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#1
Posted to rec.audio.tubes
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Tube DACs??
These seem to be popping up everywhere in audiophile circles..
what would be the purpose of such a device? Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. |
#2
Posted to rec.audio.tubes
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Tube DACs??
On Nov 24, 12:21*pm, cipher wrote:
These seem to be popping up everywhere in audiophile circles.. what would be the purpose of such a device? *Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. Well, given the silliness of a DAC and a tube, the purpose is so that the manufacturer can say that their device (were it actually 'all tube' would be the size of a large building and require its own power- plant) is "tube". There is no legitimate reason in my opinion. My guess is that at-best, the unit uses a tube at the analog output end - nowhere in the actual conversion process. That same crowd that purchases speaker cable catenaries, $X,XXX.XX cables and patch cords, magic rocks and so forth will eat it right up. Nothing counter-intuitive about separating the sheep from their wool. Peter Wieck Melrose Park, PA |
#3
Posted to rec.audio.tubes
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Tube DACs??
"cipher" wrote in message 0... These seem to be popping up everywhere in audiophile circles.. what would be the purpose of such a device? Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. **There is no such thing as a "tube DAC". Given the requirements of a typical DAC, to build one from tubes would occupy the volume of a small house. Power consumption would likely be in the order of many tens of kWatts. -- Trevor Wilson www.rageaudio.com.au |
#4
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Tube DACs??
On Nov 24, 4:21*pm, "Trevor Wilson"
wrote: "cipher" wrote in message 0... These seem to be popping up everywhere in audiophile circles.. what would be the purpose of such a device? *Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. **There is no such thing as a "tube DAC". Given the requirements of a typical DAC, to build one from tubes would occupy the volume of a small house. Power consumption would likely be in the order of many tens of kWatts. -- Trevor Wilsonwww.rageaudio.com.au Awwww... c'mon, guy!! http://www.angelfire.com/biz/bizzyb/TADAC.html http://www.audioreview.com/USBTDcrx.aspx http://www.highendpalace.com/HEP%20CD.htm Peter Wieck Melrose Park, PA |
#5
Posted to rec.audio.tubes
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Tube DACs??
In article ,
Peter Wieck wrote: On Nov 24, 12:21*pm, cipher wrote: These seem to be popping up everywhere in audiophile circles.. what would be the purpose of such a device? *Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. Well, given the silliness of a DAC and a tube, the purpose is so that the manufacturer can say that their device (were it actually 'all tube' would be the size of a large building and require its own power- plant) is "tube". There is no legitimate reason in my opinion. My guess is that at-best, the unit uses a tube at the analog output end - nowhere in the actual conversion process. I would agree with you there, most likely these devices use a silicon solid state DAC followed by an analog tube based output buffer stage. However I don't agree that a tube DAC would "would be the size of a large building and require its own power plant". I suspect that the real problem with building a tube DAC would be achieving the required 16 bit accuracy, and not that a totally unreasonable number of tubes would be required, as you suggest. I can think of at least three possible approaches to building a reasonably living room friendly real tube DAC, perhaps with enough effort one of these approaches could be made to provide the required accuracy. Your comments suggest that you are thinking of not just a tube DAC, but also a tube DSP, for it to "be the size of a large building and require its own power plant". -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#6
Posted to rec.audio.tubes
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Tube DACs??
The good thing about a "tube DAC" is that you can feed the DAC's
converted analog signal straight into the grids of the input tubes together with the DC on the signal, which becomes part of the bias. It's an elegant way of doing it and many including myself believe it sounds better than transformer out or a solid state output stage. andy |
#7
Posted to rec.audio.tubes
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Tube DACs??
One possible approach not requiring a roomful of equipment: An analog
voltage representation of a sixteen bit value can be achieved by summing the voltages corresponding to the states of the individual bits. This would require sixteen voltage references with .01% error, sixteen precision analog switches, and a precision summing junction. As John points out, achieving the required accuracy would be the challenge here. |
#8
Posted to rec.audio.tubes
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Tube DACs??
"cipher" wrote in message 0... These seem to be popping up everywhere in audiophile circles.. what would be the purpose of such a device? Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. One thing I have noticed about stereo stacks... everything has an output in one way or another, even if it is the sound itself, from a speaker. And, the output stage of a DAC would be the point, just for that tube's worth of sound quality. Any output stage to another component, is an amplifier. This is my FIRST post, as a reply, in this NG. Alex SoCalifornia |
#9
Posted to rec.audio.tubes
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Tube DACs??
