Schiit Modius ticking/clicking noise via Toslink/Coax — Grounding or reclocking issue?

[andlum]

TL;DR:
Getting a steady ticking/clicking noise from my Schiit Modius — only during playback, not silence. Most noticeable via Midgard + Arya, also faintly present via Saga 2. No issues with vinyl, Node’s internal DAC, or my active speakers.

Suspect lack of USB grounding on Modius when using Toslink/Coax causes clock instability.

Considering iFi iPower2 + iDefender+, Tomanek ULPS Mini, or battery-powered USB supply.

Looking for others who’ve had this issue — or solved it.


Hey everyone,

I’m trying to isolate a persistent clicking/ticking noise that occurs during playback when using my Schiit Modius DAC. The ticking is rhythmic, only present while audio is playing, and does not occur in silence.

It’s especially noticeable when listening over headphones (planar), but it seems the source of the issue is the Modius itself — not the amp or cans.


System setup:
Analog chain:

• Turntable: Technics SL-1200GR
• Phono stage: Lindemann Limetree Phono 1
• Preamp: Schiit Saga 2
• Output: RCA to Midgard, XLR to Neumann KH120 II

Digital chain:

• Streamer: Bluesound Node N130
• DAC: Schiit Modius
• Inputs tested: Coax (Mogami 2964), Toslink
• Output: RCA to Schiit Midgard headphone amp
• Headphones: HIFIMAN Arya Stealth

Power setup:

• Everything (except Modius) is connected to a Black Lion Audio PG-P Type F power conditioner
• Modius powered via USB-C to Micro-USB wall adapter (not connected to a computer)

What I experience:

• Clicking/ticking occurs only during playback, no noise in silence
• Most obvious with Modius → Midgard → Arya, but also faintly present when routing Modius into Saga 2 → Midgard
• No ticking when listening
  • To vinyl (Saga analog input)
  • Using Node’s internal DAC directly to Midgard
  • Over Neumann KH120 II monitors (from Saga 2 XLR out)

What I’ve already tried:

• Coax and Toslink → same behavior, with Coax ticking faster
• Multiple power supplies for Modius
• PG-P filtered outlet
• Physical separation of components
• Disconnected phono stage

My current theory:
Modius likely lacks a proper ground/mass reference when run via Coax or Toslink without USB data connected. This may cause clock instability or frequent re-locks, leading to audible ticks — particularly exposed by resolving planars like the Arya.

Has anyone experienced something similar with the Modius, or other Schiit DACs?

Any proven fixes? USB injectors, reclockers, galvanic isolators, etc.?

Happy to provide more details or run tests. Thanks in advance!

 

[andlum]

Update:

After some testing, I connected the Bluesound Node to the Modius via USB, and that completely solved the ticking/clicking issue. No more re-locking noises, and the Modius runs clean and stable. The problem was indeed caused by the lack of ground reference and clock sync when using Coax or Toslink without USB. Hoping this does not introduce lip sync issues with HDMI as source.

If you’re experiencing similar issues with the Modius — try USB if your source supports it!

 

[phofman]

Toslink and proper coax are galvanically isolated - no ground connection. Why should that cause some clock instability in the receiver?

IIUC only SPDIF input causes the clicking. IMO therefore either already in the SPDIF stream (the streamer issue), or caused by the SPDIF receiver, or when handling the PLL'd clock from the SPDIF receiver to the DAC.

 

[antcollinet]

the regular nature of the tick suggests to me that the Modius is failing to sync it's internal clock to the toslink/spdif - and you are getting periodic buffer under or over runs.

It could be due to cable length. What length of cable do you have between source and DAC? Does the DAC have any buffer/clocking options for clock recovery?

It might also be due to the clock in the source being out of range of the recovery PLL in the Modius. What sample rate are you using. As a test, If 44.1k (or a multiple) can you change it to 48k (or a multiple) - or vice versa)

 

[phofman]

IIUC that DAC uses ES9028 which has standard ESS ASRC. Very likely the ASRC is enabled all the time, most DAC manufacturers do that. It would be very surprising if the ASRC had problems with locking to the SPDIF receiver output.

The clicking can be already in the SPDIF signal (easy to check with another SPDIF DAC). Or the Modius SPDIF receiver looses lock on the incoming signal (which would also point at quality of the SPDIF signal).

 

[antcollinet]

IIUC that DAC uses ES9028 which has standard ESS ASRC. Very likely the ASRC is enabled all the time, most DAC manufacturers do that. It would be very surprising if the ASRC had problems with locking to the SPDIF receiver output.

ASRC also needs to recover the incoming clock.

If incoming clock recovery is not working, buffer under/over runs will result.