Would be handy to put these measurements side by side with DX7 Pro like someone did with the Sabaj unit.
That was me. I’m traveling right now but happy to put up a SMSL M500 vs. DX7 Pro comparison later in the week (and before the 11/11 sale.)
Would be handy to put these measurements side by side with DX7 Pro like someone did with the Sabaj unit.
@amirm
In a group they have done many tests with the M500. The point is that the SMSL activates the audio filters when it is in MQA and this should not happen. MQA Limited spoke about it and said the M500 is not doing it correctly. When it is MQA it must block all types of filters because what it reproduces is supposedly the original master. Please tell us if you notice audible differences in MQA, regards.
The Matrix X Sabre pro MQA is listed 1.945 €Anyone have any idea how much MQA adds to the price of the product?
The Matrix X Sabre pro MQA is listed 1.945 €
The Matrix X Sabre pro (non MQA, no longer listed in seller shop) was 1.595 €
350 € difference.
But then that's Matrix Audio high end gear.
I have not read any info on that. I can say from experience (we developed our own format which we licensed and help set prices on open standards in patent pools) that on the low side it is a few cents per device to high side of $2.50 which was the MPEG-2 video license. MPEG got away with that high fee given its dominant position in the world.Anyone have any idea how much MQA adds to the price of the product?
The M500 has for itself an unusually high max output (6.90V, same as ADI-2 DAC). If used as a preamp, it may deal with any power amp sensitivity.For those of you considering whether to buy the M500 or the DX7 Pro, the DX7 Pro has full control over which outputs (XLR/RCA/Headphone) are active: All, one, or any combination are possible. Plus the display is very clear about what's on. And it's very easy to switch using the remote. Just sayin'.
Glad to see it do so well especially the amplifier, about as good as DX3 low gain? Nice!
It's really weird though, I saw reports of people complaining about anemic XLR output? When it goes to max 6.8V?! Odd.
I suppose the output impedance is 2ohm SE and thus ~4ohm balanced?
The M500 has for itself an unusually high max output (6.90V, same as ADI-2 DAC). If used as a preamp, it may deal with any power amp sensitivity.
It's built around an ES9038PRO, so no. ESS chips use a redundancy in bit depth to avoid that problem.
Some info from roon on what they do, it's all sensible and matches what you found.So I tried this. Quite fascinating. When I turn on DSP in Roon, the "LED" indicator on M500 changes color from green to magenta. I can't make heads and tails out of the colors from either M500 manual or what they have posted from MQA:
However, I popped up the Roon pipeline with DSP on and off and got this useful information:
View attachment 37226
So what is happening is that when you turn on DSP, roon internally decodes the MQA stream. It then ups the bit depth to 64 bit, applies the DSP and then embeds the MQA flag that says this is MQA but is not the original bitstream ("ORFS"). The signal at this point is decoded PCM stream with just the MQA flag. I suspect the DAC is still allowed to upsample to 192 kHz (this content is 96 kHz so I can't test it).
I don't understand how an aliasing artefact can be larger than the real signal?By chance, I found some test tones in Tidal that are MQA encoded! They use a frequency of 375 Hz for some reason. I performed a quick comparison, streaming the Tidal MQA versus straight PCM from my analyzer to M500. Here is the comparison (at 44.1 kHz):
View attachment 37229
Everything is identical until we get near end of this spectrum (90 kHz) with a rather strong spike to -60 dB. My guess is that the gentle MQA filter is allowing an aliasing component to show up there. Not an audible thing but information nevertheless.
*average audiophile triggered*The figure 8 power cable is not as optimal as an IEC connector but does make for a lighter weight cord.
Larger? The real signal is at 0 dB (the tall peak way to the left). The aliasing component is 60 dB lower at -60 dB.I don't understand how an aliasing artefact can be larger than the real signal?
But the real signal is at 300hz or something, not high frequency, how can that leak.Larger? The real signal is at 0 dB (the tall peak way to the left). The aliasing component is 60 dB lower at -60 dB.
Indeed, you are quite right .
I appreciate very much that Amir made this measurement and found out about that huge spike artifact caused by MQA!
If people could enlighten me, there one 2 things I don't quite understand as they don't seem to be really consistent to me .
First, re. such huge ultrasonic artifacts:
- On one hand, during the fantastic TotalDAC discussion on ASR this summer ( the whole thing was so incredible that I read the 100 pages twice!, and that really motivated me to join ASR ), such ultrasonic components were found out, a few subjectivists said that it didn't matter as they cannot be heard, yet what I perceived as the "dominant", "enlightened" view an ASR was that it was really bad because it could quite negatively affect the electronics of further devices (e.g. an amp for speakers) downstream or the behavior of transducers ( tweeter, headphones).
- On the other hand, when it is created by MQA it is OK because it cannot be heard .
Second, re. apparently fraudulent marketing claims:
- When this is the case with a device such as Schiit, TotalDAC, PS Audio, it is really bad (and OK to speak of " scam ").
- With MQA it would be OK because part of the necessary marketing discourse for establishing a new standard .
Spoiler: it won't perform well.Would love to see this tested by Amir.