LGLA wrote: "cipher" wrote in message 0... These seem to be popping up everywhere in audiophile circles.. what would be the purpose of such a device? Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. One thing I have noticed about stereo stacks... everything has an output in one way or another, even if it is the sound itself, from a speaker. And, the output stage of a DAC would be the point, just for that tube's worth of sound quality. Any output stage to another component, is an amplifier. This is my FIRST post, as a reply, in this NG. Alex SoCalifornia Welcome to our little group. I hope you have a wardrobe full of flame suits to protect yourself from the barbs, sarcasms, inuendo, and downright BS that this group generates like mushrooms springing up in compost. Between the lines of BS there is much to be treasured here, and if you increase the treasure then you'll get by better than some. If you did all the functions of a D to A converters using tubes, methinks you'd have no room to keep a wife at your house and you'd be horrified by the power bills. The Green Police would call to arrest you for causing so much greenhouse gas. Rather a lot of tubes are needed. However, their purpose would be to perform un-digitalling tasks which can be done better with zillions of transistors in a chip. But the tubes are very nice things to use as the fist device to handle and filter the audio coming from the DA chip. But soon the digital world will be rocked with DXD etc, so prepare to say tata to CDs. The world has always hosted a mix of the best and the worst in any product. MP3 is the worst, but the DXD could be the best but only for those who can afford it unless the DXD becomes a real cheap alternative due to parallel developments in data processing speeds, memory capacities and broadband data transfer rates. Put it this way, in 25 years time, will anyone remember how CD players worked? Will replacement lasers be available? Will anyone know how to install them? And won't 44kHz x 16 bit all seem even more primitive than vinyl? And will we have holographic porno online streaming? and film character / plot choice? and a host of other gee wizz ways of creating entertainment without actors, actresses, and orchestras? Hu nose? I don't. And the future might arrive and I'll be too old to enjoy it. Patrick Turner. |
#10
Posted to rec.audio.tubes
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Tube DACs??
In article ,
Patrick Turner wrote: If you did all the functions of a D to A converters using tubes, methinks you'd have no room to keep a wife at your house and you'd be horrified by the power bills. The Green Police would call to arrest you for causing so much greenhouse gas. Rather a lot of tubes are needed. However, their purpose would be to perform un-digitalling tasks which can be done better with zillions of transistors in a chip. But the tubes are very nice things to use as the fist device to handle and filter the audio coming from the DA chip. Patrick, methinks that you are confusing "D to A converters" with DSPs. A tube D to A converter wouldn't be anywhere near as complex as you imply, the problem is how to achieve the desired 16 bit accuracy. I believe D to A converters built from tubes, of less than 16 bit accuracy, actually existed back in the 1950s, although I am not going to look for any links right now. -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#11
Posted to rec.audio.tubes
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Tube DACs??
"Peter Wieck" wrote in message ... On Nov 24, 4:21 pm, "Trevor Wilson" wrote: "cipher" wrote in message 0... These seem to be popping up everywhere in audiophile circles.. what would be the purpose of such a device? Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. **There is no such thing as a "tube DAC". Given the requirements of a typical DAC, to build one from tubes would occupy the volume of a small house. Power consumption would likely be in the order of many tens of kWatts. -- Trevor Wilsonwww.rageaudio.com.au Awwww... c'mon, guy!! http://www.angelfire.com/biz/bizzyb/TADAC.html http://www.audioreview.com/USBTDcrx.aspx http://www.highendpalace.com/HEP%20CD.htm Peter Wieck Melrose Park, PA Trevor is dead right or even a little conservative with his estimation. Look at the very first link you posted and read the specs as it uses a "96k max input data speed, Crystal 8414 feeds a 192k 24-Bit Burr-Brown 1793 Advanced Segment Verification Jitter Free D/A chip" So it has a silicon chip in it that is *not* a tube, BTW check this link out and see how hard it is to just make a digital clock out of tubes. http://www.engadget.com/2006/06/26/a...in-the-making/ And you want to make a DAC chip out of them? Best of luck ;-) Perhaps people should accurately call these things what they really are a "tubed output stage DACs" Cheers TT |
#12
Posted to rec.audio.tubes
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Tube DACs??
On Nov 28, 5:15*pm, "TT" wrote:
Perhaps people should accurately call these things what they really are a "tubed output stage DACs" Your sarcasm-detector needs adjustment! Peter Wieck Melrose Park, PA |
#13
Posted to rec.audio.tubes
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Tube DACs??
