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Post by Deleted on Nov 20, 2012 23:09:54 GMT
Hi All i thought that this may be a good time to start a thread to explore ways of getting music from computers (MAC or PC) Its a subject that i find really interesting and maybe others will also. take care
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Post by Deleted on Nov 20, 2012 23:39:37 GMT
Hi All i thought that this may be a good time to start a thread to explore ways of getting music from computers (MAC or PC) Its a subject that i find really interesting and maybe others will also. take care O.K. To start the ball rolling, I have attached a copy of a reply in C.A. by Clay who is a U.S.A. software writer, and a supporter of mine in C.A. I am sure that Clay will not mind me quoting him here. Clay is a great supporter of Firewire DACs also. I don't necessarily agree with everything that Gordon Rankin says, but his views make interesting reading. Alex www.positive-feedback.com/Issue41/ca_rankin.htm
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Post by Deleted on Nov 21, 2012 1:16:31 GMT
Hi Alex I'd never move an others post without asking first unless it was spam which your post clearly was not and raised some interesting point worth further discussion. ''Using a USB hard drive will only add to the load on the CPU, and thereby compete with the music player, whose primary method of improving the sound is to lessen undesired CPU activity'' Yup really good point and something I've been thinking on sorting out but for the mean while I've tried something else. just as a side question i thought that lessening CPU activity was Jplay/Cplay reason to exist? my hard drive is only active whilst loading songs into RAM and not at all during playback. CA i remember reading the ''CA pocket rocket music server'' articles and one thing really stood out and made me think. they used the SOTM usb card and the reason they gave for using it made me sit up. to give SOTM usb ports ''its own information super highway''. (i would post there more often but it's a bit of a flame fest.) mmm now i don't really know enough about the inner workings of PC's to make a judgment of that statements accuracy. but it would be nice to learn a little on that. it did make me interested enough to try a much much cheaper PCI /USB card. yes it still uses SMP from the PC but that is as far as Vbus gets. PC ground is not directly connected to the DAC as Teleporters prevent that. did the PCI USB card make a difference? (it would be just great to say YES ) but no it did not as far as i could tell but the system is dead silent at the LS/HP and it never was with SPDIF from the DS. and it did plug up the hole left by the DS quite nicely ;D IMHO having PC noises playing softly in the background while i play music is a little distracting and I've not noticed that with any of my USB OP TBH. so the question is maybe is my application of USB/I2S/DAC the worlds best? hell no not by any means. but it's the best i can make it until i learn more. most importantly to me it sounds really good to my ears. i do use USB devices through your lovely PSU injector but only one plugged in at a time . as you know i have Will's music PC which has W7 and two software players and a few drivers. so IMHO if the CPU can't cope with that small stuff then I'm going to need a new PC and the hammer must fall. I'll read Gordon Rankins stuff because he's so i built his 45 Bugle amp once and it was really nice and very cheap to build (45 now expensive and a little hard to find). just a question have you tried I2S directly into one of your DACs? i occurred to me that the GTG stated preference may be more to do with the quality of your DAC's rather than the medium used to transport the signal to them. any takers on the inner workings of PC/MAC please feel free to post or link the ramble of the week take care
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Post by Deleted on Nov 21, 2012 1:55:43 GMT
No. Partly because I don't feel the need to do so when the SC DAC is giving such great results, as well as the risk of damaging a relatively expensive soundcard, but also because I would lose input switching and volume control via remote. If it aint broke, don't fix it ! Besides which, I still have to investigate using a 1PPM TCXO with a Cricket in the SC DAC. Present theory says it shouldn't matter, but then neither should using an external oscillator compared with the original on board 24.576MHZ Xtal reference.Reports from others say that it did give an improvement. Yes, but it doesn't matter how good the DAC is if it is fed noisy/Jittery SPDIF. Jeff demonstrated recently how a simple buffer stage he fitted in a CD player resulted in a marked SQ improvement. I will need to investigate further options when/if Allan can demonstrate that his present approach has closed the gap or outperforms what I have so far. At last listen to Allan's B3 through my Class A system he still had quite a gap to close in the soundstage department .( Although Allan may not be in total agreement) A funny thing was that the SC Crystal DAC with discrete output stage built by "Owdeo" from DIYAudio sounded quite recessed compared with the other DACs and sources listened to. cPlay requires you to do those things manually, which can't be done completely if your PC is a general workhorse. jPlay is a little too expensive for this old fart. Also this one from Gordon Rankin appears to be possibly before jPlay, and perhaps even before playback from System memory became common ? Perhaps in theory, but although many use them, and they are obviously worth the expense to obtain cleaner USB power for those not into DIY, I have yet to see any reports about marked SQ improvement, only small SQ improvements, which seems to indicate to me that perhaps you guys are possibly getting overall better results by DIY methods . Alex
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Post by Deleted on Nov 21, 2012 7:54:10 GMT
Besides which, I still have to investigate using a 1PPM TCXO with a Cricket in the SC DAC. Present theory says it shouldn't matter, but then neither should using an external oscillator compared with the original on board 24.576MHZ Xtal reference.Reports from others say that it did give an improvement. Alex I've yet to try the offboard oscillator, I'll be very interested to hear your thoughts on the TCXO. I've been chasing the USB route of late so have fallen way behind. In another recent thread you briefly summed up your set up as it is now but lost me. Could you clarify, thanks. Sent from my HTC One S using proboards
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Post by Deleted on Nov 21, 2012 9:16:16 GMT
