It doesn't sound like someone who uses IC op amps as much as I do. The reason for the discrete buffer has to do with something I posted earlier on page 26.
Based on what I know about IC processing, getting round the non-linear capacitance from the inputs to the rails would require an SOI process. For an op amp manufacturer this is not enough reason to do so. This is pretty much the only serious drawback I can name for IC op amps. This issue causes exactly no problem at all when you balance the impedances at both op amp inputs. Unfortunately there's just no way you can do this in a follower stage because the impedance at the inverting input is fixed (the feedback network) and at the noninverting input it's whatever the source throws at it.
The closest you can get to having no problem is by keeping both impedances low. Now, if there's one thing you can't count on when selling amplifiers into the consumer audiophile market it's the output impedance of the preamplifier. Just think about passive controllers.
Under those circumstances having a discrete input stage definitely helps. The NC400 is intended as a no holds barred design so discrete is what it became. Now, adding cascoded emitter followers in front of an ordinary IC op amp equally does the trick but once you've done that you've already built half an op amp. That and the fact that you don't add the input noise of the IC.
This sounds a bit pretentious and dismissive of others work in the field
That was a bit of creative quoting of my own just now
The snippet you're referring to is a heavily condensed version of my answer to the question who I thought was equally working to push the bounds of audio performance and theoretical insight in class D. In that case indeed Lars, Sören and the rest of the TI crew come to mind. I think what they're doing in silicon terms is pretty trailblazing. The guys who did the original Mueta design are also still actively researching modulation theory but not doing any practical audio work (on account of being too busy making rather amazing sensorless motor drives).
M&H's interpretation sounds a bit crass but I can't help noticing a certain paucity in the number of published class D measurements approaching those of Ncore. That could either mean nobody's doing it or there's suddenly going to be an Ncore killer from a hitherto unknown designer. The former makes people uneasy because it's simply not on to say (or even think) you're ahead of the game, the latter makes me uneasy because I have no idea what or who I'm racing against. But the least you can say is that I'm not doing too badly. Of course there is the occasional outburst from those who advance philosophical arguments to excuse less than stellar results ("it's more digital!" "measured results matter only until they're as good as mine", "the stuff you hear is something different altogether" etc) but I don't think it would be pretentious to suggest that they're in an entirely different game.
Last edited:
Bruno,
I have a pair of nCore 400's arriving tomorrow. Looking forward to auditioning them.
Question. And please just direct me if this has already been addressed elsewhere in this or another thread.
For those with digital sources the nCore requires an upstream DAC and PRE (unless a digital attenuator is used). Do you believe it is feasible to design a commercially viable integrated device which could substantially improve sound quality of a DAC/PRE/nCore signal chain? This device would input a PCM signal via USB or SPDIF which would then be converted to Pulse Width Modulation, reclocked via a high quality clock, amplified in the digital domain, reclocked again, and then demodulated at the output of the amplifier to drive a speaker directly using some form of volume control (e.g. a voltage controlled attenuator that resides outside the signal path)?
Supposedly, Core Audio Technology in California is offering a product like this under the name Kratos. Currently it only outputs 20wpc so it is rather limited to high efficiency speakers.
Thanks for your perspective on this.
I have a pair of nCore 400's arriving tomorrow. Looking forward to auditioning them.
Question. And please just direct me if this has already been addressed elsewhere in this or another thread.
For those with digital sources the nCore requires an upstream DAC and PRE (unless a digital attenuator is used). Do you believe it is feasible to design a commercially viable integrated device which could substantially improve sound quality of a DAC/PRE/nCore signal chain? This device would input a PCM signal via USB or SPDIF which would then be converted to Pulse Width Modulation, reclocked via a high quality clock, amplified in the digital domain, reclocked again, and then demodulated at the output of the amplifier to drive a speaker directly using some form of volume control (e.g. a voltage controlled attenuator that resides outside the signal path)?
Supposedly, Core Audio Technology in California is offering a product like this under the name Kratos. Currently it only outputs 20wpc so it is rather limited to high efficiency speakers.
Thanks for your perspective on this.
Theta Prometheus....................................6000 dollars for one mono amplifier featuring ncore....and linear power supplies....
Gallery: Audio Electronics at CES 2012 | Sound and Vision Magazine
Last edited:
Thank you for that promise. Very much looking forward to reading your feedback. ETA? If not this thread, where?
Your comment reminds of the one of Zaph Audio's better DIY monitor designs...searched forever and could hardly find a couple sentences of feedback.
