iFi Zen Phono 3 Preamplifier Review

[BDWoody]

Do Brits use the phrase "close enough for government work"? That's the rough US equivalent for crude but effective.

More precisely, it means that the kludge held together with duct tape is good to go; ship it to the customer. ("Government work" = Defense Department contract.)

That's one I heard my father use quite a bit. Haven't heard it lately.

 

[somebodyelse]

More precisely, it means that the kludge held together with duct tape is good to go; ship it to the customer.

Kludge seems to have different connotations across the Atlantic too - in Britain it's rarely a good thing. Possibly related to its Scots meaning of 'toilet'.

 

[Bob from Florida]

I have test LPs. I just don't know where to start with an optimized cartridge/turntable setup.

Amir - once again appreciate your testing "stuff"!

The Gurus - @JP , @Balle Clorin , @SIY , @USER , and others doing the cartridge measurement script could advise on good or ultimate setup of your table. Once there, that can be your "constant" - within reason - for the preamp testing. It won't be as precise as digital testing, but should be "good enough" for the intended function. Who knows, you might even find a couple of well recorded albums enjoyable enough to play occasionally!

 

[Frank Dernie]

Do Brits use the phrase "close enough for government work"? That's the rough US equivalent for crude but effective.

More precisely, it means that the kludge held together with duct tape is good to go; ship it to the customer. ("Government work" = Defense Department contract.)

I have not heard that in England, Wales or Scotland but had a US colleague who used it a lot.
He had worked for NASA

 

[JeremyFife]

Do Brits use the phrase "close enough for government work"? That's the rough US equivalent for crude but effective.

More precisely, it means that the kludge held together with duct tape is good to go; ship it to the customer. ("Government work" = Defense Department contract.)

"Good enough for Jazz" ... related to tuning

 

[DSJR]

The RIAA EQ deviation obsession with perfection results in those twin seas of SMD caps and resistors.

Pit they didn't focus on the important things more, like noise, overload and distortion. The distortion figures are OK, but I've seen a lot better in 30 and 40 year old phono stages.

And all you need to do is fuss with cartridge azimuth by a 'knats' or adjust VTA or tracking force a little, to totally negate any need for uber-flat RIAA correction. Been there, done that and worn a zillion tee-shirts to prove it to myself

 

[AudioSceptic]

That board looks over-populated to me and for such small signals, especially MC ones, isn't it all a bit too neatly laid out involving extra signal track and so on. Maybe it's not important as the basic performance is okay EXCEPT for hf overload, right where surface ticks and splats may overload it with a more 'exuberant' cartridge with an hf rise, as is common these days.

Anyone care to explain why the iFi's board looks so messy and cluttered compared with, say, Michael Fidler's super-clean and elegant Classic Audio pre-amps?

 

[AudioSceptic]

And all you need to do is fuss with cartridge azimuth by a 'knats' or adjust VTA or tracking force a little, to totally negate any need for uber-flat RIAA correction. Been there, done that and worn a zillion tee-shirts to prove it to myself

Surely you mean a "gnat's"? ;-)

 

[AudioSceptic]

I learned the phrase by watching your Top Gear! They use agricultural to mean unrefined/older tech. Here is an example: https://www.topgear.com/videos/top-gear-tv/richard-hammond-drives-chevy-corvette-series-4-episode-10

With this tag line: "The fast, agile but agricultural Corvette is a handful on the track, but Richard has heaps of fun in it anyway. Don’t talk to him about chassis engineering, this is adrenaline."

I recall James May use the term.

Yes, we commonly use "agricultural" in that sense, basic/crude/unrefined but it works. Anyone who's ever driven a tractor or operated any farm machinery will understand...

 

[AudioSceptic]

Speaking of the use of the term "agricultural" by British people to describe something - just read some of the literature describing vintage British motorbikes or vintage British cars. I owned a 1972 Norton 750 which was described in the press as being agricultural. I always assumed it means that the engine used was originally an irrigation pump, or for cars that the engine came from a tractor. The term always conveyed to me a kind of homely mechanical honesty, a low level of technical advancement, and a product that could be repaired with only a pair of pliers and a hammer.

A Commando, a clever design that mounted a big parallel twin in rubber "suspension" so that the vibes didn't rattle the rider's teeth and eyeballs like previous big twins such as the Norton Atlas?

 

[AudioSceptic]

"Good enough for Jazz" ... related to tuning

"Close enough for rock'n'roll" is what I've heard a lot.

 

[DSJR]

Surely you mean a "gnat's"? ;-)

HA! The Linn 'K' vibe intervened, decades after I thought I'd purged it

 

[DSJR]

Anyone care to explain why the iFi's board looks so messy and cluttered compared with, say, Michael Fidler's super-clean and elegant Classic Audio pre-amps?

