AKSA 55, 100 - Listening impressions

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Here is short description of AKSA 55 and AKSA 100:
The Aksa 55 is a solid state, push-pull power amplifier module
delivering 55 watts RMS into an 8ohm load.
Input sensitivity for 55W output into 8R is 548mV rms into a Zin of 47K.

Designed with sonics as the primary focus,
the AKSA employs extremely refined circuit design and topology
to produce a stunning sound quality rivaling the best audiophile grade amplifiers in the world.

-------------

The Aksa 100 is a solid state, push-pull power amplifier module
delivering 109 watts RMS into an 8ohm load and 218 watts into a 4R load,
depending somewhat on the regulation of the power transformers.
Input sensitivity for 100W output into 8R is 740mV rms into a Zin of 47K.

For more info Aspen Amplifiers - Products


hifryer said:
I am a long term lurker!
I know Hugh Dean (AKSA) fairly well and will now unveil him!!

1. Hugh is FAR more the engineer than he ever lets on.
2. He has the most lucid and detailed grasp of how amplifiers REALLY work than any engineer I know and that any SPICE model will ever reveal ( tough luck pseudo objectivists).
3. He starts with strong theory and LOTS of measurements.
4. He KNOWS why simple is often better and the hidden deficiencies in complex ( e.g. current mirrors, tight active regulation etc).
4. BUT He then goes on for MANY hours with painstaking changes & listening tests to turn the proverbial sows ear into the silk purse.
5. This cost is why AKSA is worth many times its parts cost!!!

Belief in mathematical models alone is total folly. They are models NOT real world devices!!

We all ( hopefully ) end up building what sounds best to us! BUT all our ears are different!! They is an amp out there waiting for everyone!! ;-)

cheers!!

It is time we explore the ASPEN AMPLIFIERS somewhat more.

What are your listening impressions of AKSA amplifiers?
Are they worth the money spent?
 
Worth every cent IMO.

I own a AKSA 55N+ and it presents the music and doesn't just play it. No waffle on imaging and blah blah, but it has been the most satisfying amp I have ever had in over 30 years and besides commercial offerings I've owned, I've built the P101, P88, P3A (2), LM3875 (2), LM4780, Jaycar Silicon Chip amps and have a T-Amp.

I went down the path of building several amps plus intermixed with commercial pre's and could have saved heaps of money if I went and built the AKSA first. I'm glad I didn't as it showed me how good it is against others I've built plus it's been a fun trip doing the others..... most of the time.

Initially it might sound expensive but when you add the price of well chosen good quality parts, having parts supplied so it works as the designer intended (not to be under estimated), great instructions for assembly and diagnostics plus Hugh's support, it's a cheap buy. That doesn't even allow for the immense R&D that Hugh has done plus the sound quality.

I've only recently completed one of Hugh's GK-1 pre amps. Sure, it took a little bit of tube rolling to suit my music tastes (you can't expect one size to fit all), but has taken the AKSA 55N+ to new sonic levels.

When you buy an AKSA, you don't just get an amp, you become part of the AKSA family with Hugh at the head of the table. Even with all the pressures of running a business, he's always willing to make time to chat, help and advise.... money can't buy that. If you have a problem, he's there, when running and amp in and the sound is going strange, he's there to reassure you that after x hours it will come good... and it does. He's lived and breathed these things for so long.

Bottom line.... love my AKSA and I thank Hugh for his great design and support.
 
As far as I see, the circuit of the Aksa amplifier is basically not very different from my 25 years old Sansui amplifier : good sounding, nothing exceptionnal.
Maybe Hugh Dean can be promulgated a great engineer, but is he golden eared too ? If so, when adding some commercial skills, how many qualities in one person at a time !
Choosing not to use a constant current source and a current mirror in the differential input on the basis of listening tests is just proving one thing : the engineer/listener (with a very a very sensitive ear, indeed). prefers more distorsion than less. That's is his own right. However I can't agree when one tries to convince the whole earth that it's for better sound quality.

~~~~ Forr

§§§
 
It's sure great to find someone who can compare amplifiers by just reading schematics.

As distortion measurements a la current mirrors etc must lead to sonic Nirvana - all amplifers that need to be designed have already been designed!

Just go build Randy Slone's Design 12 with THD of 0.0038% and about 0.01% at 20KHz - as Randy says "30 times less than audible".

What more could we ever want? ;-)
 
forr said:
As far as I see, the circuit of the Aksa amplifier is basically not very different from my 25 years old Sansui amplifier : good sounding, nothing exceptionnal.
Maybe Hugh Dean can be promulgated a great engineer, but is he golden eared too ? If so, when adding some commercial skills, how many qualities in one person at a time !
Choosing not to use a constant current source and a current mirror in the differential input on the basis of listening tests is just proving one thing : the engineer/listener (with a very a very sensitive ear, indeed). prefers more distorsion than less. That's is his own right. However I can't agree when one tries to convince the whole earth that it's for better sound quality.

