iFi's Pro iDSD (official) - NEW Firmware - MQA and more.

[applesnowleo]

Just now, Stings said:

Oh, i figured out how to upsample. You press the Filter knob to switch between passthrough, DSD512 and DSD1024.

 

Yes, and if you press the input selector know you can dimm the display.

 

There are also the function Press and hold, on the imputes selector, press and hold changes the polarity, and on the filter selector pess and hold to configure WIFI by WPS.

[Stings]

There is a option to control the volume in the Spotify app but it doesn’t work on the IDSD pro dac. It works on my other DACs though.

[Stings]

Applesnow, does the IDSDpro sound better with the USBridge or with a direct Ethernet connection and Tidal or Spotify?

[applesnowleo]

37 minutes ago, Stings said:

Applesnow, does the IDSDpro sound better with the USBridge or with a direct Ethernet connection and Tidal or Spotify?

 

Thats a good question, I find the ethernet connection on the Pro IDSD a fantastic result, by usb connected to the computer it depends on the computer generated noise and quality of the usb connectors used inside, in my case was good but not on par with the ethernet UPNP protocol on Audirvana.

 

For this motive I acquired a SOTM SMS200 Ultra and an SPS500, this resulted on a positive combination and a welcome upgrade. But I have to say that the ethernet has more separation and focus, the soundstage is smaller on the iFi than the SOtM SMS200 Ultra and SPS500, but not worse, in my case I have the best of both worlds.

 

The sound of the iDSD Pro by UPNP by Ethernet Cable is something that amazes me, and if better support in software is given to the iDSD Pro, ethernet connection should be the way to go, and if future ROON software support is added you will have the ultimate killer one box DAC, I think you do not need much more to have a marvellous sound.

 

My updates where a little extreme, and the benefits is grown a bit. a bit more not a lot more, but not in the proportion of the final added cost, and even then with all the changes, that was a consequence of bad software support at the moment.

 

I find the iDSD Pro ethernet has a separation and sound stage that I never heard before in any other hardware, the USB requires some good hardware and cable pairing to be on the same level or above.

 

When I heard the ethernet sound produced, I saw what the iDSD Pro can give for the first time, and that made me to remove the computer from the equation, now it's working only as a remote control.

 

So both have advantages, but if you can go totally by ethernet, yes, is cheaper, sounds better, and needs more support from software at the moment.

 

English is not my home language, so forgive me some gramatical errors.

[AMR/iFi audio]

15 hours ago, Stings said:

Oh, i figured out how to upsample. You press the Filter knob to switch between passthrough, DSD512 and DSD1024.

 

Yup, filter knob needs to be pressed and DSD remaster mode (1 press = DSD512, 2 presses = DSD1024) is engaged.

[Stings]

How do you access, play and share your music library on USB3 hard drive? Is there a web GUI that we log into to manage and share our music library? I want to be able to access my library from multiple computer devices and locations on my network. How do we do it? I plugged a 512gb USB flash drive into the pro idsd but how do i play from it and how do i connect to it from other computers or stereo systems?

 

Thanks

 

Stings

[AMR/iFi audio]

15 hours ago, Stings said:

How do you access, play and share your music library on USB3 hard drive? Is there a web GUI that we log into to manage and share our music library? I want to be able to access my library from multiple computer devices and locations on my network. How do we do it? I plugged a 512gb USB flash drive into the pro idsd but how do i play from it and how do i connect to it from other computers or stereo systems?

 

Thanks

 

Stings

 

Please use MUZO app to do this. 

 

Our Pro iDSD review is at www.6moons.com and it's a good one! 

 

http://6moons.com/audioreviews2/ifi/1.html

 

Enjoy!

[asdf1000]

Hi @AMR/iFi audio

 

The below block diagram was shared for the micro iDSD and iDAC line and it was helpful in understanding how these DACs treated PCM vs DSD.

 

Can you ask the Technical Team to please share an updated version for the Pro iDSD?

 

I've gone through all the technical material shared here and on Head-Fi and I don't think this has been explained. Since it's the same DSD1793 used, I assume it's similar but would love confirmation.

 

Cheers!

 

 

[AMR/iFi audio]

Folks, our latest XMOS firmware 5.3C is alive! It adds one VERY SPECIAL thing: The GTO filter. What is it, you might ask. Well...

 

iFi audio - The GTO filter 
Part 1/4 - The TL;DR

 

What iFi GTOTM is?

 

Based on AMR’s ‘Organic’ mode, the further refined iFi GTOTM Digital Filter resolves a number of audible problems associated with both classic digital filters AND non-oversampling systems, sounds on par (or better in optimal systems) to the latter and its transient optimised performance is similar.

