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About Spark

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  1. It is then possible that the integrated one, is the one you are talking about or near power circuitry. I hope it works out for you. Anyway, as I tell you, if you know about an electronic technician, with the scheme I have, it would be possible to make some more attempt. I have been making improvements lately in my equipment and now is when I am enjoying the M51 in its measure. It's a good CAD. Regards and luck.
  2. Hello L J T. I feel the problems you've had. The tricky thing is to figure out where the fault may be. If it is a problem in a particular component, several etc. Otherwise it could be a matter of changing components that is not complicated except for some larger integer. I have the electronic schematic of the NAD C510, which is very similar in case you out of interest. In this model, the optical inputs, AES and coaxial, pass to the main processor through an integrated AK4118AEQ SPDIF interface. ¿Did it stop working for no apparent reason? Power cut etc ¿Did you see the interior in case you saw any broken components?
  3. Hello again. I have been doing some tests and I will comment on the current results, although there are still some more tests to do. And I will put a few pictures about it and some comments about them. Also later, I'll post photos of a couple of USB converters I'm using with very good results. I suppose you will already know it, there is a version of the M51 called Rowen, that apparently has some elements of the different analog output stage. It's a shame not to know, because it would be easy to change them and a cheap upgrade. I was able to get an electrical schematic of the NAD DAC C510, on the analog part, it is practically identical. I do not know if the quality of components is the same, but the numbering does. The fact is that I used continuous filters to filter the output of the LM317 and LM337 but with poor results, the sound loses quality significantly. I do not know the cause, since the filters really are fun and measurable. Probably a mass problem. The red and black colors, are inverted with respect to logical correspondence of positive and negative. There are several cables, but they are all connected to the same point. Operational LME49990 and the nearby controller that powers it. Try the filters that I currently have installed on an amplifier. That as I say, does not work. The sound instead of improving, it got worse. I have orders, two substitutes for the LM317 and LM337 of very low noise. They are not expensive. http://www.ebay.ie/itm/TPS7A3301-Ultralow-noise-LDO-regulator-3V-18V-1V-step-1A-LM337-79x-replace-/252533452377?hash=item3acc2aae59:g:msEAAOSwGtRX1PN- http://www.ebay.ie/itm/TPS7A4700-Ultralow-noise-4-VRMS-LDO-linear-regulators-1-4V-20-5V-LM317-replace-/252710100444?hash=item3ad6b21ddc:g:18wAAOSwgmJX1PKh The source by the test, install it in the box of the Gustard U-12. I also made a metal separation, but it is possible that to test, change the switched source to a linear one. For now, it will stay. I'll be putting some updates as I do. A greeting.
  4. Indeed, I am aware of this situation. To some extent, may not be worth it, to continue to spend money on the M51. But it is also true, that until I have used a USB converter, I was not aware of the quality of the DAC. Now I really enjoy listening to music. And on the other hand, I think there are no guarantees, that for example a more updated CAD, do not also have this weakness. This model of XMOS is quite recent. I hope that manufacturers of DACs will incorporate it progressively. And the worst thing is that if you prove it, you are not aware of it and from what I read, it is a relatively generalized "problem" in many CAD models that improve significantly with these aids. It would be desirable, that the future DAC'S, amplifiers etc. They were less dependent on accessory equipment, balanced powers and filters, cabling, USB converters etc. Although it is difficult to improve something that a good engineers have designed, I also like playing with gadgets since I was little. Disassemble them and check their operation. I would like to prove that this defends the M51 with its particular form of conversion in front of these new models, but for now, I will settle for the NAD. I've been in love with him since I saw him in magazines. I will comment on them and with time some photo. Happy new year and greetings to all.
  5. scumbag. It is indeed a shame, that in equipment of this price and quality, the USB input is not as refined as the rest of the entries and from what I read about the topic in forums and webs, seems to be quite common. Addicted to music. Thanks for the suggestion, although I do not know the market for this type of amplifier, in principle the technical characteristics of the LME49990 are very good. I would only dare to make modifications to the power supply. My knowledge about electronics, is not very wide. Criptik. Thank´s for reply too. I am using a device similar to the Regen of Uptone And I notice a slight smoothing of the sound. Not much but appreciable. roger7 I´m sorry, I was not able to run the HDMI connection between the Pc and the M-51 and it's a shame, because I have the impression that it should be a good choice. Anyway, I will try to do it again, if I get it I will comment. I am using the AES/EBU connection with a DH Labs d-110 cable. Also