Issue with Moon 390 and 330A: Fuses blowing while adjusting volume in Roon (ref#8GUQ04)

What’s happening?

· Something else

How can we help?

· None of the above

Other options

· Other

Describe the issue

Beginning of June (2nd I think) I posted this message:

I said within seconds but thinking about it, it was within a second that the fuses blew and it happened while I was adjusting the volume in Roon. The sound was very distorted and full volume. Thankfully there was no more damage than the blown fuses.

Can you help me regain trust in Roon?

Describe your network setup

Router KPN experia 10 (WiFi disabled), LinkSys MX4000-series for WiFi, D-link switches. Moon directly connected to switch, Roon (on NUC) connected via another switch.

This appears highly unlikely, both that high volume blows the fuses in the power amps and that Roon runs havoc and presents full volume to the preamp.

How are your setup configured? The 390 runs Mind2 i suppose, have you set volume adjustment as device controlled, software or disabled?
I.e. do you also use the remote control to adjust volume?

And why would Tidal be more reliable, do you utilize volume differently there?

Please also describe your speaker setup. It is unprobable that a pair of 330A’s would blow fuses based on full volume, unless theres a serious mismatch/misconfiguration? They are run bridged, right?

Hello Mikael,

Thanks for your very fast response!
The 390 is fully updated and I use Mind2. I usually adjust volume within the app I am using at the moment i.e. Roon, Moon, Tidal or even Spotify. Sometimes, when I don want to turn on the iPad, I use the remote to control the 390.
It might be a coincidence but the deafening noise lasted for a brief period and then all was silent… After disconnecting speakers and 330’s all I found were the blown fuses in the 330’s after which all, thankfully, worked without problem again. As I was using Roon at the time to adjust the volume, I assumed Roon was to blame but that is an assumption.
As my confidence grows again I will slowly start using Roon again with the remote for the volume and hope all keeps on working as good as I was used.

Were you adjusting the volume in Roon while this incident took place?

And please show us how you configured Roon to manage volume?

This actually sounds like a disturbance on the power grid, rather than a software issue. Any neighbours experienced similar anomalies?
(other that your systwm going berzerk!)

Hello Mikael,

Wow, impressed by your fast responses!

Please see attached screenprint for volume-settings (I hope this is what you mean).

I doubt if it was a power-glitch as all other electronics (NAS, PC etc.) gave no problems at all and power to the Moon setup is via an Audioquest Niagara 1200 Power Conditioner.



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Thank you, i just happened to browse the forum frequently today! And, to clarify, i am not a Roon representative, just a fellow user. (Who happens to run Moon hardware also, though only rarely with Mind2)

Thank you for your info, it helps Roon @support to log, identify and hopefully explain the happenstance.

I have yet to hear of any other incident like this with Simaudio hardware. Are you on latest firmware in the 390 and Mind2-module?

Ah, that explains it :wink: My nephew suggested me to post my question here and be patient because Roon support will answer but it might take some time. Thats why I was so impressed by your fast response…

As far as I know I am fully up-to-date with the firmware (I regularly check this). I sometimes read about unexplained volume-changes by Roon so I thought this might also be the case.

Will patiently wait for Roon support to reply. Anyway thanks for your time!

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A smart nephew :+1: :slight_smile:


Hi @J.H_van_Heteren,

Thanks so much for writing in and sharing your report!

In the future, please share any similar reports directly to our Support channel so our team can get notified (I hope you don’t experience anything similar and therefore won’t have to share any new reports, of course)!

We’ve enabled diagnostics from your Roon Server to take a closer look into what might have happened in the background. We’re hoping the report will date back far enough to cover the event - I will follow up with more information either way, once our team investigates. :pray:

Hello Benjamin,

Thanks for reply. Hope will have no more issues with Roon but if I do have them, I will it in the Support channel.
I turned on the Roon-NUC as I always turn it off when not in use…

Hope you find something or that it was an one-off issue…

Hey @J.H_van_Heteren,

We were able to pinpoint the issue from your Roon Server logs - I’ll share the snippet specifically:

Trace: [Simaudio MOON 390 @] [raatclient] GOT [5] {"action":"Changed","status":"Success","controls":{"source":{"is_standby_supported":true,"info":{},"value":"selected"},"volume":{"min":0.0,"type":"number","max":80.0,"step":0.5,"mute":false,"info":{},"value":8.0}}}
Trace: [Simaudio MOON 390 @] [raatclient] GOT [5] {"action":"Changed","status":"Success","controls":{"source":{"is_standby_supported":true,"info":{},"value":"selected"},"volume":{"min":0.0,"type":"number","max":80.0,"step":0.5,"mute":false,"info":{},"value":80.0}}}

The important piece here is the “value” at the very end of the log, in combination with the ‘GOT’ trace. This tells us that something sent the command to Roon to push the volume to max. So we can confirm in this case that Roon was not the culprit behind sending the volume adjustment.

Unfortunately, I’m not able to give you any additional insight into what specifically sent the command, outside of it relating to your Moon 390 device.

As an extra precautionary measure for the future, we do have volume limits you can set - here’s more info:

I hope this gives you a bit more to chew on!

Goodmorning en thanks for your fast response and analysis. As I was using the Roon app on mij iPad (both fully up-to-date) at the time, I still suspect a Roon software glitch.
Anyway, as suggested by mij Moon dealer I already updated the volume limits so I hope this will never happen again.

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