I'm seeing my Marantz MODEL 40n's signal path change from Lossless to Enhanced, with "Sound United DSP" / "Device Sound Mode: Stereo" showing as the active stage. I think this started after I updated to Roon 2.70. Nothing has changed on the amp itself in that time.
What I've already checked and ruled out:
MUSE: all filters removed, all toggles off (parametric EQ, crossfeed, volume leveling, balance, headroom management, sample rate conversion, speaker setup) HEOS app: no EQ, sound mode, or DSP-related setting that would explain this Source Direct: enabled on the amp (this only affects the analog tone stage, not network streaming) Firmware: HEOS app reports "Firmware Current" Source of material: tested both Qobuz streaming and local library FLAC files — same result in both cases, so this isn't specific to the streaming service
Setup: Roon Server running on Windows 11 PC, Marantz MODEL 40n connected via Roon Advanced Audio Transport, output confirmed as Stereo speakers.
Given the timing lines up with the 2.70 update rather than anything on the amp, and the issue is consistent across both local and streamed sources, I'd appreciate it if you could check whether this is a known/reported issue, or take a look at what might have changed in how Roon reads/reports the 40n's signal path.
Same on my Cinema 60 and no way to change when in ROON ready playback. Initiallly I had direct set as my prefeered setting on the AVR - I changed this to PURE DIRECT on the HEOS app when playing direct from TIDAL (I’m sure you can select sound mode on the 40N front display as well) and this showed Sound United DSP as Device Sound Mode Pure Direct and then I changed to Direct and that that then was reflected on the Signal path correctly. I think this was the result of a HEOS update that downloaded this week. ROON is merely reflecting the setting in the AVR I think, but why it defaulted to stereo rather than what I actually had set, I don’t know …
Thanks for that response. HEOS doesn’t have any EQ or Direct settings for the Model 40n afaik. The amp is set to source direct via the front panel though toggling it makes no difference to the signal path being ‘enhanced’ or not.
I assume that it’s just a different way of how the amp is being reported in the app but it’s not my preference to see it in this way.
Just checked on the path showing for my M4 which is more analogous in having only the two filters which are controlled in the HEOS app - similar to the 40n, according to the manual. I seem to show 2 Sound United DSP processes. This may be truthful but not clearly informative- and I personally don’t think is an improvement. Not sure if this is a ROON or a HEOS decision!
Thanks for checking. From my side, this is a change of status, not a new disclosure of something that was always there. Same setup (Source Direct on, no MUSE processing, tested both local FLAC and Qobuz) consistently showed Lossless before something updated, and Enhanced afterward, with nothing changed on the amp side.
Peter’s post above suggests this may actually trace back to a HEOS-side update that changed how/what Sound Mode is defaulting to, which Roon is then accurately reporting so the honesty of Roon’s reporting isn’t in question, but something upstream (the amp’s reported Sound Mode) does appear to have changed rather than always being Enhanced.
It’s shown enhanced the Marantz players for a while, probably since ROON ready certification. I was surprised when I found the specific setting was not that which was actually set on the AVR (but it easily corrected) and the two Sound United DSP steps with rather uninformative labeling may actually be new - I don’t usually check. HEOS did some interesting things in a firmware update this last week.
Someone on Reddit found an official D&M Holdings firmware archive in Japanese, though it turned out to cover the AV receiver line rather than the 40n. Tracked down the correct one for the Hi-Fi/network component line instead (used AI to help parse/translate it): https://my.ebook5.net/soundunited/MZ_update_hifimini/
The 40n went from firmware 3.88.532 to 3.139.173 in an update that rolled out July 22 to August 5, right in the window I first noticed this. Confirmed via HEOS that I’m on 3.139.173.
The officially listed changes are narrow (TuneIn repeat bug, Qobuz Connect dropping mid-track, an unclear error message during Qobuz playback, Qobuz Connect connection failures. Nothing about Sound Mode or DSP reporting). But it’s a big version jump (88.x to 139.x), so I suspect it pulled in broader platform changes that weren’t itemized which would match what you said about HEOS doing interesting things recently, and would explain the new Sound United DSP step appearing.
So sounds like this wasn’t a Roon change after all, but a HEOS firmware update landing in the same window and with no Sound Mode setting exposed anywhere on the 40n, there’s no way for me to correct it the way you could on the Cinema 60.
Exactly - that’s a great resource I had been searching for full info on the firmware as it managed to impact my nextRHEOS app version by fundamentally altering the G-streamer behavior (the underlying HEOS engine). Nothing I could find in the English speaking world to document this (for me a lot of work - the change here is inconsequential).
The top entry is happening right now. The 2026/7/22 – 2026/8/5 rollout is mid-flight as of today, pushing HEOS module 3.139.173 to essentially the whole Hi-Fi Mini lineup. Marantz staggers these deliberately, so your speakers may be on different versions for the next few days — which is exactly the kind of thing that makes a bridge behave inconsistently across zones for no apparent reason. If something starts acting up, check the version on each unit (HEOS app → Setup → Help → System Diagnostics → Information) before you go spelunking through your own code.