Hi Chris It is basically as per the photo at rockgrotto.proboards.com/index.cgi?action=downloadattachmentpage&board=m&thread=4477&post=116334At the very bottom of the output PCB there is now an additional PCB pin between the 4 blue caps. A heavy gauge wire connects this earth area to an additional earth from the right centre of the nearby JLH. Presently only half of the Cricket is used,but the other half will be used to supply the TCXO 3.3V instead of the existing osc PCB. The Cricket supplies 3.3V to the Input PCB, but this then ONLY goes via the IDC cable to the DAC I.C. due to a removed strap. 3.3V for the Input PCB is from the 3.3V Paul Hynes series regulator which is fed from +5V. Different toroidal transformers and PSU PCBs are used for Input and DAC PCBs as per the diagram at rockgrotto.proboards.com/index.cgi?board=m&action=display&thread=4477&page=18Make sure that the earth sides of all RCA sockets are isolated from chassis. Ensure that the wiring from both transformers to the PSU PCBs uses the same transformer wire colours for both primary and secondary windings,and Connects to the same terminals on the PSU PCBs. The JLH for the + and -15V to the DAC PCB uses a low ESR and a normal type 16V electro in parallel per supply rail, unlike the other JLHs that use 2 x low ESR in parallel. Regards Alex
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Post by Deleted on Nov 21, 2012 10:04:59 GMT
Hi Alex ''No. Partly because I don't feel the need to do so when the SC DAC is giving such great results, as well as the risk of damaging a relatively expensive soundcard, but also because I would lose input switching and volume control via remote''. fair point but it does make a direct comparison between SPDIF and USB/I2S a little difficult on a level playing field. ''Yes, but it doesn't matter how good the DAC is if it is fed noisy/Jittery SPDIF. Jeff demonstrated recently how a simple buffer stage he fitted in a CD player resulted in a marked SQ improvement.'' yes good point again and as you rightly keep saying ''implementation is everything'' ''I will need to investigate further options when/if Allan can demonstrate that his present approach has closed the gap or outperforms what I have so far. At last listen to Allan's B3 through my Class A system he still had quite a gap to close in the soundstage department .( Although Allan may not be in total agreement) A funny thing was that the SC Crystal DAC with discrete output stage built by "Owdeo" from DIYAudio sounded quite recessed compared with the other DACs and sources listened to.'' that seems to me like it could be more about your preference for one DAC over another. it's not wrong and we all do that when making personal choices about the equipment we use. ''which seems to indicate to me that perhaps you guys are possibly getting overall better results by DIY methods'' . i totally agree with the above and your work on clean supplies for USB has shown me how much the PSU used can have an influence on the sound. for my part it's nice to have a choice about the way that i deliver DATA to my DAC and like most people i chose what suits me best. not because i believe in any inherent superiority SQ wise but because it fits my needs. IMHO what we really need is more choice and as you rightly pointed out firewire/thunderbolt could be an interesting proposition. i must admit to being intrigued by Allan,s suggestion of going I2S direct from sound card into Teleporters. sounds like another nice option. BTW i remember feeling quite shocked when a first spotted G Rankin's name associated with digital. I'd only ever read his tube work but he is a careful and considered man in that regard. flooded in today so of to listen to some op amps take care
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Post by Deleted on Nov 21, 2012 11:09:26 GMT
"fair point but it does make a direct comparison between SPDIF and USB/I2S a little difficult on a level playing field." A U.S.A. expert commented about the SC design having too long connections between PCBs, which meant it was not 24 bit capable. If you guys think you can connect i2s leads of longer lengths without even using the normal data, earth, data,earth IDC cabling and keeping it close to chassis while maintaing correct impedance without penalty such as lower max resolution ,and increased noise pickup, then I would think again. "that seems to me like it could be more about your preference for one DAC over another. it's not wrong and we all do that when making personal choices about the equipment we use." David2vk said that this DAC was very close to that of a $5K DAC he heard recently at Len Wallis Audio IIRC, but truly outclassed by a $20K DAC he heard around the same time. Unlike the other DACs used, "Owdeo's" SC Crystal DAC with discrete analogue area had a sound stage that was quite recessed and like it was behind the speakers.His own designed DAC was much closer to all the others and quite good. I judge DACs mainly by their ability to project a non fatiguing 3D image that sounds natural. You have the Class A preamp and 15W Class A too. Can you get good surround sound from many DTV programs, or fill the while listening area with surround sound right back to the listening position from 24/96 stereo downmixes of "Queen-Another One Bites the Dust", "The Eagles -Hotel California, or even 16/44.1 of "Dön Dorsey-Ascent,"or even from the BluRay of Avatar when using your DACs? That's with a very mediocre Oppo 981 which doesn't come even remotely close to what I heard recently via David's Oppo 95 with a Corsair plugged in using a JLH PSU, then into the SC DAC.The 2 downmixes referred to were played via home made DVD-A. Allan didn't get to hear David's Oppo 95 through my system.I may be able to arrange that again if he is interested, along with his stuff. I was in lust after hearing that, but haven't been able to work out how I can afford the 93 which is virtually identical when used as a transport. Allan should be able to provide you with email addresses of another couple of Sydney members who have been present at recent GTGs if you would like feedback from them. Regards Alex
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Post by pagan on Nov 21, 2012 11:31:48 GMT
"fair point but it does make a direct comparison between SPDIF and USB/I2S a little difficult on a level playing field." A U.S.A. expert commented about the SC design having too long connections between PCBs, which meant it was not 24 bit capable. If you guys think you can connect i2s leads of longer lengths without even using the normal data, earth, data,earth IDC cabling and keeping it close to chassis while maintaing correct impedance without penalty such as lower max resolution ,and increased noise pickup, then I would think again."
