hybrid pre-amp (modded)
Power Amp: AKSA LifeForce 100 (aka LF100)
Speakers: Ambience Ultra 1600SE ribbon hybrids (Hovland xo’s); Selah Audio ScanSpeak References (Deluxe crossovers).
Subwoofer: Rythmik Audio DirectServo sealed subwoofer.
Room: 19’ wide x 24’ deep x 9’ ceilings, DIY acoustic treatments.
Power: Dedicated 20A lines, PS Audio High Current Ultimate Outlets (one on source, one on pre-amp).
Cables: Audience Au24 IC’s, Eichmann Nightingale SC’s, Eichmann AC Enhancer PC’s & PS Audio xStream Plus PC.

First Impression:

Upon installing a new component I usually hear 2 or 3 significant differences within the first few minutes, then listen longer to ensure that these differences are actually improvements, and to identify the less obvious differences. The most obvious areas of improvement upon firing up the LifeForce55 were: bass power and articulation; dynamic headroom/effortlessness; purity across the entire audible range; and openness and imaging. However, even more fundamental than this was an immediate and overwhelming impression of listening to a live performance rather than a hifi system. Everything just sounded ‘right’, natural and alive.

Bass:

It was immediately obvious that the LifeForce amp has plenty of stump-pulling grunt. Bass slam and quality were easily superior to the AKSA Nirvana Plus amps, with greater weight, impact, detail, and control. The palpability and detail of the bass was improved and we heard chords in the bass that were not noticed previously. The LifeForce 55 and 100 amps sound identical, other than the LifeForce 100 possessing even greater power reserves and control. The LifeForce amps really are the proverbial iron fist in a velvet glove. Though there are some higher powered amps that may equal the slam and dynamics of the LifeForce, I haven’t heard any that are also able to make the bass sound as realistic, palpable and acoustic as the LifeForce does. Crisp and punchy, round and growly, or heavy and gonad rattling, depending on the particular recording.

Mids:

Before hearing the LifeForce, there was always a little voice in the back of my head telling me that I would only find true satisfaction (in the mids) with a tube amp. Several months before the release of the LifeForce I auditioned Hugh Dean’s reference Glass Harmony tube monoblock amps (hot class A amps that were unfortunately too inefficient and expensive to be brought to market). Simply lovely, with a more complete harmonic envelope than the AKSA Nirvana Plus, this is what I had been yearning for. Overall though, the LifeForce is a better amp than the Glass Harmony. Compared to the great tube amps, the LifeForce may not quite have that very last iota of tube ‘wetness’ or ‘magic’, but its transparency, ultra low distortion and purity allows a far more complete and realistic harmonic envelope than any solid state amp I have heard and some tube amps too. The mids are wonderfully open, uncoloured, organic and convincingly real.

Treble:

The LifeForce is a wide bandwidth design and this is evident in the lack of rolloff in the higher frequencies. It is more extended and open than the Plinius and much more refined than the AKSA Nirvana Plus. Shortly after release of the LifeForce, Hugh replaced a capacitor that acts as a low pass filter, reducing any RFI and high frequency noise. This change has been retrofitted to all supplied LifeForce amps. After the capacitor change, the top end became even more open, detailed and natural, with the elimination of a very slightly hot top end that had masked some inner detail and soundstaging information. I really didn’t expect to hear a difference, but the change was unmistakable.


to be continued next post.....

[AKSA]

- the remainder of DSK's post....


Soundstaging & Imaging:

In my experience, tube amps typically portray a more complete and convincing portrayal of the soundstage and images thereon than their solid state brethren. They seem to have greater depth of image and better front to back layering. The LifeForce equals anything I have heard in these respects. I think this is perhaps due to the exceptional transparency and the completeness of the harmonic envelope that it offers. Whatever is on the recording, you will hear it, or in this case ‘see’ it. Whether a small, intimate studio or club performance, or a symphony in a large hall, you will not have to search for the audible cues to create an accurate picture of the venue in your mind’s eye.
Also impressive, is that the sense of the venue acoustic is not diminished during dynamic orchestral passages, there is no congestion or flattening of the imaging or soundstaging. The performance just continues in a completely open and unhindered manner. This control imbues a sense of power and majesty that is only evident from the very best amplifiers and seems to instill in the listener a sense of greater dynamic range, or at least greater effortlessness and control within the dynamic range. Very few amps seem to get right the ‘swell’ of an orchestra, homogenizing the various instruments into one big lump. Not so with the LifeForce.
In addition, the clarity and detail floating up from instruments deep in the soundstage on classical music is extraordinary. On many amps, these instruments are buried or just hinted at.

