Shop OBEX P1 Docs P2 Docs Learn Events
SMD devices for the audiophile - need advice — Parallax Forums

SMD devices for the audiophile - need advice

LoopyBytelooseLoopyByteloose Posts: 12,537
edited 2011-02-01 21:03 in General Discussion
Audiophiles put all and everything under a microscope. I have an interesting schematic for an Ultra low noise phono cartridge schematic that I am thinking of constructing. But it seems to me that it might be easier to use SMDs in some of it rather than larger components.

At odds are whether there are audiophile quality resistors and capacitors available in SMDs. I just don't know.

Comments

  • LeonLeon Posts: 7,620
    edited 2011-01-02 01:18
    Don't you mean audiophools?
  • wjsteelewjsteele Posts: 697
    edited 2011-01-02 05:05
    Actually, Leon, there is a big difference between the quality of a lot of audio equipment out there and since the components make it up, I think his question is very valid. Here in the US I can think of two perfect examples... Pyle vs. Bose. They do the same things, but I can guarantee that the Bose system will produce vastly superior sound, even to a non audiophile. Just because you don't have a good ear doesn't mean that there are others out there that don't and as you correctly suspect, there are others who take advantage of the ones that don't have a good ear, but think they do. However, it also doesn't mean that Loopy's question is invalid in any way.

    My suggestion, Loopy, is to buy high quality components with very tight tolerances and you should be just fine. The important part is truly understanding the complexities of audio reproduction in your circuit design.

    Bill
  • LeonLeon Posts: 7,620
    edited 2011-01-02 05:26
    That's what I meant. Buying special "audiophile" parts is a waste of money. Properly selected good-quality standard parts and good circuit design will work just as well, if not better, and be a lot cheaper. Anyone who thinks differently is an audiophool with more money than sense.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2011-01-02 07:33
    And so .... Am I to conclude that SMDs are not good enough for audiophile? In particular capacitors and resistors are what I am looking at. The solid-state components pretty much have been migrating to SMD regardless of use. There are some very interesting Ultra-low noise op-amps with ultra low distortion.
  • LeonLeon Posts: 7,620
    edited 2011-01-02 07:40
    They should be fine, if the circuit is designed properly.
  • Martin HodgeMartin Hodge Posts: 1,246
    edited 2011-01-02 08:30
    Like Leon said, as long as you pay particular attention to the tolerance rating of the parts, it doesn't matter if they're SMD or come on the back of a truck. Anything that purports to be specially made for audio is bunk, imo.

    >>EXAMPLE<<
  • Mike GreenMike Green Posts: 23,101
    edited 2011-01-02 08:39
    Wow! That's pricey power cord! I wonder whether someone who'd buy that would also rip out the walls in their home to install similar cable to the distribution panel. Where would they get circuit breakers of a similar construction? What about the cable from the distribution panel to the nearest transformer? (and on and on ...). How would they get their electric utility to replace that?
  • LeonLeon Posts: 7,620
    edited 2011-01-02 08:51
    An audiophool and his money are soon parted!
  • wjsteelewjsteele Posts: 697
    edited 2011-01-02 09:04
    Loopy Byteloose wrote: »
    Am I to conclude that SMDs are not good enough for audiophile?

    Absolutely not! As long as they are good quality components, SMDs will make for a very nice and compact design.

    Bill
  • wjsteelewjsteele Posts: 697
    edited 2011-01-02 09:05
    Leon wrote: »
    An audiophool and his money are soon parted!

    Agreed! BTW... I have some lottery tickets available if anyone wants to buy them... the're last weeks tickets, but I'm selling them for 50% off!!!
  • LeonLeon Posts: 7,620
    edited 2011-01-02 12:04
    How about fuses for $34.95 each?

    http://www.thecableco.com/product.php?id=3494

    I especially like the ceramic casing, rather than glass, for better resonance characteristics.

    Here is a "review":

    http://www.positive-feedback.com/Issue32/fuses.htm
  • WBA ConsultingWBA Consulting Posts: 2,935
    edited 2011-01-02 16:29
    There are products that definitively make a difference with the quality of the components and opinions about parts is not usually a factor because of the quality difference. (the Pyle vs Bose example is perfect for that) Unfortunately, there are many products on the market that attempt to take advantage of ridiculous sounding"specs" to make a sale to someone with more money than intelligence. There is a lot of "info" on the internet that support both sides, so this just further instigates cloudy debates. On the other hand, while many parts may seem unimportant, I have direct experience where it DOES matter.

    I know of an XMOS based high end USB audio design that will be announced at CES that had struggles through prototyping due to the quality (tolerances) of the components. Most SMD resistors had to be changed to 0.1% to stabilize to the desired results. Some of the power supply parts were also changed to make the voltage rails very tight since the processor is extremely sensitive to voltage variances. In the long run however, this product will have specs that will be new to the high end USB audio market. Using standard tolerance parts would not allow a product like this to be completed.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2011-01-02 21:12
    Heh. he.....
    Actually, I do tend to lean towards the feeling that the endusers are 'Audiophools', but the quality control of ultra low noise, ultra low distortion is a very real issue. From my research on the web, every once in a while an intelligent engineer comes up with a very good design and builds it as a proof of concept of what can be done. (see the JLH Class A solid-state amp) and then others 'massage' it into audiophile tweaks that keep the religion intact.

    The main thing I am exploring is whether there is any real need to build a nice 10 watt Class A system with vacuum tubes. I suspect not. At this point, I've pretty much figured out the Power Amp and the Power Supply, but the Pre-amp design is a bit more of challenge as RAII Photo cartridges offer up a signal at micro-volts.

