Metrum Acoustics Pavane DAC listening impressions

Actually, I'm pretty familiar with both the Pavane and Onyx i2s modules. You are correct, they are quite different. The Pavane module is very simple with just RJ45 connector to resistors, the 100 Ohm impedance you mention, to the main board header. The Onyx, on the other hand is doing lots more complicated stuff. I would point out that there is no receiver, per se, in the Pavane i2s module, just resistors, so some of this is marketing.

From what Cees confirmed to Mr. Roberts, the Metrum and Sonnett i2s data is in the same format, but unfortunately not the same physical layout.

I can't speak to the singxer or denafrips, but the Pi2AES actually has two ways of delivering i2s. For PS Audio and similar, they have differential i2s over HDMI which may be the cleanest way to send i2s longer distances. For Metrum and others that use direct i2s data, the data is buffered so that it can drive longish cables and has an output impedance to match the cable, 100 Ohms if I remember correctly. I don't know of anyone who has tried 30 meter cables, but for normal cables, it does fine with Pavane and Onyx i2s. I will say that my system has sounded its best with the Pavane and the Pi2AES, but I have never compared it to an Amber.

Anyway, I just wanted to mention an option that works very well for me. Certainly, if you want to keep everything Metrum and designed in compatibility, the Ambre is a good choice.

 

Prior to going with the Ambre+I2S feed I was using AES from a Singxer Su-1. Hard to quantify, but I found the improvement of going to I2S + Ambre to be worth the cost (the I2S module is cheap - the Ambre is not). Something like a 10% to 20% improvement. Significant, but not life changing. AES via the Singxer was very, very good, but the I2S from the Ambre is better.

 

Yep, I only use the balanced connections throughout my setup with the exception of my vinyl side, so that's good to know that I was already using the better output.

I'll take a look at the pi2aes thread. I just realized my Pavane doesn't have the i2s input, however, but it sounds like an Ambre using AES would be a step up from USB regardless?

 

Were you able to swap out the i2s module in the Pavane yourself? Or is it a factory job?

 

Did it myself. It was easy enough, and I'm not very good at that sort of thing - so just about anyone should be able to do it.

 

The Ambre is great for enabling the I2S input. Pavane uses a RJ45 I2S input on the chip - not HDMI like many other devices - so you need a device that can supply I2S in RJ45. Ambre does that by design. It is Roon ready - so I connect to Ambre via ethernet and it does the magic to supply I2S to the Pavane via RJ45.

The Singxer SU-1 I use to convert USB to AES, and this is fed into the Pavane.

The improvements from AES to I2S were subtle but noticeable to my ears. Blacker background, larger and more precise soundstage, more intimate vocals. YMMV.

 

The PI2AES uses source series resistors to drive the parallel lines. This ensures little or no reflections regardless of the end impedance. The 100 ohm resistors on the metrum are simply there for terminating the line, not matching the impedance of the line. The end result is that you get a very clean, quiet signal fed into your DAC. This has been verified by several users who have a lot of experience with the metrum DAC 's and can attest to the sound quality.

 

Thanks for the clarification.
Does length of the rj45(i2s) cable matters with pi2aes ?
I am asking because according to metrum support short i2s cable is not necessary.
Ambre comes with 2 cat6 1.5m UTP cables for LAN & I2S.
What length do you recommend for pi2aes & Pavane?

 

I don't know if anyone has tested various lengths to compare performance changes. If they have I'd like to know because I went conservative and did the very short length of 1ft.

 

Length is a bit complicated is it depends on the cable parameters (total capacitance, crosstalk, leakage, etc) coupled with the series resistance and rise/fall times of our output buffer. In other words, I don't know! This is one of those times when we rely on the experience of other folks. We do know that 1 meter (~3ft) has worked for our customers who have given us feedback. So 1.5M is likely fine as well.

 

I have a Pavane arriving next week for a 30-day trial. I have just set up my PI2AES which arrived a few days ago. Prior to that I've been using USB uniquely. I am not going to buy an Ambre for a trial and I am going to assume that the L3 that's on its way to me doesn't have the I2S module (but it might), so is AES the next best thing here?

