Indeed, the Holo Red has its own USB isolation between it and whatever comes before it (e.g. PC). Here, there is a USB connection between the Holo Red and Marantz SA10. Assuming by default that the USB card in the Marantz does not have galvanic isolation, there may be some benefit by inserting a USB isolator in that connection.
Does this FIIO now count as being fully native DSD after this recent update.
TLDR is
- K11 R2R new firmware M79, now supports 1bit DSD native decoding!
Since its launch, the K11 R2R’s 24bit R2R DAC sound quality has received widespread recognition and praise. We sincerely appreciate your support.
After release, we maintained close communication with users and received requests about implementing DSD native decoding on the K11 R2R. Through relentless efforts by our engineers, the K11 R2R now achieves 1bit DSD native decoding! Interested users can upgrade firmware to experience this (Note: the K11 R2R doesn’t support OTA upgrades. Please download the upgrade tool on the PC for manual upgrade). We would like to receive your feedback on the listening experience after trying the new firmware
That’s not about the topic of this thread (at least as I understand it). The name of this thread causes confusion.
From the link you posted: “Rotate the knob to switch the settings menu DSD DOP to DSD 1Bit.”. From that sentence it is clear it is about supported USB transfer mode of DSD data (DoP vs. native) but not about internal direct DSD path.
See more explanation for example here: Which DACs bypass digital filtering? - Page 34 - DAC - Digital to Analog Conversion - Audiophile Style
Is someone here using the Denafrips Pontus 15th with HQplayer ? And is it glitch free ? No clicks , pops , crackling no need to restart the unit and all these type of things. 
Or is the Holo Cyan 2 still a better more affordable option?
Have you had a chance to look at/listen to a FiiO k11 R2R with the 1 bit playback firmware installed?
Clearly it’s not just me that is confused in that case as I can see @Rugby asking about the same thing.
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Hi Michael,
I’m not confused, at least I hope not. If you read the documentation, the firmware update is about decoding 1 bit DSD, not USB transmission changes. I am curious to hear Jussi’s take on what this is doing and if he has had a change to test it, or, will be testing it.
If anyone is unclear they should read the section in the document (which Michael provided a link to above) called " 2.2 Working principle of 1bit DSD native decoding" which the firmware is enabling.
quote:
When the input signal is DSD and the menu is set to 1bit mode, the R2R network functions as an FIR filter, sequentially processing the DSD signal, effectively acting as an FIR-DAC.
this definitely reads very interesting
From the Chapter 2.2 - two citations:
- “If the input signal is PCM or DSD operating in D2P mode, the R2R network functions as a voltage divider.”.
The term ‘D2P mode’ is used for DSD to PCM conversion.
- “The specific working principle is as follows: The weight of each bit is exactly half of the previous bit.”
That clearly reveals binary weighted signal representation. They are still mentioning bit so this happens still in digital domain. DSD signal is unary weighted, weight of each bit is the same and there is no “byte” of any length defined. For DSD signal input, binary signal representation without format conversion is not possible. But then that’s not direct DSD path as we usually think of it.
I didn’t believe you were, not was I (too) confused either having read the post and instructions the day before
I was tempted to get one to use with HQPlayer, hence my post . It was already a neat device before this.
The explanation was more complicated though than my ability to fully comprehend, hence my throwing it to smarter people over here 
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I found a FiiO link which clearly explains D2P mode as DSD to PCM conversion: 19. The difference between DoP mode and D2P mode of X3 2nd gen's SPDIF Out-FIIO---BORN FOR MUSIC
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So you burst my bubble with that one 
It is CS43198 DAC chip, so it is a pure delta-sigma DAC, not related to R2R by any means.
This chip from conversion stage point of view is same as the old CS4398 which I’ve used in some of my design in Direct DSD mode (and can be found also from Marantz HD-DAC1 which I’ve had for ages). In the CS43198 incarnation they’ve updated the DSP front-end. Maximum it can do in direct mode is DSD128.
Overall, the chip works nicely in direct mode if the analog stages are properly implemented. But this device is not something I’m planning to purchase with my limited budget.
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K11 has R2R edition too Desktop DAC and Headphone Amplifier-K11 R2R
The link @Michael_Harris posted is related to K11 R2R edition.
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OK, I don’t know about that one…
But what you described sounds like a very rudimentary 2nd order moving average filter.
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