    Audio does certainly seem to attract some of the dubious sorts of electronic engineers.
  • wjsteelewjsteele Posts: 697
    edited 2011-01-03 03:14
    You know... if your Pre-Amp has tubes in it.. you'll sell 100 times more of them, however. :-)

    Bill
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2011-01-03 04:48
    Don't get me started.... Many years ago, I purchased a few dozen 12AX7 in matched pairs and original Textronics boxes from a Ham swap meet for 25cents a pair. People were dumping tube oscilloscopes and all that went with them due to size, calibration, and other issues. About a year after I came to Taiwan, I let them go in a garage sale as a 'package deal' with my Fisher 500 Stereo Amp and FM tuner - too much to bring back to Taiwan.

    Nonetheless, that is the point, to move beyond tubes and into this century, completely.

    In reflecting upon the past few decades I must say that we have left behind a golden era of audio hi-fi and gotten more and more into visual technologies. In some ways, it is quite ironic. The truth is I really don't have any vinyl disks to listen to and not much of an audio collection. It is the conceptual engineering that appeals to me. There just seems to be some very good components available that don't cost an arm and a leg because no one is producing them anymore.
  • Tracy AllenTracy Allen Posts: 6,666
    edited 2011-01-03 10:54
    SMT resistors are less of a problem than the capacitors. I cringe when I see unbiased electrolytic and tantalum capacitors used for coupling in the signal path. A plastic capacitor the size of a sausage is out of the question. Panasonic makes a very nice lineup of SMT film capacitors. Link here. There are three dielectrics, for different purposes, and the link has further links to circuits showing where each type is appropriate. In particular the ECPU series has a resin dielectric (like acrylic) that is especially suitable for coupling. Coupling capacitors may be the most important factor in total harmonic distortion (THD). Panasonic sells ECPU caps up to 0.68µF in a 1206 footprint. If a circuit calls for 10µF, it may be necessary to tinker with the circuit input impedance or feedback, or use several capacitors in parallel.

    I'm attaching a short article from EDN that talks about audio coupling capacitors and THD. It compares mainly X7R and X5R ceramics, but the principles are well laid out as they apply to any coupling capacitor.
    pdf
    pdf
    PC_coupling_capacitors.pdf
    398K
  • davejamesdavejames Posts: 4,047
    edited 2011-01-03 13:35
    @Mr. Allen: good info - thanks much.

    DJ
  • kwinnkwinn Posts: 8,697
    edited 2011-01-03 14:31
    After all the time, effort, and money spent on moving beyond the limitations of tube amplifiers I have to conclude that anyone touting or even considering a vacuum tube as part of an audio system is an 'Audiophool'. Paying a large premium for it only ups them to the level of 'Audiomaroon'. And no, that's not a misspelling, I'm misquoting an authority.
  • MicrocontrolledMicrocontrolled Posts: 2,461
    edited 2011-01-03 17:04
    If I remember correctly, there was a thread on this exact thing last year, with a link to the $3,500 power cord.

    There is a difference in the sound of good audio equipment vs. bad audio equipment, but it's been made so that you can take it too far, and fools will still pour their money into it.
    What really matters I think is the build of the circuit. Does it have a lot of traces? The more metal, the more noise, and although there are ways to reduce it, it still makes a difference.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2011-01-03 23:35
    @Tracy Allen,
    Thanks for your very useful input. I had suspected that capacitors have move techonologically forward while the audiophilia are going Mach 1 in reverse. If I can get some good ones, this will make a fun project as it may sort out which is the leading edge and which ain't.

    The main idea here isn't to gripe about the high cost of dubious audio, but to share real knowledge about real devices that really don't have to cost an arm and a leg to get it right. One can build a rather complete solid-state stereo system that will perform as well or better than tubes for less money and not have to sweat future purchases of tubes.
  • BeeboDaMooseBeeboDaMoose Posts: 10
    edited 2011-01-30 16:15
    riaa.JPG


    http://www.national.com/an/AN/AN-346.pdf
    riaa.JPG
    810 x 269 - 19K
  • skylightskylight Posts: 1,915
    edited 2011-01-31 01:27
    Another example of the sales pitch for audio equipment making people part with their money is the use of gold as in contacts, people thinking that gold being pure and one of the most precious of metals must be the best, which would they buy gold or silver contacts? yet those in the know know that silver is by far a better conductor than gold yet the audio "experts" will think they are buying second best if they bought silver ones!
    Only benefit I can see is that silver may tarnish making the contact more resistive unlike gold which is inert.
    People when given a choice tend to go for the most expensive thinking they are getting the "best" Bose being a prime example
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2011-01-31 03:50
    Actually, much of the WWII surplus radio equipment used silver connections and it did indeed tarnish and was in constant need of polishing to maintain it. They even created a special gel cleaner that became branded and was popular for many years.

    Here in Southern Taiwan we have a sub-tropical climate and a major steel industry, everything corrodes quite quickly. My first computer here begain to rust in two years, whereas my computer in California never showed any corrosion. So I will go with gold connectors in any audio that I build to last. Chrome is a porus plating and requires an undercoat of copper to prevent the base of iron from rusting - certainly a more complex process than a single layer of gold plating.

    I don't take issue with items that are functional. It is when people go beyond reasonalble engineering to junk up a design with all and everything exotic and expensive that audio becomes absurd. I doubt I would use pure silver wire for tweeters as some are doing these days when just a larger diameter copper might do the job.
  • LeonLeon Posts: 7,620
    edited 2011-01-31 04:08
    The tarnish on silver is conductive.
  • BeeboDaMooseBeeboDaMoose Posts: 10
    edited 2011-02-01 21:03
    audiophile capacitors
    check out Wima capacitors
Sign In or Register to comment.