Yes, not easy to understand. Especially since 90% of this machine is nicely designed. With few buck, changing few parts, you can transform a very cheap component in a real top of the hifi one.
I believe *cheap* is in the ADN of Behringer, so they try to save cents everywhere they can, instead of trying to get the best compromises.
But it is not so bad, in a way. It allows members of the poor man hall of fame like me to get a good digital filter-equalizer in their system, having fun in modifying-it ;-)
About SMPS, i love to use them in analog audio, preferring Linear ones for digital. May-be i'm wrong for the digital.
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I wonder what would happen to a modern PC machine if its power supply was exchanged for a unit like the old Cromemco (remember them?) PC did back in the day? They had this truly massive analog PSU, using "computer grade electrolytics", 5 or 6 of them, each rated at 33,000 uF?
Regulation used Motorola TO-3 power devices and so forth. The heat sinks alone would make many of us cry for joy. A heavy monster that was, built like a dreadnaught. But I'm willing to bet the end result in terms of sound would pay off - richly. Not because nobody knows how to make a good switching PSU, but because today it's a little about quality and it's mostly about the cost.
In 2000, a late colleague and friend and I tested 8 PC SMPS supplies for output noise. We were interested to see whether our MK.3 power line filter would make any significant difference. WE were shocked to discover that most of these supplies kicked back into the grid signals with noise levels of just -30 dB. We did run into one CoolerMaster unit which did -70 dB. Then we looked some more, to discover why was it so much better than the rest and in the end we concluded that it was all about a filter capacitor they used. Where others used 220 uF, these guys used a 1,000 uF/400V cap.
To verify, we installed a 1,500 uF/400V cap in its place, and sure enough, the noise went down another 6 dB or so. Obviously, it's not about knowing how to do it, but about the cost, if memory serves that 1,500 uF cap was both hard to find and cost a pretty penny indeed.
So it seems most of the shortcomings we run up against are by their nature not technical but purely economic. So it was then, and so it is today.
To be fair, there are still some very competent designs around, a very good example being Andrew's 180 WPC amp. He used 5 8,200uF caps per PSU line per channel, anticipating possible transients of up to 40 Amps. My feeling is he's being very pessimistic, people (e.g. H/K) get about that much from much less, so I would expect even more. That's 82,000 uF per channel, 164,000 UF for a stereo amp. I like whoppers like that, I consider this good engineering practice for what he set out to do. It's painful only when you have to replace them after 10 or so years, but hey, no pain, no gain.
Regulation used Motorola TO-3 power devices and so forth. The heat sinks alone would make many of us cry for joy. A heavy monster that was, built like a dreadnaught. But I'm willing to bet the end result in terms of sound would pay off - richly. Not because nobody knows how to make a good switching PSU, but because today it's a little about quality and it's mostly about the cost.
In 2000, a late colleague and friend and I tested 8 PC SMPS supplies for output noise. We were interested to see whether our MK.3 power line filter would make any significant difference. WE were shocked to discover that most of these supplies kicked back into the grid signals with noise levels of just -30 dB. We did run into one CoolerMaster unit which did -70 dB. Then we looked some more, to discover why was it so much better than the rest and in the end we concluded that it was all about a filter capacitor they used. Where others used 220 uF, these guys used a 1,000 uF/400V cap.
To verify, we installed a 1,500 uF/400V cap in its place, and sure enough, the noise went down another 6 dB or so. Obviously, it's not about knowing how to do it, but about the cost, if memory serves that 1,500 uF cap was both hard to find and cost a pretty penny indeed.
So it seems most of the shortcomings we run up against are by their nature not technical but purely economic. So it was then, and so it is today.
To be fair, there are still some very competent designs around, a very good example being Andrew's 180 WPC amp. He used 5 8,200uF caps per PSU line per channel, anticipating possible transients of up to 40 Amps. My feeling is he's being very pessimistic, people (e.g. H/K) get about that much from much less, so I would expect even more. That's 82,000 uF per channel, 164,000 UF for a stereo amp. I like whoppers like that, I consider this good engineering practice for what he set out to do. It's painful only when you have to replace them after 10 or so years, but hey, no pain, no gain.
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Dvv, my computer mother board, like many modern ones, use very complex circuitry and programs, to drive the processor's rail voltage. You can even over compensate-it, making the V to increase a little under heavy charges. This can compensate the losses in the paths.
And all this with a 5GHz CPU !
I wonder if we could think about such a technology for our power amps ?
