Ashley James

David I can't thank you enough for your kind words, they come at a time when I most need them. It seems that simple provable facts are all it takes to get a thread locked on this Forum right now. One final point I'd make about the M-Audio is that is extracts 24 Bits from a USB socket and provides an optical digital output that isn't normally on PCs. This is very useful because it avoids electrical connection with a potentially noisy computer chassis and gives the opportunity to compare lots of other DACs with a cheap reference. Chris argues, wrongly in my opinion that there are big differences between DACs but there is not if they are correctly implemented because they all measure so similarly. They are the best performing part of a hi fi after the noughts and ones from the computer. hi end. The Chinese DAC suggest by Steve may be using the original Philips TDA 1541 which is fast achieving cult status amongst anacrofiles at the moment. We stopped using it in 1993/4 to switch to the very obviously better 20 Bit Burr Browns and each time we've found a better one we've moved on until we now use the Wolfson WM8741 that Linn claim is the best in the world. Ash

Here is a World Leaders retail DAC chip prices for you to compare with the eventual product. http://www.analog.com/en/digital-to-analog-converters/audio-da-converters/products/index.html Here is a list of technical support provided: http://www.analog.com/en/design-center/index.html This give some idea how a typical Hi Fi Dac Manufacturer will be helped to do the best possible job. $10K for a DAC is a little hard to justify IMO, especially once you've heard an M-Audio Transit from Pro Audio Giant M-Audio and Pro Tools who are leaders in their field. It's $89 in the US I believe and the size of a pack of 20 cigarettes. Ash

Chris said: No, not connected to Benchmark at all. He has such a unique point of view I decided to read more about him and found some rather disheartening info that causes me to second guess his opinions. Chris I don't think that this chaps opinions need be considered if the DAC1 measures as it should do, and it seems to. When a DAC Manufacturer selects the DAC chips that he is going to use (Benchmark use Analogue Devices who are one of a group of World Leaders in the field) they will come with comprehensive instructions on how to use them and the MEASUREMENTS that will result if you do it right. That really is the end of the story. However if you wanted to nit pick, you could point out that all DACs run at high speed, typically 33 mHz and that this makes them a radio transmitter and means that layout is absolutely crucial if this RF isn't going to get where it shouldn't and feed into power amps. A small amount always will and it does affect some power amplifiers. In other words Hi Fi Amps are happy in the 20-20 kHz region but not not necessarily if they have to cope with 33 mHz! Distortion can rise significantly The present situation therefore is that all DACs far exceed 16 Bit because they are 24 Bit devices and all are remarkably similar in specification and virtually all produce small amounts of RF. This means that correctly implemented, they are extremely hard to tell apart, but that they may react to imperfect amplifiers. IMO DAC reviews are hard to justify for these reasons and because there is much more noise and distortion in the rest of a typical hi fi system that will mask any problems. Ash

Tim You have it in one. When you make an immediate change, the image collapses and the sound becomes harsher etc. Whatever anyone says about manipulation of the records or digital recordings, you still have to compare the vanishingly low noise and distortion of the CD playing system with all the problems in a record player. Surely the difference is acknowledged and it is just what some people prefer to listen to. Ash

I must also have missed the wit, humour and general "bon homme" in a valid point of view being likened to believing in magic. Bob I've now PM'd Chris with proof that I was not expressing an opinion but quoting simple provable fact. If you don't believe in the facts, what do you believe in? How about coincidence and one that might amuse? Martin also has a 2 Watt SET and open baffle loudspeaker. It's in a 1926 RCA Radiola I think it's called. Ash

