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Brand New Super AKSA - the SAKSA 85!

No, AS, the SAKSA is the entry product; the larger powers are allocated to the Maya, which I expect to sell fully built.
You can use slightly higher power on the rails of the SAKSA to bring it up to 100W, but this will be the maximum. Certainly the output stage is very robust!
The issue I find is that when I try to assess what the market wants, then design and build the product, there are a few customers who want something more, and/or do not wish to spend the extra money. I can understand this of course, but I have to make decisions, and I cannot make everyone happy! The usual conundrum for a maker..... and often I get special orders, which involve a lot of my time and of course the reason in most cases is to save money for the customer. Result: I spend a lot of time customising a one-off to make the product the customer wants, and I lose. It's very difficult!

Cheers,

Hugh
 
Hi Lyn

Spotted your comments re buzzing transformers, whilst re-reading all the posts about the SAKSA 80. Many years ago, I built an Elektor Crescendo MOSFET amp, using 2 x 625va toroids, bought from Electrovalue in the UK. One toroid was made by ILP, the other by a company in Ireland (can't recall the brand). The Irish trannie buzzed noticeably....which I eventually fixed (>95% of it, anyway) by building a DC-blocking circuit (on one of Pers Anders PCBs), and installing it in its own box, between the powerboard and amp's power plug. Rod Elliott published a similar circuit on the ESP website, but does not offer a PCB.

Regards, Peter R
 
Hi ML,
For the SAKSA I use 280W mosfets and for the Maya I use a complementary pair rated to 480W.

As long as they are correctly driven and stabilised they arereliable and viable devices for audio.

I do a version of the Maya up to 280W but no plans to do a 500W. These amps need huge power supplies and massive thermal reserves increasing cost to the point so few are sold that the economics are unviable. Most audiophiles who need these amps normally buy Class D proaudio designs.

HD
 
No, ML, they are hexfets. Laterals have very low transconductance, but easy to compensate. The hexfets are very difficult to compensate; I have finally figured out how to do this accurately. Laterals are very expensive too, and limited in power too. They need a lot of negative feedback to drive a low impedance speaker.

Cheers,

Hugh
 
Hi Hugh,

Looking at your initial post with the attached pictures, correct me if I'm wrong and ignore my ignorance but is that a single PCB with 2 channel with separate psu on board so all we need to do is find a case and transformer? Basically I gather that's $k just for parts alone so it comes non populated.

Will you be able to sample a live one in Melbourne?

Peter
 
Yes, Peter, you have it!
I populate, adjust and test all my amp modules these days. I do not sell bare pcbs.
Once running, all you need is a case (I have them available at moderate cost, designed specifically for my modules so no drilling or threading or painting), two transformers for the Maya or one transformer for the SAKSA.
That's it! And I have plenty of stock right now; about ten of the Maya single channel large amps, and 20 of the SAKSA dual channel with power supplies.

Hugh
 
Hi Jim,

Aha! I have been finessing the amp and it is now ready. I have quite a few now in stock, and can supply starting next week!
I have to let people better through my website. I am somewhat confused about using some new software to make changes and it is sorely needed.....

You have a NAKSA 80, Jim, or is it the 70? In any event, this new amp delivers much stronger bass, and easier listen with bad recording (perhaps 90% of them!) and supernatural quiet. It's also able to drive 4R loads since I've double the output stage power.

Thanks for the post!

Hugh

PM: Paul K. seems to have gotten through his surgery and the inevitable complications. His spirit seems to be coming back.....
 
Hugh,

Thank you for the quick reply. Am I correct the Saksa uses the same 300VA transformer with two 30V taps? If so, it's a drop-in to for a Naksa 80 amp.
You are correct I have the Naksa 80 which is a very fine amp; but the madness continues.:)
BTW, what are you recommending for line input fuse on The Naksa 80. I've blown a couple of 5 amp 125V fuses so I'm now using a 10 amp 125 V fuse.

PM. I hadn't heard about Paul. We haven't been in touch for quite some time. Glad to know he's on the mend.

Thank you.

Jim
 
Hi Jim,

Sorry for slow reply.
Yes, you are absolutely correct; this new SAKSA uses exactly the same transformer, 300VA with 2 x 30Vac secondaries. The footprint and all output devices are in the identical spot too, so it's a remove and replace with no drilling! You may need to solder the input coax from the RCA inputs, but all the rest is 6.3mm 1/4" spade connectors just like the NAKSA.

The 5A fuse for a 120Vac mains 300VA toroid is not enough. I agree; a 10A for this lower mains voltage is mandatory.

I also offer a custom enclosure for this amp which is one piece 3mm Al, very swish and 300mm wide, 250mm deep, and 65mm tall. This is very small, very high WAF. It has all holes and connections all drilled and ready and fully powder coated, with nice SAKSA 85 front label. It is $AUD120, or $USD92. A bargain for guys who hate metal work!

I am selling the SAKSA 85 for the identical price as the NAKSA 80, which is around $USD710 in present exchange rates ($AUD930 per stereo).

Thank you for supporting my products, Jim, this is lonely work but I am thrilled your NAKSA 80 continues to give pleasure! The next model is my latest creation close to Nirvana!

