Darn that WAF ...
My GF actually demands from me that the new ncore case should *not* be black, but rather standard anodized aluminium, she is "willing to put up with the logo", but it'll cost me dearly I'm afraid.
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I could move the speakers to my garage / man cave / pShed, but the acoustics of the concrete walls would not be great...Darn that WAF ...
Anyone have arguments against actually using CAT7 S/STP shielded data cable for a 6 m analog audio run between preamp and the nCore boxes? Any experience of data cable for audio applications? (works OK for the telephone
)I think I have the answer to that: no. read this: The Truth About Digital (Class D) Amplifiers — Reviews and News from Audioholics
I remember someone saying "it will be fun seeing how you get people to agree"
I think it's not long until someone asks for a PC case or something A lovely commercial. I liked this statement especially "off any high-end amp". I believe assuming band was up to 100KHz at least while class A tube amps goes above that.
Anyone have arguments against actually using CAT7 S/STP shielded data cable for a 6 m analog audio run between preamp and the nCore boxes? Any experience of data cable for audio applications? (works OK for the telephone
I have tried various CAT cables for audio applications -both for speaker cables and IC´s. Almost 10 years ago I tried using the then CAT5 cable for speaker cabling. It was unshielded and had (if I remember correct) four twisted pairs. When using one entire cable (all 8 conductors) as on conductor and avoiding them to twist I remember it as sounding good. The later CAT6 (if I remember correctly) had 4 shielded twisted pairs and didn´t sound good -either twisted or straight. I also tried one of the CATs as interconnect and I remember it as it worked but not something I listened to for long -so there was probably something wrong to my ears.
Please do experiment with CATs (I prefered the unshielded version back then), you may very well find them to be usable. As long as you buy them cheap you have nothing to loose, and they are probably not much more flawed than most so called hi-end IC´s -if you know what
.cheers,
you seem to have missed the "while I'm the designer of that circuit and thus some care reading this statement is warranted..." part.
it's my personal belief too that the "power DAC" idea is nothing but naive and has no intrinsic advantages whatsoever, like some would suggest.
PS: soon the AP2 friend will kick in and we'll be back to a nice friendly conversation...
I wouldn't be.
Unlike most home situations, pro audio commonly has long cable runs that actually need the noise rejection to work.
I've heard lots of mediocre PA sound quality, but not hum/noise that I can remember.
OK. I couldn´t wait any longer so I made RCA SE -> XLR Balanced converter so I could use my NC400s at home before my DAC is finished.
Here are my initial impressions:
My signal link is the following:
Mac mini HDMI out -> Harman Kardon AVR255 (yes not a good source) -> NC400 -> Dynaudio Focus 140.
I disconnected my trusty old Vincent SP331 amp and eagerly connected the NC400s. Sat down and turned up the volume a bit.
Wow! It was like there some kind of filter that has been removed. Everything sounded more wide and open. Small nuances and timbres of familiar sounds was revealed that I had not heard before. Drums (esp snare and kicks) and acoustic guitar strings sounds much more dynamic and snappy. The bass is much better and tighter. The sound space is much bigger and I can hear much deeper into a "complicated" mix where a lot is happening than I could before.
It´s almost as having a new and better pair of speakers, and remember this is with a crappy source. I can´t wait to finish my buffalo III DAC!
Here are my initial impressions:
My signal link is the following:
Mac mini HDMI out -> Harman Kardon AVR255 (yes not a good source) -> NC400 -> Dynaudio Focus 140.
I disconnected my trusty old Vincent SP331 amp and eagerly connected the NC400s. Sat down and turned up the volume a bit.
Wow! It was like there some kind of filter that has been removed. Everything sounded more wide and open. Small nuances and timbres of familiar sounds was revealed that I had not heard before. Drums (esp snare and kicks) and acoustic guitar strings sounds much more dynamic and snappy. The bass is much better and tighter. The sound space is much bigger and I can hear much deeper into a "complicated" mix where a lot is happening than I could before.
It´s almost as having a new and better pair of speakers, and remember this is with a crappy source. I can´t wait to finish my buffalo III DAC!
Not unless I add an ADC to take feedback from the output stage back into the digital domain. The power stage is analogue, and so is the feedback signal. So if you're coming in with a digital signal and you somehow want to avoid making it analogue you end up having to make the analogue signal digital.
Seriously. Ncore is analogue from back to front and al the way back. It has no truck with digital signals. No DAC designer in his right mind would ever seriously consider building one using power FETs. You'd never get anywhere near the performance you can get using a normal DAC and a good analogue amp like Ncore.
If you're interested in why I think class D amps aren't digital (and why that is a good thing), check out http://www.hypex.nl/docs/papers/AES120_353BP.pdf. I've read on several occasions that people think I write this just because I "happen to make analogue class D amps". That's quite the wrong way round. I stake a claim to world's best performing "true power DAC" (http://www.hypex.nl/docs/papers/AES112BP.pdf). That makes me one of two people with seriously good power DACs to their name who ended up deciding that this is a very roundabout way of doing something that comes almost naturally if you don't try to drag unnecessary digital processing into the equation (the other works for TI). So I chose to go all analogue because that's where the facts led me. The only remaining sensible route is the one I hinted at earlier, which is to digitize the feedback signal (http://www.hypex.nl/docs/papers/PaperAESDenmark.pdf). For the moment it's not very sensible but in theory you could cram such a design onto a smaller silicon area than its fully analogue equivalent. That would be its only significant advantage.
So no digital-input modules for the foreseeable future. I prefer to make good amps, not shoddy DACs.
There's one already on the SMPS so no need.
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Please correct if I am wrong but class D amp is basically a switching PWM AFAIK. Output devices are either fully open (fully conductive) or closed (max restance).
However anologue amplifier means that output devices can be in any state in between.
Class D amp cannot be an anlogue one once it's PWM based.
So a switch mode powersupply is a digital powersupply? And every analog synth that has square wave oscillator is really digital ?
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yes you are wrong. I admire Bruno's politeness even when most people would lose patience, but...
switching has NOTHING to do with digital. digital means quantization. quantization means dividing a continually variable voltage/current into discrete steps and using some kind of symbolic representation for those steps.
a class D amp would be digital only if the moments when the output devices switch to on or off state were discrete.
so, when posting things like:
please make sure you do your homework first, otherwise you risk losing credibility.
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You'll require a pretty fast, low-delay ADC to pull that off with a short enough time delay - I'm picturing a tens-of-MSPS thing sensing the output and directly feeding the FPGA or whatever is generating the PWM output.
Plus, the ADC has to be linear, as non-linearity in the ADC and feedback path will create an inverse nonlinearity on the output. Most high speed ADCs don't tend to be designed for great linearity.
I dealt with this puzzle in an AM broadcast transmitter design. We digitally generated multiphase PWM for the modulators using a FPGA, and sampled the RF output to linearize it. Direct feedback control was nowhere near fast enough to be stable, so we went with an adaptive system. Lots of late hours went into that.
Putting that kind of work into an audio amplifier probably won't give you a result that can beat an analog input amplifier.
thumbs up
thing is that most people ask this kind of questions based only on the naive beliefs that "class D is digital" and "digital is end all be all" so I'm afraid technical explanations won't help too much.
I don't see suntechnik mentioning a class d amplifier being digital but mere switching PWM, so I don't understand your rather agressive reply.
You might criticize him for regarding switching PWM being "not analog", but that does not mean "digital" IMO.
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