XTRProf
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Post by XTRProf on Dec 14, 2012 16:01:38 GMT
Asking as I had forgotten. Is it 21VDC +/-? Wanted to get 2A super Vregs for it. Please response quick as wanted to add that order to the list if affordable.
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Post by Deleted on Dec 14, 2012 19:37:06 GMT
Asking as I had forgotten. Is it 21VDC +/-? Wanted to get 2A super Vregs for it. Please response quick as wanted to add that order to the list if affordable. + and - 20V. BTW, I wouldn't recommend the use of Super Regs there, as I originally tried a JLH with the CL section bypassed. and the sound became "hard" and too focussed.What works well with opamps doesn't necessarily work as well with discrete circuits.
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XTRProf
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Post by XTRProf on Dec 15, 2012 4:32:48 GMT
+ and - 20V. BTW, I wouldn't recommend the use of Super Regs there, as I originally tried a JLH with the CL section bypassed. and the sound became "hard" and too focussed.What works well with opamps doesn't necessarily work as well with discrete circuits. Thanks Alex. I guess I will try either unregulated with DNM caps or a Diy shunt regulator. As the AK HA is disrete and analog, unregulated is also viable. Not for digital though as they need very stable power to run at their best. Anyway, those super Vregs are not cheap too and have to use 4 pieces. What Diy shunt regulator (> 2A) you recommend? Any schematic. I prefer shunt in analog as they have the lowest noise of the regulators. Digital, shunt and series also can as noise don't affect digital signals. Only need the tightest regulation for stability for the best digital processing.
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Post by Deleted on Dec 15, 2012 5:28:08 GMT
Chong The Class A HA/preamp doesn't draw much more than a little over 100mA on each rail in each module.That is set mainly by the bias current setting and the heatsinking used on the output devices. Bias can be set higher if you wish, but make sure output transistor heatsinking is adequate.The easiest way would be to use 1 or 2 JLHs with the current lmiter values of 1 ohm emitter resistor and 1.8K base resistor in each JLH. Best performance will be with 2 JLHs used in dual mono for highest channel separation. A JLH can also handle 2A at 12V without the current limiter, but relying on the current limiting of the preceding voltage regulator.e.g. a MC78T12 3A regulator. The CL Toshiba device and the Toshiba device with the 33 ohm emitter resistor should have small heatsinks fitted for both the HA and a 2A supply. I don't claim that the JLH will outperform the far more expensive shunt regulators, but it will only draw a little more than the load current, run cooler and cost less. The small additional current draw over a big shunt could mean savings on the transformers and heatsinks etc. JeffC and Allan are also using the JLH in high current PSUs. Check with Allan Pagan for hints in that area. Alex
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pagan
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Post by pagan on Dec 15, 2012 6:27:35 GMT
Alex I use the JLH's only on the front end of my amps, the power for the output devices are run through an CRCCC filter.
Allan
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Will
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Post by Will on Dec 15, 2012 6:30:18 GMT
I'd completely disagree with that statement, based on the differences I've heard when using low noise supplies in digital only circuits. But that's just me and my ears
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Post by Deleted on Dec 15, 2012 6:47:07 GMT
Alex I use the JLH's only on the front end of my amps, the power for the output devices are run through an CRCCC filter. Allan Allan I use JLHs for the complete HA/preamp as the current drawn is only a bit over 100mA per rail. I only use a JLH for the front end of the 15W Class A , and the output is already powered with VREGs. Alex
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Post by Deleted on Dec 15, 2012 6:49:00 GMT
I'd completely disagree with that statement, based on the differences I've heard when using low noise supplies in digital only circuits. But that's just me and my ears Likewise.
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pagan
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Post by pagan on Dec 15, 2012 6:56:50 GMT
I'd completely disagree with that statement, based on the differences I've heard when using low noise supplies in digital only circuits. But that's just me and my ears Yes but, A DAC is not a purely digital device. Digital circuits are not prown to noise issues, In a 5volt digital circuit anything above ~3.5Volt is high, anything below ~2volt is low. Digital devices switch for high and low, so 10-100mV noise is irrelevant. In a 3volt digital circuit it below ~ 1volt and above ~ 2volt. The problem is when putting a digital signal into and analogue circuit. The digital noise has to go somewhere. Allan This might be a reason why the sabre dac is so susceptible to psu quality, Being that one of the digital voltage lines are 1.2V. The bandwidth between high and low is very small.