Ciao,

Hugh
 

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Hi Mark,

Thank you for your post! Good questions..... why would you buy a SAKSA?
Some answers:

1. The AKSA 55 appeared in 2000 and hit quite a spot around the world. It had wonderful midrange clarity and bell like top end. This became my gold standard, and all later amps were compared with the AKSA.
2. All successive amps met the AKSA demands, and some. A few of them were benchmark amps and sold well, such as the Soraya, the Lifeforce II, the NAKSA series, and finally the Maya, which is a stellar amplifier, arguably my best, but more expensive.
3. The intervening years have given my the time and capital to figure out what makes a good amp. It is as much psycho-acoustic in fact as engineering. The engineering is relatively straightforward, but the big help has been the analysis of the harmonic artefacts of amplifier design. Keeping low THD is important, but going further into the distortion and extracting the harmonics has been more important. I'm getting much better at designing for harmonic profile, whilst keeping THD less than 0.05%.
4. The NAKSA topology hit on superior harmonic profile and rail efficiency. It brought down the parts count, giving me more reliability, and a new layout which allowed a stereo and full on power supply onto a single pcb.
5. The SAKSA, my latest design, was an attempt to bring the magic of the AKSA to the punch, simplicity and clarity of the NAKSA. It's been very successful and people love the sound quality, which is peerless. I have doubled the output stage, and can drive down to 4R and even lower speakers, including the electrostatics. I have removed an offset adjustment - it's automatic - and tweaked the statial presentations of this amp, so it throws up a deep, wide sound stage. It sounds very, very powerful for an 85W amplifier and can be trimmed down to a 300x250x65 case, VERY small and efficient.

You asked the question to upgrade - here, my thoughts, but more than pennies regrettably!! I have kept the price of the SAKSA 85 the same as the NAKSA 80 - $USD707 - which is highly competitive with very expensive amps in your market!

I have a daughter lives in Brooklyn, Mark, and happy to give you an audition since you are an old customer. This way you can listen before you buy.......

Ciao,

Hugh
 
Hugh,

I have always appreciated your designs and looked at them with endearment. Can you explain part 3 in your post above in some detail? What order distortion is desirable in an FFT spectra? How much overall THD is too much? Which of the various methods of IMD measurements have you found useful? How do they correlate psychacoustically?

It's not that measurements don't matter, it is which measurements and why. Most amps can pass a square wave but we are way beyond that in 2016! The devil seems to be in the details.

Best,
Anand.
 
Ah, Anand, this is a very philosophical question........

OK, let's start formally!

1. Audio is about conveying music, which is a culture of human beings, and involves forgetting the technology and, with eyes closed and a beautific grin, and could be termed 'engagement' (or endearment!) with the music. To this end, we have to figure out what the human likes about music, and what he (or she) does NOT like.
2. An analysis of music is as much subjective as objective. To this end it is very difficult to be objective about the subjective, but we could say that the listening experience is subjective, and the technology behind the sound is objective. Most of the measurements we make are single (or dual) tone; not strictly the same as a musical waveform. The relationship between the single tone measurements and the musical experience is the stuff of argument, but if you find a sound system 'musical', you generally can pick it immediately without recourse to measurement.
3. Most pleasing musical instruments tend to promote even order harmonics over odds. The harmonic profile is highly complex, giving us 'tone', or 'timbre', and this gives a belief that distortion from a sound system needs to depress ALL harmonics. But if some harmonics are present, they should be even orders rather than odds, and the reality is that all systems generate unwanted harmonics, even the best systems. As it happens, H2 adds warmth to the sound, while H3 adds the sharp, highly 'clean' sound; a sense of resolution. H4 adds a bit of body, and higher than these we really do not like them at all. These are all subjective observations but they explain a lot about tube amplifiers and why people like them.
4. If a sound system promotes H3, H5, and H7 but no others, it will be sound resolving but tend to sound 'machine-like', as some describe as 'digititus', or sterile. There are some people who like this sound, however.
5. Feedback has an effect on the sound quality and particularly the spatial characteristics of the sound. This is often described as 'imaging', or 'sound field'. If an orchestra is well recorded, a good system will throw up and image of the many instruments and precisely where they are located, laterally and by depth. This makes the system believable, and realistic. The ear is sensitive to the source of the sound; this is a primordial skill we have to avoid danger and seek out prey. Large levels of global feedback militate against this image depth, but high gnfb brings low THD figures, which do look good on paper. Most tube amps do this very well, and significantly use very little global feedback. I try to aim THD no higher than 0.05% at 1KHz from 12.5W into 8R, which is +20dBU. I generally get gnfb down to 31dB and even lower, no higher than that. Fast devices are important, nested feedback can reduce the distortion at the driver point in an amp, and I use 200MHz ft devices as voltage amps.
6. Many musical qualities are not easily measured. I try to aim at phase shift of no higher than 3 degrees at 20KHz, and ensure that all devices are fast and working with optimal compensation. This forces you to rely on subjective listening, both with the designer and a sample of selected audiophiles who are willing to do the long time listening tests. You do need a lot of tests and measurements regardless; amps must be engineered so that at clip they behave, deliver a higher S/N ratio, that at low levels they sound clear, and with complex music they deliver clean sound with no 'smearing'.

These are some of the issues I address in my designs and with lots of experimenting over a few years I've found how to bring out the musical qualities in my amps. This is R&D and it is very expensive and creative. I have spent as much on this as I have made selling amps, so it's almost a zero game exercise. You would only do it if you are compulsive, a bit cracked. Certainly I enjoy the pursuit, it's enjoyment for me.

Answer your question, Anand? Good questions, too.......

Hugh
 
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