Discussion in 'Digital: DACs, USB converters, decrapifiers' started by zerodeefex, Sep 28, 2015.
NADIT and Sescom impedance adapters have been discussed a lot in the Lynx AES-16e/E22 etc threads
looks similar to the SESCOM AESEBU1 that @purr1n has recommended in the past, and that I used with success with a Pi2aes for awhile.
Sometimes the inputs can tolerate a simple direct adapter, but it's not just an impedance difference I believe there's a voltage difference as well.
I have had the opportunity to recently review some state of the art clocking options from Mutec.
This review was exclusively done on speakers, it was done as an experiment over several months with no expectation to purchase thanks to https://indiehifi.com.au/ once again for supplying the test equipment.
PC ROON or sft-1 SE+ cd transport usb/aes/spdif > mc3+ -ref10/rockna bal sig > ATC sca2 pre > ATC150ASLT in a purpose built listening room.
DAC settings, Linear/Local/Dither OFF - I tested stream as well
In this comparison between the Mutec mc3+ using the ref10SE as an external clock I spent several weeks at first comparing PC USB direct to my DAC, vs PC USB to the mc3+ reclocked and AES to the DAC.
mc3+ is not capable of true bit perfect play back and is probably not the best DDC option so I found no improvement in SQ other than it was more inconvenient as I could not get ASIO to completely lock to it.
It really wasn't better or worse.
So I decided over this weekend to compare on my cd-transport which I've used for years as a reference. To see if re-clocking the signal would offer any benefit compared to just straight to the DAC,
SPDIF direct to DAC vs AES to mutec/clock AES back to DAC
Maybe there was a tiny bit more energy when using the Mutec XLR vs the spdif, but the more I switched back and fourth the more I felt that wasn't the case.
So i switched it around:
AES direct to DAC vs spdif to mutec/clock spdif back to DAC and I can't identify one from the other.
So I detect no difference with usb from PC, no difference from AES or spdif from my cd-t transport.
Who needs this product?
I guess if someone needs a clock distributor for busier pro environments, in a hi-fi environment I think if you have a DAC that has poor clocking you should buy a better DAC rather than buy this combo at the asking price of something like 7kusd for the combo.
Perhaps my system is not resolving enough, or my ears not good enough to detect the differences that actually do exist.
Perhaps Rockna just doesn't get the potential improvements due to its design:
"With these facts in mind, we designed for the Wavedream an advanced clock system called the femtovox. With femtovox in place, one is assured that only extremely small amounts of jitter are present at the dac conversion clock input. It’s unique architecture employs that conversion clock is directly synthesised at the dac input, without any conditioning, giving constant jitter performance at any sample rate. The conversion clock is controlled with 1 ppb precision, while exhibiting about 300 fS of jitter. The smallest jitter figure in the world? No. The smallest jitter figure where actually matters? Probably."
I feel what is probably more likely true, is this product is unnecessary, at least in my situation. I don't have any other DACs to compare because it could of been fun to take a DAC with known jitter/clocking sensitivity and test to see if the mutec could resolve the issues.
At least my clocking nervosa has been well and truly put to bed.
Anyway I must apologise for not being very active over the last year, I haven't tested much new and have minimal interest in headphones now days. I will strive to make some useful community posts in 2023.
May all the joys of the holiday season fill your heart and follow you throughout the coming year.
Mutec MC-3+ is one of the few games in town if wanting to provide a Rubidium referenced digital audio data stream to components without word clock inputs. It was very useful for disciplining a Modi Multibit at a show years ago with very good results. Lately I have sending Rubidium disciplined LiveClock to word clock on Focusrite D16 and dispensing with MC-3+ with slightly better sounding results.
Main use of an external clock to me is to keep multiple devices in sync, not necessarily to be super accurate. I can maybe see an application with a transport -> DAC and connecting the clock to both.
Where I really see this to be applicable is for for a multi-way system with DSP crossover. A 3-way system has 3 DACs plus miniDSP processor and possibly the source or ADC for analog source. That’s 5 digital devices that need to have an accurate clock to have coherent sound. Also for an over the top home theater system where all 7.1 channels have their own DAC
Usually this is a 1-box solution which would already use the same clock, but if you want to use R2R DACs you’re not likely to find it.
Whilst from a functionality standpoint the MC3+ is quite handy regarding clock distribution etc, it's worth noting two things:
1) It is NOT bitperfect in all situations. I'm not sure exactly when it is/isn't but some configurations do have some digital processing involved. (And I don't just mean the DSD to PCM conversion, I mean PCM to PCM)
2) Jitter performance was pretty mediocre ( https://goldensound.audio/2021/10/05/mutec-mc3-usb-ddc-reclocker-measurements/ ). far higher jitter than a much cheaper pi2aes for example. As well as most of the DDCs I've tested.
I'm not sure how it may change when used with a 10Mhz clock, though regardless of whether you're running it standalone or with a 10Mhz input, it is being forced to use a fractional PLL due to neither the 1000Mhz internal clock or the 10Mhz clock being able to be divided into 44.1khz or 48khz base rates.
Subjectively I didn't find it impressive either, and that was before measuring.
Idk, it certainly seems it'd fill a use case in some professional environments, but for consumer/high end listening, it doesn't seem to be a great option imo
GoldenOne, is the Holo Audio Red Streamer your new reference now?
Wowwww this thing looks really spicy
At the moment the two best performing digital sources I've tested have been the Rockna Wavedream NET and the Holo RED. Both perform at very similar levels and within margin of error of eachother.
But the Red is an order of magnitude cheaper so for me it's the current reference. (it also has more I/O functionality and higher sample rate support, though of course lacks the CD ripper and server features of the NET)
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