Metrum Acoustics Pavane DAC listening impressions

I will enumerate, based on @lehmanhill awesome post, why going I2S with the Metrum Acousitcs Pavane/Adagio is probably NOT a good idea w/o their proprietary Ambre solution (or similar):

1. No LVDS:
2. Needs inch long cable (w Pi2AES):
3. Requires buffering & reclocking:

It should be apparent from the above that the Metrum I2S interface needs life support in the form of their proprietary Metrum Ambre to work (they seem to have a proprietary RJ45 arrangement to support the interconnect - different pins for different I2S signals).

And then I further read here that the USB implementation is glitchy and fucked up *sigh*.

I don't doubt @lithiumnk impressions. But bare in mind that the setup has Metrum's Ambre "life support" system (or other such as the Pi2AES or similar). The Ambre seems to be a LAN to proprietary I2S deal. And do note that LAN payload has a shit ton of jitter and requires all kinds of regeneration (it's a packet based protocol).

Why did the Pavane does not just incorporate LAN connectivity, or support an RJ45 module directly instead of their proprietary I2S module beats me.

That said, and based on folks here, it seems it works. So life is good.

 

Though I'm always in favor of separate "boxes" for each function (streamer/SPDIF, DAC, amp, etc.), so I can get really good pieces and mix and match however I want, I do hope to see more manufacturers incorporate streaming functionality into the DACs.

You could then ensure a super short I2S path inside the DAC. And with stuff like the DigiOne Sig or Pi2AES, you wouldn't have to worry so much about if the source is good, cables, impedance matching, etc.

Speaking of, I'm pretty sure the Ambre is just a Raspberry Pi with a custom HAT and PSU all wrapped in one box. Not to downplay that necessarily, because some of the RPi HATs sound very good, but it does beg the question what secret sauce, if any, you're really paying for.

 

LOL! actually for certain things an FPGA will destroy an ARM processor in terms of speed, but it will consume shit tons more power. It's not just clock speed. It's the fact that FPGAs are HW emulators (gate arrays) and execute concurrently.

A couple of feet of cable might be ok as well, but if you are concerned about signal integrity using SPDIF, those couple of feet are not doing I2S any favors.

Also note that these I2S connectivity solutions are somewhat ad-hoc. I don't think there are I2S RJ45 standard connectors.

 

DSPs have a high degree of parallelism. And it's nowhere near that of an FPGA. Think of FPGAs as almost ASICs. You are "programming" gates. There is no PC counter or crap like that. All things "execute" at the same time.

Players need to be power efficient. Specially portables. They are the perfect market for DSPs, not FPGAs.

Yup.

 

Don’t forget to wrap each I2S wire in the thickest shielding you can (2” diameter will suffice), then put it in a silicone mold to keep it in a proper geometric shape and reduce cosmic vibrations.

 

This should put a 9" pacifier in the mouths of your Metrum I2S concerns.

Humbled like a worm, with my panties down, and with no bra, I present what only my google powers can:



That's right bitch: Wireless cables.

 

by the gawds- the impedance matching possible with that cable must be perfect and sublime under all conditions!

 

I've actually been meaning to ask if anyone has recommendations for suitable, drop-in replacements for the LL1540, which is what the Pavane uses.

No doubt they're a bit soft and veiled; A bit too midrange focused, bass somewhat indistinct. I've been thinking about swapping them out.

 

Sorry, totally shouldn't have said "drop-in replacement." I didn't actually mean one I could solder directly in place on the PCB, but rather one that would be of similar-enough specifications to work in its place.

My Pavane is basically a DIY version put together using OEM parts and a custom case. Easy enough for me to fit other transformers in the case and run wiring as needed to the PCB.

My bad, I was not at all clear when I said that.

As for subjective impressions, I've found bumping up the midrange, usually in the 500Hz-1KHz range, can give a sense of greyness. And lack of speed, punch, and incisiveness in the bass and treble can give the sense of subdued dynamics at times. So, we are probably just using different terms to describe the same thing. I've heard it too and know what you mean on the Pavane.

 

What’s the output of the Pavane? Could try CLMI600 or CMOL 2X600 from Cinemag. Can always ask David Geren there. He’s super helpful.