Playing with dynamic during high transients.
And all this with a 5GHz CPU !
I wonder if we could think about such a technology for our power amps ?
Playing with dynamic during high transients.
Sorry Christophe, but I do not see the analogy. We did have Class H, "the switchers", amps typically runned at say +/- 40V but capable of short term witching to say +/-55V, and where is that technology today? Practically forgotten. There was no mor nned for it, the semiconductors developed to the point of becomig much better, much cheaper and quite a bit more powerful, For BJTs, just look at ON Semi's MJL 4328/4302, both specs and data sheet, and tell me - what more could you really want? And that's just one example.
As for motherboard CPUs, I think that people using them under average conditions have little to gain by running the at higher clock rates as opposed to filling the MB with 8 GB of RAM, so they can allocate 3 or more GB of RAM as a disk cache. Only when you do that do you even realize just how much of your work depends on disk access.
A long time ago, my seemingly redular IBM PC was runnning circles around objectively and measurably faster AT models. How? Simple, it had 3 CPUs, the whole Intel family in those days. The centreal processing was delegated to an Orchid Turbo board, using a 80286 ar 8 MHz with no wait states, the original 8088 at 4.7 MHz was used to take care of the peripherals, an an 80186 running at 8 MHz, optionally with zero w/s with its own 4 MB or RAM was caching the disk(s). Typical jobs were at least three times faster than on the standard IBM AT, and if much disk acces was required, it was fater than the AT by at least, and often more, times than the AT.
All those chips are dirt cheap today, memory is cheap today, and I believe that's the way to go, not by idiot raising of the CPU clock. All you get is more waiting by the cPU until whatever is fetched from external memory. And I have a Toshiba 500 GB 7.200 rpm HDD, certainly no slouch.
Since audio is not as modular as a PC, doing similar things to a say power amp doesn't work that way. If you want more capacitance, you typically have to replace the existing ones with new and bigger ones. If you want more output current capability, you have to eaither use similar package higher power output transistors, or build in more power transistors, or both, but that's not an afterthought.
As for motherboard CPUs, I think that people using them under average conditions have little to gain by running the at higher clock rates as opposed to filling the MB with 8 GB of RAM, so they can allocate 3 or more GB of RAM as a disk cache. Only when you do that do you even realize just how much of your work depends on disk access.
A long time ago, my seemingly redular IBM PC was runnning circles around objectively and measurably faster AT models. How? Simple, it had 3 CPUs, the whole Intel family in those days. The centreal processing was delegated to an Orchid Turbo board, using a 80286 ar 8 MHz with no wait states, the original 8088 at 4.7 MHz was used to take care of the peripherals, an an 80186 running at 8 MHz, optionally with zero w/s with its own 4 MB or RAM was caching the disk(s). Typical jobs were at least three times faster than on the standard IBM AT, and if much disk acces was required, it was fater than the AT by at least, and often more, times than the AT.
All those chips are dirt cheap today, memory is cheap today, and I believe that's the way to go, not by idiot raising of the CPU clock. All you get is more waiting by the cPU until whatever is fetched from external memory. And I have a Toshiba 500 GB 7.200 rpm HDD, certainly no slouch.
Since audio is not as modular as a PC, doing similar things to a say power amp doesn't work that way. If you want more capacitance, you typically have to replace the existing ones with new and bigger ones. If you want more output current capability, you have to eaither use similar package higher power output transistors, or build in more power transistors, or both, but that's not an afterthought.
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Just look your V right at the collectors (it seems you prefer BJTs) of your power transistors, playing music at loud level.
I was not talking about class H, oh Lord ! Just better rails on AB amps.
(And, making a lot of photography post production, i can talk about the difference with a faster CPU and faster RAM, but it is out of topic. And, don't you use LTSpice, sometimes ?
This said, if you like fast load of your programs and OS, why still using conventional HD ? Just go for SSD. Even comparing to my 10 000tr/mn Velocraptors in raid 0, it is day and night ;-))
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It was a Joke, of course.
I propose to change the title of this Topic for: "Everything BUT John Curl's Blowtorch preamplifier"
Much manipulation can be done esp with DAW which are now sooo flexible that a music creator using DAW might not know what the DAW is doing or which settings are on or off when they should be etc etc et.
In the end, does the music sound more real and does the music sound like the source, live or even the master recording? Much is done with DSP and they have their own issues.
Dither will add a veil to the sound..... not just what the noise floor level is. So does distortion.
