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Author Topic: Jitter Measurements  (Read 1801 times)

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Marvey

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Jitter Measurements
« on: May 30, 2012, 09:13:49 PM »
This is for you mav. Jitter spectrum for DCX2496, PWD2 using JTest 48kHz.
« Last Edit: June 19, 2012, 11:37:19 PM by purrin »
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maverickronin

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Re: Jitter Measurements
« Reply #1 on: May 30, 2012, 11:44:17 PM »
Cool.  You managed to find a JTest test file already?

I think that's the first measurement of the PWD2 I've even seen anywhere.  I went looking for some the first time I saw you mention it it but I couldn't find any.  It looks pretty damn good too.  Not much spread and no symmetrical sidebands poking up above the noise floor (probably of your ADC and not the PWD2).
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maverickronin

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Re: Jitter Measurements
« Reply #2 on: June 05, 2012, 10:05:28 PM »
Do either you or Anax have any sort of technical info you could link me to about the PWD?  I'd be interested if you have anything in particular you could point to that you think makes it so good.

Considering that they also sell $1800 power cables and silly expensive power conditioners that amount to a dual conversion UPS that someone forgot to install a battery into I had pretty much written off their DACs until I saw this.
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Marvey

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Re: Jitter Measurements
« Reply #3 on: June 06, 2012, 01:46:34 AM »
http://www.stereophile.com/digitalprocessors/824/ (Digital Lens - implemented on Bridge in mk1 and a part of the system in mk2.


Other than that, just good solid construction, good board layout, "boutique" parts (probably higher tolerances), over-built power supplies, etc. The DAC/Analog board is extremely simple. The digital receiver board with the Lens built in is very complex. I should have taken pictures when I took it apart for the mk2 upgrade.

The analog section is discrete parts running on rails of higher voltage than op-amps. I have no idea how they made it sound so detailed and unlike any Wolfson I've ever heard. It probably comes down to the details of the execution, board layout, taking measurements, short signal paths, etc.
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maverickronin

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Re: Jitter Measurements
« Reply #4 on: June 06, 2012, 02:26:28 AM »
Hmm...

The digital lens is a pretty cool concept but the idea of introducing extra latency is probably a deal killer for me.  I don't want to really have use a separate DAC games and movies and/or always have to remember to turn it on and off.
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Currawong

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Re: Jitter Measurements
« Reply #5 on: June 06, 2012, 03:20:50 AM »
There's a member on HF who writes for one of the online mags that has the proper equipment to measure jitter down to femtoseconds. I've long been meaning to ask him about measuring stuff and posting the results.
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Anaxilus.

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Re: Jitter Measurements
« Reply #6 on: June 06, 2012, 03:37:12 AM »
Quote from: maverickronin on June 06, 2012, 02:26:28 AM
Hmm...

The digital lens is a pretty cool concept but the idea of introducing extra latency is probably a deal killer for me.  I don't want to really have use a separate DAC games and movies and/or always have to remember to turn it on and off.


I've been using mine for TV, movies and PC with no issues.  I'm watching Majic Johnson talk about how sad the Miami Heat are right now, perfectly in sync.  Then again, I have a mk1 w/ no bridge.


Marv, can you run some KOTOR BG's and verify on the mk2 if you haven't already?
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maverickronin

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Re: Jitter Measurements
« Reply #7 on: June 06, 2012, 04:21:03 AM »
Quote from: Analixus on June 06, 2012, 03:37:12 AM
I've been using mine for TV, movies and PC with no issues.  I'm watching Majic Johnson talk about how sad the Miami Heat are right now, perfectly in sync.  Then again, I have a mk1 w/ no bridge.

Marv, can you run some KOTOR BG's and verify on the mk2 if you haven't already?

I don't think that it would really amount to much with most transports but it's the kind of thing that would never stop bothering me unless I could measure it and verify it was low and stayed the same over time with each transport.

I get OCD and paranoid about certain things.
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Anaxilus.

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Re: Jitter Measurements
« Reply #8 on: June 06, 2012, 04:39:23 AM »
Quote from: maverickronin on June 06, 2012, 04:21:03 AM
I don't think that it would really amount to much with most transports but it's the kind of thing that would never stop bothering me unless I could measure it and verify it was low and stayed the same over time with each transport.

I get OCD and paranoid about certain things.


Rightly so.  It's a good chunk of change to be let down by something basic.


Yeah, it's best to separate the Perfect Wave from the rest of the lineup. 
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Marvey

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Eximus DP-1 DAC Jitter
« Reply #9 on: June 19, 2012, 11:39:30 PM »
Eximus DP-1 Jitter Measurements with 48k input.
  • No ASRC - async sample rate converter
  • ASRC 96kHz
  • ASRC 192kHz

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