Schiit Modi 3+, ground hum problem?

Support
1

Core Machine (Operating system/System info/Roon build number)

QNAP TS-251+, latest Roon build

Network Details (Including networking gear model/manufacturer and if on WiFi/Ethernet)

FritzBox 6490, Ethernet

Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)

Allo DigiOne > Schiit Modi 3+ > Audio Note UK valve integrated amp

Description Of Issue

I have a problem with a new Schiit Modi 3+ DAC. I use an Allo DigiOne as Roon streaming device which is connected with Coax to the Modi 3+. Within Roon i got some sort of ground hum on the beginning of each track if I switch from an 16/44, 24/44, 24/48 track file to 24/96 HI-RES file and vice versa. If I run the Modi with USB and RPi 4 all is ok. Please someone have an advice to solve the problem?

2

What Ethernet cable do you use?

3

A normal one, nothing special…@Martin_Webster

4

Okay, I would suggest you try playing around with positioning and if possible try another coaxial cable.

5

ok, where should I place the Modi in your opinion, do you think that it could be possible that the Modi 3+ is damaged? It is really strange, because all works until I change to a track higher than 24/48.

6

Since the Modi 3+ shows no hum from USB, I’d investigate a possible ground loop or other electrical issue between the DigiOne and the Modi. Schiit DACs (I don’t own a Modi but I own/have owned others) have relays to switch sample rates, and I could imagine something weird happening with them if the signal from the DigiOne is not up to spec.

1 Like
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I think the signal from the DigiOne is up to spec, because there are no problems when using a Topping E30 DAC.

8

It could be that the Topping is more tolerant than the Schiit. Are you using the BNC output? Also, try another cable if you have one.

9

no solution yet, Roon customer support please help!?

10

How new is the Modi 3+? Have you tried contacting Schiit?

11

Have you tried to add a resync delay of a few msec on Settings>Audio>Device Setup for the DigiOne? The way rate changes are communicated in S/PDIF is different from how they are communicated in USB, and Schiit rate relays are in some cases a bit sensitive to rate change timing (speaking from experience with some older Schiit DACs, although I’ve never had this issue with my current Yggdrasil). Alternatively, either the DigiOne or the Modi may have hardware faults in their coax circuits. Either way, this is not a problem in Roon itself.

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1 week old, yes Schiit wrote they think there is a problem within Roon.

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Already if I begin with a 24/96 track I get the pop, strange.
After adding resync delay I get the pop, then the delay and then the music starts.

14

You have 15 days to return it if you are not satisfied according to them. Ask for an exchange because it is defective. If they won’t do it then return it and try something else

2 Likes
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I’ve used Roon with Schiit DACs, as well as several other DACs, via different endpoints for several years, never anything like this. I very much doubt Roon can debug this problem themselves as it seems so specific to your setup. The fact that you have no problem with the Topping DAC on the DigiOne, or with the Modi on USB, really hints as a problem with the Modi. And as I said, Schiit DACs, while great otherwise, can be a bit temperamental with respect to rate changes.

1 Like
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So, tried now Audirvana and the problem still is here. I will contact Schiit and send the Modi back.

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