Metrum Acoustics Pavane DAC listening impressions

I think the only way to "test" the different manufacturers' tranny flavours would be to build a bunch of these:

https://ampsandsound.com/products/x...76785&pr_ref_pid=1314571944017&pr_seq=uniform

IMO this one in particular is grossly overpriced but not hard to DIY.

 

But also

 

A couple of nights ago, I was comparing Pavane XLR to RCA outputs and found a big difference, similar to @m17xr2b's results. That made me curious about the difference in the Onyx and if the Onyx had transformers, a summing circuit, ??? So this morning, I pulled out the Onyx and did some listening.

The difference between XLR and RCA output is much smaller than in the Pavane. In fact, with a couple of days between listening, I think the Onyx RCA is better than the Pavane RCA. At least in my system. The RCA output of the Onyx lacks a little stage depth, a little detail, and a harmonic decay on string instruments to the XLR. Overall, the Pavane XLR is the best, but the SE output is disappointing.

I couldn't remember what the Onyx looked like inside, so I pulled the cover and the SE output is pretty simple, see pictures. The relays appear to control switching between XLR and SE. I pulled the DAC module closest to the outputs as shown in the close up picture. In this case, the RCA outputs are at the top of the picture. This could be a summing circuit, but I couldn't identify many of the components from their markings. The Ti chip is a logic chip and the other mostly show up as Schottkey diodes when searching their markings, but no exact match.

https://www.dropbox.com/s/is9qmv3hxja5jly/Onyx Output b.JPG?dl=0

https://www.dropbox.com/s/xejmeuam0sqhwuf/Onyx SE out close b.JPG?dl=0

One thing is clear. No transformers in the Onyx and better sound. Hmmmnnn.

 

One other thought/question. Maybe a question for David at Cinemag.

When using transformers at the input of an amp, I was taught that the amp impedance has a big effect on the transformers. Bandwidth, Distortion, and transient damping all change with the impedance of the amp. The link is for the CLMI -15/15b that I used as an input to a tube voltage stage on a DIY amp. I ended up have to tradeoff the input impedance to keep the transformer happy.

Could the output transformer of the Pavane be interacting with the load impedance and affecting what we are hearing?

https://cinemag.biz/line_input/PDF/CMLI-15-15B.pdf

 

The reason why I went with transformers is for the +4V SE input on my amp since the input tube only has a gain of about 10 and the standard 2V wouldn't be enough.
Care must be taken to choose a step down transformer for input and not a 1:1. Some amps are already loud at 9 o clock, additional gain wouldn't be ideal.

US has easy access to Cinemag, Sowter is the main for UK and I do highly recommend their transformers. The 10k:10k I'm using is only 20% more than the inbuilt ones.

 

Hello
I have always used XLR on Pavane. So, never cared about RCA.
I recently got a 45 DHT/717A hpa/pre from soundgate japan made by ken uesugi.
After reading the last few pages i am curious about RCA quality. @EagleWings

From @m17xr2b impressions Jensen is not a good match.

Has anyone tried Amp n sound black box xlr to rca converter with pavane?
Any recommendation.
DIY is not an option for me.

 

You want something nicely transparent, maybe the Freya S?
https://www.schiit.com/products/freya-s

 

I had tried Jot R passive preamp mode. It was not a good match at all.
I will look into Freya S.

 

My opinion, the Pavane RCAs are not that bad, it's just not on the level of the XLR outputs.

I haven't heard the Freya but there are impressions here.

 

And the Pavane RCAs are only an issue at the high end and another step up. If you're worry is transparency the last thing I'd do is add a mid level preamp or any preamp unless you actually need it or the additional gain. Less is more in this case. I'm working to ditch even the sowter input transformers as good as they may be.

Try to be sure you have a problem before trying to fix it. Most input transformer boxes will use Lundahl, Cinemag or equivalent iron so you won't necessarily get an upgrade, sidegrade more likley and just because it's different it may not be better even if purchase bias might not let this fact sink in immediately. Sowter has proven itself to me not just in this case but many others. On the same level or even slightly above you have Tamura,Tango,Monolith,Hashimoto etc. basically the best in the business and expensive.

 

I am thinking of trying Neutrik FXLR to FRCA adapter which will convert 4vrms XLR to 2vrms SE. This is the shortest path possible.

 

I'm feeding my Freya S with my Jade's balanced outputs.

When I need to feed single ended headphone amps (BW2 or Torpedo III) I actually use passive mode on the Freya S. I feel it sounds better than the Nexus stage (which effectively converts differential to single ended).

In other words, taking only have a differential signal is not always a bad way to go. I'm sure it's a trade off between losing a bit of details and adding a bit of hardness. I chose the former.

 

A&S uses Cinemag

 

what do you think about the CMOQ-2H or 4H. CMRR is poorer, but bandwidth/phase and THD specs look better than Cinemag’s other offerings. Am I missing something important? Shielding? The metal core?

 

Thanks Marv. I was not paying attention to the loading. It’s remarkable how much poorer these things perform when lightly loaded. Reading the charts, it looks like my amplifier’s 47kΩ Input impedance will sound heavily colored, even for CMLI-15/15B.