Stairway to Heaven ...

[North_Sky]

▪ https://hometheaterreview.com/ifi-audio-pro-idsd-44-reviewed/

 

[North_Sky]

▪ https://ifi-audio.com/products/pro-idsd/

 

[North_Sky]

Amir, could you please measure this ... stairway to heaven?

 

[hmscott]

ifi galvanic isolation along with other techniques trickled down from AMR for external noise rejection and internal noise reduction as applied in the iDSD Pro has attracted my interest from early on. Given the cost of purchasing the external devices to "fix" lessor designs by using patches like the Defender 3.0+, iSilencer, Galvanic 3.0, iMicro USB, iNano USB, etc, if you have problems with "noise" - it's almost cheaper long term to get the ifi products with solutions designed in from the start.

"Galvanic isolation is the ‘holy grail’ of computer audio. All inputs are galvanically-isolated (including USB). The USB input section has its own separate power management system with multiple regulators and filtering operating from the galvanically-isolated voltage generated to power this section."
https://ifi-audio.com/products/pro-idsd/

Galvanic isolation - Is it the same as in iGalvanic3.0 Nano?
Question: How is the USB galvanic isolation done on the iDSD Pro and is it the same as iGalvanic3.0 Nano (trickle down perhaps)?

Answer: No, in the iDSD Pro we operate it very differently.

We use a suitable isolation barrier between the digital (noisy) section with XMOS, WiFi/Networking and the Chrysopeia and the DAC's / Reclocking / Clock. In essence, all noisy digital processing is confined to a blocked off "island" on its own board and isolated from all audio circuitry.

This parallels the way in which for example the JVC K2 system is implemented for playback and the isolation of the DAC from digital noise found in the Legendary Marantz CD/DA-12 system featuring the TDA1541.

All this is essentially trickle-down from the DP-777. (AMR DP-777(SE))

The iGalvanic3.0 Nano isolates the USB connection instead, so it is a less complete solution, as it cannot isolate noise inside the DAC itself."
https://support.ifi-audio.com/kb/faq.php?id=796

One bothersome item is the use of a USB 3.0 "B" connector, so I'll want one of those expensive ifi Gemini or Mercury USB B 3.0 cables. Especially the Gemini as useful for the split data and power runs, but not cheap. Are there any competitive split data / power USB B 3.0 / 2.0 cables out there?

As much as I like the new iDSD 4.4mm balanced upgrade it costs $300 more at $2799, and the previous iDSD model with a 2.5mm balanced output costs $2499 - and ifi has a bundle with a Gemini USB cable for $2519 (Update: now $2619, hello ifi $ - new, so a "used" previous model might be a bit cheaper still as owners divest of the 2.5mm balanced iDSD Pro to upgrade to the new 4.4mm iDSD Pro.

@North_Sky - it would be nice to have a list of what actually changed in the latest 4.4mm version from the last iteration with the 2.5mm balanced output, and how it affects the audio performance, beyond the slightly greater power output of balanced / SE outputs.

@amirm - it will be nice to see the testing results of the changes in the new ifi iDSD Pro, and how they effect the measurement results.

Update: After a little digging it looks like the iDSD got it's last firmware update with version 2.08 in October 2019, and there were still outstanding problems introduced by the version 2.01 firmware - is the new 4.4mm iDSD going to continue to get firmware updates? If I see another useful firmware update for the iDSD I might be interested in one for myself.

 

[North_Sky]

I'm sorry Monsieur Scott, I wouldn't know what is required.
Amir is certainly well positioned to measure with objective analysis.

 

[hmscott]

I'm sorry Monsieur Scott, I wouldn't know what is required.
Amir is certainly well positioned to measure with objective analysis.

Thank you @North_Sky, I meant the question of what changed more as a open question.

Amir is busy, but perhaps he can fit in a re-test at some point.

 

[MediumRare]

What's the purpose of the tubes and how do they affect the specs?

 

[Vini darko]

I'm sure the tubes will tame these room acoustics with warmth

 

[North_Sky]

What's the purpose of the tubes and how do they affect the specs?

Good question; we all like to know ... sound signature and warmth with our music listening ... in ultra high res audio and high dynamic range ... 119dBA.

 

[North_Sky]

I'm sure the tubes will tame these room acoustics with warmth

Cool, I also like this version, very ...

 

[Vini darko]

Cool, I also like this version, very ...

Yeah that is a really good one thanks I enjoyed it. Much better room too.