Yesterday, along with 3 other friends, we had the opportunity to try out the QRONO d2a in a listening session that lasted about three hours. We used the Lumin P1, which belonged to one of the friends.
I’ve read some comments from people who don’t perceive the difference with the QRONO filter active. The key to hearing the differences lies in knowing what to look for.
The filter effectively and audibly eliminates the ringing produced during the conversion process. Just listen to a guitar or any impulsive signal to clearly notice a “smear” left by the transient, which is eliminated as soon as QRONO d2a is activated.
The effect is truly sensational and is audible across the entire frequency spectrum, including the low end which, with the filter active, sounds cleaner and less resonant. Perceiving the differences might be easier with a fairly rhythmic electronic music track; during complex passages with many instruments, a “haze effect” is generated which disappears when the filter is active, making all instruments more outlined and intelligible.
Another striking difference is in the soundstage reconstruction. It shifts from a very wide and holographic stage (extending even behind and all around the speakers) to a reconstruction that is more frontal, precise, and stable with the filter active. The change is so noticeable that a new speaker fine-tuning might even be necessary to restore some soundstage depth. A more in-depth analysis is needed, but since I no longer have the P1 available, this won’t happen anytime soon.
During the test, I also made some comparisons between the P1 and the Mola Mola Tambaqui, the latter used via the Ethernet input. The Tambaqui produces an even more holographic and ‘material’ sound, at the expense of a certain “weight” in the mid-low range, which it gains when using an external streamer (like I did in the past with Auralic Aries S1 - now sold - you know why).
With my ears “tuned” to look for the negative effects of ringing, it immediately became clear that the Tambaqui seems immune to this phenomenon; evidently, its sophisticated proprietary conversion system must have accounted for it. Timbrally, the Tambaqui is more rigorous and neutral, while the Lumin is warmer and has a slight emphasis on the midrange. Very pleasant indeed.
In short, I would say that QRONO d2a genuinely impressed me. I consider it a must-have for all Lumin owners, as it effectively solves the inherent timing issue of the Sabre DAC Chips. I will find it truly difficult to listen to a Sabre-chip DAC without this function activated in the future.
QRONO d2a will give you the awareness that you’ve solved a problem you didn’t know you had.
Regards,
Giuseppe
P.S.
I have few questions for Peter. @wklie
I’ve noticed that the P1’s display shows the filter status, but I’ve observed differing behaviors.
When the Lumin is set to full MQA decoder mode and QRONO d2a is ON:
- MQA source file ==> The display shows “MQA Studio” and seems to disable the QRONO filter.
- PCM source file ==> The display correctly shows “Qd2a < PCM 44.1 kHz 16bit”.
However, when using Roon and letting Roon perform the first MQA conversion (the first unfolding), the QRONO filter on the Lumin remains active. This suggests it’s being applied even after the initial MQA software unfolding.
I have two questions:
- How exactly does the QRONO filter behave when an MQA source is playing?
- Roon currently has no visibility into whether the QRONO filter is active or not. Do you think it would be possible to implement a mechanism to display the filter status in the Roon signal path? I recall that Roon was able to correctly detect and report when I had enabled the upsampling function on an Auralic streamer, for example.
Thanks!