[kyrill]

I am in love with my AKSA 55 watts amp.

Already, and have not yet implemented the Nirwana + upgrade
I am a transparent junky I found out. It is difficult to discern what you love most. IS it  the musicality of the system? Meaning (for me) you can listen for hrs without getting tired, there is some naturalness about the sound that defies electronics. But it still can be veiled,  too friendly  without sharp transients and obscuring finer or intrinsical details
Is it the 3dimensionality, the placement of the players, the palpable space around the actors and the ambience of the room. IS it the focus, the rock steadiness of the boundary of the objects. The transparency? The complete lack of grain?
Because they are all there in real life, like elements of a circle, without a beginning and an end. Thru equipment the wholistic nature of a performance is distincted in the above and more properties and one apparatus is better in some properties than another brand or type.

Because I don't have my favourite preamp in the house (Klyne LX 7 preamp klyne.com) I had the opportunity to listen to different  but lesser preamps of yesteryear.  Manley's "Ultimate tube preamp, electrocompaniet II preamp, Naim series 5 preamp, Nad 3020 and NAD T751. Manley: musical, 3dimensional but veiled, ELectrocompaniet: transparent, fast but suffered from old fashioned electrolytics--> grainy, and a terrible volume potentiometer. Naim series 5, too friendly, musical and slightly out of focus, NAd 3020, big, spacey musical and a lot out of focus, NAd t751, no grain,detailed, in focus, veiled and smaller soundstage and instruments (too small, to be honest) and I found out I prefer the Electrocompaniet, because it is so crystal clear and transparent and full of intrinsical details. Two different cd's really sound different, one can be aggressive sounding, the other dull, depending on the recording engineer. But less than 30 minutes later I have to stop listening. Fatique and annoyance is setting in.
So for 500 US $ I can let it be upgraded (local hifi shop) with a better volume potentiometer and panasonic  pws caps and BG for the rest or another fine brand. That will take care of the grain.

The AKSA showing so clearly the differences in preamp merits the best that I know of.  So next to the Nirwana + (still in transit) I ordered today Tantalum 0,5 watt resistors from http://www.hificollective.co.uk/componentshome.html
I used Hugh's suggestion: "If you'd like to go replacing resistors on the 55W with Rikens, here's the list:

R1, R9, R13, R14. That's it. The others are not worth changing"
Too many reviews and forums on the web pointed to the transparent but musical properties of the tantalum's so I picked them over the Riken's

I will use The AKSA (and a second AKSA still to come) to steer the individual drivers of my self made loudpseakers with active digital crossovers and digital room control ( http://www.DEQX.com ) I will bypass the DEQX AD and DA converters. They are not transparent enough for me  and not high end as I hear them. So digital in, digital out

I have not yet decided which speaker drivers to use.
I am thinking of a 2,5 way system. A 2 way system and a subwoofer. I already have the (fast) subwoofers with an integrated amp.

 Which speakers would you choose if you would have "perfect" >100db per octave phase distortion free crossovers at any crossover point at your choosing? They must complement and preferably be beyond the characteristics of the AKSA's .
Is it true that a high efficiency speaker can reveal more minute and fine inner details of the sound than a let's say 85db/1 watt speaker?

Will a tlp between dac and AKSA not "hinder" the AKSa in its gorgious transparency while adding musicality?

PS The tranparency of the AKSA is enhanced with the use of a balanced power conditioner (+ 110 volst agains -110 volts, http://www.transcendentsound.com/power_supply.htm ) and I have on top of that one ( http://www.bluecircle.com/index.php?menu_id=1755 ) passive a filter combi They all are in love with
the AKSA.

PS I have to change my metal housing for a wooden one. copper foil inside will still preserve the "cage of faraday" properties of a metal housing, but wooden enclosures just sound better. See C37 articles on the web. Weird and interesting. ( http://www.ennemoser.com/ )

[MSeddon]

Kyrill,
Tell me more about the DEQX DAC problem?  Are you going to run 2/3 individual seperate DACs (after the DEQX) instead of using the DEQX internal DACS?

I have been looking at the DEQX and it looks amazing, but if the DACS are no good, then maybe it will not meet my needs.

Cheers,
Mike

[Tinker]

I am in love with my AKSA 55 watts amp.

I will use The AKSA (and a second AKSA still to come) to steer the individual drivers of my self made loudpseakers with active digital crossovers and digital room control ( http://www.DEQX.com ) I will bypass the DEQX AD and DA converters. They are not transparent at all. and not high end. So digital in, digital out ...

Hi Kyrill,
   I like active and digital crossover systems too. In fact I haven't had a passive system for over 5 years now. I am interested to know how you arrived at the conclusion that the DAC was bad and that it isn't say, a jitter problem or a limitation in the math of the filter implementation. For example, very steep FIRs have quite degraded transients. AndyR and myself have been looking at the DEQX for a bit now and would be quite interested in any tests you could conduct before going any further with one of these.