@restorer-john explained it in post #45

 

[fedocable]

I have a Denon DL-304 and I prefer it to the ubiquitous DL-103.

Get the Michael Fidler MC phono stage. Then you will really hear what that cartridge can do. (My other choice would be the Parks Audio Waxwing.)

Thanks to you and Markstein for pointing out Michael Fidler, I didn't know about him! The MC Pro is definitely out of my budget -and anyway, following Steve Guttenberg's advice I intend to keep the Denon SUT, so I'd go for a MM preamp. But I could definitely consider the Spartan 15, which apparently hits all the right spots. I will research it. Regarding the Waxwing, I admit it would need a bit of psychological work to accept inserting a digital link in the phono chain -tubey ignorance is bliss, you know!

 

[ryanmh1]

I have test LPs. I just don't know where to start with an optimized cartridge/turntable setup.

I am still waiting for an ASR analysis of actual LP playback SINAD. If Amirm needs a test LP with test tones on it, I will send him one, just let me know.

I'm not sure there would be much of a point to it, honestly. There's already a thread here about doing just that, I believe with measurements of a lot of cartridges. SINAD is awful, but due in large part to distortion. You really need to separate out distortion and SNR. Dr. David Rich did some very detailed work on cartridge measurements years ago for Secrets which was even better, and the German site lowbeats has also tested multiple phono cartridges. The results all tend to more or less line up. The distortion levels very quickly illustrate that the distortion levels of the phono preamp are most likely than not wildly irrelevant to anything unless they're really, really bad because even the best cartridge is atrocious, comparatively. And also that buying a microline, Gyger, van den Hul or similar profile is the way to go unless you don't care what happens on the inner grooves. It seems that at about $250 for an VML540ML, you're pretty much 95% there, so I bought that one. Save a couple bucks and the AT-VM95ML or VM95SH is fine. Go real cheap and get the nude elliptical, but beyond that it's more dicey. Drop double that and you can get flat frequency response to boot with a Nagaoka MP500. (The real unanswered question is what happens when you pop that stylus on the cheapest Nagaoka body.) I have a bunch of moving coil cartridges that I probably won't use just for now because I'm paranoid about them getting destroyed by little hands, but many of those also have desirable profiles and good distortion figures. The "fun" thing about all of this is that the levels are so bad and the carts so different, you probably actually will hear some clearly audible differences and improvements, unlike with a lot of things where you're listening for the sound of sunlight filtering through the leaves.

So far as the SNR component, according to Michael Fidler, it is theoretically possible to take advantage of most or all of the SNR in his preamps, and leaving a tiny bit of extra room for margin. His stuff is all very, very good, and his technical descriptions show he cares about this stuff, so I tend to trust what he says and haven't thought about it too hard as a result... My guess is his MM would be 82 to 85dB if he measured them traditionally (into a resistive load) instead of with a cartridge connected. His technical descriptions imply that's probably about the case. But that's apparently just past the limit of what you can get from the very, very best and most quiet of setups. And it's not clear whether cartridge versus resistive loading results in the same degredation of the measurements across cartridges, and across phono preamps. (In other words, is an 83dB measured SINAD 78dB when hooked to a cartridge, or 74dB, and does this change per pre-amp and per cart?)

But back to the Zen. I wouldn't be surprised at all if what is on offer here is more than adequate in terms of SNR for the bulk of what's out there. At just under 75 for an MM and around 65 ideally for a MC, you're probably at or even past the limits of an average setup by a good margin.

But on second thought, I think Amir is quite right to call out the high frequency overload. I should have paid more attention there. Looking at this a bit today, people who know a lot about these things all tend to agree it is highly important--perhaps one of the more important characteristics. And the Zen doesn't do so well here. It might not have enough margin at high frequencies. That said, I've only looked at this issue for less than an hour, but it seems you still generally want at least as much overload margin at 20kHz as you have at 1kHz to best handle pops and clicks, and this doesn't have it. Something like the NAD PP2e, on the other hand, does. It has 6 or 7dB more margin. Then there's how all this works with RIAA curves and whatnot, how they did the specs, and calculating the actual margin based on what was done and how, and it all gets a bit annoying to work through quickly. In the end, I'd take a NAD PP2e or whatever comes in the stock Marantz AV10 (and likely other Denon/Marantz receivers) over this. 20dB all the way out to 20kHz seems desirable for safety, and this isn't there. How audible is it? I don't know. You'd have to take a really hot and ideally somewhat beat up record and listen to them back to back to work that out. If all your records are pristine, it may not matter at all.

 

[Rgv250]

I tried a zen phono 3, but had terrible problems with interference from my mini pc and it’s wireless mouse/keyboard. Current phono stage (an old Benz pp1) had no such problems. Unfortunately outside of moving things around I didn’t know how to try and resolve this so returned it.