Character:

The LifeForce is a very neutrally balanced amplifier. Neither warm nor cold, it will simply allow the personality of the rest of the system to pass through unaltered. Simply spice to taste with your choice of pre-amp. In concert with the GK-1 tube hybrid pre-amp, I have found the tonal balance to be superb.

Perhaps most impressive is the sheer transparency, openness and lack of colouration afforded by the LifeForce. Along with the quietness of the amp, these traits allow tremendous inner detail to emerge in a completely natural manner and invoke a strong sense of purity and refinement. Thankfully, there is no solid state ‘thinness’ or ‘leanness’ to the sound of the LifeForce, it has excellent body or ‘meat on the bones’.

Strings and vocals are more lifelike and palpable than other amps I’ve heard to date, with a beautiful balance between the body and breathiness of voices, and also between the body and strings of stringed instruments. Percussion and guitar plucks are superb, with cleaner and faster initial attack, and the ability to float up more effortlessly from a quieter soundstage, thus sounding more pure and 'in the room'.

The LifeForce portrays vocals, drums, percussion, piano and stringed instruments in a more convincingly lifelike manner than any amp I have heard to date, with wonderful timbral and tonal accuracy.

Despite, or perhaps because of, the high levels of transparency and inner detail, the LifeForce is an extremely musical and engaging amplifier. In this regard, the listening experience is more like that from a good tube amp than a solid state one. Differences between various recording techniques and equipment are even more obvious than ever, as are any underperforming components in the system.

When we listen to bands at clubs there is a real weight to the bass lines that underpins and carries the entire performance, giving it a real sense of rhythm and life. Most stereo systems do not reproduce this feeling very well, leaving a comparatively lightweight and unconvincing performance. The LifeForce amps do this better than any I have heard, giving the performance a real (dare I say it  ) … Life Force.

It’s cliché I know, but the system has disappeared and I’m just enjoying the performances. The music has more poise and delicacy, the emotion and artistry just flowing out effortlessly. The suspension of disbelief is no longer periodically interrupted by artifacts that remind you that you are not at a live event (quality of the recording permitting). There is no conscious sense of listening to a tube or solid state amp, just real performances.

Conclusion:

As may be well evident by now, I am rapt in the LifeForce. I’ve spent many years in this crazy, obsessive hobby and believe that I’ve finally found an amplifier that I can live with for the long term. Matched with the AKSA GK-1 pre-amp, I am experiencing wonderfully realistic and emotional performances that I have not heard bettered, even by the systems I’ve heard with a total cost in the 60k to 80k range. On decent recordings, I am more consistently ‘in the room’ with the performers than ever before.

Though the LifeForce may be just the tiniest smidgeon short of great tube amps in harmonic completeness, it fares better in this regard than any solid state amp I have heard. It is impressive everywhere else (even in a ‘cost no object’ sense) and is a beautifully balanced amplifier that plays music in a very refined and engaging manner. No grain, no glare, no peakiness, no unnatural emphasis of any frequency range. It just sounds REAL.

Is it the proverbial straight wire with gain? Well, overall it is the closest thing I have heard yet.

Perhaps I can finish with the initial teaser I sent Hugh after hearing the LifeForce in my system for the first time...

“Hugh, F@#K THIS AMP is GOOD!”


By the way, this review is written purely from a performance point of view, without regard to price. IMHO you would normally need to spend pretty serious money to achieve this sort of performance. However, compared to the cost of some of the amplifiers with similar overall performance, the LifeForce is a true bargain. The only catch is that you will need to build it yourself or have someone do it for you. Hugh may be able to put you in touch with someone. More info, specs and pricing details are available on his website. (See http://www.aksaonline.com/index.html)

Disclosure: I have no vested in interest in AKSA other than being an immensely satisfied customer.

Darren, Thank You!  This is VERY comprehensive, covers the whole range of audiophile attributes.

Cheers,

Hugh

[David Ellis]

This is a re-post from my forum:

I have some... bad news.  I have invested too much money in my Golden Tube SE40SE (about $2400 total).  It has slight/pleasant tube-like sound and very good detail, but, it's inferior to the AKSA LF55.

