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Old 31st December 2015, 02:57 AM   #1
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Default Maya200

I have the first I believe Maya200 from Hugh.

I've been burning it in over Christmas after Aussie Post lost it for 9 days silly silly wombats.

I must say it sounds very musical and powerful sounds like more then the 250W it pushes into 4ohms.
The low end driver grip is very strong and the sound stage is very wide.
No fatigue or SS glare at all tube like but with power.

Looking inside there are only two output devices per side for each channel.
I'm very happy with this AMP much better then the Bryston SS7T's it replaced.

Highly recommended.
Happy New Year
Garry
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Old 31st December 2015, 07:58 AM   #2
AKSA is offline AKSA  Australia
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Thank you Garry! I am very pleased you put the Maya in such good company, this is quite a pressie for 2016! The output devices are BIG, they are rated EACH to 480W. It took some time to figure out how to use them, they are extraordinarily robust.

You are the second Maya customer, in fact! I have a few more on queue right now, pity the weather in Melbourne is HOT at present; 39C today.

A very Happy New Year to you and your family - 2016 will see some changes in the world I'm sure.

Ciao,

Hugh
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Old 31st December 2015, 08:21 AM   #3
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Happy New Year to you Aussies
Hugh,I'm realy hoping the Maya travels the world
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Old 31st December 2015, 11:34 PM   #4
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Default Maya

The cat is poking it's head out of the bag now. And 2016 is the year of the Maya Amplifier. I'll leave it to Hugh to fully get the cat out of the bag at the proper time.

However, I have been building and listening to prototype versions of the Maya for several months while Hugh continued work on the final product. This is a special amplifier with wonderful sound and spatial qualities that are easily heard with all genres of music. I continue to be amazed at every single listening session, which is most every day.
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Old 1st January 2016, 03:26 AM   #5
AKSA is offline AKSA  Australia
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Yep, Steve is on the money...... and my sincere thanks to him for incredibly patience taking the Maya through its paces to ensure it will be utterly reliable and durable. We are both at last happy with this long gestation!

As most realise, I'm a lousy salesman, but this does mean that I understate most of my comments and you can be quite sure my descriptions are precise and up to date!

I'm listening to a 50V Maya at present, on classical guitar. This amp will be released with 62V rails, which relates to an easy 210W into 8R and much more, depending only on the transformers, into 4R, at least 300W. The topology is unique, different to the NAKSA, and the flagship for Aspen. I will be offering the modules for $AUD2250, which is $USD1642 on the present rates. This is actually pretty much the same as the original N125, which was sold at $AUD1620 when the Oz dollar was almost at parity, so in a sense it's a lineball price, and much more technology and performance.

Features:
SS relay speaker protection, which tripped with more than +/-2V DC on the output.
Soft turn on and fast turn off for the speaker.
29dB of global feedback, delivering wonderful spatial characteristics, viz sound field.
Blinding speed; the amp is limited with a low pass filter on the input, but will deliver real power up to 150KHz. Quiescent is 125mA, and total dissipation of output stage is up to short term 940W.
Very low THD, less than 0.025% into 200W, and very low noise, lower than -105dB.
Very low odd order harmonics in the distortion profile; this is the primary aim in this design, which is supernaturally musical - tube grace with SS muscle.

Attached is the module, which is double sided on 2mm black FR4 and 70 microns copper. Every attempt has been taken to address all detail in the layout of a SOTA Class AB amp.

I am now finishing the documentation, but I will not be publishing the schematic!

Cheers,

Hugh
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Old 2nd January 2016, 07:51 AM   #6
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Wombats777,


The SS7t would be a Carver amplifier if I'm not mistaken, or is it the Bryston 7B sst?

Colin
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Old 2nd January 2016, 10:40 AM   #7
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Colin,

I found this at Enjoythemusic, by Dwayne Carter:

Quote:
O.K. now the price? The Bryston 7B ST mono amp (remember, you need two of 'em for stereo folks) go for about $ 2400 ea. ($ 4800 a pair). I will be saving my pennies for a pair of these amps, count on it. Now where the hell are my car keys? The weather channel says we're in for some heavy rain, and I feel the need to humble a Humvee... subtly of course.

