IFI SPDIF iPurifier for Dolby Digital and DTS

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audioengr

IFI SPDIF iPurifier for Dolby Digital and DTS
« on: 25 Dec 2017, 09:41 pm »
I recently purchased a couple of SPDIF iPurifiers and I'm using one from my smart TV via Toslink to my SS proc. and the other from my OPPO with coax to my SS proc..  I use my OPPO to play Blu-rays.

I recently made jitter measurements on the OPPO and was not happy with the results.  My excellent Synchro-Mesh reclocker will only reduce jitter for PCM 2-channel, so I was pleasantly surprised when I learned these IFI devices would work.  Not only do they work, they have coax or toslink in and out. I just needed some adapters for 75 ohm BNC etc..

These inexpensive devices do a great job of reducing jitter for movie sound.  I am using one of my fast-reacting 5V LPS on it and it is better than the included wall-wart.  I would recommend to try the Sboost LPS.

I watched "Gravity" again and this time I heard all of the faint radio chatter detail in the beginning that I missed before.  Now the movie makes sense.

If you use a SS proc., HT receiver, Smart TV or Blu-Ray player in your HT, this is a no-brainer.  Just buy it.

Steve N.
Empirical Audio

rodge827

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Re: IFI SPDIF iPurifier for Dolby Digital and DTS
« Reply #1 on: 26 Dec 2017, 04:05 pm »
Hey Steve I agree and power mine with an Uptone Audio Ultracap LPS-1 with excellent results.  :thumb:

Chris

highstream

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Re: IFI SPDIF iPurifier for Dolby Digital and DTS
« Reply #2 on: 4 Jan 2019, 07:03 am »
A couple of questions:

- The Uptone LPS-1.x outputs 1-1.1A, depending on the version, while the iFi spdif purifier wall wart outputs 2A, according to iFi support. Would that cause a problem?

- I'm using the iPurifier between an Oppo 203 and Directstream dac, with the wall wart plugged into a PS Audio Regenerator and the sound has been noticeably improved with two good coax cables; i.e., I can hear a clear difference with/without and can't hear anything like what has driven some to an LPS with the iFi (here and on AudioCircle). Which leads me to wonder, does the Regenerator mitigate the need for a separate LPS?

Thanks,
« Last Edit: 4 Jan 2019, 07:28 pm by highstream »

WGH

Re: IFI SPDIF iPurifier for Dolby Digital and DTS
« Reply #3 on: 5 Jan 2019, 12:02 am »
I thought SPDIF and Toslink didn't have the bandwidth for the uncompressed Blu-ray audio so I did a quick search:

"Neither of the S/PDIF standards for transferring digital audio--optical and coaxial--can transmit the bandwidth necessary for Blu-ray-specific audio formats like Dolby TrueHD, DTS HD Master Audio, and Linear PCM. That requires HDMI. Blu-ray players send Dolby TrueHD signals down S/PDIF cables as Dolby Digital, DTS HD MA as DTS, and 5.1 PCM as two-track stereo PCM."
https://www.techhive.com/article/215202/hdmi_vs_spdif.html

Unfortunately I don't have a Blu-ray copy of Gravity to see if I hear the radio chatter in the beginning using HDMI, the last time I saw the movie was in a theater with excellent sound.
Gravity is directed by Alfonso Cuarón and won 7 Oscars, Cuarón's latest film is Roma, which I think is a masterpiece. An interesting observation is that friends who watched it on Netflix thought it was slow and meh so see it on a big screen if you can as Cuarón intended. Roma was shot on 65mm film in stunning black and white.

Gravity won 2 Oscars for sound editing and sound mixing, for Alfonso Cuarón the sound in Roma is just as important and immersive.
https://www.nytimes.com/2019/01/02/movies/alfonso-cuaron-roma-mexico-city.html

Phil A

Re: IFI SPDIF iPurifier for Dolby Digital and DTS
« Reply #4 on: 5 Jan 2019, 12:36 am »
I have Gravity on 3D Blu-Ray but have not listened in quite a while but since my main system is an integrated AV system, it is pretty clear on most things.  When I've had people over to listen to things, they have always commented about hearing things they didn't hear before (had a friend over Wednesday to watch Avatar in 3D).

highstream

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Re: IFI SPDIF iPurifier for Dolby Digital and DTS
« Reply #5 on: 5 Jan 2019, 12:43 am »
Don't know if the limitation is technical or licensing. I can get Blu-Ray sound with from Oppo 203 to Directstream dac either via coax with the spdif purifier or with the Oppomod HDMI/I2S card (HDMI cable). I watched Gravity at home as an mkv file and liked it. Not for every personality.

WGH

Re: IFI SPDIF iPurifier for Dolby Digital and DTS
« Reply #6 on: 5 Jan 2019, 01:51 am »
I can get Blu-Ray sound with from Oppo 203 to Directstream dac either via coax with the spdif purifier

The Gravity .mkv file size has to be either 22.24 GB (REMUX) or 42.98 GB (full disk) to get DTS-HD MA sound, anything smaller and it's not Master Audio.
The Directstream dac is an excellent stereo DAC but I have no idea what it does with a DTS-HD MA signal.

Gravity Blu-ray:
DTS-HD Master Audio / 5.1 / 48 kHz / 2369 kbps / 16-bit
DTS Core: 5.1 / 48 kHz / 1509 kbps / 16-bit

DTS - the standard DTS core is 16 bits at 1.5 Mbps and is a little louder but basically sounds the same at AC3.

DTS-HD MA - DTS-HD Master Audio, is a lossless audio formats. DTS-HD supports variable bits rates on a Blu-ray disc of up to 24.5 Mbps, with a maximum of 192 kHz sampling and 24 bit depth in two-channel stereo mode, and up to 8 channels at 24 bits at a sampling frequency of 96 kHz.

highstream

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Re: IFI SPDIF iPurifier for Dolby Digital and DTS
« Reply #7 on: 5 Jan 2019, 02:04 am »
Thanks for the clarification. Btw, while I watched Gravity as stated, I was actually thinking of his recent Roma, which I liked much better but is not for all (though it should be).

I do hope someone has some thoughts about the effect of plugging into a regenerator vs. using an LPS with the iFi spdif iPurifier.