Here is info about the room:
Wilson Audio Specialties Sasha loudspeakers, D’Agostino Master Audio Systems Momentum monoblock power amplifiers, Transparent Audio cables, and Peter McGrath handling the tunes via an iPad and Meridian Sooloos MC200 media center.
http://www.wilsonaudio.com/product_sash.shtml
http://www.transparentcable.com/products/show_product.php?recID=24&perfID=1&catID=1&modCAT=1
http://www.meridian-audio.com/sooloos/downloads/mc200-ds.pdf
The Meridian Sooloos System : The Components
Thank you for this informations. Perhaps one of the members was there and have get first impressions from the listening session.
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The best description I have seen so far. Apparently the meter was inspired by a Breguet watch:
An externally hosted image should be here but it was not working when we last tested it.
Go figure.
The pressure meter on my pool pump comes to mind as well. One of the ugliest amplifiers I have seen. Dan succeeded to be radically different he could have called it Cyclops.
We are drifting slowly from the actually topic.
Furthermore, it did not interest me, for which user d'Agostino's amplifier outline design is ugly in appearance.
The real reason why I start this thread was not to discuss the outline considerations of this amplifier (please read my headline exactly).
Is my english so bad?
BTW - this amp cannot be call "Cyclops", because there are already at least two other brands with such a name for their amplifier model
http://www.positive-feedback.com/Issue9/cyclops.htm
http://www.odysseyaudio.com/products-cyclops.html
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According to an engineer pal who spoke to Dan recently in Melbourne, this is definitely new technology, at least for audio.....
Output stage is open loop, for starters.
Hugh
Output stage is open loop, for starters.
Hugh
That could be gleaned from the DF spec alone, one would expect...
_-_-bear
PS. I believe nothing said by most big$$ high-end people in the biz. How about you?
_-_-bear
PS. I believe nothing said by most big$$ high-end people in the biz. How about you?
Bear,
What precisely do you mean? Certainly, no one was talking, this is a very close industry, all smiles and no information, but it's not too hard to figure out what is happening with Dan. Even his new company name infers a certain irony.....
Hugh
What precisely do you mean? Certainly, no one was talking, this is a very close industry, all smiles and no information, but it's not too hard to figure out what is happening with Dan. Even his new company name infers a certain irony.....
Hugh
Those Vivid audio speakers are amazing. At RMAF it was one of the best sounds. They were driven with Luxman though.
I don't understand this term:
Here several informations about the dome tweeters:
http://www.vividaudio.ch/drive-units/drive-units/d26-tweeter.html
http://www.vividaudio.ch/drive-units/drive-units/d50-tweeter.html
http://www.vividaudio.ch/images/docs/brochure.pdf
This could be one of the first metal diaphragm speakers, that sounds good. Unfortunately I haven't heard, but I'm excited to the perception sound character.
Here several informations about the dome tweeters:
http://www.vividaudio.ch/drive-units/drive-units/d26-tweeter.html
http://www.vividaudio.ch/drive-units/drive-units/d50-tweeter.html
http://www.vividaudio.ch/images/docs/brochure.pdf
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With many output devices in a normal loop feedback amp the DF would be very high, I would expect that the DF without loop feedback would be pretty low, under ~100 and somewhere (guessing) around 40-50 or even lower... that's what I was saying.
_-_- bear
The Vivid speakers are Designed by Lawrence Dickey, that also was the man behind the B&W Nautilus speakers. I do have great respect for his designs.
He has, as one of the only in the industry, been working a whole lot with what goes on behind the membranes...He has by a smart magnet-motor design reduced rear-wave reflections from the driver hard structures. He has also been working quite a lot with transmission-line loading of tweeters and mid-ranges.
He relies solely on the use of anodized aluminum cones, and to me that is the greatest compromise in his designs. as they will have resonance peaks just about an octave away from their linear region. And to me there are other and better materials that could be used with better results...Or so I believe there is....Lawrence may think other vise...🙂
He has, as one of the only in the industry, been working a whole lot with what goes on behind the membranes...He has by a smart magnet-motor design reduced rear-wave reflections from the driver hard structures. He has also been working quite a lot with transmission-line loading of tweeters and mid-ranges.