~~~~ Forr

§§§


Hi Forr,

With all due respect, the thread topic asks for "Listening impressions" For some reason I get the impression that you have not listened to one. Do you have something against Hugh?

Please, let's not muddy the waters. Many of us are curious how this amp actually sounds in comparison to some of the other popular DIY amps.

Blessings, Terry
 
Upupa Epops said:
So be brave, Terry : tell us, which amp, which you had make, is by your opinion the best...Telling, that some sounds " curious " to others, is rather alibistic... ;)


:confused:

I have not heard the AKSA yet. I'm not qualified to give an answer to the main topic either. I was trying to keep the thread on topic because I am interested in these amps. Seems others would prefer that not happen.

I can't find where anyone said anything about something sounding "curious". Have you got your threads confused?

I couldn't find a definition for alibistic. I'm afraid I'm at a loss to answer you.

Blessings, Terry
 
Listening impression is ONLY listening impression - if you don't compare it with others... Only in case, if listener is VERY expirienced, you can get results, which have some " weight ".... Listening without comparing is silly habit, which learn us popular magazines, 'cos they can't lose customer...
 
Upupa Epops said:
Listening impression is ONLY listening impression - if you don't compare it with others... Only in case, if listener is VERY expirienced, you can get results, which have some " weight ".... Listening without comparing is silly habit, which learn us popular magazines, 'cos they can't lose customer...


Listening impression is what was asked for. Certainly lineup understands that the answers will be subjective. I guess some folks believe that if something doesn't measure a certain way it can't sound good. Perhaps they should steer clear of threads asking for peoples listening impressions.

Just look, we've spent a whole page discussing whether someone can judge and amp by it's sound. Folks will probably be afraid now to give their impressions. Maybe that was the intent. :xeye:

Does everything have to become a soap-box?

Blessings, Terry
 
Never heard an AKSA

lineup said:
What are your listening impressions of AKSA amplifiers?
Are they worth the money spent?
It depends what you are after. From what I'll gather most of Hugh's customers are rather pleased. Don't forget what the customer target is. The product idea is not so expensive, pretty good sound, decent electrical characteristics. What does it mean converted to listening experience? I don't know. I have never listened to an AKSA amp.
 
OK, I'll have a go at some listening impressions.

First, my biasses! I love good tube amps and generally dislike many SS amps. I love SET's and listen to DIY amps like 211 and parallel 845.
I also own mainstream push pull pentode amps like Audio Research and EAR 509's. I have built a number of highly specified magazine based SS amps in the past and always been disappointed!

I hate Naims and Krells. To me, many SS amps are just not worth listening to. They may measure fantastic but they just don't do it for me.

I have compared the AKSA to a highly regarded and very expensive 150W Symphonic Line SS amp which I liked but I preferred the AKSA.

I own two AKSA 55 N+.

I cant speak to the N+ improvement just yet as the upgrades are recent and they still seem to be running in and changing. But even the base AKSA to these ears is an excellent sounding amp.

I find the AKSA in many ways superior to most tube amps. The bass is very defined, articulate, fast and extended. The amplifier is highly dynamic. The image is very stable. The top is extended and smooth and the mids are clear and full.

What appeals to me is the AKSA does NOT sound like a typical SS amp. It sounds part way towards a very good tube amp. It does not sound the SAME as a tube amp and SET's have attractions the AKSA doesnt quite manage BUT its close and I'm comparing it with amps costing perhaps 6 times as much to BUILD with up to 12 or so power supplies etc!!!!

For the money, compared to building tube amps, the AKSA is a total bargain and can hold its own in any company.

As I said I love big SET's but I sure get sick of all the heat and warm up times.

