Anyone has heard the Bel Canto REFLink Asynchronou

The uLink and REFLink reduce jitter to 50 femtoseconds.

This is not true. The value you are quoting is a clock (crystal oscilator) jitter. The clock is just a part of a greater whole, chence the total jitter, as measured at SPDIF out will be much greater.

The converter with the lowest measured jitter at the SPDIF out I have seen is the Audiophilleo - 2ps or thereabouts.

The problem in measuring jitter on such a low level is the cost of the equipment needed, which can easily exceed $100k. Very, version few hifi companies even have such an equipment.

That said, the BelCanto REFLink seems to be a very well engineered product. It uses the ultra low phase noise clocks, made by Crystek. The first converter that used those were BADA Alpha USB, which is even more elaborate in trerms of measures taken to isolate the computer from the DAC. The downside - it costs $300 more.

I highly recommend anyone interested in top quality converter to include the BADA Alpha USB on his short list.

Scottmac62.

Without a doubt, with the RefLink, your DAC3.5VBMkII will be significantly improved, right out of the box. Just simply base on the 192K capability on the RefLink over the LightLink 96K limitation is good enough reason for you to upgrade. The RefLink provide me the best sound I could get from the DAC3.5VBMkII.

(Audio)

Interestingly, I have had the chance to audition the Berkley alpha usb and dac
for about a month from the cable co. Curiosity got the best of me. Needless to say, the bada usb used in conjunction with my Bel Canto Dac 3.5 VBS was not a
joy to listen to. The sound was as hard as nails digital sound as compared to my light link. I could not sit down and enjoy one song in its entirety. Listening fatigue was instant. This may work with a system that is really dull sounding, but I have zero tolerance for digital glare. In addition, the bada usb and bada dac had the same effect in my system. Bright, in your face digital sound. Unfortunately, the cable co does not have the Reflink for audition. So, I think I will just have to take a chance and get one.

I think you are missing the point with your reply to my post. While the numbers are indeed difficult to ascertain using instruments ($150K for an Agilent 5052 for example…we prefer to let our key suppliers amortize this expense) the proof is in the listening. While design decisions are informed by the numbers and engineering decisions driven by those numbers, the final decisions are driven by listening tests! We easily hear the improvement between the excellent clocks in the mLink versus the uLink, close in phase noise (below 100 hertz) is nearly identical but the phase noise from 100 Hz to beyond 1MHz is some 10-20dB improved on the Ultra-Low Phase-Noise clocks in the uLink and REFLink. This phase noise represents some 250fS (0.25pS) in the mLink and some 70fS (0.07pS) in the uLink and REFLink. The REFLink improves on the noise floor of the clock by offering further isolation from the computer (the USB Input section and processor are isolated from the clock section yet they are still self-powered with a low noise isolated internal supply-unlike the BADA which powers this function from the computer) and overall lower noise power supplies in the REFLink. The results of these 2 improvements are easy to hear between the uLink and REFLink (although difficult and expensive to measure as you state). My conclusions are that simple measurment of jitter is no longer adequate to understand the impacts of clock noise on audio reproduction quality. You reply also understates the critical importance to audio quality of advancements represented by our new Links and products like the BADA.

I asked John Stronczer for his input