Anyhow, do you have pair of "ordinary" speakers handy? ie. passive crossover, or at least ones that won't blow up if you put a full range signal through them. Would you consider doing a listening test like setting up the DEQX crossover as an all-pass network and then comparing this to just the CD or DVD player straight into the amp. If this sounds fine, try adding a delay in the DEQX chain and see how that sounds.

Glad you like your 55! I have a phoenix (digital and electrical active XOs - no opinion on which is beter yet!) and the 55 is the best amp I've heard in this system, and believe me I've tried a few!

Cheers,
   T.

[kyrill]

Hi Tinker, MSeddon

The DEQX ia a very promising approach and I think an unavoidable one in the (nearby) future. The in real life implementation of their creative and bold move must be very very costly if you want to reach high end standards. Their price between 2500-3000 US $ is in high end circles the price for a midlevel preamp alone, or a poweramp or a dac .... or in audio pro circles (studio's etc.) the price for a good stand alone 19 inch AD converter.

To have all those goodies (except poweramp) in one sleek package including remote volume control for that price is a bargain to almost any standards. The way I will use it digital in digital out will be still a bargain..

It is impossible to have high end ad's and 3 high end dacs and the complete userfriendly software and the two built in "computers"(dual SHARD DSP) for that price.
SO you have to tweak it. The Burr Brown 24 bit dacs need a very very stable power supply. Deqx uses the kind you find in a computer. I think it is a digital supply, No main power transformers, very small and few elco's.
I don't know how good a digital pwr supply is. Anyway a dead silent pws for a 24 bit dac is cumbersome and costly alone by itself.

SO how did I find out I did not like the ad and dac's?

I used the DEQX between cd player ( who is heavily modded and ultra transparent, you hear passages buried in the signal of the music which were mixed away by the recording engineer) and the AKSA.
I did not use any filter with the DEQX:(bypass mode)
The Copland cd player has analogue and digital out.,
With analogue out and digitilised by the DEQX the sound was constricted with no transparency at all, 2 dimensional, no transients. It was so obvious I stopped listening after two contrast checks of 2 minutes (comparing with Copland digital out and DEQX digital in)
With DEQX digital in the transients were somehow back and it became listenable on hifi level. But not very hifi. If I substituted the DEQX for the NAD t751 (HOME THEATER DTS DD receiver) built in preamp, the NAD was easily superior  in transparency and musicality. ANd the NAD is my last choice between the other preamps I have .

I think jitter is the main culprit as it probably always is.
A look inside the enclosure reveals one big pcb as big as half the unit and  the two big DSP chips on a small parallel board on top of the mother pcb. All components are of the SMD type. the motherboard resembles very much that of a computer and will be very hard to tweak for normal "operators" like me ( the shallow amateur)

I have not used the filters yet as I still need a second amp for bi amping.  My 30 kilo's 400 watts Melos triodes mono amps are too big for my future self to be build speakers.

But even if I used the filters ( ...a jitter problem or a limitation in the math of the filter implementation. For example, very steep FIRs have quite degraded transients)  those warnings do they apply to the DEQX?  the filters are in the digital domain. the drawback with beyond 100 db filters,  according to their manual is "only" latency. But their maximun latency with 300 db/oct is less than 30 millisec They choose for very low latency so that the units can be used for dvd video payback and sound and video are still in sync.

With digital out you can set the DEQX to accept an external "masterclock" as it is done in studio's. This synchronisation is what I need? Maybe not.

I don't have the digital out board yet. They will send it to me next week.

Hopefully I can use the DAKSA at the end of this year, who knows? But then I need 3 of them.

Tinker: "Anyhow, do you have pair of "ordinary" speakers handy? ie. passive crossover, or at least ones that won't blow up if you put a full range signal through them. Would you consider doing a listening test like setting up the DEQX crossover as an all-pass network and then comparing this to just the CD or DVD player straight into the amp. If this sounds fine, try adding a delay in the DEQX chain and see how that sounds."

I did that with the music. to install delay is possible, but  I don't know the DEQX too well at the moment. I waited until the AKSA was ready and then as a try would use the NAD 3020 power amp part or one of the amps of the NAD t751 in biamping, install the DEQX software and get to know the enormeous  versatility of the software with its many many wizards. My hat of for their software, it is full of graphs and show probably all the freq properties of the speaker units, that you can think of.
But after my experiences i rather wait for the digital out board before I experiment further.

But who wants to answer my speaker questions?
: )
K.

PS Tinker,
I will send you an email on aksa1@optushome.com.au

[gonefishin]

Thanks for your thoughts on the Aksa 55.  I may have to give this amp a try.  Of course, I'd probably just go with the lower Wattage Aksa 55.  

 Although, 55 Watts into my >100db speakers would be something      


  thanks for the review,
  dan

[thayerg]

kyrill,

I'd say that rather than revealing huge differences between preamps what your AKSA is really doing is revealing its own sensitivity to line input impedance.

[Occam]

kyrill,

I'd say that rather than revealing huge differences between preamps what your AKSA is really doing is revealing its own sensitivity to line input impedance.