 

How iFi GTOTM does it?

 

Our GTOTM filter tuned to fit inside the ‘ringing envelope’ of our own hearing makes ultrasonic ringing objectively measurable yet not perceived. It essentially ‘masks’ this time-domain distortion to make it inaudible.

 

Why do I want iFi GTOTM?

 

Because it provides natural sound free from audible time domain distortion!

 

Stay tuned folks! We have a lot of filter related goodies to come!

[Newson]

I currently use the IFI Idsd black and HQplayer + room.
The upsampling for DSD512 sounds fantastic using my PC.

 

The question:

Does anyone who owns the Idsd Pro compared the upsampling to DSD512 using the pro Idsd x HQplayer using the PC?

[gordec]

27 minutes ago, Newson said:

I currently use the IFI Idsd black and HQplayer + room.
The upsampling for DSD512 sounds fantastic using my PC.

 

The question:

Does anyone who owns the Idsd Pro compared the upsampling to DSD512 using the pro Idsd x HQplayer using the PC?

I have. I have settled on DSD512 after giving all the filters a good run. To my ears HQP's upsampling is not adding anything more, so I went back to use Iriver for better interface. 

[Newson]

12 hours ago, gordec said:

I have. I have settled on DSD512 after giving all the filters a good run. To my ears HQP's upsampling is not adding anything more, so I went back to use Iriver for better interface. 

 

I regret the indifference and / or absence interest (mutual?) In support of Roon.....

 

thanks Gordec

[gordec]

6 hours ago, Newson said:

 

I regret the indifference and / or absence interest (mutual?) In support of Roon.....

 

thanks Gordec

 

I don't have Roon any more. I think if I still have Roon I would still use HQ Player with it's CUDA offload to GPU. I'm not quite sure what you are asking :).

[asdf1000]

19 hours ago, Newson said:

The question:

Does anyone who owns the Idsd Pro compared the upsampling to DSD512 using the pro Idsd x HQplayer using the PC?

 

Hi,

 

I'm using HQP Embedded (Linux) to Pro iDSD (DSD512 up-sampling). I had the iDSD BL before also.

 

I'm very happy with it.

 

I tried different programs playing HQPe (via UPnP mode). But Roon playing to HQPe is easily the best experience and interface for me.

 

Sometimes UPnP can be a little unreliable with music randomly stopping.

 

The Roon + HQP integration works flawlessly for me.

 

[Newson]

1 hour ago, gordec said:

 

I don't have Roon any more. I think if I still have Roon I would still use HQ Player with it's CUDA offload to GPU. I'm not quite sure what you are asking :).

 

Sorry my dear for my English.

I did not refer to you.

The IFI pro Idsd is a good product.

But, for me to buy .... a good integration with Roon + HQplayer is required ..☹️

[gordec]

15 hours ago, Newson said:

 

Sorry my dear for my English.

I did not refer to you.

The IFI pro Idsd is a good product.

But, for me to buy .... a good integration with Roon + HQplayer is required ..☹️

I don't think Roon endpoint is ever coming for pro Idsd, but you can always use microrendu, sotm, or even an iPad to run pro Idsd as a Roon endpoint. Roon randomly assigns Asian music ID tags and won't let me customize it, so I had to give up on it.

[AMR/iFi audio]

iFi audio - The GTO filter 

Part 2/4 - Introducing the iFi GTO™ Digital Filter

 

ALL DIGITAL FILTERS FOR AUDIO ARE WRONG.

ALL OF THEM, INCLUDING THE 'NO FILTER' OPTION.

THIS IS WHY WE NEED YET ANOTHER FILTER!

 

All digital filters (including no filter) differ in how they are wrong and how this influences objective measured performance as well as subjective listening performance with music and indeed, specific types of music. All digital filters add specific distortion signatures in either time vs. amplitude domain or frequency vs. amplitude domain. These distortions become all the more relevant the lower the sample rate. So, the most abundant digital music source -CD quality - is most impacted with greater possible audible consequences than High-Res content.

 

Wherever there is a difference, there is also a preference. Subjective listening preference may be informed by a range of factors including a learned or acquired response to recorded sound (e.g. what sounds ‘right’ or ‘hifi’ is not what sounds natural in comparison to a live performance), including direct referencing acoustic music performances.

 

However, with sufficient data from extensive listening tests and some inductive thinking, one should be able to propose and implement a digital filter that offers substantial improvements in removing ultrasonic noise over the ‘no filter’ (non-oversampling) case while avoiding as much as possible erring too far in the other direction with excessive and audible ringing.