Tonality 91
Sub-bass (10 Hz - 60 Hz) 90
Mid-bass (60 Hz - 200 Hz) 90
Midrange (200 Hz - 3,000 Hz) 90
High-frequencies (3,000 Hz on up) 89
Attack 92
Decay 87
Inner Resolution 88
Soundscape width front n/a
Soundscape width rear n/a
Soundscape depth behind speakers n/a
Soundscape extension into the room n/a
Imaging 94
Fit and Finish 95
Self Noise 99
Value for the Money 91

Wattage: 500 watts mono( 2 or 8 ohms), 800 watts mono(1 or 4 ohms)

Distortion: Less than 0.007% from 20 Hz to 20 kHz at 500 watts

Slewing rate: Greater than 60 volts per microsecond, parallel,
Greater than 120 volts per microsecond, bridged

Features: Series/parallel switch
Massive heat sink
Regulated power supplies to all voltage gain stages
Gold plated input and output connectors
Switchable balanced XLR and RCA unbalanced inputs

Warranty: 20 years parts, labor

Dimensions: 19 x 5.25 x 15.5 inches 48.25 x 13.33 x 39.4 cm

Weight: 42 lbs. each

I await Garry's reply, but this is, I think, the amp he owns. He told me it was a Bryston, and it's a very well made amp with good figures. These are well made and a technical de force, with a patented, clever and elaborate output stage. I understand they have been around for more than ten years, and VERY powerful.

Colin, as you know, and you go for this too, I'm trying to peel back the subjective listening experience with my designs. In 50 years SS has been obsessed with technical specifications, particularly THD, and I discerned that there was a place for going to the sound quality, assessed by critical listening tests. This is why Pass' amps, JLH's Class A, Le Monstre from Hiraga, and the recent DartZeel from Delacretaz really pricked my ears. My recent amps are designed in the ethos of all these amplifiers.... regardless of specification, which is pretty good but not exceptional.

Thanks for your post, and Happy New Year!

Cheers,

Hugh
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Old 2nd January 2016, 11:19 AM   #8
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Hi Hugh,

Out of curiosity, why did you choose FQA40N25 instead FQA28N15 as a FQA36P15 complement...FQA40N25 has ~1/3 higher gfs and parasitic capacitance than FQA36P15?

Happy New Year
Ivo
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Old 2nd January 2016, 10:04 PM   #9
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Quote:
Originally Posted by aparatusonitus View Post
Hi Hugh,

Out of curiosity, why did you choose FQA40N25 instead FQA28N15 as a FQA36P15 complement...FQA40N25 has ~1/3 higher gfs and parasitic capacitance than FQA36P15?

Happy New Year
Ivo
I'm not Hugh, but the mosfets you are posting about are the ones in the Naksa 125. The Maya, topic of this thread, uses different mosfets altogether. Hugh can comment further.
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Old 2nd January 2016, 11:02 PM   #10
AKSA is offline AKSA  Australia
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Hi Ivo,

Happy New Year to you!

I use much bigger, 480W mosfets for the Maya, and yes, they have much higher transconductance and parasitic capacitances. The NAKSA 125 uses 280W devices.

I could fill a page on this; it's my stock in trade for the last twenty years. Firstly, higher transconductance means there is very little change in Vgs on these devices over the full waveform, and the Cgs (input capacitance Ciss) is bootstrapped by a common source configuration. These devices have transconductance around 25S plus, where bipolars are markedly less (typically 20S for a C5200), so the waveform compression of mosfets is generally superior to equivalent bipolars by 1:1. A single pair of very large mosfets are superior to multiple pairs of bipolars; more resolution and easier to drive (no gate current). It is much easier to drive large mosfets than most expect, and in fact I found using drivers increased phase shift and gave no subjective improvement in sound. We are working with audio, not radio frequencies, and up to 20KHz a high driver current is more than sufficient drive. In fact, the Maya will do huge output to 100KHz and beyond if not fitted with a mandatory LP filter.

There are some dark secrets in using mosfets in this way. They are skittish devices, inclined to self-oscillate. Robert Cordell helped me from a 1984 white paper on these fascinating devices. These days I would not use anything else, and we can thank SS traction technology for this; hybrid electronics use them in VFD modules.

Thanks Steve, absolutely, different devices, and we think, you and I, that the bigger mosfets sound as good and even a bit better.....

Hugh
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Last edited by AKSA; 3rd January 2016 at 01:04 AM.
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