"Peter Wieck" wrote in message ... On Nov 28, 5:15 pm, "TT" wrote: Perhaps people should accurately call these things what they really are a "tubed output stage DACs" Your sarcasm-detector needs adjustment! Peter Wieck Melrose Park, PA Perhaps. Your posts are usually very sensible (unless replying to Arny or Jute) and if you were using sarcasm then I did miss it ;-) Obvious both Trevor and I took the points literally. Cheers TT |
#14
Posted to rec.audio.tubes
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Tube DACs??
"flipper" wrote in message ... On Sat, 29 Nov 2008 07:15:02 +0900, "TT" wrote: "Peter Wieck" wrote in message ... On Nov 24, 4:21 pm, "Trevor Wilson" wrote: "cipher" wrote in message 0... These seem to be popping up everywhere in audiophile circles.. what would be the purpose of such a device? Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. **There is no such thing as a "tube DAC". Given the requirements of a typical DAC, to build one from tubes would occupy the volume of a small house. Power consumption would likely be in the order of many tens of kWatts. -- Trevor Wilsonwww.rageaudio.com.au Awwww... c'mon, guy!! http://www.angelfire.com/biz/bizzyb/TADAC.html http://www.audioreview.com/USBTDcrx.aspx http://www.highendpalace.com/HEP%20CD.htm Peter Wieck Melrose Park, PA Trevor is dead right or even a little conservative with his estimation. Look at the very first link you posted and read the specs as it uses a "96k max input data speed, Crystal 8414 feeds a 192k 24-Bit Burr-Brown 1793 Advanced Segment Verification Jitter Free D/A chip" So it has a silicon chip in it that is *not* a tube, BTW check this link out and see how hard it is to just make a digital clock out of tubes. http://www.engadget.com/2006/06/26/a...in-the-making/ And you want to make a DAC chip out of them? Best of luck ;-) You're making the same mistake Trevor did in confusing a DSP with a DAC. We are discussing DACs - Digital Analog Converters right? Things that convert 1s and 0s to sine waves? The basic principle of a "DAC" is rather simple, Yes it is for a silicon chip ;-) and a whole lot simpler than the tube clock you mention, I beg to differ. A tube DAC would be as Trevor described it. but it's moot as there's no 'audio' value to doing digital circuits with tubes. Correct but people still do. Perhaps people should accurately call these things what they really are a "tubed output stage DACs" If it makes you feel good but there's nothing particularly 'wrong' with calling it a Tube DAC either. Yes there is when no part of the DAC circuit is controlled by tubes! Just as there's nothing particularly 'wrong' with "tube record player" instead of "tubed output mechanical audio reproduction device." Record players *DO NOT* require tubes or any other amplification circuitry to work. The signal from the machine can be passed to any device you so wish or in the case of a gramophone no other device is even required. That is a bad example you used! It's just that the means of getting from pit marked plastic to 'audio' is a heck of a lot more complex than a wiggling needle but,, once audio, the active device is, in both cases, tubes. You have failed to convince me ;-) There is no such thing as a Tube DAC for 16 bit audio. There are, however a lot of tubed output stage DACs available as the DAC is still a silicon chip. Cheers TT |
#15
Posted to rec.audio.tubes
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Tube DACs??
John Byrns wrote:
In article , Patrick Turner wrote: If you did all the functions of a D to A converters using tubes, methinks you'd have no room to keep a wife at your house and you'd be horrified by the power bills. The Green Police would call to arrest you for causing so much greenhouse gas. Rather a lot of tubes are needed. However, their purpose would be to perform un-digitalling tasks which can be done better with zillions of transistors in a chip. But the tubes are very nice things to use as the fist device to handle and filter the audio coming from the DA chip. Patrick, methinks that you are confusing "D to A converters" with DSPs. A tube D to A converter wouldn't be anywhere near as complex as you imply, the problem is how to achieve the desired 16 bit accuracy. I believe D to A converters built from tubes, of less than 16 bit accuracy, actually existed back in the 1950s, although I am not going to look for any links right now. You could theoretically build a DAC with a few dozen tubes, but you would need a precision resistor network. These days DACs are usually of the delta-sigma type that do not need precision parts but do use thousands of transistors, they work much better. Keith |
#16
Posted to rec.audio.tubes
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Tube DACs??
cipher wrote: These seem to be popping up everywhere in audiophile circles.. You mean audiophool circles. The same people who pay hundreds upon hundreds for speaker wire and silver plated mains cables. The Shakti Stone and Tice Clock are probably some of the most extravagant examples of this nonsense. http://www.gcaudio.com/products/reviews/infoshakti.html http://electronicdesign.com/Articles...ArticleID=6134 A personal favourite is this though ! http://www.museumofhoaxes.com/hoax/w...comments/4309/ what would be the purpose of such a device? To add distortion. Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. You have good sense. Graham |
#17
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Tube DACs??