 

So here it is - the ever so musical iFi GTO^™ Digital Filter in the Pro iDSD which is the first ever seen in any DAC. In due course, technological hurdles permitting, we will try to implement it as a firmware upgrade for just about all[1] iFi audio digital products.

 

What is the iFi GTO^™ Digital Filter?

The Gibbs Transient Optimised filter (GTO) is named after the ‘Gibbs phenomenon (2)’ in mathematics. 

 

Wikipedia referred to the Gibbs phenomenon as “the peculiar manner in which the Fourier series of a piecewise continuously differentiable periodic function behaves at a jump discontinuity. The nth partial sum of the Fourier series has large oscillations near the jump, which might increase the maximum of the partial sum above that of the function itself. The overshoot does not die out as n increases, but approaches a finite limit.”

 

Most crucially, this is one cause of ringing artefacts’ in signal processing which the GTO addresses.

 

Way back in May 2011, the parent company of iFi audio, AMR, pioneered an earlier version of this filter in the DP-777 digital processor where it was available as an ‘Organic’ filter. Since 2011, more time has been invested into producing a filter that offered both better compatibility and technical performance than non-oversampling, while delivering a transient optimised performance that differs as little from non-oversampling as possible, delivering the new GTO™ filter.

Non-oversampling Transient response vs Organic- Digital Filter AMR DP-777

 

No doubt there will be extended debate if our GTO^™ digital filter offers the right trade-off, compared to others. To us the two key qualities we sought was to shape of the unavoidable transient or time domain distortion so that is free of any ‘pre-ringing’ and that completes its impulse response within a fraction of the Haas (precedence effect) window; to remain in effect, inaudible to the human ear.

 

What we really refer to when we are talking about ringing in digital filters is actually a form of ‘Echo’ or ‘Reverb’ where, in addition to the actual transient time-shifted lower amplitude, copies of the impulse are generated using delay lines (see also the transients and digital filters section later on).

 

The human hearing itself is subject to an inherent transient post (impulse) ringing that completely decays within around 0.7mS[1] (see also the transients and the human hearing section later on).

 

The GTO filter’s transient post-ringing decays completely within 0.72mS for a 44.kHz source, ensuring that the unavoidable blurring of the transient response cannot be heard, but is integrated by the human hearing into the original transient.

 

This is in stark contrast to some alternative filter concepts. For example, the ‘Transient Aligned’ filter seeks a maximum number of taps, leading to an impulse response that falls well outside the Haas window. ie. its ‘ringing’ is very audible, in part because there is a pre-ringing (or pre-echo) present and in part through the sheer length of the delay line used.

 

For example, the 16k tap Transient Aligned filter in the Pro iDSD has an impulse response with equal pre- and post-ringing trail of around 186mS @ 44.1kHz sample rates, or a total 386mS worth of ringing. This is certainly sufficient time delay to be perceived as reverb. Using an even larger number of taps lengthens this impulse response even more.

 

 

Transient Aligned Digital Filter Transient response vs GTO™ Digital Filter iFi iDSD Pro

 

It may be of course, that some will prefer the sound of a very long filter, with large amounts of ringing/reverb/echo as the result is often perceived as extra added spaciousness, however, to anyone seeking to be close to the original musical performance such additives are usually unwanted.

 

In the end, with the iFi GTO filter, by keeping the filter short and without pre-ringing, the filter response is inaudible because it is masked by the limits of the human hearing system. At the same time this filter still permits significant attenuation of unwanted ultrasonic images, compared to non-oversampling and also other attempts at “low tap number digital filter”.

 

Analogy: if a 20million mega pixel camera was used to take a picture of a straight line, the naked eye would see only a straight line. As the resolution is ‘beyond’ that of the human eye, any ultra-fine imperfections are not ‘seen’. This is the same as with the GTO filter with human hearing.

 

If the GTO™ digital filter is so ‘perfect’, why include the other filters with the Pro iDSD? As remarked before, individual listeners may have different listening preferences and rather than imposing one option, even if we feel this option is not the best, we prefer to leave the choice down to the individual.

1) The original iDAC micro cannot receive this upgrade
2) https://en.wikipedia.org/wiki/Gibbs_phenomenon

3) “Response of the human tympanic membrane to transient acoustic and mechanical stimuli: Preliminary results” Payam Razavi, Michael E. Ravicz et al - Hear Res. 2016 Oct; 340: 15–24.