Yesterday I conducted the official listening test with Mrs. Ellis, and she confirmed greater detail, layering, depth of soundstage, and bass resolution when using the AKSA LifeForce 55wpc amplifier.  The difference wasn't monumental, but it was present, and I agreed wit my wife's comments.  She doesn't speak "Stereophile", but the words that kept coming up were, "Yep, this one is better".  She would then explain why this was true from varying aspects.  The summation is that the LF55 is indeed a marginally better amplifier than my heavily modified Golden Tube SE40SE. 

I really don't know what Hugh did inside this amplifier.  My guess is the parts quality is a consideration and indeed the capacitors are all top-notch stuff.

Congratulations to Hugh Dean for making an incredibly good amplifier.  I didn't think this would happen, but it did.

There are several afore mentioned products that I have not auditioned/experienced.  The current hierarchy list is:

1.  AKSA LF55/LF100
2.  Golden Tube SE40 Modified by Jeff Glowacki at www.soniccraft.com
3.  VanAlstine Ultimate 70 (2 years old).
4.  Jolida 302b - modified

I will also offer some comment herein regarding the common commercial amplifiers.  The short summary is... the best quality parts are necessary to obtain the best possible results.  There are many good amplifiers on the market with fancy marketing campaigns touting their circuit typology.  While this matters (i.e. the Levinson 33 massive regulated power supply), the very best sound quality WILL ALWAYS  be obtained when using the best possible components internally.  Specifically, electrolytic capacitors with labels "Black Gate" (by Rubycon), "Elna Cerafine", "Nichicon Gold" are arguably the best possible components.  Coupling capacitors in tube circuits with labels "AudioCap Theta", "Sonicap", "AuriCap", "Jensen", "Mundorf Silver/Oil" etc. etc. .  There are certainly better quality diodes too.  It is worthwhile to note that high quality components will cost 10x to 20x more than "standard" components.  This is why 99.9% of hifi amplifiers don't use them... and remain inferior. 

This assertion is a generalization that assumes equally competent amplifier designs, design goals, and quality control.  I believe it is well within the reach of most amplifier designers to build a great amplifier using high quality components.  I do NOT believe it is within the reach of the accounting department to build a great amplifier using high quality (i.e. expensive) components.  Typology matters, but parts quality IS significant.  Given the same typology, an amplifier with better components will indeed sound better.

Dave

[pipedream]

I have some... bad news.  I have invested too much money in my Golden Tube SE40SE (about $2400 total).  It has slight/pleasant tube-like sound and very good detail, but, it's inferior to the AKSA LF55.

Mr. Ellis - Do you now own the LF55?

[David Ellis]

The LF55 in my living room belongs to Steve Harrison.  Steve allowed me to borrow his amp while in Australia for the winter.

Hugh is sending me some LF modules for my own amp.

Dave

[blizzard]

That is good news Dave.  Being that you liked the AKSA N+, I had a feeling you would like the Life Force even better.  I bet it sounds amazing with the 1801's.

         Happy Holidays,
               Steve

[stvnharr]

Let me just add a few comments here.  The Life Force 55 amp that David currently is using, i.e. mine, is configured with series attenuators on each channel and there is no preamp in the system, just direct connection from the digital source player.  This is about as simple as it gets.

Steve

[AKSA]

David,

Many thanks for your comments - appreciated, and substantial.

I think, like you, that the parts selection is certainly important, but the topology is arguably important too.  I once read something from a world renowned designer which mentioned equal parts of topology, component choice, and layout.  I believe it's more like 3 parts topology, 2 parts component choice, and one part layout.

I'll email you a bit later - much to discuss about forthcoming RMAF!

Cheers,

Hugh

[TomS]

Thanks everyone for the carefully written observations on the LF's.  Hugh obviously has a great product on his hands.

It was mentioned that the amp David Ellis had just used attenuators with a digital source straight in, though doesn't say what it was.

I've become very hooked on the direct to amp mode, but my resident BEL 1001 amps have very low sensitivity (2v for full output when bridged).

With 860mv input sensitivity (+30.3db) for full output on the LF100, has anyone tried a Bolder modified Squeezebox (1.1v max) direct into one to see if it yields satisfying levels and sonics with reasonably efficient speakers (87-88db)?