Alex don't know about that... It's i2s data, digital.
I don't like SC's, long IDC cable run myself. As for noise pickup, IDC are not the best, the sigals being sent are not balanced, they also fold over itself too.
I2s is mean't for short track runs, on pcb, or timing(jitter) between each data signal line is compromised.
The LVDS sends balanced signals over twisted pair data lines. A better approach than long and folded IDC cables.
Allan
Oh also When I was playing with a WM8804 receiver with i2s out into a dac, I noticed a sound difference when the i2s line were either crossed or very close. The wires used, were solid core cat5e stripped out of an old lead, and very short approx less than 1.5 inches long.
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Post by Deleted on Nov 21, 2012 11:46:15 GMT
Allan Yes, but you guys aren't doing that. "Qusp" in DIYAudio has already made several comments about that aspect in a similar project. www.diyaudio.com/forums/digital-line-level/223936-i2s-cable-wire-type.html] As has already been demonstrated with shorter USB cables, it seems highly unlikely that this method with much longer lengths needed to keep a noisy PC out of the listening area, is going to give results as good as a proper IDC cable of say 20CM length between PCBs in a screened metal case . You are more than welcome to convince me otherwise with a demo, and I will invite David along with his Oppo 95 to provide high quality source material. BTW, the Class A preamp is now more revealing than you last heard it,(improved S/N) so that will help to make differences even easier to pick. Alex As Frans might say. "Expectation Bias." Did you verify that with DBTs ? ;D
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Post by Deleted on Nov 21, 2012 15:38:54 GMT
Hi Alex i think that you may have misunderstood what i was saying. I'm not for one moment doubting the quality of your DAC which I'm sure is good. but that's not really what we're talking about here. ''If you guys think you can connect i2s leads of longer lengths without even using the normal data, earth, data,earth IDC cabling and keeping it close to chassis while maintaing correct impedance without penalty such as lower max resolution ,and increased noise pickup, then I would think again'' yes agreed I2S has it's limitation and cable length is one of them so that need to be thought about before installation as most things do. by the way after reading QUSP's posts on I2S and thinking on Allan's comments i installed 3cm UFL coax cable for all I2S signals each having it's own ground return. i just wanted to be technically correct on that but TBH it's changed the sound a little also for the better. so those remarks from QUSP and Allan where really helpful to a novice like me. Allan i just read this as i was typing my reply. ''I noticed a sound difference when the i2s line were either crossed or very close.'' yes based on my own experience with the UFL cable it does seem to matter. ''As Frans might say. "Expectation Bias." Did you verify that with DBTs ? '' no but i listened at least once ;D my point is that nothing is perfect and each method has it's own advantages and disadvantages. knowing the pro's and cons make choice much easier. take care
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Post by freddypipsqueek on Nov 21, 2012 16:20:50 GMT
On the USB front I have one machine with the DAC attached to the following card (as the only device). I worked on the basis that it would separate out the noisy USB 1&2 traffic from the DAC. www.eclipsecomputers.com/product.aspx?code=IO-PEUSB32I didn't notice any real difference. I have been meaning to try a better PSU attached (via the on board molex) to it but I do not understand the USB3 spec enough to understand if will make a difference.
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Post by Deleted on Nov 21, 2012 17:54:32 GMT
On the USB front I have one machine with the DAC attached to the following card (as the only device). I worked on the basis that it would separate out the noisy USB 1&2 traffic from the DAC. www.eclipsecomputers.com/product.aspx?code=IO-PEUSB32I didn't notice any real difference. I have been meaning to try a better PSU attached (via the on board molex) to it but I do not understand the USB3 spec enough to understand if will make a difference. Hi FreddyPS i have the PCI version of that Startec card and heard no difference SQ wise either. take care
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