Usernaim - Sadly I think you've a point and I've heard than even fans who care nothing for hi fi are complaining about some of it. About 13 years ago we measured loads of modern recordings and I well remember the best example of dynamic range we found was Joan Armatrading's Me Myself I. If we played it at a relatively loud 600 milliwatts the drum needed 600 Watts and it was breaking the voices coils of the cones of ATC PA drive units in an EAW system. There were loads other recordings with huge peaks too and Classical Music was not as extreme. We built a device that displayed the continuous average power into speakers, the peaks and it flashed red when the Amp clipped and we showed it at the Heathrow Penta to prove the point. Although all the usual journalists trouped in and appeared surprised and resolved to report it, they didn't. Presumably because it proved that lots of well reviewed amps were clipping like hell. I dug it out the other day and set it up and was surprised to find that a few pop tracks we have had very little dynamic range. I think we'd deleted them or avoided them because they don't sound right. However it may be that out customers are the same, because not many turn up with the flat sounding recordings and of those that do, some state that they were hoping our speakers would cure it. As soon as they are played something more lifelike. They understand that the record companies are to blame and scoring another home goal. I'll shut up now, but I am eating humble pie. Ash. PS. I still hate vinyl though!

usernaim - we're really mostly expressing opinions, but where I can be factual is with dynamic range. It means the peak to mean in the recording, which has to be compressed for vinyl in order to stop the stylus jumping out of the groove as it used to with Telarc's 1812 Overture, and the power and SPL capability of the replay system that needs to play it without clipping. This means that if I have an Active system with 325 RMS wpc with a 200 Watt RMS Sub and the drive units to match, I'm going to have appreciably more dynamic range that most two way passive systems. In fact I made the comparison by using my 620 monoblocks on a pair of passive 6.5" two ways and was surprised at how much more powerful, dynamic and controlled the Active system was. The difference is caused by the intrusive nature of passive crossovers. They are lossy. I also have a 5" two way system here that sounds very nice indeed, it images well etc, but it does audibly compress the dynamics in the recording when I compare it with the Active system. It is driven by 100 RMS wpc. However there is a bit more to it than this in that producers do all sorts of trick on some recordings to give the impression of big peaks, but don't actually use amplifier power to do it. This is achieved by stopping the music suddenly and heavily emphasising the top end and often adding masses of distortion. You may be hearing some of this and not liking it, I don't either and it doesn't compress to an MP3 at all well. I was basing my opinions on the reasonably wide range of different recordings people bring here for audition as well as my own stuff I hope this make sense. Ash

Bob Not so long ago you were extolling the virtues of hand made guitars and pointing out that Yamaha who are one of the largest musical instrument makers in the world, would not be able to do as well. This is believing in magic to me, for although there is something magical about craft skills at their best, there is no way a craftsman can achieve the accuracy and consistency of CNC controlled machinery producing in high quantities. I don't think I was being derogatory and I never intend to offend anyone, but I am damn sure that what I'm saying is the truth and I stand buy it. So if I am trying to sell anything, it is first and foremost a reliable method for people to evaluate what they may be considering buying. IMO Subjectivism has robbed them of that. Don't be so harsh, I promise you I have no ulterior motive and if it looks like I have, I promise it is not one I'm aware of beyond the obvious message. Ash

