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    Looking for quality KIT DAC

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    sailor

    Posts : 269
    Join date : 2011-04-04

    Re: Looking for quality KIT DAC

    Post by sailor on Thu Feb 20, 2014 5:16 pm

    As audio people we tend to focus in on the analog side of DtoA equipment I guess because it is what we know. But digital side is where the objectionable material is produced. I think the best way to describe it is to compare it to the best phono stage hooked up to a $5 cartridge. It may be the best that cartridge ever sounded but a better front end would make the whole thing sound better. The fact is the analog stage is usually nothing more than a single OPAMP and the power supply that powers it. This can easily be bypassed or replaced with any analog stage you want, op amp, transistor or tube. I once ran a wire from the chip direct to my preamp bypassing the analog section completely. Guess what it worked.

    sailor

    Posts : 269
    Join date : 2011-04-04

    Re: Looking for quality KIT DAC

    Post by sailor on Thu Feb 20, 2014 5:23 pm

    The OPPO uses an USB asynchronous DAC. It eliminates the original clock timing from the computer and re times it to remove all of the jitter.

    daveshel

    Posts : 147
    Join date : 2011-11-06
    Location : Tucson AZ USA

    Re: Looking for quality KIT DAC

    Post by daveshel on Thu Feb 20, 2014 8:01 pm

    sKiZo wrote:
    USB power isn't really an issue if you go with an external DAC - all the USB port is doing is pushing the signal out to the box. Exceptions there are them cute lil Fireflies and their clones, but those have a very small power draw. I've seen some that have a tap for a power brick - I'd suspect that if they provide that, they have doubts as to whether you should be trying to power it just from the USB port.

    I wasn't thinking of powering the DAC with USB - I was thinking of using an external USB optical drive as a transport so as not to have to dedicate my laptop to my audio system, but questioned whether the USB input of the DAC would be able to power the drive. I guess I could insert a powered USB hub between the DAC and the drive.

    mazeeff

    Posts : 122
    Join date : 2014-01-06
    Age : 61
    Location : Grand Rapids, Michigan, USA

    Re: Looking for quality KIT DAC

    Post by mazeeff on Fri Feb 21, 2014 6:50 am

    Just wanted to point out that the Nuforce ICON IDO is on sale for $99 at a number of retailers. Just do a google search. I have one on my ST-70, and it sounds very good. It has jitter reduction, USB host mode interface to Iphone/Ipod, and can drive 250 ohm headphones. It has a convenient volume control, and looks nice next to the Dynaco. I have tried a whole lot of different DAC's from cheap to high end. The ICON is what I listen to most often. The only downside is getting flac files to play on the Iphone/Ipod. I ended up using mconnect, which allows me to play my flac collection from my DLNA server. There are a lot of professional reviews on the ICON. For $99, you can't go too wrong!

    arledgsc

    Posts : 340
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Looking for quality KIT DAC

    Post by arledgsc on Fri Feb 21, 2014 11:20 am

    "I was thinking of using an external USB optical drive as a transport so as not to have to dedicate my laptop to my audio system, but questioned whether the USB input of the DAC would be able to power the drive. I guess I could insert a powered USB hub between the DAC and the drive."

    I'm afraid that won't work.  Both the DAC and optical drive are USB "devices".  You need at least one USB "host" (like a PC) to control the USB bus.  But you could hook S/PDIF up directly to the DAC.

    arledgsc

    Posts : 340
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Looking for quality KIT DAC

    Post by arledgsc on Fri Feb 21, 2014 12:05 pm

    WASAPI is the best thing Microsoft has done for audio playback from a Windows computer.  WASAPI is a CPU kernel mode driver that delivers unaltered bit-for-bit audio to the USB port with very little overhead on the CPU.  Otherwise you have to use Windows Sound Mapper that resamples the audio depending upon on the playback setup.  For instance your fancy 192Khz or 96 KHz files could be resampled to 44.1kHz.  So Windows Sound Mapper is not bit for bit.

    There is no way a DAC can use asynchronous USB audio directly.  There has to be some form of buffering the data and re-clocking.  And reconstruction of the audio stream with low jitter is what currently distinguishes the best USB DACs from the bad and mediocre.  Very few companies do this well and a lot of companies do it poorly.  So choose wisely for best sound quality.

    sailor

    Posts : 269
    Join date : 2011-04-04

    Re: Looking for quality KIT DAC

    Post by sailor on Fri Feb 21, 2014 12:48 pm

    Actually the 9018 chip can because it re times everything on chip. Again the only chip I know that does this. If you look at the chips architecture you will see it is different from all of the competition. I do think the OPPO has the available memory to store information until it is ready to use it.
    I did notice on ebay a Chinese company is selling a DAC board with the 9018 chip. Price does not include op amps.

    mazeeff

    Posts : 122
    Join date : 2014-01-06
    Age : 61
    Location : Grand Rapids, Michigan, USA

    Re: Looking for quality KIT DAC

    Post by mazeeff on Thu Feb 27, 2014 6:40 am

    Just thought that I would share my experience with a Nuforce ICON USB DAC, that I purchased a few days ago. I already had a Nuforce ICON IDO that interfaces to a Ipod. I was quite happy with the IDO, but wanted a better user interface with the USB DAC. The USB DAC worked fine on one of my laptops, but was full of digital noise on my very high end media server, with I7 16gb SSD GTX650 850W etc. It also worked fine on a AMD 5300 APU desktop. I tried swapping power supply's, usb ports, etc. Nothing worked, until I removed the GTX650 video card. No more noise! Swapped in a GT 430, and the noise returned. Desktop computers are simply full of noise sources, and these high end videos cards seem to be the biggest culprit. When I did a google search on the subject, there was a lot of discussion on this with various manufacturers of USB DAC's. I ended up running a dual USB extension panel with shielded wires, to the lowest slot in the desktop. This keeps the USB ports as far away from the other components as possible. I also found that the most noise seem to come from using the back panel USB motherboard ports. No idea why! Without the video card, I have been running noise free for the last day.

