Meitner MA3 Integrated D/A processor Associated Equipment

Sidebar 2: Associated Equipment

Digital sources: dCS Rossini SACD/CD transport, Rossini DAC, and Rossini Clock; EMM Labs DV2 Integrated DAC; Synology 5-bay NAS 1019+; Roon Nucleus+ music server with HDPlex 200 linear power supply; Uptone Audio etherRegen, Small Green Computer Sonore opticalModule, TP-Link gigabit Ethernet media converters plus multimode duplex fiberoptic cable (2), Linksys routers (2); Small Green Computer linear power supply & Small Green Computer/ HDPlex four-component, 200W linear power supply (3); external hard drives, SSD USB sticks, iPad Pro; Apple 2017 Macbook Pro computer with 2.8 GHz Intel i7, SSD, 16GB RAM.
Preamplifiers: Dan D'Agostino Momentum HD, darTZeel NHB-18NS.
Power amplifiers: Dan D'Agostino Progression M550 monoblocks.
Loudspeakers: Wilson Audio Specialties Alexia 2 with Wilson Acoustic Diode footers.
Cables: Digital: Nordost Odin 1, Odin 2, and Valhalla 2 (USB and Ethernet); Frey 2 (USB adapter); Wireworld Platinum Starlight Cat8 (Ethernet), OM1 62.5/125 multimode duplex fiberoptic cables. Interconnect: Nordost Odin 2. Speaker: Nordost Odin 2. AC: Nordost Odin 2, AudioQuest Dragon, Dragon HC, and Thunderbird. Umbilical cords for HDPlex LPSs and NAS: Ghent Audio Canare and copper.
Accessories: Grand Prix Monza 8-shelf double rack & amp stands, 1.5" Formula platform, Apex footers; Nordost QB8, QX4 (2), QK1, and QV2 AC power accessories, QKore 1, 3, and 6 with QKore Wires, Titanium and Bronze Sort Kones, Sort Lifts; AudioQuest Niagara 5000 power conditioner & NRG Edison outlets & JitterBugs; Tweek Geek Dark Matter Stealth power conditioner with High Fidelity and Furutech options; GreenWave AC filter; Ansuz Darkz T2S resonance support feet; Wilson Audio Pedestals; IsoAcoustics Orea footers; Stillpoints Aperture panels; Resolution Acoustics room treatment; Stein Music Super Naturals, Blue Suns/Diamonds, Quantum Organizer; Bybee Room Neutralizers; Absolare Stabilians; Symposium Ultra Platform; Marigo Aida CD mat.
Room: 20' L × 16' W × 9' H.—Jason Victor Serinus

Meitner Audio
119–5065 13th St. S.E.
Calgary, Alberta
Canada T2G5M8
(403) 225-4161

Archimago's picture

Interesting results John and thanks for Footnote 2.

Curious if over the years you have an idea of how this IDAT filter routing works in the modern DACs. Given the age of the technology (since 1993), if it's similar in implementation, it likely isn't anything complex.

I wonder based on these measurements if all it is is a detection of when you're just sending the DAC a single sine tone like the 19kHz, 1kHz, and 50Hz 0dBFS measurements. It then implements a steep FIR in order to achieve that -120dB image suppression as shown in the 19kHz graph.

Anything else more complex like the 19+20kHz CCIF (Figure 12, which is still very much "continuous") will just be treated with what basically looks like a straight forward linear interpolation resampler.

Related to this is the question of the latency between switching filters. Most of the time it must be just using the linear interpolation. And on the occasional time when it detects a constant tone, it then switches to the steep FIR filter. I wonder how many cycles it takes to detect and switch!? Would be very interesting to know within a piece of music just how frequently this filter switching takes place (if even ever in real music!).

Soundguy123's picture

Good questions Archimago!

The fact that “complex” music (nothing complex about two test tones 1KHz apart) is processed with a very leaky filter is indeed concerning. Although the in band IMD isn’t at very worrying levels one can’t help but be concerned about such strong non-music related signals aliased ghost images passing through the D to A conversion stage.

The philosophy of IDAT seems odd - use of an IIR filter will add phase issues. As everyone should know, a linear phase FIR filter is the best and most accurate approach despite a small overall computational delay. A delay is only of concern in live music - so FIR filters dominate consumer playback. Today there are much easier mathematical ways to get round the brick wall filter in band issues (upsampling for example, can help push the filter further away from the in band signal producing excellent in band phase).

That said MQA deliberately messes up in band phase by adding group delay at higher frequencies and MQA claim this form of added distortion is somehow a more accurate conversion….

An intelligent discussion of simple first or second year university physics/engineering time series analysis is it seems no longer possible… even major audio chip designers like Sabre have implemented filter solutions that are intentionally distorting the conversion process….

Mathematical rigour seems to be in short supply these days…but no shortage of arm waving!

Of curiosity - could the rumoured interest by DJ’s in Meitners MA3 converter be simply related to live production - the DJ may prefer an IIR fast filter in order for adjustments to sound to be instant rather than appearing after a slight delay?

Indydan's picture

Would it be possible for JVS to write just one review in which he doesn't dry hump MQA? Geez....

Jason Victor Serinus's picture

for Jason to state his honest feelings about MQA without some people feeling the need to oppose his viewpoint?

ayang90's picture

Thanks for the review of the MA3. I am in the process of looking for a new Roon ready DAC and a quality MQA implementation is important to me. Definitely going to audition the Meitner MA3.

Lonestar166's picture

Thanks for the excellent review. Loved the footnotes about the Cadillac and the Rambler. I remember them both. My grandfather, a one-armed vet, had a green Rambler with a white roof.