 

[AudioSceptic]

I'm not sure there would be much of a point to it, honestly. There's already a thread here about doing just that, I believe with measurements of a lot of cartridges. SINAD is awful, but due in large part to distortion. You really need to separate out distortion and SNR. Dr. David Rich did some very detailed work on cartridge measurements years ago for Secrets which was even better, and the German site lowbeats has also tested multiple phono cartridges. The results all tend to more or less line up. The distortion levels very quickly illustrate that the distortion levels of the phono preamp are most likely than not wildly irrelevant to anything unless they're really, really bad because even the best cartridge is atrocious, comparatively. And also that buying a microline, Gyger, van den Hul or similar profile is the way to go unless you don't care what happens on the inner grooves. It seems that at about $250 for an VML540ML, you're pretty much 95% there, so I bought that one. Save a couple bucks and the AT-VM95ML or VM95SH is fine. Go real cheap and get the nude elliptical, but beyond that it's more dicey. Drop double that and you can get flat frequency response to boot with a Nagaoka MP500. (The real unanswered question is what happens when you pop that stylus on the cheapest Nagaoka body.) I have a bunch of moving coil cartridges that I probably won't use just for now because I'm paranoid about them getting destroyed by little hands, but many of those also have desirable profiles and good distortion figures. The "fun" thing about all of this is that the levels are so bad and the carts so different, you probably actually will hear some clearly audible differences and improvements, unlike with a lot of things where you're listening for the sound of sunlight filtering through the leaves.

So far as the SNR component, according to Michael Fidler, it is theoretically possible to take advantage of most or all of the SNR in his preamps, and leaving a tiny bit of extra room for margin. His stuff is all very, very good, and his technical descriptions show he cares about this stuff, so I tend to trust what he says and haven't thought about it too hard as a result... My guess is his MM would be 82 to 85dB if he measured them traditionally (into a resistive load) instead of with a cartridge connected. His technical descriptions imply that's probably about the case. But that's apparently just past the limit of what you can get from the very, very best and most quiet of setups. And it's not clear whether cartridge versus resistive loading results in the same degredation of the measurements across cartridges, and across phono preamps. (In other words, is an 83dB measured SINAD 78dB when hooked to a cartridge, or 74dB, and does this change per pre-amp and per cart?)

But back to the Zen. I wouldn't be surprised at all if what is on offer here is more than adequate in terms of SNR for the bulk of what's out there. At just under 75 for an MM and around 65 ideally for a MC, you're probably at or even past the limits of an average setup by a good margin.

But on second thought, I think Amir is quite right to call out the high frequency overload. I should have paid more attention there. Looking at this a bit today, people who know a lot about these things all tend to agree it is highly important--perhaps one of the more important characteristics. And the Zen doesn't do so well here. It might not have enough margin at high frequencies. That said, I've only looked at this issue for less than an hour, but it seems you still generally want at least as much overload margin at 20kHz as you have at 1kHz to best handle pops and clicks, and this doesn't have it. Something like the NAD PP2e, on the other hand, does. It has 6 or 7dB more margin. Then there's how all this works with RIAA curves and whatnot, how they did the specs, and calculating the actual margin based on what was done and how, and it all gets a bit annoying to work through quickly. In the end, I'd take a NAD PP2e or whatever comes in the stock Marantz AV10 (and likely other Denon/Marantz receivers) over this. 20dB all the way out to 20kHz seems desirable for safety, and this isn't there. How audible is it? I don't know. You'd have to take a really hot and ideally somewhat beat up record and listen to them back to back to work that out. If all your records are pristine, it may not matter at all.

This is one of the best summaries on the limitations of vinyl that I've ever read (I started reading cartridge reviews over 50 years ago)!

 

[ryanmh1]

This is one of the best summaries on the limitations of vinyl that I've ever read (I started reading cartridge reviews over 50 years ago)!

Well, thanks! Not too bad for not giving it a lot of thought until this week! I finally decided to get my vinyl setup going again since I finally got the rest of the two channel setup back on its legs. It's amazing the difference a pair of speakers I actually like can make. The Linn was quite fiddly, and the power supply was going bad, so I took that as an excuse to buy a new direct drive TT. Finally had to figure the rest of it out. After getting the MM cart figured out so I didn't have to attach nearly $1000 to the end of a stick and risk shooting fire from my eyeballs when someone broke it, that left phono stages.

Looked at it a bit more today, and I still think shooting for 20dB overload is good across the board. At high frequencies, less will do. I finally worked out the math and wrapped my head around RIAA curve, and it would seem that as Amir measures it, for a 5mV that's only going to be 50mV 1kHz and also that at 20kHz. These measurements are with the RIAA curve applied, so the actual voltage is more like 500mV at 20kHz, for preamps that spec it that way. NAD with with its 900ish spec has about a 25dB margin, which holds across the board. Divide voltage by 10 to match up the measurements with a spec measured without the RIAA in there.