[Stings]

I tried using the MUZO Player app to play from a USB flash drive that i inserted into the Pro IDSDs USB-A slot. Whenever i try to play a new song the Pro IDSD locks up and i have to power cycle it to get it running again.  Spotify works fine but I can’t play from the USB drive. When a song crashes the IDSD I am no longer able to play from any source. The network level of the iDSD freezes. The wifi disapears and the device also disappears from the network until I power cycle the Pro iDSD. Its like it is having a problem knowing if it should be looking at the network or the USB input.

  Muzo is the only option for playing from a USB device? There is no internal GUI right?

[Stings]

What is the USB-B looking connector on the ifi idsd pro? It is different than the standard USB-B to USB-A cable connectors? Is this so we have to buy ifi USB cables? Will our normal USB-B cables work? If not, where do I buy a longer 5’ USB-B to USB-A cable from ifi, that or an adapter?

[gordec]

1 hour ago, Stings said:

1 hour ago, Stings said:

I tried using the MUZO Player app to play from a USB flash drive that i inserted into the Pro IDSDs USB-A slot. Whenever i try to play a new song the Pro IDSD locks up and i have to power cycle it to get it running again.  Spotify works fine but I can’t play from the USB drive. When a song crashes the IDSD I am no longer able to play from any source. The network level of the iDSD freezes. The wifi disapears and the device also disappears from the network until I power cycle the Pro iDSD. Its like it is having a problem knowing if it should be looking at the network or the USB input.

  Muzo is the only option for playing from a USB device? There is no internal GUI right?

 

1 hour ago, Stings said:

I tried using the MUZO Player app to play from a USB flash drive that i inserted into the Pro IDSDs USB-A slot. Whenever i try to play a new song the Pro IDSD locks up and i have to power cycle it to get it running again.  Spotify works fine but I can’t play from the USB drive. When a song crashes the IDSD I am no longer able to play from any source. The network level of the iDSD freezes. The wifi disapears and the device also disappears from the network until I power cycle the Pro iDSD. Its like it is having a problem knowing if it should be looking at the network or the USB input.

  Muzo is the only option for playing from a USB device? There is no internal GUI right?

Is your USB drive FAT32 format or NTFS? Only FAT32 works.

1 hour ago, Stings said:

1 hour ago, Stings said:

What is the USB-B looking connector on the ifi idsd pro? It is different than the standard USB-B to USB-A cable connectors? Is this so we have to buy ifi USB cables? Will our normal USB-B cables work? If not, where do I buy a longer 5’ USB-B to USB-A cable from ifi, that or an adapter?

 

Regular USB B cables work fine.

[Stings]

Its fat 32 and it will play some songs as long as i dont try to change the song. If i do it locks up and i have to reboot the idsd pro.

 

so, whats the seal with the USB-B connector? Is it a graouned cable or something? If it doesnt make a difference, then why did the add it?

 

thanks

 

Stings

[Stings]

okay. I figured out what the USB-B connector was and why i looks different then my normal audio cables. The connector on the ifi Pro iDSD is a USB-B 3.0 connectior not a USB-B 2.0 connector. That is what the extra piece on top of the USB-B connector is. I’m not sure what it does but at least I know how to find and order a cable now. I’m guessing the top portion of the connector is a isolated power connector. That would make sense, to keep the power signal from infecting the data signal. But again this is just my speculation. Does anyone know? And, is USB 3.0 quieter then 2.0?

 

  Is it better to stay with your old USB 2.0 cable or to buy and use a new USB 3.0 cable? Witch has a lower sound floor?

[AMR/iFi audio]

21 hours ago, Stings said:

okay. I figured out what the USB-B connector was and why i looks different then my normal audio cables. The connector on the ifi Pro iDSD is a USB-B 3.0 connectior not a USB-B 2.0 connector. That is what the extra piece on top of the USB-B connector is. I’m not sure what it does but at least I know how to find and order a cable now. I’m guessing the top portion of the connector is a isolated power connector. That would make sense, to keep the power signal from infecting the data signal. But again this is just my speculation. Does anyone know? And, is USB 3.0 quieter then 2.0?

 

  Is it better to stay with your old USB 2.0 cable or to buy and use a new USB 3.0 cable? Witch has a lower sound floor?

 

Yes, we use USB3.0 interface in our products. As far as this standard goes, please take a look here:

 

https://en.wikipedia.org/wiki/USB_3.0

[AMR/iFi audio]

iFi audio - The GTO filter 

Part 3/4 - Introducing the iFi GTO™ Digital Filter

 

How taps relates to what is heard

So far, we have identified that we prefer the GTO filter because it has few taps.

