Why does my M Scaler give no output with native DSD?
Short answer
In October 2018 Watts said native DSD works on the Hugo M Scaler with Roon and JRiver, but the SR OP switch must be set to white "otherwise it will be silent as an OP" Head-Fi, Oct 2018. In March 2019 he explained that DSD is converted to 705 kHz PCM, and "the only way of outputting 705k is via the dual BNC" Head-Fi, Mar 2019. When one owner's unit showed digital silence, he pointed at the source not transmitting the DSD file Head-Fi, Oct 2018.
The practical answer
Every relevant statement in this archive is a Rob Watts Head-Fi post, from 2018 to 2022, and all but one are about the Hugo M Scaler Head-Fi, Oct 2018Head-Fi, Jul 2022. No recording or article in this archive covers the silent-output problem.
Check the output switch first. On 25 October 2018 he wrote that native DSD "works fine with Roon and JRiver on the M scaler" and that "the native DSD uses Dave code" Head-Fi, Oct 2018. He added: "You must set the SR OP setting to white on the Hugo M scaler, otherwise it will be silent as an OP" Head-Fi, Oct 2018. His stated reason was that "native can't be TX as an SPDIF directly" Head-Fi, Oct 2018.
Use the dual BNC outputs. On 8 March 2019 he explained that the M Scaler's DSD filter is a DSD to 705 kHz PCM converter: when DSD is detected, the signal is converted and sent to the rest of the M Scaler "as if it was an original 705 kHz PCM signal; and the only way of outputting 705k is via the dual BNC" Head-Fi, Mar 2019. In May 2018, in the Dave thread and before the Hugo M Scaler's July 2018 launch, he wrote that "this conversion in the M scaler is done by the new Hugo 2 DSD filter, so it always outputs 705.6 kHz PCM from DSD64-DSD512" Head-Fi, May 2018; the post also mentions Blu 2 and does not say which M scaler it means. A September 2018 Dave-thread post says the switch is labeled OP SR, that white is "the full 705.6/768 1M taps" setting, and that "only white enables the dual data mode, all the others are single data mode with one BNC active and the other disabled" Head-Fi, Sep 2018. Read together, these posts point to white plus the dual BNC connection as the route DSD takes out of the M Scaler. He did not state that combined rule in any single post.
If you see digital silence
On 30 October 2018, answering a poster whose question is not shown in the post, he wrote that the problem "lies with the source, in that it is not transmitting the DSD file", reading the change from red ("default 44.1kHz on USB") to black as meaning the unit was digitally silent Head-Fi, Oct 2018. He also wrote "I have fed this back to Chord, and we are puzzled", because Roon works with the M Scaler on DSD and its USB has "identical drivers and USB firmware to Dave" Head-Fi, Oct 2018. The post gives no fix and does not name the poster's source.
By setup
- M Scaler over the dual BNC outputs, switch on white: this is the arrangement his 2018 and 2019 posts describe for DSD Head-Fi, Oct 2018Head-Fi, Mar 2019Head-Fi, Sep 2018.
- An output other than the dual BNC: in the March 2019 post, replying to an owner whose setup the post does not show, he said that with hindsight he "should have muxed (that means switched) the DoP signal through to the OP's in the case of this instance" Head-Fi, Mar 2019. He said this was not done because the input could be native DSD, which would need repackaging as DoP for a non-Chord DAC that "almost certainly would not support DoP via SPDIF anyway", and called himself "guilty of being 705/768k centric" Head-Fi, Mar 2019. The post does not say whether any setting or later firmware changes this.
- Hugo TT2: in the same post he told that owner that upgrading to a TT2 "will solve this issue" Head-Fi, Mar 2019. He did not say how.
Which DSD formats
On 11 July 2022 he wrote that DSD handling on the M Scaler is "identical to Hugo 2 and TT2", converting to 705 kHz 24 bit, and that "It will work with DSD64, 128, 256 and DSD512 (512 is via USB using native mode protocol and ASIO on Windows)" Head-Fi, Jul 2022. In February 2022, in a post about Chord's USB in his Watts Up thread, he wrote that "DoP DSD is fully supported up to DSD 256 with Linux and macOS" and that DSD 512 (native DSD transmission) is "limited to Windows via ASIO" Head-Fi, Feb 2022. That post does not tie the limits to one product. Neither post addresses the silent-output symptom.