To keep it on topic, I *think* the iFi would be fairly characterized as having about a 17dB margin referenced to a 5mV input at 20kHz, and perhaps 30dB referenced to a 5mv input at 1kHz. That's quite respectable, and probably good enough in most cases. Something like the ART DJ-PRE II, on the other hand, apparenly is 22, maybe 23mV. That's under 14dB of headroom referenced the same. Not good, especially if it degrades even worse at high frequencies. ART Precision Phono, on the other hand, knocks out a 28dB overload at 1kHz. Likely to be fine at 20kHz. Unless I've gone and gotten this all wrong (which is possible) it opens up a question: Soundstage and ASR measurements for overload on the original Zen Phono don't match--not even close. I think they've gone and not subtracted 20dB for the RIAA curve for the 20kHz measurements, which I don't think is the right way to report it. Either way, this little box actually does an okay job all around, when the RIAA is factored in, if the betterment over the RIAA curve on the Precision Phono is seen as a desirable.

Worth almost $200 more, though? Well... Hard to tell. SNR is possibly concerning. It's possible that when plugged into a cartridge the Precision Phono gets a whole lot worse than this does. No idea where I got 75dB from for the SINAD or SNR on this thing in my prior post. Ifi says 82dB unweighted, which is better than the 70dB SINAD here. But, once again, we don't care about the SINAD. This is not a relevant specification of any technical consequence to a phono stage (see discussion of how atrocious the distortion in the phono cartridge is). We care about SNR. Trying to sort out phono stages based on distortion readings is a fool's errand. Really hard to tell what the SNR actually is, and why if SINAD is noise limited, it's a whole 10dB worse than the manufacturer claims. That's where Soundstage's measurements of the Zen Phono come back in. They measured 80dB SNR unweighted. They then measured .02% THD+N (SINAD), which is -74dB. So, in fact, SINAD is distortion limited. In the graphical measurement, it appears to be noise limited, but it's likely not. And since, as we know, distortion in a phono stage is a total non-issue, this is in fact fine (assuming performance with cart connected). Sterling RIAA, huge overload at 1kHz, probably adequate at 20kHz, and actually quiet enough assuming it's not worse than the original. Real question is whether a flat RIAA is worth $200 over the Art Precision Phono. Can't answer that. And ah, but wait! The NAD PP2e is still quieter than this, and has better overload margins, and pretty much pancake flat too. But this has more features for possible loading with an MC cart. You could spin around in these circles all day!

EDIT: Hotlinking this photo in that Amir posted previously. Good explanation for overload margins and the best hard data I've seen for an upper limit:

I'm not entirely convinced I've got this figured out right yet on high frequencies. When they refer to high frequency overload margins in decibels, should that or should that not include RIAA? This goes on to say that 28dB is desirable in the audio band, rising to 36dB ultrasonic. That just doesn't make sense at all if you calculate the required margin in dB after tending to RIAA. @sergeackland went on to say in that thread that, "with, say, a 20dB overload margin at 1kHz, that should be near enough 40dB at 20kHz". Well, that's just how Soundstage was specifying it in decibels, so maybe they are right to do that after all.

So, I have to think they're suggesting 16dB in the ultrasonic region (subtracting out the 20dB RIAA), when measured as ASR measures it. I think this must be the right answer, since maintaining 38dB at ultrasonic would otherwise be impossible. If we call 20kHz "ultrasonic", this is only 31mV at 20kHz as ASR measures it, since the RIAA curve is applied (310mV off the cartridge). If we call 20kHz "audio band" it's an itty bitty 12mV (which I believe is still 120 off the cartridge). If so, that would put overload requirements much lower, and a lot of these declines wouldn't be very concerning at all. The performance would actually be just fine.

That said, almost nothing but the iFi Zen that has been measured actually hits this quite optimistic 28dB at 1kHz, ref 5mV. So, I'm more impressed with this than I was. I think. I hate pre-emphasis curves.

 

[mike70]

But the music bass will be in phase, rumble bass out of phase.

Even with digital ... people that use subwoofers ... they have bass in mono

 

[Angsty]

Interesting review (Thanks Amir) for a multitasking phono preamp. I particularly like the RIAA correction and the sufficient noise performance in MM mode. The headroom is acceptable for an entry/mid-range camera. The inclusion of a subsonic filter is a good idea but it seems too slow. On the other hand, on MC cartridges, the noise penalty is too high. In fact, it should be reserved for MM cartridges (or even high-level MC?). The brand would benefit from offering a phono stage dedicated to MC cartridges, provided that it seriously improves the noise performance.

Pretty good argument here for using a SUT instead of the MC gain stage.