These are just my impressions and I must warn people how impressions uncontrolled can be very misleading. Firstly AKSA's need a long break in period, so any quick A:B test with a newish AKSA will tell one little. Secondly, our ears get tuned in to the particular sound we are used to and anything different often initially sounds inferior.

My method for judging components has nothing to do with evaluating Hi-Fi characteristics. I just listen to the music I love and feel the emotional communication. If this improves I like the component. All other characteriistics are meaningless if the system doesnt better take you into and close to the music and its effects on you. If after some time, I change back to the previous component and overall miss the new one, I want to listen to the new one, so it is better to me.

I find short term A:B tests useless unless one item compared is obviously pretty ordinary.

I recognise all this is highly subjective and what I like may not appeal to all others but what else can I say? That is how it is.

One last coment. I have found it important to consider rooms, loudspeakers and amplifiers as a single unit. Assuming you are happy with your speakers and their use in your room, then all amplifiers are NOT equal when it comes to interfacing to speakers.

I have less trouble as my speakers are quite sensitive but damping factors with tubed and amps and ported speakers can be an issue.

The AKSA can drive most speakers in most domestic situations to quite loud levels. However the 55W cannot drive inefficient speakers to disco levels!! If auditioning at loud levels with speakers known to need power and the sound, esp the treble does not impress or tires - make sure you are not clipping the amps!! This usually only happens when showing off - not on normal listening.

Oh, my music preferences: mainly acoustic Jazz, female vocals, some heavy rock ( my son is a rock drummer - so I KNOW loud!! ) , some symphonic. Good symphonies seem most difficult to get right.

I use an Audio research CD2 CD player and a tube pre-amp. I still prefer vinyl to CD's but mainly listen to CD's.

I especially commend an AKSA to music lovers or anyone liking or coming from tube amps who doesn't want the cost or inconvenience.


cheers
 
I have made many comparisons, and i included some modern amplifiers and some forum

important designs.

When those amplifiers are placed under a fair A to B comparison, AKSA shows his qualities without left doubts.

It is a wonderfull amplifier, with clear reproduction, a very nice sound stage, introduce small listeanable distortion, can reproduce the noise of fingers passing over a guitar string... can show you how strange can be a violin sound when captured very close by microphones, can distinguish clearly claps from rain, have wonderfull voices and very nice trebles, the sound related many people during conversation, inside some saloon, or even under open air alive recordings, are detailed and is not perceived as noise....if you make 6 persons talk at the same time, diferent texts, in the same language, you can focus in each one of them and listen at each one separatelly, in some repeated reproductions, you will have condition to write into a papper the text they spell, you will listen definition of their words.... and this hability is not common, and under this test no one could reproduce better than AKSA!

There are other good amplifiers, there are units with deeper bass, and other with very impressive dinamics......but if you want to talk about Global, general quality, going from the Sonics into the boards quality, the wonderfull support that Hugh Dean give us during construction, the value, and cost, of the parts included, you probably will vote for AKSA under a macro analisis.

The 100 Watts unit have the bigger dinamics that appear weeker in the 55+, also the deep bass reproduction going to 8 hertz match the best bass reproduction amplifiers.

Yes, a square wave entering the 55 will start to turn triangle at 43 kilohertz...well, i cannot listen to that frequency, the rats, mouse, mice can.... will be good to keep them, the rats, unhappy offering them lower fidelity in this range, as humans will not be bothered.

The ones that do not like AKSA, you can observe, they never heard, they just observe the circuit thopologie and already decided that is old and bad..... some of them are old guys, and some of them are old man and not necessarily bad people....old and bad do not need to come together as something that you cannot separate.

So, this seems that kind of people that neverfelt the taste off orange juice and go saying that do not like orange juice...no sense those things!...this is something from kids...and those very, very young.

Others have an envy that cannot keep hidden, jellows that dominated them strongly, and moved because of those things goes attacking some amplifier, that ,at least, sounds wonderfull.

Very unfair those things, but as a counterforce, there are the AKSA owners, very satisfied that always stand, keeping a defense line against those that try to send lame on this precious brand.

Hugh Dean is a Gentleman, someone that applied money in research, and many hours checking, comparing and evaluating.

He use to go visit customers to demonstrate and to compare his AKSA with with the customers units..... he never returned with his demonstration sample to his office, always sold immediatelly.... without a good profit, as travelling 300 km, spending fuel, he reduce his profit.

