sandyk Posted April 7, 2018 Share Posted April 7, 2018 1 hour ago, kumakuma said: And if that fails, there's always: Followed soon after by: BTW, the use of the "intercourse " word is every bit as inappropriate in this forum as all the other BANNED insult words. How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted November 30, 2018 Share Posted November 30, 2018 On 11/28/2018 at 4:22 AM, GeneZ said: Try a solid state drive as well and noise is diminished Not necessarily. The current demands from the much faster SSDs may result in quite a bit of HF rubbish getting back into the main PSU. If room permits, the best way to reduce this is to try and isolate these abrupt current demands by powering SSDs from the +12V supply using an additional voltage regulator set for +5V Output. How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted December 2, 2018 Share Posted December 2, 2018 3 minutes ago, GeneZ said: How does one set this up? Any links to help me see how to do this? Thanks, GeneZ GeneZ Do you have a Desktop PC with available internal room, perhaps at the bottom of the case ? Alex How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted December 2, 2018 Share Posted December 2, 2018 On 12/1/2018 at 10:55 AM, GeneZ said: Interesting to know. I was thinking of the electrical noise of the constantly spinning hard drive which I assume introduces ripple. Not to mention the audible noise it generates in a quieted environment. I can't find the link at present, but I previously posted the specs of a recent 2TB HDD which showed the level of wideband square wave pulses going back into the main PSU.i How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted December 2, 2018 Share Posted December 2, 2018 3 minutes ago, GeneZ said: Understatement ... The case is huge. Its a fanless PC with lots of space with ventilation everywhere. click on picture to enlarge... The attached isn't the ultimate, but several members have found that this cheap ebay PSU PCB can make a worthwhile improvement. It will first need to be adjusted to +5V out before being connected to the SSD using a cut in half 4 pin Molex to SATA power supply lead. How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted December 2, 2018 Share Posted December 2, 2018 1 minute ago, GeneZ said: I appreciate that. Thanks. On the other hand... Looks like what might have been, is possibly no longer the case? https://www.quora.com/Do-SSDs-use-more-or-less-power-than-HDDs-and-by-how-much You don't need the really fast (and thirsty) SSDs for the OS etc. unless you also need the PC for things like 4K video processing etc. Neither would it appear to be a good idea to use a very fast PCI-E version SSD for audio use as it's power can't be readily further improved/isolated . SSDs like the Samsung EVO 850 are quite suitable for less demanding applications ,including video processing, but will take a little longer to do so . How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted February 6, 2019 Share Posted February 6, 2019 11 minutes ago, GeneZ said: I may even place my tube preamp for sale in the near future and concentrate on finding the right power cords. Any Preamplifier or Power Amplifier that is sensitive to power cords is either poorly designed, or is using a power cable that is inadequate for the output power demands of the amplifier. Ralf11 1 How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted February 6, 2019 Share Posted February 6, 2019 2 minutes ago, GeneZ said: Class D only you say? Show some class for once. Delete sandyk's too. So a high power Class D amplifier won't be affected by inadequately dimensioned power leads ? They usually have opamps at their Input too ! How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted February 7, 2019 Share Posted February 7, 2019 1 hour ago, GeneZ said: That may be something to keep an eye out for. I wonder what the problems may be in implementing it and bringing it to the market, other than the notion that tubes are not as readily available as they once were, and need to be replaced. How could such speed be maintained and know when its time to replace a tube? (typical question that will be asked) Let's get real here ! The DIY version could be called " The Lethal Amp" and commercial attempts would also need huge amounts of shielding as do microwave ovens etc. Lots of luck getting the FCC to pass such a design. How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 5 hours ago, opus101 said: Quite. So the fact that the DECT 'signature' was visible at the output is itself quite remarkable. How could an opamp be designed to be so incredibly sensitive to such low levels of RF? Inquiring minds want to know. Several years ago, members of a U.K. based forum constructed my modified version of a Silicon Chip magazine designed headphone amplifier (Studio Series Headphone Amplifier} which used an LM4562. Out of more than 300 constructed worldwide , not a single forum member reported any susceptibility to RF/EMI issues . March Audio 1 How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 48 minutes ago, sandyk said: not a single forum member reported any susceptibility to RF/EMI issues . I just had my memory jogged. When using a LM4562 in another Studio Series design, several constructors reported instability issues. It doesn't like driving capacitive loads, and in this case it was connected via a cable into the remote