Hi. If you see post #1050 and #1052, would be very neat if you could also run the same dB test, along with posting your speaker sensitivity and distance from the speakers etc.Hello all, first post.
I've owned the M33 for a year now and I've experienced similar issues with the gain, I've tried to solve the issue with the support but after a lot of email exchange we did not find a root cause for the problem.
My observations is also that with Dirac and tone control enabled at the same time the loss of master gain is the most significant I've ever experienced with an integrated amplifier. I own a Marantz SR6013 which I've used with Audyssey and an Icepower 1200 and never experienced such a gain reduction while using the different features.
I've also experienced that after some Dirac calibration there is additional gain loss depending of how much Dirac corrects the original speaker measurement and changing the dirac correction filter to follow the original improves slightly the available power on the master gain. Unfortunately turning Dirac off doesn't seem to restore the gain to factory settings, nor performing a simple factory reset in my case. I usually have to perform a full firmware installation via USB to get back to an acceptable master volume level.
Using Dirac seems to trigger the gain issues in my case and I always end up reverting to factory settings. I don't really need Dirac since I've a dedicated room optimised for music but I do appreciate the additional control provided by Dirac on Bass.
I mostly use Tidal (connect) as my source and I've been trying to understand how Tidal loudness normalization works in combination with Bluos track and Album gain in order to find out if some settings combination can add another handicap to the master gain. I've found this interesting article but I don't know yet if this is affecting gain management on the M33.
Tidal has adopted the loudness recommendations of Eelco Grimm, HKU University of the Arts Utrecht and Grimm Audio, for its music streaming services.audioxpress.com
I'm still very happy with the M33, the sound quality is the best I've experienced so far, It's a beautiful integrated amp. I was glad that I could use the balance control with Dirac after going crazy trying to achieve a centered image in my setup (always to the left). The recent fix of the tone controls finally makes it usable (without Dirac). It's just annoying that the software can have such a negative impact on the sound in some cases. Gain management is still a mistery to me, it's normally loud on POP, but on classical music or songs with high dynamic range I also end up turning the volume to -15db and with Dirac enabled this doesn't leave a lot of margin for a close to realistic listening experience.
Well, the guy from the HiFi shop suggested that it may be due to both the volume wheel being more linear than usual, combined with the fact that the amp has very low distortion (so loud listening doesn't trigger that earache you get from cheaper amps). I don't know - max volume has been enough so far, even with Dirac on, but for very dynamic pieces, like classical, it's only just enough. With my old NAD C375BEE, I had the volume wheel at max 40% when listening to classical music (with peaks well over 100dBa). About the same volume as 80% (where 90% is max with Dirac) on the M33. Though, I never tried cranking the wheel all the way, since it's less powerful than the speakers and would blow some expensive nautilus tweeters. For other music genres, I usually stop at between 65-75%, since the loudness war has killed just about all dynamics in modern music.
In your case, with Dirac and tone controls enabled, the loss should be around -17dB in theory - that's definitely a whole lot.
Overall I am happy with the sound too, except when listening to rock and metal. The snare drums sounded magical on the C375BEE, for some reason. No doubt it colored the sound somehow, to my liking.