Some of the complexities involved along the way to a perfect master recording is shown here with insights of how things can go wrong along the way leading up to a simple recommendation for dither. But is that always done as he describes? Probably not for pop artists and many other producers.
Dither - Digital Domain: CD Mastering | Mastered for iTunes | Audio Mastering | Blu-Ray Mastering
THx-RNMarsh
Yes, I have a strong preference towards BJTs to the exclusion of all others. I seem to in the most popular group of today.
No, I do not listen to music very loudly, nor do I need a lot of power, since my speakers are relatively efficient at 92 dB/2.83V/1m, and in practice, even my Marantz 170 DC power amp, rated at 85W/8 Ohms can cover all my loudness needs even when really letting it rip in my room. Nevertheless, my main amp, an H/K PA 2400 power amp, rated at 170W/8 Ohms, is my usual workhorse for its other virtues, not for its power as such.
The ONLY reason why I still use a mechanical hard drive rather than SSD is because the size od the SSD disks I want are still prohibitively expensive. I expect the price to drop further over the next 6 moths or som when I will make the transition. And it's true, I do not do many large picture processings, perhaps now and then one or two. Which is why I stressed the word "average" PC work. I know this from my TV studio days, to image processing nothing is quick enough.
As for PSU lines, I believe I've made it clear enough in my pevious posts that I am very dedicated to high quality and large size power transformers, use of multiple parallel capacitors and such like, so we agree on that 100%. Class H is, in my view, a dead end.
Although I own an uncommonly easy to drive loudspeaker, I still promote high current capability because not many speakers are that easy to drive and I hate choosy amps. It has to be able to drive almost anything.
No, I do not listen to music very loudly, nor do I need a lot of power, since my speakers are relatively efficient at 92 dB/2.83V/1m, and in practice, even my Marantz 170 DC power amp, rated at 85W/8 Ohms can cover all my loudness needs even when really letting it rip in my room. Nevertheless, my main amp, an H/K PA 2400 power amp, rated at 170W/8 Ohms, is my usual workhorse for its other virtues, not for its power as such.
The ONLY reason why I still use a mechanical hard drive rather than SSD is because the size od the SSD disks I want are still prohibitively expensive. I expect the price to drop further over the next 6 moths or som when I will make the transition. And it's true, I do not do many large picture processings, perhaps now and then one or two. Which is why I stressed the word "average" PC work. I know this from my TV studio days, to image processing nothing is quick enough.
As for PSU lines, I believe I've made it clear enough in my pevious posts that I am very dedicated to high quality and large size power transformers, use of multiple parallel capacitors and such like, so we agree on that 100%. Class H is, in my view, a dead end.
Although I own an uncommonly easy to drive loudspeaker, I still promote high current capability because not many speakers are that easy to drive and I hate choosy amps. It has to be able to drive almost anything.
Gosh Dick, you just don't give it up. I would be embarrassed to keep repeating such technically wrong opinions. And as usual your link does not support your statement.
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From your link,
Why do you keep putting a negative spin on it?
As to the THD + noise and dynamic range issue we are again at an impasse, the Charles Hansen, Nelson Pass, John Curl, posse are invested in open-loop topologies and damn the numbers. 70-80dB THD is a don't care in general. I have no argument with their approach and have willingly done the same myself with phono stages. I suspect that if not told so in advance I would not hear any difference between a Pono or an iPhone.
Peeking is all important, failure is not an option.
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You misunderstand my position... I am looking for an explanation why for all these years i have had CD's and players.... they have never sounded as good as the HD 24/96 downloads. So far, you have shot down every possibility but not explained this difference i and so many others have experienced. maybe you dont know either. So, I'll end the questions about could it be this or that? My conclusion is that the masters are better than the 16 versions on CD but still dont know why.
I said I purchased and heard the difference of the PONO vs BenchMark2 before i saw the data on the PONO in this months issue of Stereophile-- which to me explains what i heard. It sounded like 2nd and it measured that way. SE tubes circuits have that affect on me also when they have high enough 2nd's. They sound thicker. I can enjoy the music though. But it isnt as accurate as it could be. I dont care if it open loop or not, as long as the distortion cant be characterized so easily upon hearing. There is one person on another forum who has developed a low enough thd (<-100db) with no gnfb and i am sure I would like it as well as any high gnfb design. I am waiting to get his sample to test and listen to soon. Once the distortion is low 'enough' for me, it doesnt matter what the topology or analog or digital or what ever.... un detectable is undetectable.