John Byrns wrote: However I don't agree that a tube DAC would "would be the size of a large building and require its own power plant". I suspect that the real problem with building a tube DAC would be achieving the required 16 bit accuracy, and not that a totally unreasonable number of tubes would be required, as you suggest. It would have to be a very primitive DAC as used in early CD players. No oversampling or internal DSP filtering. Graham |
#18
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Tube DACs??
Andy Evans wrote: The good thing about a "tube DAC" is that you can feed the DAC's converted analog signal straight into the grids of the input tubes together with the DC on the signal, which becomes part of the bias. It's an elegant way of doing it and many including myself believe it sounds better than transformer out or a solid state output stage. How can added distortion 'sound better' ? Graham |
#19
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Tube DACs??
Peter Wieck wrote: My guess is that at-best, the unit uses a tube at the analog output end - nowhere in the actual conversion process. I should have made that clear in my response too. Graham |
#20
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Tube DACs??
TT wrote: Perhaps people should accurately call these things what they really are a "tubed output stage DACs" You presume the sellers care about accuracy whether descriptive or sonic. Graham |
#21
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Tube DACs??
LGLA wrote: "cipher" wrote These seem to be popping up everywhere in audiophile circles.. what would be the purpose of such a device? Yes, I am young and ignorant re electronics. something about the whole thing seems counter intuitive to me. One thing I have noticed about stereo stacks... everything has an output in one way or another, even if it is the sound itself, from a speaker. And, the output stage of a DAC would be the point, just for that tube's worth of sound quality. Any output stage to another component, is an amplifier. But tubes have WORSE audio quality than solid state ! http://www.national.com/pf/LM/LME49720.html And it'll cost less than a tube and not require special power supplies. Graham |
#22
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Tube DACs??
Patrick Turner wrote: If you did all the functions of a D to A converters using tubes, methinks you'd have no room to keep a wife at your house and you'd be horrified by the power bills. The Green Police would call to arrest you for causing so much greenhouse gas. Rather a lot of tubes are needed. Which would mean rather a lot of time spent hunting down the failed ones and replacing them ! Graham |
#23
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Tube DACs??
Patrick Turner wrote: Hu nose? A Chinese friend ? Graham |
#24
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Tube DACs??
John Byrns wrote: Patrick Turner wrote: If you did all the functions of a D to A converters using tubes, methinks you'd have no room to keep a wife at your house and you'd be horrified by the power bills. The Green Police would call to arrest you for causing so much greenhouse gas. Rather a lot of tubes are needed. However, their purpose would be to perform un-digitalling tasks which can be done better with zillions of transistors in a chip. But the tubes are very nice things to use as the fist device to handle and filter the audio coming from the DA chip. Patrick, methinks that you are confusing "D to A converters" with DSPs. A tube D to A converter wouldn't be anywhere near as complex as you imply, the problem is how to achieve the desired 16 bit accuracy. I believe D to A converters built from tubes, of less than 16 bit accuracy, actually existed back in the 1950s, although I am not going to look for any links right now. And you'd be back to analogue anti-aliasing and anti-imaging filters too. Graham |
#25
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Tube DACs??
Patrick Turner wrote: But the tubes are very nice things to use as the fist device to handle and filter the audio coming from the DA chip. In what way are they nice for this task ? Graham |
#26
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Tube DACs??
flipper wrote: A 16 bit DAC is, basically, a current/voltage source, 16 switches, 16 precision resistors, a summing junction and output buffer. That's hardly a 'house' full of tubes, much less 'conservative'. As a pure DAC, sure. Modern ones however take a serial (single wire) I2S signal input and clock. Graham |
#27
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Tube DACs??