volume control PCB. The symptoms were grainy sounding audio and being excessively warm . It was reported to be oscillating at around 30MHZ. This may have resulted in it demodulating RF around that frequency. It needs something like a 100 ohm series resistor at it's output for guaranteed stability into capacitive loads. Alex How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 BTW, the metal can LM4562HA /LME49720HA did sound better in the HAs that were constructed. How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 14 minutes ago, March Audio said: And that's nothing unusual. In this case the length of the cable would have had <100pf capacitance. It is when the Data sheets show a graph with Small-Signal Transient Response AV = 1, CL = 100pF LM4562.pdf How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 9 minutes ago, March Audio said: Why do keep saying that, it's totally non sensical? It just demonstrates your ignorance of the subject. @sandyk did your LM4562 project have mains pick up at such ludicrously high levels as shown above? It's - 90dBFS, sorry the picture came out tiny when I copied it. No. It also used a modified John Linsley Hood designed PSU add-on (A.K.A. "Ripple Eater in DIY Audio) for it's + and -15V supplies which has <4uV noise and a very low Output impedance with close to 2FARAD simulated capacitance.. How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 10 minutes ago, opus101 said: This is an interesting point - the squarewave response with the stated 100pF load shows about 30% overshoot on the positive excursion, less on the negative. Not oscillation by any stretch of imagination (or denial!). It is more likely to have been oscillating as I mentioned before , where it was reported to be oscillating at around 30MHZ, which is close to the 30MHZ maximum operating frequency of the original DECT handsets. It may have been acting like a Regenerative receiver, thus demodulating the audio ? How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 Just now, March Audio said: No it won't be oscillating due to that, it will be poor phase margin and gain peaking. As I stated before, the symptoms were grainy sounding audio and the chip running very warm. I am not going to bother continue discussing this with you about this, or go looking for the Silicon Chip Errata. I will leave you both to slug it out. How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 8 minutes ago, opus101 said: I had a quick look at Wikipedia on DECT, didn't see any mention of DECT going that low in frequency. In my understanding its >900MHz but you're a telecoms guy, feel free to educate me. You obviously didn't look hard enough, because the ones I used to have did, and the 30MHZmaximum that I mentioned was verified from the official Au requirements using Google just before I posted my reply https://www.legislation.gov.au/Details/F2017L01079/Explanatory Statement/Text How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 4 minutes ago, opus101 said: Well it is true I only scanned the Wikipedia article. But now I've had more time to look through it, I am seeing things like : Before 1.9 GHz band was approved by the FCC in 2005, DECT could only operate in unlicensed Region 2 2.4 GHz and 900 MHz ISM bands A cite for your 30MHz claim would be useful. Look at my post immediately above yours. 3. The Radiocommunications (HF CB and Handphone Equipment) Standard 2008 (the sunsetting HF CB Standard). The sunsetting HF CB Standard previously set out the applicable performance and testing requirements for High Frequency Citizen Band (HF CB) and Handphone equipment for the purposes of the Australian radiocommunications compliance and labelling regime. The sunsetting HF CB Standard had adopted, with modifications, the industry standard ‘AS/NZS 4355:2006 (R2016) Radiocommunications equipment used in the handphone and citizen band radio services operating at frequencies not exceeding 30 MHz’. How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 9 minutes ago, opus101 said: I see no reference to DECT there. Handphones of course existed prior to the establishment of DECT standards. As I said previously, I used to have DECTs at that frequency too. It should have been obvious that an LM4562 wouldn't have been able to demodulate at frequencies of 900MHZ !!! The title of the link that I posted . I am out of this silly argument now . BYE ! https://www.legislation.gov.au/Details/F2017L01079/Explanatory Statement/Text Radiocommunications (Digital Cordless Communications Devices — DECT Devices) Standard 2017 - F2017L01079 In force - Latest Version View Series How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
sandyk Posted September 2, 2019 Share Posted September 2, 2019 5 minutes ago, opus101 said: Clearly this document's going to come in above your pay-grade but others might find it relevant : http://www.ti.com/lit/an/snoa497b/snoa497b.pdf If you think that a mere radiated 10mW max signal can be demodulated without some kind of amplification to increase it's level first then you are delusional. In this case , it's not anywhere near that, as it is a radiated signal received at a far lower level , and picked up by poor wiring. You can continue your silly arguments without me !!! How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file. PROFILE UPDATED 13-11-2020 Link to comment
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