Tom

[DSK]

Thanks everyone for the carefully written observations on the LF's.  Hugh obviously has a great product on his hands.

It was mentioned that the amp David Ellis had just used attenuators with a digital source straight in, though doesn't say what it was.

I've become very hooked on the direct to amp mode, but my resident BEL 1001 amps have very low sensitivity (2v for full output when bridged).

With 860mv input sensitivity (+30.3db) for full output on the LF100, has anyone tried a Bolder modified Squeezebox (1.1v max) direct into one to see if it yields satisfying levels and sonics with reasonably efficient speakers (87-88db)?

Tom

Hi Tom,
Yes, when I first received my Bolder modded SB2 & Deluxe PS I ran it straight into my LF100 with Ambience Ultra 1600SE ribbon hybrid speakers. These are claimed 89db/2.83v/1m but after comparison to my new 83-84db speakers I would say that the 89db is rather optimistic. The sound quality was excellent, in fact so good that I left the system this way for 6 months. Eventually, I wondered how much of the improvement was due to the improved source (ie. Bolder SB2/PS replaced Sony SCD-XA777ES SACD player) and how much, if any, was due to omitting my modded GK-1 pre-amp from the system. So, I reinserted the GK-1 and .... it will never leave my system again. 

If I had not heard the system with the GK-1 back in, I would still be extremely happy. With SB2 direct to the LF100, everything was great and there were no flaws.... no apparent lack of dynamics or soundstaging etc etc. However, the GK-1 did improve dynamics, (surprisingly) offered a quieter soundstage and more inner detail, and increased the emotion factor of the music. The suspension of disbelief improved, there was a greater sense of being in the room with the performers.

For completeness I should add that I was using Y-connectors on the outputs of the SB2 to simultaneously drive the LF100 (47k Zin) and an active subwoofer (with approx 30k Zin). My GK-1 has two output pairs, one off the solid state stage for the subwoofer and the other off the tube stage for the LF100. Interconnects were all 1m long and of very high quality.

With SB2 direct to LF100, the SB2 volume averaged between 12 and 20. Supposedly, it needs to be above 16 to eliminate any degrading effects. With the GK-1 in the system, I am able to set the GK-1 attenuator at 12 o'clock and keep the SB2 volume at 25+. When I crank things up, I can set the SB2 volume to 40 (max) and it is out of circuit. I suspect that the ability to set the volume levels higher (and get them more out of circuit) when the GK-1 is in the system, is a factor in the improved sound.

Hope this helps!
Darren.

EDIT: Forgot to mention... the DAC in the SB2 is rated to drive a 5k load. Both SlimDevices and Wayne at Bolder confirmed that the modded SB2 (1.1v output) should drive the LF100 and subwoofer with no problems.

[TomS]

Darren,

Thanks for sharing your experiences.

I was a little confused on the levels you mention for the SB.  Mine goes 0 to 100 and I believe the optimum range is between 60 and 100.  Was yours maybe an early firmware such that it was a different range?

Tom

[DSK]

Darren,

Thanks for sharing your experiences.

I was a little confused on the levels you mention for the SB.  Mine goes 0 to 100 and I believe the optimum range is between 60 and 100.  Was yours maybe an early firmware such that it was a different range?

Tom

Yes, most of those users who have gone to the trouble of comparing the older V15 firmware with the later versions still declare that V15 sounds better. The volume taper was changed after V15 and the maximum setting rose from 40 to 100. I have not read of a single person claiming that V15 was outperformed by any subsequent versions. So, I have left my SlimServed version at 6.2.1 and firmware at V15 and I've never had a problem.

Also, firmware versions up to and including V15 inverted phase. So, for stock SB's you needed to swap your speaker cables around to compensate. But, for modded SB's (which also inverted phase) you didn't need to. A lot of people got confused about these changes and thought the sound quality was due to the phase change, when really it was about the volume taper change. SlimDevices claim nothing else was changed after V15 that would effect sound quality.

[TomS]

Thanks for the reminder.  I've flipped back and forth on both v15 and polarity.  I used Mgalusha's firmware selector on XP, then switched to Linux on the server and never dealt with the firmware switching issue. 

Sorry to take us OT, but I appreciate the feedback.  LF100 definitely sounds like an option.