What he has not said
- He has not given a step-by-step troubleshooting list for a silent M Scaler.
- His latest post in this archive on the silent-output behavior is from March 2019 Head-Fi, Mar 2019. This archive does not show him saying whether any firmware update changed it.
- His October 2018 instruction about the white setting names native DSD Head-Fi, Oct 2018. His March 2019 post covers detected DSD in general and mentions the DoP signal, but does not mention the switch Head-Fi, Mar 2019.
- He has not said why the October 2018 poster's source stopped sending the DSD file Head-Fi, Oct 2018.
Quotes
“You must set the SR OP setting to white on the Hugo M scaler, otherwise it will be silent as an OP”2018-10-25 Head-Fi, Oct 2018
“the only way of outputting 705k is via the dual BNC”2019-03-08 Head-Fi, Mar 2019
“only white enables the dual data mode, all the others are single data mode with one BNC active and the other disabled”2018-09-05 Head-Fi, Sep 2018
“This indicates that the problem lies with the source, in that it is not transmitting the DSD file”2018-10-30 Head-Fi, Oct 2018
“It will work with DSD64, 128, 256 and DSD512 (512 is via USB using native mode protocol and ASIO on Windows).”2022-07-11 Head-Fi, Jul 2022
Dated positions
| When | Products | Position |
|---|---|---|
| 2018-05 | Blu Mk2, Hugo M Scaler | In a May 2018 Dave-thread post, before the Hugo M Scaler's July 2018 launch and in a post that also names Blu 2, he wrote that the conversion in 'the M scaler' uses the new Hugo 2 DSD filter, so it always outputs 705.6 kHz PCM from DSD64 to DSD512; it does not say which M scaler. Head-Fi, May 2018 |
| 2018-09 | Hugo M Scaler | The OP SR switch: white is the full 705.6/768 setting and is the only one that enables dual data mode; other settings use one BNC. Head-Fi, Sep 2018 |
| 2018-10 | Hugo M Scaler | Native DSD works with Roon and JRiver, but the SR OP setting must be white or the output is silent, because native DSD can't be transmitted as SPDIF directly. Head-Fi, Oct 2018 |
| 2018-10 | Hugo M Scaler | In one owner's case of digital silence, he attributed it to the source not transmitting the DSD file, while saying Chord was puzzled because Roon works with the M Scaler on DSD. Head-Fi, Oct 2018 |
| 2019-03 | Hugo M Scaler, Hugo TT2 | Detected DSD is converted to 705 kHz PCM, which can only leave via the dual BNC; with hindsight he should have switched the DoP signal through to the other outputs; for that owner, a TT2 would solve the issue. Head-Fi, Mar 2019 |
| 2022-07 | Hugo M Scaler | DSD handling matches Hugo 2 and TT2; DSD64, 128, 256 and DSD512 work, DSD512 via USB using native mode and ASIO on Windows. Head-Fi, Jul 2022 |
| 2022-02 | General | On Chord's USB generally: DoP DSD up to DSD 256 on Linux and macOS; DSD 512 native transmission limited to Windows via ASIO. Head-Fi, Feb 2022 |
Caveats and open points
- Every source is a Head-Fi post; this archive has no recording or article on this symptom.
- The combined rule (white setting plus dual BNC for DSD) is read across several posts; he did not state it in one post.
- His latest statement on the silent-output behavior is from March 2019; this archive does not show whether later firmware changed it.
- The CanJam London 2018 transcript statement that USB handles DSD up to 256 is the presenter's, not Watts's, so it is not used.
- Head-Fi, May 2018 (May 2018) predates the Hugo M Scaler's July 2018 launch and also names Blu 2, so it does not say which M scaler it means; the March 2019 post (Head-Fi, Mar 2019) states the DSD behavior for the Hugo M Scaler.
Topics: DSD: playback and DSD vs PCM, M Scaler and Quartet settings and operation, Dropouts, clicks and lock problems