There are customers that travel to Australia, from USA, to receive AKSA from his hands, to have a dinner with Hugh.

Sales related forum are not more than 3 percent of Aspen Amplifiers Sales, so, publicity made here will not make Hugh more rich than he already is..... will just show some action to defend, to promote Hugh as a decent man, to protect the brand against evil feelings, and to show, once again, that Hugh has in each customer, a friend!

As he has the capacity to create confidence, to feed a friendly relation, to keep the relation in high level of education for the time the customer need, he never abandon his friends, he feel gratitude to the ones helped him, and he not use people to promote him, to after help done, kick their "essen" as they do not serve for nothing...once you prove to be friendly, he will be for ever giving you the attention you need.

We, customers and friends, we go promoting his brand because this is fair to tell the truth, as the quality is astonishing, sonics are close the perfection, can be compared and win the biggest majority of amplifiers you put to face it into A to B comparison, under decent controled sittuation, a blind testing, something that many guys that critised Hugh's amplifier do not even know how to make....so....as they cannot even produce the testings, when those testings were published many times in this forum, but they are not humble enougth to read, or worst, could not understand...they still ignore the method and prefer to be negative to keep their first evaluation alive...those guys never change their mind for nothing..... evolute, change the mind is a shame for those ones!
Well....they may be unhappy, and those guys cannot give us more than they have......it is hard to them to say something good as they do not feel good inside..there are a minority that have pains in their tongues when talk positive things.... they love to burn images and amplifiers on fire...as they are beeing burn inside themselves because of their own pains.

The worst is that those guys are proud...have more pride than clear mind...so...even listening AKSA, and perceiving how good it is, they will never tell here that they are wrong.

There are people that do not know even how to adjust bias.,..and facing those problems, not to perceive how small are their own capacities, start to burn the brand image...better to burn AKSA than accept that had not competence to make a simple job of adjusting bias...those ones goes inverting polarities and burning units...so they trown the unit in the garbage can and start to say that the unit has defect...when the defect was not related the circuit.

AKSA is a 55 watt unit, as small board, small circuit, small amplifier and a huge man, a big man ahead the product...when you may have bigger amplifiers, bigger circuits...with a very small man behind....

There are, unfortunattelly, people that loves to be famous, that needs to be promoted to feel that have value, so small they are inside themselves, they are rare, not more than your fingers in your left hand, those small guys have problems to apreciate, even their own families...are people very hard to feel good with something..... less than five i could count in our forum, and two of them already said good by.

A very old say, from my country, explain those things related envy:

Because not apreciate 55 amplifier, only beeing deaf or fooled by envy!

"The dogs make noise, but the carriage goes ahead"

God bless the King of Australia!, the best!, the first and the great Hugh Dean!

regards,

Carlos
 
AKSA 55 is very nice sounding and an excellent value. Of course, the exchange rate was a bit better back then. .55 US to 1 AUD, I think.

Having all the parts included made realizing a completed amp much easier for me and thus greatly enhanced its value.

I don't A/B amps but rather go through phases of listening to one for a while and then swapping. I think the AKSA has the best all around sound of all my amps: Dynaco ST-35 w/ Curcio CCDA, BrianGT LM3875, Panasonic XR45, Adcom GFA-545ii. All used primarily with Ellis 1801b's.

Over time I've been able to associate a distinct character with each and the AKSA simply is the easiest to live with.

I do have a Elliot DOZ but due to the low efficiency of my speakers, I haven't listened to it much yet.

My AKSA 55
 
still4given said:



Listening impression is what was asked for. Certainly lineup understands that the answers will be subjective. I guess some folks believe that if something doesn't measure a certain way it can't sound good. Perhaps they should steer clear of threads asking for peoples listening impressions.

Just look, we've spent a whole page discussing whether someone can judge and amp by it's sound. Folks will probably be afraid now to give their impressions. Maybe that was the intent. :xeye:

Does everything have to become a soap-box?

Blessings, Terry


Hi,

Alibistic...= alibi=covering your heinie from what I gather.

I don't know about you, but I welcome someone pointing out a possible non ideal design decision, it's not really a review/marketing forum, and if we cease to discuss the inner workings of the circuits, we lose our purpose.

Regarding everything becomming a soap box, I was thinking the same when I saw your signiature.