Nope..... The output stage device, configuation and impedence of both the GK-1 and TLP are not materially different. Its what is happening betwixt and between (the input and output of the preamps) that differentiates the two. The GK-1 is far more sophisticated.  The elegant complications inherent in the GK-1 are what is neccessary to address what Hugh felt was needed, no more, no less. The subjective differences between the TLP and GK-1 cannot be attributed to the ouput stage impedence.

[kyrill]

Hi Occam

I think Thayerg refers to my description between for instance the electrocompaniet and the Manley pre amp and so on.

I don't know out of heart what their respective output impedance is, but I doubt that their low impedance albeit probably different from each other is the main cause for the differences I hear.

All amplifiers have an output impedance. But there are bad sounding, hifi sounding and high end sounding ones with equal output impedance

[Occam]

Kyril,

You're absolutely right!

Thayerg,

Most sincere apologies.... I, unfortuneately am subject to ever more frequent 'senior momoments' . I'd just went down the Aspen board and read your response as responding to the 'Tlp vs. GK-1' thread..Total mis-interperetion on my part. S'cuse.

[thayerg]

Too late. Now I'm pissed. Only I'm not quite sure what you have to apologize for. Once I figure that one out I'll be properly frosted.

If it makes you feel any better I achieve some spectacular senior moments all the time despite being technically shy of seniordom a good seventeen years.

I still think the variations in sound quality through the AKSA have more to do with the preamp output currents than anything else. It could be one of the 'gotchas' of minimalist SS audio design.

[AKSA]

Thayerg,

You really should lay off the sauce;  I'm pissed in Orstrayun means 'I'm drunk'!

Input impedance of the AKSA is around 43K, up there with tube amps, with almost no variation with frequency.  Most SS sources have a Zout around 100R or less, and I'm not sure if impedance issues will control the sonics much.  However, if you've got any ideas on this, I'm open to suggestions!  (And I'm heartened, at my exalted age, that you too have 'senior moments'!!  This gives me hope... )

Cheers,

Hugh

[Smeggy]

Yep, it means drunk in Inglish too    

[thayerg]

Well I guess I was barking up the wrong tree. The AKSA sounds merciless.

In the US 'pissed' is the short form for 'pissed off'. In a completely unrelated (except semantically) factoid: Which world-famous Australian male sibling singing trio were known to their intimates as 'Pissy, Pilly and Potty' for their respective tastes in intoxicants?

[Tinker]

I've just caught up with the earlier part of this thread, and hats off to Kyrill for testing out the DEQX, very thorough work. On the basis of this it does seem the D/A stage is the culprit.

The "digital" power supply is probably a switch mode, which many regard as pure poison from an audio point of view. I have a few pieces of gear with switch mode supplies and while I don't hate them, I find some of the old school alternatives seem to sound better. Des gustibus non disputandum est.

As for what speakers I would use given an "ideal" crossover, that's a really hard one. I don't really know how you would identify an ideal speaker. My own penchant is for dipoles of various kinds: AMTs, ESLs, and the Linkwitz Phoenix. So I'm always interested in things with high linear excursions, but closed box speakers need quite different properties so I feel totally in free fall with that question!

If we're talking brands or technologies, Scan Speak are great but very pricey, while peerless are great value for money. If you are in the mood for experimenting it's definitely worth looking at so-called "aerogel" and "honeycomb" cones. Best sealed box mids I ever had were aerogel.

Whew, more on the crossover later.

Cheers,
   T.

[AKSA]

Thanks Ben,

I agree;  Kyrill is very thorough, and Aerogels are nice, nice, nice.  Are there many still available?  I remember Olsher's Polynatalia;  are these still around?

Thayerg, was the The BGs?

Cheers,

Hugh

[andyr]

..Des gustibus non disputandum est. ...

C'mon Tinker, you old academic wanker, tell the plebs like me what that means in Engerlish!!

Regards,

Andy

[AKSA]

Hi Andy,

Heck Mon, even I got this one (with help from Google... ):

(day GOOS-ti-boos nohn est dis-poo-TAHN-dem) Latin for “There’s no disputing about taste.” Another version of this saying is “There’s no accounting for taste.”

Hugh

[andyr]

Hi Andy,

Heck Mon, even I got this one (with help from Google... ):

... Hugh

Hi, Hugh,

Wow, I never even considered using Google!!  

Does Google find U this one (my favourite)  ... "Nil bastardo carborundum!!"

Regards,

Andy

[thayerg]

Hugh,

It was.

[Tinker]

Incidentally, I didn't mean to be flip about switchmode supplies in digital audio gear. The Behringer Ultradrive (of which I have a modest example) and I believe the dbx driverack both use switchmode supplies. I don't know about the XTA,s, but it seems that the DEQX is in good company as far as this choice goes. I do know that others have commented in the necessity for good supplies to the 24bit DACs. DANGER! Serious modding ahead! Of course this will be moot with external DACs.

T.