In article ,
Eeyore wrote: John Byrns wrote: Patrick Turner wrote: If you did all the functions of a D to A converters using tubes, methinks you'd have no room to keep a wife at your house and you'd be horrified by the power bills. The Green Police would call to arrest you for causing so much greenhouse gas. Rather a lot of tubes are needed. However, their purpose would be to perform un-digitalling tasks which can be done better with zillions of transistors in a chip. But the tubes are very nice things to use as the fist device to handle and filter the audio coming from the DA chip. Patrick, methinks that you are confusing "D to A converters" with DSPs. A tube D to A converter wouldn't be anywhere near as complex as you imply, the problem is how to achieve the desired 16 bit accuracy. I believe D to A converters built from tubes, of less than 16 bit accuracy, actually existed back in the 1950s, although I am not going to look for any links right now. And you'd be back to analogue anti-aliasing and anti-imaging filters too. Show me a solid state DAC that doesn't require "analogue anti-aliasing and anti-imaging filters too"? -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#28
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Tube DACs??
"John Byrns" wrote in message
However I don't agree that a tube DAC would "would be the size of a large building and require its own power plant". http://www.analog.com/library/analog...Tech%20 F.pdf "In 1954 Epsco introduced an 11-bit, 50-kSPS vacuum-tube based SAR ADC called the DATRAC. This converter, shown in Figure 4.3, is generally credited as being the first commercial offering of such a device. The DATRAC was offered in a 19" × 26" × 15" housing, dissipated several hundred watts, and sold for approximately $8000.00." Figure 4.3 says that the total power usage was 500 watts. Two would be required for stereo. I suspect that the real problem with building a tube DAC would be achieving the required 16 bit accuracy, Agreed. and not that a totally unreasonable number of tubes would be required, as you suggest. If enough accuracy and stability were possible, the SAR DAC technology would seem to increase the parts count linearaly with the number of bits. Since speed of components would also increase linearly with the number of bits, the total power usage per part might increase similarly. A 16 bit version would have needed to be about 50%. more parts and more than twice as much power. |
#29
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Tube DACs??
"Eeyore" wrote in
message John Byrns wrote: However I don't agree that a tube DAC would "would be the size of a large building and require its own power plant". I suspect that the real problem with building a tube DAC would be achieving the required 16 bit accuracy, and not that a totally unreasonable number of tubes would be required, as you suggest. It would have to be a very primitive DAC as used in early CD players. No oversampling or internal DSP filtering. Right the oversampling and the DSP filters would put the parts count over the top. BTW, I don't think that modern DACs include a DSP to do the digital filtering, but rather use combinatorial logic. Based on the info in this page http://www.analog.com/library/analog...0 F.pdfFigure 4.2, I would expect that a stereo 16 bit DAC, were it even possibleto achieve that kind of precision, would have at least 3 times the partscount and at least 4-5 times the power usage. So we're talking about afull rack and a couple-three kilowatts. |
#30
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Tube DACs??
"John Byrns" wrote in message
In article , Eeyore wrote: And you'd be back to analogue anti-aliasing and anti-imaging filters too. Show me a solid state DAC that doesn't require "analogue anti-aliasing and anti-imaging filters too"? In modern ADCs and DACs, the actual brick-wall filtering is implemented in the digital domain via oversampling. There are analog filters, but they are usually merely 4th order, and have a ultrasonic corner frequency. |
#31
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Tube DACs??
"Eeyore" wrote in
message Patrick Turner wrote: If you did all the functions of a D to A converters using tubes, methinks you'd have no room to keep a wife at your house and you'd be horrified by the power bills. The Green Police would call to arrest you for causing so much greenhouse gas. Rather a lot of tubes are needed. Which would mean rather a lot of time spent hunting down the failed ones and replacing them ! We been there and done that with tubed digital computers during the 50s and early 60s. In the mid-60s when I worked for IBM our field office still had one client with a 650 that did thier books, and the tubed computer at another shop had not been gone that long - some of the repair parts were still around. There was a funny story about the second computer. The tubed computers made so much really hot air that their ductwork was more like a chimney than ducts, right down to the damper. The 650 mentioned above looked like a large hot air furnace in a basement with ducts leading off in all directions. At any rate one client inadvertantly left the damper open one summer weekend. On Saturday, we had a cold snap and cold air chilled the computer down to the 50s. On Sunday there was then a hot, humid heat wave and there was massive condensation. The first shift on Monday morning came in and powered the thing up. Filament supply - no problem. A brief warm up, and then on with the HV... Kaahhh-whhham! Field engineers with hair dryers worked for 3 days before the thing would power up again. |
#32
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Tube DACs??