Chris 1. DAC Chips are relatively inexpensive and it's easy for you to show the differences between them by purchasing their manufacturers Evaluation Boards. These are as good as they can be and show any DAC manufacturer how he must use them if he is to achieve the results predicted by the specifications they supply. 2. Jitter is pre-ordained by the chips and not something that can be "improved" by any DAC manufacturer. He either does as well as the Chipset manufacturer or he doesn't, or he uses re-clocking to remove it. 3. Jitter first manifests itself as measurable noise, so any DAC manufacturer can see if he has screwed up and sort it. 4. This noise is at a lower level than in the rest of the hi fi system and almost certainly masked by it. 5. Practically all DAC chips and the accompanying parts are only a few dollars and equal or exceed 24 Bit spec. Ours is costing us £6 and was the most advanced when we first bought it. Somebody will have caught up by now, but it won't alter that fact that the rest of most systems will make more noise and have more distortion. I spoke to a few different engineers and not just Martin before I made the statements I did and all pointed out that the big problem with DACs has always been RF on the outputs and the degree to which is affects the amplifier it is connected to. This RF varies depending on the competence of the DAC manufacturer and how well he has followed the Chip manufacturers applications notes. In other words DACs can sound different depending on the system they are connected to. The final point I'd make is that because it is a much larger Industry and technically more advanced, the Pro side of things produces better DACs for less money. In fact they tend to regard a stand alone DAC as bad value and put A to Ds in the box as well and still charge far less for it. I know golden eared Sound Guru's exist on the pro side too, but often they chose things not because they sound better, but because they like what it does to their work. The great majority take the view that all has improved to a point where something that doesn't sound right is the odd one out. Paul White of Sound On Sound has said much the same and that he is often questioned because he rarely criticises. His defence is that the standard is generally high. For this reason I purchased an M-Audio Transit for £50 and had a good listen, then I gave it to others for them to do the same with the same result. One even used top quality headphones to take the hi fi out of the equation and was still surprised at how good it was. M-Audio quote specifications that are not as good as the best DACs, but the only difference is noise at 96 instead of 128 dB and more RF than is ideal, which means there are amps out there it may not sound as good with. That excepted, most will find it hard to tell the difference between it and some expensive stand alone devices. Things have advanced this far. Any manufacturer who appears on any forum is bound to arouse suspicions as to his motives, though some don't because they are blatantly promoting their products. I'm not doing that, but I do have issues with the Industry that I've cared passionately about since the early fifties when I started to play records on an old wind up Columbia Gramophone. I don't believe in magic, I don't see the bit of audio that affects hi fi enthusiasts as particularly challenging to good engineers and I do see an awful lot of avoidable problems in much of the most expensive stuff, which is not surprising since it often comes from smaller companies with less good credentials than big ones, so I speak out in defence of basic common sense and logic and against what I believe Tim may have referred to as Audiophilia Nervosa where the endless sales patter is intended to create insecurity that can only be resolved by the addition of something expensive and made by the vendor's company. This twaddle combined with subjective evaluation has gotten us marginalised and in contraction so I thought a bit of basic honesty might make a difference. The trouble is Chris that you like to believe in magic and there are more convincing people than I who will sell it to you. The idea of a PS3 and a reasonable DAC is much less appealing, but it'll be as good as any of it. Amps and to a greater extent speakers are the areas where all the problems lie now IMO. Ash

Max Sorry I sort of misunderstood and now see where you're coming from. You're absolutely right because the hi fi Industry in the UK has been declining since the early eighties when the VCR first appeared. TV has driven the market since, but sound has been given a reprieve by Apple, the company that audiophiles love to hate. I think iPod sales are up to about 180 million now and some of them sound exceptionally good. What is happening now and has been for over two years is that big TVs and or Apple and Sonos have replaced hi fi for traditional customers and in so doing have further marginalised specialist audio, partly because they've tried pretty hard to keep computers at bay. Fashions have changed too and people are now much more conscious of style and design. Racks of black boxes, cables and large speakers simply don't figure anywhere but with die hard traditionalists , and they'd probably have to be single. Much of our success has been because people want rid of all this clutter. Many of our older customers have sold hugely expensive systems to buy ADM9.1s. The thirty somethings just don't like hi fi shops or the concept of hi fi because they can see Computers, TV and sound need to be combined. Rumour has it that Apple might produce an up-market TV combined with PVR and their online facilities for rental and purchase of movies and TV programs, access to Youtube and the ability to slide show photos and access Flikr. This I'm certain is the future of home media and it will have an optical digital output so that a compact hi quality sound system can be part of it. People want this because flat screen TVs don't sound great. The PS3 is another much more important arrival than traditionalists realise too, because it plays Blue Ray, streams video as well as music, it doesn't have windows problems and it has a digital output. I think everything is better and far more exciting, but that instead of embracing all these developments and working with them, the industry has been insular and dismissive until recently and rather late in the day, it is beginning to realise that it may have misjudged things. Ash