Regards,
Chris
 
I first heard a standard Aksa 55 in direct comparison to my Llanno monoblocs. I promptly bought an Aksa 100, since upgraded to N+ status. I've compared it to my Forte 4a, my Mac240 and far prefer my Aksa. I've heard it compared to numerous amps at various get togethers in NYC. While at these comparisons, others have preferred a more tubey sound (creamier) or higher speed (Spectral SS which reminds me of having an ice pick driven into my ears), I've never heard anyone say the Aksa isn't an excellent amp, just not their specific cuppa.
Viva la diference!

Have I heard better amps? Yup. I just can't afford them. But if someone would sell me a McCormack DNA 500 for 30% of retail, I'll gladly switch amps.

Do Hugh's amps measure as well as others? No. He has made a concious decision not to use a ccs on his ltp, to use a bootstrap on his Vas.... Shame, shame, shame! He thinks his specific amps sounds better without. No one would dispute that Hugh could probably make his amps measure better. I for one, don't care.
 
still4given said:
Listening impression is what was asked for. Certainly lineup understands that the answers will be subjective. I guess some folks believe that if something doesn't measure a certain way it can't sound good. Perhaps they should steer clear of threads asking for peoples listening impressions.

Just look, we've spent a whole page discussing whether someone can judge and amp by it's sound. Folks will probably be afraid now to give their impressions. Maybe that was the intent. :xeye:

Does everything have to become a soap-box?

Blessings, Terry

Yes, with topic - Listening impressions
there would be subjective answers.
I do not think subjective is anything bad. We are all subjects.
Even when we judge objective facts, we are subjective!
It is not that easy, as we may think, to separate subjective from objective.
But I think it is good if we try to.

In my topic presentation I quote short technical description.
The very circuits, with all their details, we may not be able to discuss fully.
But of course some technical information can be welcome
to go along with telling about sound quality and subjective impressions.

Does amplifier go better with some loads, loudspeakers?
Is there any type of music, that makes amplifier do very well?


From reading old topics, I have found very few that have built AKSA
and express that they are not pleased with the result.

I guess this goes for most DIY amplifier projects:
What you put together yourself
have a special place in your heart.
:)
 
Thanks for the comments, I appreciate the open minds here.

All amps should be judged on their sound, though looks play a part too, just like everything else. We use them to play recorded music, so the function should never be forgotten, and nor should the effect of music on our emotions.

Lovely technical details are just that, but one should never confuse complexity and vanishingly low distortion figures with a good sound. They are not always the same thing.

Often complexity is grandly hyped by marketing. After all, who is not impressed by DOHC, sequential fuel injection, variable valve timing, and electronic engine and transmission management? But complexity is only justified when the primary function of the device is enhanced. Otherwise, it always costs more, and generally decreases reliability, and should be avoided where possible.

AKSA distortion from the 100W is 0.043% at half power into 8R at 1KHz. This increases to 0.05% at 20KHz. These figures are more than acceptable, but what is important is that there is not a shred of H5 or higher in these figures, taken by Robert L. Jones in December 2002 in California on a HP339A Distortion Analyser.

I'm not too concerned about conventional distortion figures, except, of course, for marketing purposes. After all, the single ended triode, almost universally loved by audiophiles the world over (particularly on simple music), has THDs around 3%! I have found that vanishingly low THD figures do not always make a better sounding amp - the best I can say is that the correlation is doubtful. However, the spectrum of this distortion is pivotal, and not widely understood by the market, although the psychoacousticians know the details fairly well. Audio technology is so mature now that any advances will only be made by taking an unconventional, almost contrary, stand; and to this end the unfashionable should again be carefully considered.

If the philosophy of amplifier design is questioned, the products will improve and eventually the market will be better informed. Then, hopefully, we will see universally good sounding amps at low cost.

Cheers,

Hugh
 
AKSA said:

If the philosophy of amplifier design is questioned, the products will improve and eventually the market will be better informed. Then, hopefully, we will see universally good sounding amps at low cost.

Cheers,

Hugh

An excellent post, however, I'm not so sure it's the design philosophy that's in question most times, but the commercialized marketing one. I can't see that changing at all myself.

Seems their markets aren't even concerned with good sound.... enter the Ipod, etc. Good sounding amps will remain in the land of the very expensive and DIY.

Best Regards,
Chris
 
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