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Audio-Gd Master 7 - Discrete Fully Balanced DAC (PCM1704)

Discussion in 'High-end Audio Forum' started by darknightdk, Sep 3, 2012.
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  1. motberg

    Thank you for the information..
    If you have time, please explain what mods you consider important for the QA660 to get best SQ with the M7...
    Are the RJ45 i2S pins same as Audio-GD?  ... or need special order the QA660 ??
  2. bballas
    i2s pins the same,short cable the best.If you have dedicated music computer with many extras,not sure qa 660 really upgrade.
    I modded just little,silver rewired the rj45 out and i2s chip between the pcb.not so noticeable.In the future maybe add extra transformers for cpu and i2s stages.The 2tcxo inside and display disturb the others(maybe)Example in the usb 32 modul disturbing the tcxo,this is sure.
    Best results add separate transformer.
    Master 7 also have 2tcxo without separated transformers!!!!!!!!
    motberg likes this.
  3. tbend

    Hi, if you see on the picture i have a jumper on PLL.
    Tried to enable Dither but i didnt like the sound, the sound image got a lot smaller, and the sound runs from the sweet spot and forward to the speakers. The dither is making a huge difference here.

    Also tried stopband -50db, in fact i liked the sound better now than the -90db. Last time i tried -50db was on other speakers, maybe thats why.

    I liked the 4x oversampling best.

    Using Linux with KS ALSA stream bit perfect with Deadbeef player. No dithering at all.
  4. Currawong Contributor
    I don't know about the PCM63 (but I would wonder). The problem with these chips is that they don't take an I2S input, but something known as "Right Justified" which I gather is the same data as I2S with a different format. That is likely why nobody has discovered this before (or bothered with it before, I don't know for sure) as in the absence of expensive DSP or FPGA programming, you must use a CS8416 or similar to feed these DACs, as they will output the correct format. 
    I reckon it'd be great if Kingwa could set up his DSP to accept input up to the highest limit possible. He might have to modify the USB input and whatnot though to accept it though, I'm not sure. Then we could try up-sampling with the latest Audirvana which can output higher frequencies. I'm not sure how it would end up sounding, but it does do wonders with Sabre DACs that accept 384k over USB.
  5. Clemmaster
    Doesn't change the fact that they both accept 192 or even 384kHz signals. My point was to say they are not limited to the base frequency announced in their datasheet (48kHz for the PCM-63, 96kHz for the PCM1704) and they are guaranteed to do 768kHz. Now that we have the proper interfaces to do 384kHz, they will take it.
    There's probably no point in doing oversampling past 192kHz input.
  6. bimmer100
    Kingwas new nos11, nos7 etc will accept up to 1536khz and 768khz with the new DSP software. They have a dedicated high spec clock . Anyhow. Is this what you mean?
  7. bimmer100
    Kingwas newest nos dacs do accept 768khz input and 1536khz
  8. mojolo
    Apparently the dsp and pcm1704 chips can accept/process 768KHz and 1536KHz but the device's inputs can only accept the following sampling rates. Since it's a NOS device, there will be no oversampling - the dsp/dac chips will never see higher sampling rates than its inputs can accept.

    IN1: BNC input, up to 24bit / 96KHz support .
    IN2: AES input, up to 24bit / 192KHz support .
    IN3, RCA coaxial input, up to 24bit / 192KHz support .
    IN4, optical input , up to 24bit / 96KHz support .
    IN5 , I2S input, ,up to 32bit / 384KHz support .
    IN6 , USB input, ,up to 32bit / 384KHz support

    That said, it does sound like kingwa anticipates a new USB interface at some point that can accept 768KHz.
  9. Currawong Contributor

    That's what I was referring to when I wrote "That is likely why nobody has discovered this before (or bothered with it before, I don't know for sure)". I should have written "...before Kingwa implemented it." I guess. [​IMG]
  10. bimmer100

    The amanero m4 768khz
  11. bimmer100

    Sorry, that's what I get for browsing with my phone.. I'm kinda excited to try the nos11. I've been talking a bit with Kingwa about it. I'm hoping to get one and do a bit of comparison. But limitations of USB interface seem to be the problem until the amanero m4 is released. :)
  12. bballas
    Isolated the digital stage transformer.The sound much better!!!!!!!!!More detail,more 3d,so clean,Wonder! WP_20160318_20_01_03_Pro.jpg
  13. guilders0
    Hi bballas,
    Is there a post or blog where you explain step by step with pictures your different mods ?
    I also read in your signature you have a silver ACSS cable. Did you build it yourself ?
  14. bimmer100

    It would be great if you could start a blog with photos of some of your mods. Or at least a good photogallery in your profile to show how some are done and what was achieved. I'm intrigued
  15. mojolo
    Yeah, I posted about the Amanero Ultra M4 a few times in the three a-gd PCM1704 threads. Do you have confirmation from Kingwa that this is indeed the next USB board? Besides the YT video, there's literally no mention of the M4 across the web. BTW, I love that kingwa's products just keep on giving! [​IMG]
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