In article ,
"Arny Krueger" wrote: "John Byrns" wrote in message In article , Eeyore wrote: And you'd be back to analogue anti-aliasing and anti-imaging filters too. Show me a solid state DAC that doesn't require "analogue anti-aliasing and anti-imaging filters too"? In modern ADCs and DACs, the actual brick-wall filtering is implemented in the digital domain via oversampling. There are analog filters, but they are usually merely 4th order, and have a ultrasonic corner frequency. So what you are saying is that "modern ADCs and DACs" use digital filters in addition to analog filters. They don't eliminate analog filters, they simply relax the constraints on them. I think Eeyore needs to hit the books. -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#33
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Tube DACs??
John Byrns wrote:
In article , "Arny Krueger" wrote: "John Byrns" wrote in message In article , Eeyore wrote: And you'd be back to analogue anti-aliasing and anti-imaging filters too. Show me a solid state DAC that doesn't require "analogue anti-aliasing and anti-imaging filters too"? In modern ADCs and DACs, the actual brick-wall filtering is implemented in the digital domain via oversampling. There are analog filters, but they are usually merely 4th order, and have a ultrasonic corner frequency. So what you are saying is that "modern ADCs and DACs" use digital filters in addition to analog filters. They don't eliminate analog filters, they simply relax the constraints on them. Precisely, which is exactly why oversampling DACs were invented. Cheers |
#34
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Tube DACs??
In article ,
Ian Bell wrote: John Byrns wrote: In article , "Arny Krueger" wrote: "John Byrns" wrote in message In article , Eeyore wrote: And you'd be back to analogue anti-aliasing and anti-imaging filters too. Show me a solid state DAC that doesn't require "analogue anti-aliasing and anti-imaging filters too"? In modern ADCs and DACs, the actual brick-wall filtering is implemented in the digital domain via oversampling. There are analog filters, but they are usually merely 4th order, and have a ultrasonic corner frequency. So what you are saying is that "modern ADCs and DACs" use digital filters in addition to analog filters. They don't eliminate analog filters, they simply relax the constraints on them. Precisely, which is exactly why oversampling DACs were invented. I thought oversampling DACs were invented because Philips only had a 14 bit DAC available when they compromised with Sony on the CD spec. and needed a way to get 16 bits out of their existing 14 bit converter? ;-) -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#35
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Tube DACs??
On Nov 29, 3:24*pm, Eeyore
wrote: Andy Evans wrote: The good thing about a "tube DAC" is that you can feed the DAC's converted analog signal straight into the grids of the input tubes together with the DC on the signal, which becomes part of the bias. It's an elegant way of doing it and many including myself believe it sounds better than transformer out or a solid state output stage. How can added distortion 'sound better' ? Graham I think the phrase you're searching for is "How can that sound better?" andy |
#36
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Tube DACs??
But tubes have WORSE audio quality than solid state ! Graham So what makes you hang out on rec.audio.tubes-have-worse-quality-than- solid-state? Sheer perversity? This is exactly the one place where nobody is likely to believe you. Sounds like banging one's head against a brick wall to me. Maybe in life's rich pageant somebody somewhere has to do it. andy |
#37
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Tube DACs??
John Byrns wrote: Show me a solid state DAC that doesn't require "analogue anti-aliasing and anti-imaging filters too"? Are you kidding me ? Graham |
#38
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Tube DACs??
Arny Krueger wrote: "John Byrns" wrote Eeyore wrote: And you'd be back to analogue anti-aliasing and anti-imaging filters too. Show me a solid state DAC that doesn't require "analogue anti-aliasing and anti-imaging filters too"? In modern ADCs and DACs, the actual brick-wall filtering is implemented in the digital domain via oversampling. Exactly. There are analog filters, but they are usually merely 4th order, and have a ultrasonic corner frequency. Just to roll off some residual ultrasonic trash. There's not much of it anyway. Graham |
#39
Posted to rec.audio.tubes
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Tube DACs??
John Byrns wrote: I think Eeyore needs to hit the books. Eeyore builds with them. The very mild filtering is NOT there for anti-aliasing or anti-imaging purposes. Read a ****ing data sheet ! An UP TO DATE one perhaps ? Graham |
#40
Posted to rec.audio.tubes
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Tube DACs??
John Byrns wrote: I thought oversampling DACs were invented because Philips only had a 14 bit DAC available when they compromised with Sony on the CD spec. and needed a way to get 16 bits out of their existing 14 bit converter? ;-) Clearly you're a bit muddled. Graham |
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