    Mike

    deepee99

    Posts : 1333
    Join date : 2012-05-23
    Location : Wallace, Idaho

    For Unbntu Linux users

    Post by deepee99 on Thu Feb 27, 2014 7:01 pm

    Quite a bit of chat on their boards about this. Actually, the player op in beta from Spotify works for me. There's a couple of hacks you need to do, like making sure you've got X universe, or Xdeb, but that's just a command-line entry to open up the repositories. I'm listening to it right now and it's very, very sweet.

    Maintarget

    Posts : 209
    Join date : 2013-02-10

    Re: Looking for quality KIT DAC

    Post by Maintarget on Thu Feb 27, 2014 10:47 pm

    Decided to give up on building a DAC and went with  Schiit Gungnir external DAC with USB capability
    Many good reviews, once I get a few hours on it I'll post feedback.

    mazeeff

    Posts : 122
    Join date : 2014-01-06
    Age : 61
    Location : Grand Rapids, Michigan, USA

    Re: Looking for quality KIT DAC

    Post by mazeeff on Fri Feb 28, 2014 9:46 am

    Maintarget wrote:Decided to give up on building a DAC and went with  Schiit Gungnir external DAC with USB capability
    Many good reviews, once I get a few hours on it I'll post feedback.

    Nice unit. I like the replaceable DAC's. It is also nice to see that they readily reveal the DAC being used. Some companies keep that secret. Look forward to the review.

    sKiZo

    Posts : 1310
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Looking for quality KIT DAC

    Post by sKiZo on Sat Mar 01, 2014 12:09 am

    Really nice to be able to roll the op amps ... here's my Maverick with a couple OPA627's on a BrownDog adapter instead of the stock LF343N. The board is already socketed, so that takes a lot of the work out of it.



    Can't see it, but there's another chip hiding underneath between the extension legs. The TubeMagic takes two, one for pass thru and one for the headphone amp.

    Difference is pretty spectacular. There's several other op amps you can roll into the box, but I'm real happy with what I got now.

    pmarcin

    Posts : 131
    Join date : 2009-01-20
    Age : 69

    Re: Looking for quality KIT DAC

    Post by pmarcin on Mon Mar 03, 2014 5:13 pm

    Dave,
    LOL about AVA. I had a similar experience with a PAT-5. I built a kit and had a cold solder joint. I sent him the kit and he returned it saying that a cap was bad and proceeded to grouse at me. It had the same problem. I tracked down the problem. I found out another customer, who built the PAT-5, and had the same problem. Frank had returned the unit in the same condition as was sent to him.

    I did like the PAT-5 a lot and it held up well in A/B comparisons with tube gear.

    I concur the Schlit unit looks promising.

    For a general, external conditioner, see DIP

    Mr. Poon's DACs all come with a pre-amp, e.g., the NM24.


    Last edited by pmarcin on Mon Mar 03, 2014 5:43 pm; edited 1 time in total (Reason for editing : errors)

    Tube Nube

    Posts : 641
    Join date : 2008-12-06
    Age : 53
    Location : Calgary, AB

    Re: Looking for quality KIT DAC

    Post by Tube Nube on Tue Mar 04, 2014 1:44 am

    Maintarget wrote:I have been looking at the Audio Note Kits but not actually hearing one first would be an expensive gamble I'm not willing to take, I found an interesting web site with a kit built DAC that I had considered but in the end the same problem as the ANK
    http://www.computeraudiophile.com/blogs/mbrennwa/dddac1794-no-ordinary-dac-329/
    As far as assembled product I have considered the Schiit Gungnir if nothing else I like their business model and honesty
    After researching and wading through all the sales crap and gimmicks finding a quality DAC has turned out to be a real PITA.
    Thank you all for the responses.

    Audio Notes Kits look impressive, as far as I can tell.

    I received a component from them in a timely manner, and an apology that several caps were missing. Promised and not received, and again, and again. For well over a year now.

    I guess I'll have to risk proceeding with the build and hope I can figure out what I need and where to get it. But it's left a taste of kaka in my mouth. If I ever build it, I'll probably sell it no matter how good. I dont want to look at it.

    It is the worst experience I've had in the hobby. Maybe its not such a big deal, but when you pay $1300 or $1600 for a kit, theres reason to expect better than unfulfilled promises.

    pmarcin

    Posts : 131
    Join date : 2009-01-20
    Age : 69

    Re: Looking for quality KIT DAC

    Post by pmarcin on Tue Mar 04, 2014 3:10 pm

    I ordered the Welborne upgrade a few years back. It was delivered six weeks later sans five resistor values and shielded cabling. That took another four weeks. It ran hotter than a firecracker, even with the resistor drain 'fix'.

    Sam Kim had interesting things to say about several designs, as well as the Dynaco Doctor.

    No commentary, but Sam's backgound:Guru

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