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Post by Deleted on Dec 15, 2012 7:04:03 GMT
Not so. PSU noise and ripple affects timing (hysterisis ) You need just as clean a supply for digital areas as you do for analogue. Perhaps even more so.
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pagan
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Post by pagan on Dec 15, 2012 7:43:45 GMT
Not so. PSU noise and ripple affects timing (hysterisis ) You need just as clean a supply for digital areas as you do for analogue. Perhaps even more so. Alex More so for the later digital ic's where lower voltage is applied. And the difference between high and low is getting narrower. The better ATX psu's are stating low noise figures of 100mV. The cpu's psu is re-reg'd again before it goes on die. Allan
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Post by Deleted on Dec 15, 2012 8:06:35 GMT
Allan Somehow we have got way off topic here. What would you call a USB memory stick , an analogue device ? Despite having an internal 3.3V reg , it is as you are well aware, still very much affected by the quality of it's PSU, both when storing and playing back music files. Of course this kind of thing doesn't matter so much in the kind of data you work with in the A.P.O.
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Post by pagan on Dec 15, 2012 8:41:23 GMT
Allan Somehow we have got way off topic here. What would you call a USB memory stick , an analogue device ? Despite having an internal 3.3V reg , it is as you are well aware, still very much affected by the quality of it's PSU, both when storing and playing back music files. Of course this kind of thing doesn't matter so much in the kind of data you work with in the A.P.O. Off topic? ? yeh great isn't it. ;D What i'm saying is the noise doesn't affect digital... But the digital artifacts get into the analogue side, how dunno Maybe via the ground lines. Allan
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Post by Deleted on Dec 15, 2012 8:57:10 GMT
Allan Obviously it does, or the digital artifacts couldn't get into the analogue side. There is a thread in DIYAudio where several have said that digital is just another variation of analogue, and in some situations it is possinble to even get analogue out without even a DAC! Alex
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Post by pagan on Dec 16, 2012 4:59:06 GMT
Allan Obviously it does, or the digital artifacts couldn't get into the analogue side. There is a thread in DIYAudio where several have said that digital is just another variation of analogue, and in some situations it is possinble to even get analogue out without even a DAC! Alex Alex well PWM and PCM mainly transmission types.. but on a motherboard between ic's.... about as analogue as a square wave. And the devices only switch on or off relevant to their voltage threshold. Allan hold on PCM I need to check again
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XTRProf
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Post by XTRProf on Dec 17, 2012 1:27:09 GMT
Chong The Class A HA/preamp doesn't draw much more than a little over 100mA on each rail in each module.That is set mainly by the bias current setting and the heatsinking used on the output devices. Bias can be set higher if you wish, but make sure output transistor heatsinking is adequate.The easiest way would be to use 1 or 2 JLHs with the current lmiter values of 1 ohm emitter resistor and 1.8K base resistor in each JLH. Best performance will be with 2 JLHs used in dual mono for highest channel separation. A JLH can also handle 2A at 12V without the current limiter, but relying on the current limiting of the preceding voltage regulator.e.g. a MC78T12 3A regulator. The CL Toshiba device and the Toshiba device with the 33 ohm emitter resistor should have small heatsinks fitted for both the HA and a 2A supply. I don't claim that the JLH will outperform the far more expensive shunt regulators, but it will only draw a little more than the load current, run cooler and cost less. The small additional current draw over a big shunt could mean savings on the transformers and heatsinks etc. JeffC and Allan are also using the JLH in high current PSUs. Check with Allan Pagan for hints in that area. Alex Wow, didn't come back on this and already grown quite a lot in this thread. It shows quite many are interested in super power. Just to get things all clear up, I do have 2 JLH in mono form for the AK HA. That's the first JLH I have tried. Yeah, you are right to have the heatsinks on the Toshiba as they are quite warm. I have not done that yet. Only time to move on to some thing subjectively "better" to try. That's why the unregulated and maybe shunt super power that can do 2A to avoid any dynamic compression from insufficient A. I always like to do things very much in excess just to make sure it's the best and banned all insufficiency from coming into the purity of playing the music signal. We are not writing of just to meet basic engineering specs and safety factor but the whole realm of excellent music reproducer. So just meeting basic requirements is surely not good enough. It has been shown to be correct from experience from hearing other systems with this "no limit" concept. You can call it whatever but I will call it the no boundary American free wheeling style.