Because:

 

More taps = more reverberation.

Few taps = minimal reverberation

 

Reverberation[1] is artificial. Sound engineers add reverb to make recordings more spacious, artificially so. Digital filters introduce reverb by the nature of their operation. In fact, a digital reverb unit operates precisely like a digital filter in principle – as depicted in this diagram.

 

Within digital filters are Digital Delay Lines which is defined by Wikipedia:

 

"A digital delay line is a discrete element in digital filter theory, which allows a signal to be delayed by a number of samples.

Delays of N samples is notated as {z} ^{-N} motivated by the role the z-transform plays in describing digital filter structures.

Digital delay lines are widely used building blocks in methods to simulate room acoustics, musical instruments and digital audio effects."

 

To our ears, the GTO filter simply sounds ‘right’ without any hint of artefacts or exceptional detail that feels ‘processed’, by avoiding large number of tap’s that add excessive reverb.

 

 

 

Transients and the human hearing

The human ear is a marvelous system with an incredible dynamic range (~135dB in middle frequencies) huge bandwidth (almost 1:1000) and a transient resolving ability that exceeds the upper limit of hearing steady state tones. Yet it is also subject to limiting factors which result in, so to speak, “blind spots” in its behavior that do not exist in purely mechanical systems (e.g. microphone). These “blind spots” can mask some behavior which objectively is distortion to be inaudible. For example, harmonic distortion masking has been well documented since the at least the 1950s if not earlier and it is reasonable to consider that ‘ringing’ on transients is also masked to a certain degree.  

 

If we wish to produce audio gear that is capable of operating in a way that subjectively sounds undistorted to the human hearing (the most logical preference), we must understand its limitations and capabilities. Here, we focus on the time-domain capabilities.

 

It has been shown that the human hearing’s time domain resolution for the initial transient may be as small as 5μs. Some debate remains as to the exact limits, though work done by Dr Peter Lennox of Derby University suggests a median between 13…18μs, or a location accuracy of less than 2 degrees.

 

 

Additionally, the transient response of the human hearing includes 500...700uS ringing caused by the ear’s mechanical system (Tympanic Membrane, Malleus / Incus / Stapes).

 

 

This ringing occurs after a transient event, there is no pre-ringing. The ringing in the ear’s system will mask any similar external ringing, which will instead be integrated into the transient, so it is inaudible.

 

Any pre-ringing is not masked by the human hearing, nor is any ringing that continues substantially beyond 500...700uS.

 

 

---

[1] https://en.wikipedia.org/wiki/Reverberation#Digital_reverberators and https://en.wikipedia.org/wiki/Digital_delay_line

[MoWa]

On 8/25/2018 at 3:55 PM, AMR/iFi audio said:

 

Please rest assured that very soon things will happen. MQA is going nicely and will be with you folks soon.

 

Hi ifi,

 

any news regarding the firmware upgrade of the Pro iDSD, to enable MQA ?

 

It is a brave statement of you regarding the GTO filter in a forum, where people are going to painful lengths, in order to run the HQPlayer at full capability.

 

However just my short point of view: I did only use the GTO once I got the Pro iDSD, however after sneaking here into this forum and one guy recommending to try upsampling to DSD with the HQPlayer I became curious...Now I even changed my roon core to a wintel machine, so I can run native  DSD512, which the Mac cannot.

 

I do not know how they do it, but some of the filters in HQPlayer do sound really fantastic and better to my ears, as coming out of the computer in 44,1kHz (or upsampled) and then upsampling only in the Pro iDSD with the GTO filter (or other filters of the iDSD) applied.

 

The different filters in the HQPlayer do sound different and very much like briefly described by the developper. I can distinguish this on my set-up in a reproducable way.

 

What is the truth and what is not: I think it shall be allowed, what makes it good for yourself, but since we are naming us audiophiles it should be within some practical tolerance window, in order to ensure quality reproduction, which I believe there will be a wide range of opinions for. 

 

I was also thinking about a suitable analogy: How about processing pictures or video content with suitable software. Is it closer to reality thereafter or just better for us to see, recognize details and enjoy ?

 

You put tubes into the DAC, which is very nice for getting a relaxed sound - and we can choose it, if we like it -, but after switching onto these you do not need to discuss any longer about differences coming from the different upsampling filters, the sound alterations coming from the tubes are bigger than that.

 

The Pro iDSD is also a super DAC when fed with native DSD512, without any further processing before conversion, and we do also have the GTO and the conversion to DSD1024 inside, so we can choose - perfect.

 

Now we are waiting for the MQA support.

 

....