My main amp is line-level high-pass crossed, 1st order @ 275 Hz, 3rd order @ 80 Hz, requiring no deep bass.
Any reason not to install three Ncore amps in one chassis (pure analog Trinaural 3.1 music system)? The center is the most critical channel (think of the L/R as ambiance effects). A mono bloc has no proximity advantage because the equipment rack is 12" behind the center speaker.
Which, if any, Hypex power supply is recommended for three Ncore amps?
If anyone plans or desires to cut/fit a specific chassis for three Ncore amps, please PM me. It might be less costly to prepare two chassis simultaneously.
Sum total work appears to be:
Am I missing something?
Pros/cons EI core vs. toroidal transformer?
Is there easy method to add high-pass line-level crossover to Ncore? Prefer 4th order, fixed 120 Hz OK.
Any reason not to install three Ncore amps in one chassis (pure analog Trinaural 3.1 music system)? The center is the most critical channel (think of the L/R as ambiance effects). A mono bloc has no proximity advantage because the equipment rack is 12" behind the center speaker.
Which, if any, Hypex power supply is recommended for three Ncore amps?
If anyone plans or desires to cut/fit a specific chassis for three Ncore amps, please PM me. It might be less costly to prepare two chassis simultaneously.
Sum total work appears to be:
- Purchase appropriate chassis, 3x Ncore amps, Hypex power supply, transformer, inputs/outputs, and fasteners
- Cut/punch chassis holes
- Install and wire all parts
Am I missing something?
Pros/cons EI core vs. toroidal transformer?
Is there easy method to add high-pass line-level crossover to Ncore? Prefer 4th order, fixed 120 Hz OK.
Last edited:
My nCores are scheduled to arrive tomorrow morning. I will post my review right here and perhaps on another forum.
Yep...that's correct...
Cheers,
Jan-Peter
These days
High-end = High Price tag - Fancy box - and the least amount spent on the electronics that they can get away with
Last edited:
before getting the Confidence's I had planned to build Zaph's ZD5 but what made me not to was this lack of reports.
OTOH look at my report in the multi-way section, after my friend built the Seas Idunn project. I was as frank as I could be (my only involvement was building the XO's) and I compared them with a commercial system in the same price range. but TBH I wish I kept my mouth shut. but if it were about this we'd see some NCORE's for sale already (I wish...)
what is really really funny about these types is that they can't get right even the most basic stuff even the die hard subjectivist can't argue about, like SNR and channel separation. my favorites are 47labs and Audio Note. I'm always delighted to read about the "5 mm signal path" and then look at the channel separation graph boasting an impressive 40dBThese days
High-end = High Price tag - Fancy box - and the least amount spent on the electronics that they can get away with
one local company is doing some OEM stuff for the likes of MSB Tech and PS Audio and knowing the owner I have some insights on this. some "high end" makers are basically case designers with a marketing department, all actual electronic design being outsourced. and to avoid any useless discussion, I'll add the disclaimer that I'm not talking the two names that I mentioned above, reportedly they actually do have strong engineering departments.
so is there a chance that we actually read a third report tomorrow?
Last edited:
High-end = High Price tag - Fancy box - and the least amount spent on the electronics that they can get away with
That's the cynical view. The non-cynical view of most high end is having philosophies instead of facts and esoteric parts instead of circuitry. Oh no that's still cynical. But there's a point. If one cared to look inside most high end equipment you'd find that whatever they lacked in knowledge they sure made up in expensive content. Heck, some buy up loads of obsolete parts under the presumption that they're better than the new stuff and on the other end of the scale some have their own power transistors made in an esoteric new technology. These guys are spending money, not raking it in.
Leaving aside the question of how well-designed the innards of an audio products are, there are some very basic economic facts:
1) Regardless of market, the mark-up between the BOM and the end-user price is around a factor 5. Most of that goes to the retailer. Then the distributor. The remaining pittance goes to the manufacturer.
2) Economy of scale: production cost drops with the logarithm of quantity until you hit the raw materials cost (i'm told that the old Philips TV factory in Bruges could reliably estimate the cost of a TV set by weighing it). The same product, manufactured in tens or in thousands ends up with a markedly different price tag.
3) People want their money's worth. You spend 5k on a piece of kit, it has to look expensive. I'm talking fit and finish, not looks. It may look "butt ugly" so long as it's polished like a baby's bottom (with only as many visible seams).