If AES is the way to go can some kind soul point me in the right direction for whatever connector I might need to make 'PI2AES -> AES -> Pavane' happen? (I own a coax SPDIF cable already so if it's not worth forking out for the AES interconnect then please let me know.)

Also, just in case the Pavane has the I2S module do I just need an HDMI cable to make 'PI2AES -> I2S -> Pavane' happen?

 

The S/PDIF connection does just fine with a good source. To be fair, I haven't compared S/PDIF to AES3 XLR, but they both use the same AES3 modulation, only that the XLR version uses higher voltages on a balanced line and so is less susceptible to outside RF noise. I'm skeptical there is much, or any, difference between them for short cable runs. I use a proper 75ohm coaxial cable for mine.

But USB sucks.

 

If you decide to go the I2S route, you’ll need the add-on for your Pi2AES which is $25 and an RJ45 cable, (the type typically used for Ethernet).

I will be comparing the various inputs (except usb) on a Pavane I recently acquired in a couple weeks or so. Need to move and then let it warm up for a bit.

I think the default is USB so you probably have that module.

 

https://www.amazon.com/dp/B0010CFQRE/ref=nav_timeline_asin?_encoding=UTF8&psc=1

 

You need RJ45 LAN CABLE to use I2S and also I2S module on both Pavane and Pi2AES. Also keep the cable short.
For AES, 110 OHM XLR cable will work.

 

I have done back to back comparisons of coax, AES (XLR), and i2s inputs to the Pavane L3. In my system, AES is definitely the best after i2s. For me, coax is good, but a noticeable step down from AES.

For i2s, the HDMI doesn't work with Metrum. There is a buffered i2s output header on the Pi2AES. If you are a DIY guy with the right parts, you cut a CAT5 cable and make something that connects directly to the Pi2AES, but most people don't want to take that on.

 

Spoiler: RCA TO XLR

Hello friends, how you doing? I was reading this old thread and I thought to improve my pavane a little bit. So I bought a I2s module, make one of those cables xlr-rca and was going to buy a great transformer from @skem. But I think I have messed something with the pavane, because after I inserted the Is2 module, none of the inputs are working. Very sad in here. Really don't know what I did. So I was looking the inside search for burned fuses and I just noticed that my pavane don't have the Lundahl transformers... hey I don't think it has any kind of transformers.... WTF????? . Already contacted Metrum acoustics, and one of their engineer about the output problem. But what do you guys think about this pictures? Where are the transforms?? Im attaching a picture from an OLDER pavane, and mine ordered in 2019.. (mine its the last picture. on man

 

Hey man, sorry to hear you are having problems.

1. Is the i2s module in the picture yours? That one says Pavane on it and is the correct one for a Pavane. The other available i2s module is a Onyx module and the Onyx module will give you no output if installed in a Pavane.

2. I don't know about the output transformers. Hopefully the new Metrum guy can shed some light on things. Things were pretty sketchy at Metrum in the later half of 2019, so it is possible they changed something.

That said, the dac output is balanced and goes to the XLR. The transformer converts balanced to single ended for the RCA. Frankly speaking, they didn't do that conversion very well. The RCA output of the Pavane with transformers is a big step down from the XLR in my opinion. Actually, I like the Onyx RCA output a little better than the Pavane transformer. Maybe they did you a solid and changed the circuit to something like the Onyx.

 

Interesting...re no transformers. Maybe for the SE they’re throwing half the signal away (I tried that and it doesn’t sound terrible, but it is missing some detail/accuracy). Or maybe they’re using stage-killing op-amps.

On the Adagio, if you disconnect the power you MUST use the remote control to unmute the relays upon power up. That has tripped me up several times. I wouldn’t be surprised if there a similar procedure for Pavane. The Pavane manual seems to suggest otherwise... it says “Mute function: By powering up the dac the mute function will be activated for five seconds. When switching the dac to standby mode muting will be active again.” But I would just try the remote input select to be sure.

 

If I recall, I always had to select an input after powering up the Pavane, but I think I needed the remote. But a good thing to check.

Skem,

I laughed at your "People's Republic of Cambridge". I that the Commy Russian themed bar in Cambridge, MA?

Jac