Experience with iFi SPDIF iPurifier2

The iFi Audio SPDIF iPurifier2 is a small devise designed to clean up jitter in digital signals on the DAC end of a coax cable. If you want galvanic isolation from the source, the iPurifier2 will convert the 75ohm digital signal to Toslink optical and can output that to your DAC’s Toslink input.

Why I got one: I recently purchased a used Chord QuteHD to replace the Arcam irDAC I had been using for quite some time, most recently fed by a Bluesound Node (V3) used mostly to serve PCM music files from mp3 up to 24/192 quality from an SSD. The two DACs are similar vintage, but when new, the QuteHD cost about 2.5x as much as the irDAC, and sounds that way to me (more on that). Although it sounded wonderful, the QuteHD was temperamental connecting to the Node via coax. I thought maybe there was a problem with the QuteHD, although Toslink and USB both worked terrific. Some research on the Bluesound website indicated other examples of Node difficulty handshaking with Chord Qutest, and one remedy was to use an iFi SPDIF iPurifier. Liking both the functionality and sound of the Node/QuteHD combo, I thought I would try the iPurifier as a relatively (but not super) cheap hack.

What happened first: The iPurifier2 fixed the handshaking issue between the Node and the QuteHD, but made the DAC sound like a layer of syrup had been poured over the music. The signature Chord detail, PRAT and dynamics were all taken down a notch. I checked the iPurifier with the irDAC in place of the QuteHD, and got the same effect, although maybe to a slightly lesser degree. There was a new smoothness to the sound, especially to voices, but I was not sold. Thinking I needed the iPurifier to make the Node/QuteHD combo actually work, I doubled down on iFi and bought their iPowerX power supply to replace the stock iPower supply, sort of grasping at straws at this point. I read on Agon where someone said that an lps improved the benefit from the iPurifier. I have three aftermarket lps in my system, with both the QuteHD and my ProJect phono presmp supplied by custom lps to good effect, and I have assembled five of the PCs used in my system, so I guess I am kind of a power geek. But now this “little hack” was starting to add up.

What happened next: Wow! The iPowerX changed everything for the iPurifier2 in my system for the better. The energy and dynamics of the music returned from the QuteHD, but now had a slightly more organic sound overall. Notes suddenly flowed from one to another in a very pleasing and natural way, and decays hung in the air for just the right length of time. Both male and female voices alone, in harmony and in chorus had great touch and body with little or no unnatural sibilance. ‘Laughing’ by David Crosby in 24/192 makes me stop doing everything and just listen. The detail, the micro and macro dynamics, the solid bass and the both broad and specifically articulated soundstage of the QuteHD supported by an MCRU linear power supply were now back, but everything was more three dimensional, like the music had new connective tissue holding every together and helping it all make more sense to my ears and brain. I liked it. I liked it a lot.

Conclusion: the iFi SPDIF iPurifier2 works great, but for me, only when used in association with the iFi iPowerX in place of the stock iPower supply. I was ready to send the iPurifier back until I tried their upgraded supply. I don’t have any other switching supplies in my system, with quality power cables all around and a dedicated AC supply circuit and power conditioning, so maybe it is all down to better capacitors in the iPowerX. Whatever, a device I added to just allow sound to come out of my system at all has improved my overall digital music experience significantly. I have experimented with taking the iPurifier2 out, and it’s not a fluke, each time I am motivated to put it back in immediately.

Final note: the funny thing is, the BNC adapter that came with the iPurifier fixed the handshake problem between the Node and Qute2, but I didn’t figure that out until I tried the pairing with the iPurifier2 supplied by the iPowerX. Happy accident.


Ag insider logo xs@2xknownothing

I power my iPurifier2 with a cheap LPS. I also connect my player with a glass toslink cable. This enables a "good" toslink connection and a "oh wow" connection for whenever I get "serious."

The iPowerX changed everything for the iPurifier2 in my system for the better. 

Thanks for posting this, I use the iPurifier2 and will try the upgrade, thx.

@fuzztone sounds like you consider the iPurifier2 input as “oh wow” and Toslink as “OK”. That is my experience too, at least between the Bluesound Node and either of the DACs I’ve tried: coax+iPurifier2 > coax > coax+iPurifier2+Toslink to DAC > Toslink in terms of sound quality. Both coax and optical cables were DH Labs fwiw.