He relies solely on the use of anodized aluminum cones, and to me that is the greatest compromise in his designs. as they will have resonance peaks just about an octave away from their linear region. And to me there are other and better materials that could be used with better results...Or so I believe there is....Lawrence may think other vise...🙂
tief - "biz" is short for business.
I do not believe most of what is said in public by those in the high-end business. Certainly the part that can afford to advertise in the glossy magazines... some are truthful and honest, but that is an exception in my few years of experience. Others may have had different perceptions and experiences.
That's all...
_-_-bear
I do not believe most of what is said in public by those in the high-end business. Certainly the part that can afford to advertise in the glossy magazines... some are truthful and honest, but that is an exception in my few years of experience. Others may have had different perceptions and experiences.
That's all...
_-_-bear
I spoke to Dan for about 15 minutes last Friday evening at the Melbourne show.
I can confirm that the LTP is zero transconductance and the VAS produces only 30dB of voltage gain. The output stage operates in class AB but the bias point is set to an operating temperature rather than an optimum v bias. I gather that the intrinsically low output impedance from so many devices reduces the gm*2 distortions into the noise without the need to set an optimum v bias point. The feedback loop exludes the final EF stage but apparently the driver stage is within the global feedback loop as well as the VAS miller loop. Of course Dan did not want to divulge all of the circuit highlights and there are a couple of patents pending related to the use of nested feedback and output stage biasing, so I was privileged to get as much info as I did. The output devices are matched for vbe and hfe to 0.1% and ditto all other paired devices. Apart from the output stage the rest of the amp is a fully complimentary design. A single mono amplifier draws 90 watts at idle which is less than past Krell’s but still considerable for a class AB design.
In Dan’s brief speech to the general audience he focused most of the discussion on the use of copper and the venturi effect to draw heat away from the output devices.
Personally I liked the amps – driving the Wilson Sasha’s, but I would stop short of hailing them the best amps I’ve ever heard. It’s my own view that Dan is using his name, a few fancy design ideas, and a 'swiss watch' appearance of class and precision, aimed to appeal to the well heeled Ferrari driving executive ahead of the discerning audiophile.
For outright sound quality my favourite Krell is still the original FPB300 and my favourite commercial class AB amplifier is the lastest offering from Bryston, not Dan’s Momentum.
Of course, if I owned a Ferrari and had a few spare $m in the bank I would have a pair in my living room too.
I can confirm that the LTP is zero transconductance and the VAS produces only 30dB of voltage gain. The output stage operates in class AB but the bias point is set to an operating temperature rather than an optimum v bias. I gather that the intrinsically low output impedance from so many devices reduces the gm*2 distortions into the noise without the need to set an optimum v bias point. The feedback loop exludes the final EF stage but apparently the driver stage is within the global feedback loop as well as the VAS miller loop. Of course Dan did not want to divulge all of the circuit highlights and there are a couple of patents pending related to the use of nested feedback and output stage biasing, so I was privileged to get as much info as I did. The output devices are matched for vbe and hfe to 0.1% and ditto all other paired devices. Apart from the output stage the rest of the amp is a fully complimentary design. A single mono amplifier draws 90 watts at idle which is less than past Krell’s but still considerable for a class AB design.
In Dan’s brief speech to the general audience he focused most of the discussion on the use of copper and the venturi effect to draw heat away from the output devices.
Personally I liked the amps – driving the Wilson Sasha’s, but I would stop short of hailing them the best amps I’ve ever heard. It’s my own view that Dan is using his name, a few fancy design ideas, and a 'swiss watch' appearance of class and precision, aimed to appeal to the well heeled Ferrari driving executive ahead of the discerning audiophile.
For outright sound quality my favourite Krell is still the original FPB300 and my favourite commercial class AB amplifier is the lastest offering from Bryston, not Dan’s Momentum.
Of course, if I owned a Ferrari and had a few spare $m in the bank I would have a pair in my living room too.
Such comments I want to read. This is the most interesting report regard this topic until now - thank you very much therefore. A similar feedback connection as mentioned above is realized in several "STASIS" devices from Threshold - have a look to the attached schematics and go to
http://www.diyaudio.com/forums/pass...overview-schematic-collection-all-models.html
Attachments
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So if enough of us can each go to one of these presentations and coordinate what is asked of Dan D'A, he will think he is not revealing enough information, but each person can ask a specific and different question eventually unraveling all of the circuit details... 😀
_-_-bear
_-_-bear