In my opinion a high proportion of modern digital recordings are stunningly good and better than they have ever been. There are bad ones too I dare say, but I don't hear that many, not even with modern commercial music I don't much like. I have heard stuff that has been compressed to make it sound loud and I've measured the odd CD that has digital clipping, but it's a small proportion of generally excellent modern recordings. Lets face it, modern pro audio gear is better, cheaper and far more advanced than hi fi. If your user name is a guide then you're using an amplifier that was designed forty years ago! 128K MP3's sound amazingly good over the best systems, but not over lesser ones, so if you're hearing what you describe you need to look at your system and not blame MP3s. I have a BBC sound engineer friend who confirmed our findings. That is that they sound soft and less clear than the full file so they add a bit of treble. However 128K MP3s are only used for internet radio stations, where IMO they can sound extremely good. Apple and Amazon now sell 256K and these can be difficult to tell from a full file, especially Apple's AAC. I loath vinyl and always have done, I sold my turntable in the eighties and had nothing to do with it for ages until a few years ago we dug out one we had at the factory and fitted it with a £150 cartridge. We even used an EMI test disc to get the distortion down to -30dB on both channels by adjusting the vertical tracking angle, so we could be sure it was as good as it was going to be. The result was awful, but the customer liked it and bought a system. We both found it hard, aggressive and phasey, sort of FM with more noise. Martin thought he'd import some of his LPs to iTunes while we were at it so, using one of the downloaded programs he did a few. Interestingly the very best records he had hissed and crackled at -40dB and 78s were -30 dB. So I apologise but can't agree with anything you've said, although I appreciate that you like the sound of vinyl. Ash

Max I agree with much of what you say, but not that there has been no progress since the eighties. Recording Studios have always been ahead of hi fi and never more so than now, the quality of many modern recordings is absolutely stunning and they can be produced with a Macbook Pro, some outboard gear and £300 worth of Logic Pro. In the eighties it cost over half a million to equip a studio and sound quality is audibly inferior to what is achieved today. As far as MP3s are concerned, the lowest bitrate you can buy I think is 256K and these are difficult to tell from the original, which means that there are plenty that sound better than some 16 bit CDs. This combined with the astonishingly good sound quality of some PMPs is yet another reason for people to see hi end hi fi as not delivering IMO. You're right that there is a load of crap recordings around now, but that has always been the case, but over time they fall by the wayside and the good stuff floats to the surface, despite the record companies. I didn't work for Quad but I was good friends with Peter and Ross Walker and Alan Mornington West, I knew Laurie Fincham when he was at Kef and I liked them all very much because they were so nice and so enthusiastic, but above all they were honest. Peter used to joke that he was surprised by the success of the ESL's because he thought the BC1's might be better. I was also friendly with john Borwick, Ivor Humphries and Geoffrey Horn at Gramophone and regarded them highly too, they had measuring equipment and a very good understanding, so you could explain in great detail to them what you'd done. They never wrote bad reviews, they just sent products back to manufacturers they didn't like and for the rest, you could read between the lines. It was an intelligent approach and always expressed as opinion. If something worried them, then all the reviewers would meet with the item in question and they'd all agree before the review was published. They hated the subjective BS as much as I do. As BEEMB and or Tino have pointed out the magazines, or some of them are now trying to embrace computers, but it wont be popular with companies anxious to keep computers at bay and not to lose the upgrade path. The standard of reviewing is still very poor too IMO. I'd hate to be a reviewer and I know I'd make terrible mistakes, but it doesn't seem worry them. Could it be that they believe the evidence of their own ears and that they are completely ignoring the measurements? Ash

Dr. Chris Smith of Roke Manor sent us this. He's got nothing to sell us. Reading through that CA thread on jitter, it occurred to me that no one had bothered to check out the science. So here it is. The effect of jitter on a sampled signal may be expressed as a signal to noise ratio :- SNR(jitter) = -20*log(2*pi*tor*freq) dB Where tor = the jitter in seconds. freq = frequency of the sinewave test signal in Hz. So the degradation is proportional to frequency, and the worst case would therefore be freq=20kHz. However, as the ear's sensitivity has rolled off by at least 20dB at 20kHz, a more realistic test would be ~4kHz. If we set the SNR target due to jitter at 100dB at 4kHz, so as to be masked by the 16 bit quantisation noise, plugging the numbers into the equation above gives us the absolute minimum audible jitter = 400ps. This is way above the level deemed to be necessary by the armchair experts. Maybe you could run it past Martin. I did and Mart agreed. Ash

Max You're a Saint but don't be surprised if they stick pins in your effigy as well as mine and a few others. Ash