Wondering at what point diminishing returns are achieved in terms of power supply quality for iPurifier2. I was shocked at the gains provided by $109 iPowerX.

Also wondering if the iPurifier2 is fixing a deficiency in the Node source, the QuteHD DAC, or both devices.

Thanks @kota1, these are the only iFi products I have tried, and they are very high value.

Just pray you never need customer support.  It’s awful, shameful, insulting, and basically non existent.  I had a problem with the Wi-Fi connection to my Zen Stream and not even their US distributor could get them to help me after going thru the normal channels was an utter fail.  It’s unconscionable to me that a company that sells products in the volume that iFi does can’t spring for a simple customer support phone line.  Argh!

I concur regarding the use of an aftermarket power supply. I'm using a Swagman Labs LPS connected to my iFi iPurifier2. Results are opening up the soundstage, better quality bass, and an overall smoothness to the music. 

IMO, the Node2i doesn't have very good jitter control, I'm using SPDIF  output. The addition of a good quality coax cable will also improve the performance of the Node.

@lowrider57 I am using a DHLabs 75ohm coax which I would describe as “pretty good”.  A poor quality coax cable I tried at first could not reliably support 24/192 signals from Node to dac.  

Swagman makes good power supplies, I use an SE model on my phono pre and a standard model on my Amazon Fire Box.


Great to hear you're pleased with Swagman, I'm also using an SE.

Cables really matter, I've read good user reviews about the DH Labs digital cable. I'm using a High Fidelity Cables SPDIF coax. I must say that the Node2i is a good entry-level into streaming, but the small SMPS powering the device is a drawback and I guess its mediocre jitter correction is to be expected in a basic streamer. Using the iPurifier with a good PS is quite an upgrade.

@lowrider57 there is a review from about a year ago, I think by Simon Price at 13th Note, where he tried a number of streamers and decided the Node was a better pure streamer than it was combined streamer/dac, and that the streamer function performed on a par with more expensive products.  That said, the positive results with the iPurifier2 makes me think there’s definitely room for improvement.  

Fwiw, I am using a custom power cord I built with Furutech continuous crystal copper bulk cable and SONARQUEST carbon fiber/rhodium connectors, stepped down with a Voodoo Cable c7 adaptor to supply the Node, and it clearly sounds better with the Node than the stock cable and the best of the various cables I have laying around here.  YMMV.

That's a great way to get better power. I'm using a C7 PC from Cullen Cables which is dramatically better SQ than stock. I also have Cat8 wired from my router which is plugged into a Brick Wall power conditioner with RFI/EMI filtering.

@lowrider57 I tried to run down your High Fidelity Cables coax on the web.  I couldn’t find any info on that wire, but their cable designs in general look pretty exotic.  Does your cable have magnetic components?


HF Cables is out of business. The owner and designer was Rick Schultz who was a high-end cable maker for various companies. He offered cables and power conditioning, I own 5 of his plug-in conditioning modules. His concept of using a magnetic field to ride along the electromagnetic sine-wave resulted in a low-noise signal (I am not a physicist). His business model and overpriced products couldn't keep the company afloat.

Yes, i have 2 SPDIF cables, magnets are in the RCA connectors. The result is a black background with organic sonics.




He had a niche market, the wealthy audiophiles. Covid shut him down and then he had to close due to supply chain shortages. He needed rare earth metals and fabricating equipment.

@lowrider57 I am experimenting with different coax cables between the Node and the Chord.  +1 to that suggestion.

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@lowrider57 yes, I am comparing three cables at various price points that were lent to me by a dealer.  There are clear differences, but I am giving each cable some time to warm up in my system until I get consistent results.  My initial impressions were somewhat surprising, more later.

Same as my iFi Micro iUSB-3.0 with upgrade iPower-X to replace the old first gen iPower. the effect is wow for me too. 

@knownothing good for you! So many people on here drop in a cable or component and sit right down to asses. For transparent/high resolution systems, 48hours of settling is safe and what I’ve tracked over and over. Heck, I can jostle or move a cable plugged in cable and bass extension will change for a day. 

@jriggy ha, yeah I had a whole review ready to post based on a first listen to each cable, and then thought “you know better than that”.  Getting close to having it figured out.

@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.

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