So you want to make a "better than average" product? That will make it more expensive than average. So you'll sell fewer of them. So your manufacturing cost will go up and you need to increase your profit margin. The price starts getting a bit "exclusive". So people will not want the same folded casework as a $25 DVD player. Some of these look pretty sleek with the sort of plastic casting that's available when you make 100k units. If you want to get the same quality with 1k units, it'll have to be machined. This spiral continues until a company almost but not entirely runs out of customers and equilibrium is reached. Of course, that leaves room for many more small companies with slightly different offerings who appeal to a different but equally small subset of potential audio buyers. All it takes is the above 3 obvious truths to explain why the high end market is saturated with innumerous tiny companies trying to be slightly different from one another. The same spiral explains why the middle segment (where say 1500 euros would buy a very decent stereo) has pretty much vanished from the market.
People seem to have the impression that manufacturers of high end gear are greedy bastards who are making way too much money. I can assure you that the companies that churn out cheapo DVD players have a boardroom full of way richer guys, none of whom actually give a damn for audio. Even a middle manager may fetch rather more than some of the people manufacturing the high-end gear that's meeting with such opprobium for their price tag.
You can have me ranting about the complete lack of technical sense shown by equipment designers and whatnot, but as far as economics goes, the smart ones and the stupid ones are in the same boat.
Bruno, that's exactly my view and I can't say I disagree with anything at all.
what I do find sad is that I know the run of the mill, not technically inclined audiophile's view too. and all too ofter there is this this blind, unconditional, religious trust in anything with an impressive case and a name that would rather suggest expensive wine.
what I do find sad is that I know the run of the mill, not technically inclined audiophile's view too. and all too ofter there is this this blind, unconditional, religious trust in anything with an impressive case and a name that would rather suggest expensive wine.
one local company is doing some OEM stuff for the likes of MSB Tech and PS Audio and knowing the owner I have some insights on this. some "high end" makers are basically case designers with a marketing department, all actual electronic design being outsourced. and to avoid any useless discussion, I'll add the disclaimer that I'm not talking the two names that I mentioned above, reportedly they actually do have strong engineering departments.
so is there a chance that we actually read a third report tomorrow?
MSB Tech ?? Is that the same company that bags the ESS SABRE DAC claiming that it is only a 6 bit DAC even though the measurements say otherwise ??
What about 32 bit DACs
And of course it is only fit for the consumer market
Sounds like a dude that is worried about a mass market high performance dac that essentially makes his megabuck all singing all dancing DAC obsolete yes it's the same MSB Tech.
indeed that, what should I call it, rant? seems to be written by the marketing dept in collaboration with the janitor. I don't know much about their products but claiming that the ESS chip is actually 6 bit doesn't sound like coming from an engineer. they should've stopped after saying that the digital filter and async resampler can't be bypassed.
indeed that, what should I call it, rant? seems to be written by the marketing dept in collaboration with the janitor. I don't know much about their products but claiming that the ESS chip is actually 6 bit doesn't sound like coming from an engineer. they should've stopped after saying that the digital filter and async resampler can't be bypassed.
With you all the way Bruno.
I make no secret of the fact that my little company, ACOUSTICIMAGERY acousticimagery - HOME uses standard Hypex UcD400HG+HxR modules and the SMPS400A400 in our D400M mono amps and we do so for two main reasons.
1. I cannot design electronics but, I've listened to plenty of amps over the last 30 years to know how a good design should sound.
2. The Hypex Class D is the best amp I can buy which is right for me and the plans I have for the future development of my company.
Bruno is dead right about the margins and if you want to stand out then you have to go the 'extra mile' to get the detail right and it doesn't come cheap.
One thing never mentioned in all the discussions about small manufacturers is EMC and CE approval testing. Each product you offer for sale has to be tested by an independent laboratory and my own costs for our pre-amp and the D400M power amps is approx 6000 euros each to be certified by TUV.
Our confidence in Bruno, Jan-Peter and Hypex was recently justified beyond even my wildest dreams when Hi Fi News( Jan 2012 issue ) reviewed our amps and heaped (justifiable) praise on the Hypex modules.
The DIY community is very privileged to have access to true audiophile components such as the Hypex modules and with NCore even more so.
Meanwhile the vast majority of the 'music listening public' are happy with an I Pod and of the 5% or so who are audiophiles, the vast majority of them wouldn't ever dream of grasping a soldering iron and 'doing it themselves' so hopefully there's room for us small manufacturers to provide excellent hi fi equipment, with the help of suppliers like Hypex.
Cheers........John
- Status
- Not open for further replies.