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XTRProf
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Post by XTRProf on Dec 17, 2012 1:40:48 GMT
I'd completely disagree with that statement, based on the differences I've heard when using low noise supplies in digital only circuits. But that's just me and my ears. I believe you and the so called technical experts must investigate further why this is so just like in Dac where they are finding phase noise is more important than jitter. So the technical experts must change tone to reflect that? We are here to discover and not to heatedly rebute from what is present but based on something not discovered yet to advance the Art and Science of AV. That's what great inventors or discoverers are all about. Heh, heh, heh, we can call them the "mad" scientists if we like. Just like in audio, the subjectivitists are called the "mad" as well. Doesn't he looked like one?
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Post by Deleted on Dec 17, 2012 2:02:04 GMT
Chong The problem is that most people who report hearing these things usually don't have the training or suitable test equipment to pursue these things. Many of the "Technical Experts" refuse to accept what subjectivists report if it goes against what they were taught, no matter how many supportive reports there are.They usually demand those flawed DBTs, and even if the findings are positive, still refuse to accept them because THEY personally, didn't organise the DBTs. Alex
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XTRProf
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Post by XTRProf on Dec 17, 2012 2:05:13 GMT
There is a thread in DIYAudio where several have said that digital is just another variation of analogue, and in some situations it is possinble to even get analogue out without even a DAC! Maybe infinity sampling? Then we are back to analogue. So no need digital any more.
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XTRProf
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Post by XTRProf on Dec 17, 2012 6:34:06 GMT
My take on digital. I agreed with Allan that digital will not take on board the noise as it's just 0 or 1 state. It's these series of states that the converter recognises to convert to analogue wave form minus the noise as it's just decoding the 0 and 1s and the converter don't recognise noise. As we can see, a digital system will stop working if it doesn't recognise those 0 or 1 and no sound will be produced. The noise will not make the digital converter works. Also, it's based on CRC and error correction, if error corrected wrongly, we can hear those crackers. So the error correction is an important equation to the final sound. Will noise make the error correction in error as the decoder just recognises 0 and 1 step states whereas noise is continous analogue state and not step. So can noise make a digital decoder work to add additonal artifacts to the sound? So there is more to noise than we know now.
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Post by Deleted on Dec 17, 2012 7:05:39 GMT
Then check Allan's previous reply and my answer to him. Allan has conceded in his post that SOMETHING is getting through as he has heard the differences between .wav files with identical check sums on quite a few occasions now. Whether it is noise or Jitter, or whatever, nobody appears to know at this point in time. It should be obvious to Allan too, that it has nothing to do with ground lines when both .wav files are stored on a USB memory stick ! Not only has Allan heard differences between 2 wav files with identical check sums stored on a Corsair Voyager, he has also heard further improvements in the SQ of those .wav files when the same Corsair Voyager is plugged into an external JLH +5V PSU then a W7 PC, as well as plugged into an Oppo 95s USB port. Again, there was further improvement with the Oppo 95 when the Corsair Voyager was used with the JLH PSU. Several other Sydney RG members have also heard these differences both directly from my P.C. and david2vk's PC at various listening sessions.A qualified Sydney E.E. and DIYAudio member,with wide industry experience, was also able to hear the difference between 2 different rips of "Yello-Bostich (Reflected) a couple of months ago at the most recent listening session at David's house. It should be obvious that there is far more to digital than is currently accepted. Alex BTW, this is completely off topic.
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Post by Deleted on Dec 19, 2012 6:40:58 GMT
It should be obvious that there is far more to digital than is currently accepted. Hi Alex, Time for me to stick my head up again. What do you mean by digital? It is a very generic term. "currently accepted" by whom? Engineers, Audiophiles, layman? Electronic Engineers fully understand Digital Electronics. The average layman and Audiophile seems to understand very little. regards Greg
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Post by Deleted on Dec 19, 2012 7:00:38 GMT
Greg I said this in my previous post. If you wish to discuss this further , I suggest that you start another thread. In the meantime, I suggest that you check out some of the recent threads in Computer Audiophile, including replies from Recording and Mastering Engineer Barry Diament.There are heaps of threads too about USB cabless, which provided that they aren't faulty should all sound the same according to present theory, and there now even discussions about audible differences between various Network cables.TBH, at this time of year , I don't feel like getting into heated discussions, especially with friends. You could also read that article from HiFi Critic Vol.6 No.1 if you haven't done so already, and dismissed it as rubbish. Regards Alex
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Post by Deleted on Dec 19, 2012 7:10:48 GMT
Thanks for not answering my 2 questions.
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