The negative spin --- doubts. Because, I still wonder why CD I have heard for so long do not sound as good as the HD downloads and offered some possible areas in hope that someone could explain it to me.... no such luck. But so what. I can get low enough distortion now in digital as well as analog and I am happy with that.
Thx-RNMarsh
I said I purchased and heard the difference of the PONO vs BenchMark2 before i saw the data on the PONO in this months issue of Stereophile-- which to me explains what i heard. It sounded like 2nd and it measured that way. SE tubes circuits have that affect on me also when they have high enough 2nd's. They sound thicker. I can enjoy the music though. But it isnt as accurate as it could be. I dont care if it open loop or not, as long as the distortion cant be characterized so easily upon hearing. There is one person on another forum who has developed a low enough thd (<-100db) with no gnfb and i am sure I would like it as well as any high gnfb design. I am waiting to get his sample to test and listen to soon. Once the distortion is low 'enough' for me, it doesnt matter what the topology or analog or digital or what ever.... un detectable is undetectable.
The negative spin --- doubts. Because, I still wonder why CD I have heard for so long do not sound as good as the HD downloads and offered some possible areas in hope that someone could explain it to me.... no such luck. But so what. I can get low enough distortion now in digital as well as analog and I am happy with that.
Thx-RNMarsh
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Unless we are listening to music that is recorded at the lsb level what is the nonsense that you can possible hear a change from using dither? I just fail to see the connection to dither and any interference with the quality of the sound at normal and even less than normal listening levels? Why are we speaking about something that seems to have such a strong basis in science and the use of dither? It just seems to be a case of twisting the facts of the mater in how and why dither is used.
Christophe,
I am still sitting on the sidelines waiting for ssd technology to mature and for some of the problems with life expectancy to be improved and the price of larger drives to come down. I also have 10,000rpm drives in my laptop and 6gb of ram with an i5 processor. I do need a faster machine now that I am again doing mostly design work on my computer, I especially was reminded of that the other day having to do some rendering of some cad files, what a waste of time that was but something that I have to do. It reminds me of my original Compaq computer with a 20mb hard drive and getting a new scanner, one scan and the entire hard drive was full!
I am still sitting on the sidelines waiting for ssd technology to mature and for some of the problems with life expectancy to be improved and the price of larger drives to come down. I also have 10,000rpm drives in my laptop and 6gb of ram with an i5 processor. I do need a faster machine now that I am again doing mostly design work on my computer, I especially was reminded of that the other day having to do some rendering of some cad files, what a waste of time that was but something that I have to do. It reminds me of my original Compaq computer with a 20mb hard drive and getting a new scanner, one scan and the entire hard drive was full!
It is beginning to appear to me that mis-use or excessive use dithering in production of a music file is a contributor. But many other mis-steps in the recording process can leave much to be desired ... Seems like the best recordings and the best mastering get on HDTracks et al and that has possibly the greatest impact on what I hear. Though one step closer to the master may also help some (24/96).
Otherwise, all is forgotten and forgiven. I'm still going to buy a ADC and run thru the numbers and listen. if that measures near perfect enough.... then I will be even more inclined to think it is the production side of things. and do Vuki suggestion as well as others.
THanks all,
RNMarsh
Otherwise, all is forgotten and forgiven. I'm still going to buy a ADC and run thru the numbers and listen. if that measures near perfect enough.... then I will be even more inclined to think it is the production side of things. and do Vuki suggestion as well as others.
THanks all,
RNMarsh
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I think it was Vanderkooy/Lipshitz who showed that dithering made digital reproduction essentially analog in nature.
You'd thunk they would have received the audio equivalent of the Nobel for it, but no. Instead, we seem to rely on wild speculation here. Quite wild, in fact.
Richard, I do agree on one of your points: the production side has much, much more impact on the final audible result than 24/96 etc.
Jan
You'd thunk they would have received the audio equivalent of the Nobel for it, but no. Instead, we seem to rely on wild speculation here. Quite wild, in fact.
Richard, I do agree on one of your points: the production side has much, much more impact on the final audible result than 24/96 etc.
Jan
Thanks Richard for the excellent article on dithering. It is refreshing when someone with REAL experience tells us what dithering can potentially do, both good and bad.
Yesterday, I went to visit Jack Bybee at his place that is about 1 1/2 hours away. He never ceases to amaze me with what he can do with physics.
Yesterday, I went to visit Jack Bybee at his place that is about 1 1/2 hours away. He never ceases to amaze me with what he can do with physics.
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