a Wireworld Starlight 7 and the Singxer factory USB cable. http://www.head-fi.org/t/803111/xmos-xu208-usb-bridges-the-latest-gen-has-arrived I decided to buy it, reading a post about it new integrated XMOS in the forum Head-Fi. I suppose you will already know it. I read very good opinions on the Singxer F-1 in it and I decided to replace the Yellowtec, also very good but at similar prices, by number of conections and audio quality, I prefer the SU-1. In it, the author makes a ranking between the different models, that he has tested and agreeing with him on the performance between the U12 and the Yellowtec I already had, I decided to buy the SU-1 and I am very satisfied with it . Tomorrow I will try to show you some pictures. Atomictheory. The natural successor of the U12 with the U8 core, is the new generation also of XMOS with the xCORE-200. Apart from Singxer, there are a couple more manufacturers that contain it. The Singxer F-1, is a simple and cheaper version of the SU-1 in case you are encouraged to try. Although it has no box and only a coaxial output. In the link I put on Head-Fi, there is a lot of information about it. Sorry for my bad English. I hope you understand me. A greeting.
  6. Hello scumbag. Thank´s for reply. I absolutely agree with you. It can depend on the rest of the installation, etc. But in my case, until I have not used a USB converter, I have not been able to take advantage of what I think is 100% capacity of the NAD M51. Practically, most of the time I listen to music through the PC. The USB port, does not seem bad to me, but it does improve. I am currently using a Singxer SU-1 with very good results. Would recommend the test. Along with a Nano iUSB 3.0. Powering the motherboard of the same, and also the USB input. Previously I had a Yellowtec Puc2 Lite, less versatile and somewhat inferior in sound quality, and before, the Gustard U12 when I had a DAC Gustard X-10, but stopped using it, because I found the USB input of the M51 better than U12. I will consider doing some modification, although I do not want to damage it and I do not know if I will get any benefits. Currently as I commented, I am using a DC ipurifier at the output of the power supply, and may be enough. There are power supplies, with a background noise of only 0.8uV, and it is possible, that it could improve the performance of the LM317, LM337. But it is also possible that operational amplifiers, do not pose any problem a noise in the power. It is the doubt that I have. I will comment, if I encourage myself to do something. Greetings and thank you.
  7. Hello again. With the intention of improving the good, I would like to ask them, if they know of any modifications to improve the sound of the M51. I have recently used a dc filter for the power supply, but even without enough time to test for improvement or not. I have been reviewing the circuitry of the similar NAD C510, and I see relatively feasible, modifying the power of the amplifiers operations with the LM317 and LM337, with some external source of less noise. What do you think about the topic? Some of you have tried any modifications of this type? Thank you. A greeting.
  8. If the male USB connection, don´t touch the female USB, metal part with metal parts (ground´s) and you can get hum/buzz, then I do not think it's a problem of masses I thought, over USB. It is a strange fault. Typically, the noise appears when both ends of the USB cable are connected. But if ocurr too with the HDMI cable, it´s posible what the DAC can be a fault. Also why we should discard noise on + 5V USB. On which there are often quite noisy too. I can get noise too in some USB female in my PC, in motherboard i can hear every "clic´s" as if a sync problem, but when i connected to a PCI / USB card, the clic's disappear. I don´t know what is the concrete cause, but somehow, the card isolates the problem. In the same USB port in the motherboard and using a USB/SPDIF converter, i don´t have the problem.
  9. Hello scumbag. In our DAC M51, the ground of 220V power supply, and the ground of signal out (RCA) ground USB connector and ground of the PC (chassis) etc, etc Are conected finaly with the amplifier input (RCA) ground of signal. I think that could be causing the noise. You can try this, wrap with cellophane one of the connectors on the USB cable, so you do not make electrical contact NAD chassis and PC chassis through the USB cable. Your nad m51, grounding will only feed of power suppy. I'm testing sound internally disconnect the feeding ground (only evidence is unsafe for us) and i use a USB cable without ground connection between connectors A-B. Sorry my bad english.
  10. Addicted to music, Thanks for your offer. I searched various forums and websites and I could not find a valid link for version 1.39. I'll send a private message if you do not mind. Thank you.
  11. Hello from Spain.

    djb and EVcali. Thank you both. True, It is a universal feeling.
  12. Hello all. First sorry for my bad english. I´m from Spain, and I recently purchased a new NAD M51 and have found this forum with information on this model. I have read that the best audio quality is offered by version 1.39, and mine currently, have version 1.50 ¿Could you tell me where I could get version 1.39? Thank´s.
  13. Hello from Spain.

    Thank you very much JohnL
  14. Hello for all. Although my English is not good, sorry. The music and sound are my great passions. A greeting to all