Experience with iFi SPDIF iPurifier2

@lowrider57 ​​​​@jriggy, I spent a fair bit of time sorting out my digital cable situation with the Bluesound Node and my Chord dac, pretty much by accident.  I ended up enlisting outside help, but I learned quite a bit, and I think my system will be in a much better place as a result.  Thanks for the suggestion lowrider.

I went into a local dealer to buy a different item and mentioned in passing I was interested in trying a different digital cable, and he handed me three and told to take them home and try them out.  My initial impressions were so positive I went to another local dealer and they handed me another five cables to try.  Combined with two I already had at home, that was a total of ten new and used cables priced from $25 to $1,500 to compare. Cables were: Pangea Premier, Blue Jeans X ‘Better’, DHLabs Silver Sonic, naim DC-1, Chord Shawline, current and past Signature Digital Super ARAY models, and Nordost Blue Heaven and Heimdall 2.

I am no stranger to cables.  I have assembled from parts over ten power cables of different types, and have used many different ICs, speaker, USB, Toslink and HDMI cables.  But until I got the Node, I had never really experimented with coax cables.  I have a system for comparing cables that includes listening to a few of the same cuts with each cable and taking general notes.  I compared all the cables with the iFi iPurifier2 out of the circuit, and enlisted my son who has a very good system and good listening skills for blind testing a few of the cables.

I will only touch on some highlights here.  

First, I have never listened to either Chord or Nordost cables in a controlled context, and at least for their digital offerings, I am impressed.  I had thought that my DHLabs Silver Sonic coax cable sounded pretty good, and it is often recommended as a good budget cable, but it was really left behind by most of the others I tried in my system.

Second, some of these cables sounded dramatically different, and you get what you pay for.  My son easily identified as his favorite cables the two most expensive cables tested in a blind listening.  The amount of detail and nuance on offer made that result nearly a certainty.

Third, putting these high quality cables between the latest iteration of the Node and the Chord QuteHD dac indicated how good the Node functions as a server for HD, 16/44 and low res files, and proved lowrider’s point that digital cables make a difference in this context.

The lower level Chord Shawline and Nordost Blue Heaven are both lovely cables.  The Shawline is balanced with good spatial detail and broad soundstage.  The Blue Heaven is super musical with great PRAT, an emphasis on leading edges and a lower center of gravity.  Of the two, there’s a bit more detail on offer from the Shawline. Compared to my Silver Sonic, both had less grain, sounded more organized and less shouty.  Either would have been an improvement, and I probably would have bought the Shawline if I hadn’t listened to cables further up both lines.

The Nordost Heimdall 2 is a lovely cable, similar PRAT and flow as the Blue Heaven, but more high frequency information, better tone, oodles of detail and very accurate placement of instruments and voices in the sound field, all without sounding lit up or over the top.  It took this cable a few hours of playing to get to this point.  When I first dropped it in, it sounded a little thin.

Chord Signature Super ARAY is also a great cable.  My son in the blind listening described it as not quite as punchy on leading edges as the Heimdall 2, but he felt the midrange was to die for, and this cable did voices better than any other cable in my test.  Very good tone, and detail and spatial resolution was also convincing with this cable.

One surprise in my listening was the Blue Jeans digital cable made specifically for Hawthorne Stereo.  At just shy of a hundred bucks, this was a very good deal.  It lacks the PRAT of the Blue Heaven, but it was smooth, good tone, sound stage and separation and bass definition.  The treble is a bit tipped up, but no jitter glare.  It doesn’t set a foot wrong, and especially for the price.  I did have trouble getting the RCA connectors to grip the socket on the Node, and the cable is stiff, which didn’t help.

Towards the end of my testing I reinstalled the iPurifier to see if it still added value on top of a $1,000 digital cable, and it did, especially with the spatial presentation.  Great sound got even greater.

So, in conclusion, yeah, trying different coax cables with the Node was a real ear opener.  I am going to save up my pennies and buy one of the more expensive cables, because after listening to them in my system, there is no going back.

Follow up on the Bluesound Node/iFi iPurifier 2 (iFi iPower X)/Chord QuteHD DAC set up. I eventually purchased a used Chord Signature Super ARAY coax cable to connect the Node with my DAC. Super happy with that choice made after carefully comparing about 11 different coax cables in my system. I have done some experimenting with the iPurifier 2 in and out of the circuit, and here is what I have heard and decided.

The Signature Super ARAY coax (an older twin cable version) is a revealing but balanced sounding cable. When connected directly from the Node to my QuteHD DAC, it provides a bright and fast presentation. Leading edges are enhanced, nearly to point of being etched. This works very well for some rock and classical music as the transients and things like violin solos and snare drum hits can be breathtaking. The Signature Super ARAY cable alone complements rather than mitigates the Chord DAC’s focus on details, and while there is almost zero grain with this cable, the combination can become a bit strident on certain electric guitar, piano or vocal passages. This set up is good for impressing myself and others in a short listening session with the dynamic capability of my whole system. For long listening sessions, it can be a bit too much of a good thing.

Adding the iPurifier 2 to the chain calms things down just a bit, and as I described earlier in this thread, the notes have a better flow and the overall sound is more natural and organic. Dynamics are still present, but not in my face (or on my eardrums). Voices sound more like real people, bass remains tight and coherent, and the noise floor seems a bit lower on quiet passages. I put this effect by the iPurifier 2 "fixing" some issues with clocking in the output of the Node. In any case, for most listening, and for all longer listening sessions, I leave the iPurifier 2 in the line and am quite happy. I may try a dedicated LPS for the iPurifier 2 as lowrider suggests as a next move. Because of my positive experience with the iPurifier, I may eventually try a more capable stand alone DDC - although that would mean buying another good quality digital cable...

+1 @knownothing . Thanks for the update. And I'm still recommending a LPS for the iPurifier 1 & 2.

@lowrider57 👍