ifi Zen Phono Review (phono stage)

[Baudrillard_J]

You might be able to audibly live with non-shielded single-ended interconnects for high level line connections such as a DAC to a pre-amp, if you don't have any electrically noisy things in your house and live some distance from transmitters. But for Moving Magnet and especially Moving Coil phono feeds, screened connections are necessary.

Yes indeed and from what I now realize it is not easy to find a good, reasonably-priced pair of phono RCA cables. From what I read "good" means at least a double-braided, 100% coverage copper cable. I am not sure about the actual signal wire, if it is considered best practice to be single core or braided, most implementations of "high-end" phono cable seem to use a braided signal wire (not counting the braid which acts as the return path or ground for the single-ended signal not the external turntable ground). From a brief search online, these cables run upwards of $500 and can reach up to ~$10.000 for the Fono Acustica Armonico Phono. And no, this is not an ad feel free to post an even more expensive one if you find it. Maybe then we can get @amirm to test it!

Now, it seems to me that many choose to make their own phono cable using good quality microphone cable and rca plugs of their choosing. For that case, my understanding is that you care about the capacitance of the cable only for the case of a MM cartridge and that for the MC case your goal is to keep the resistance as low as possible. As for inductance, in my case of the MC-Low DL-103 into what @Thorsten Loesch recommends as proper loading of 1KOhm (which is what the Zen phono presents to the cartridge at the MC-Low input) any cable inductance effects are already taken care of by that 1KOhm input resistance. Again, this is from what I read online.

I am also sharing here for reference two photos of the Zen phono (internal) PCB. It seems that it is using the STC 12LE5A60S2 microcontroller and OVA2637 opamps for which there are no spec sheets since it's in-house.

 

[Bob from Florida]

Yes indeed and from what I now realize it is not easy to find a good, reasonably-priced pair of phono RCA cables. From what I read "good" means at least a double-braided, 100% coverage copper cable. I am not sure about the actual signal wire, if it is considered best practice to be single core or braided, most implementations of "high-end" phono cable seem to use a braided signal wire (not counting the braid which acts as the return path or ground for the single-ended signal not the external turntable ground).

The homemade cables of mine were all shielded and quiet. Either coax or 2 conductor shielded with separate ground wire for grounding the arm to the phono preamp ground post. The 2 conductor version had the shield and the "minus" wire together at the Din plug for the tonearm - shield not connected at RCA end. The coax version - shield connect at Din plug and RCA "minus" of course. Both quiet with no hum. Then a friend gave me a Kimber KCAG phono cable - not in their catalog any longer. Three silver wires in a weave for each channel with 2 of the 3 connected together at both the Din side and RCA side for each channel. No hum in use, which shows you can have a quiet phono cable without a braided shield if done correctly. See photos below.

 

[MaxwellsEq]

No hum in use, which shows you can have a quiet phono cable without a braided shield if done correctly. See photos below.

As I mentioned before, it is location and system dependent. If your house or locale have a lot of electrical noise or if there are high energy systems or transmitters nearby, you may have no choice but to use a screened cable.

Personally, I'd rather use a quality screened cable from Belden, Canare or Mogami with some reliable connectors.

 

[Bob from Florida]

As I mentioned before, it is location and system dependent. If your house or locale have a lot of electrical noise or if there are high energy systems or transmitters nearby, you may have no choice but to use a screened cable.

Personally, I'd rather use a quality screened cable from Belden, Canare or Mogami with some reliable connectors.

I have a noisy location due to power cables in the wall right behind my turntable. I was quite surprised when this cable worked as well as my shielded cables. This was with my old turntable that had a Din plug where I could use it. My current table is wired straight through from cartridge wires to RCA plugs. I do agree that usually you want the braid shield.

 

[Baudrillard_J]

So the rf interference (radio, vhf, etc.) was taken care of using shielded cables. As said, I was not aware of the extent of the problem because apparently REGA sells their tables with pretty good cables from the factory.

However the 60Hz mains was still there. Just swapped the thick mains power cable that came with the Technics with a cheap power cable from an unused monitor and hum is gone. This was a test but I was amazed as to the result. I will get a proper cable at some point but I cannot help myself but wonder what all this thickness was for Technics?!

I will agree with @MaxwellsEq it is very location specific and from what I experienced, especially in urban settings a shielded cable is probably needed.

@Bob from Florida the Kimber cable looks very similar -at least superficially- to the Project Connect-it. But I am really glad you liked it and curious about how the unshielded Kimber cable managed to supress rf intereference for no reason other that I like Kimber cables, I use them for the speaker connections.

P.S. I went with Gotham Gac-1 UltraPro and will also test their EMT-2111 replica with Deltron and KLEI plugs but it was kind of a let down to find out that behind all this “Swiss” marketing they actually source from a factory in Turkey.

 

[Bob from Florida]

@Bob from Florida the Kimber cable looks very similar -at least superficially- to the Project Connect-it. But I am really glad you liked it and curious about how the unshielded Kimber cable managed to supress rf intereference for no reason other that I like Kimber cables, I use them for the speaker connections.

Just to be clear - my turntable location is susceptible to 60 Hertz hum coupling from AC wiring in the wall behind my rack. I have not had any RF - radio stations picked up at any time.
The Kimber phono cable achieves hum cancellation because of the "weave" of the 3 wires. Using 2 out of the 3 for the "ground" return also gives some degree of shielding similar to a braided shield. This works with common mode hum equally picked up by the cable wires. If your cartridge is picking up the hum - think Grado's - then you will have hum no matter what cable you use.

 

[DSJR]

The Amazon basics RCA cable I recall, was opened up and found to be very good, with good shielding and no skimping on the inner conductor either!

I've used Van Damme Tour grade with Rean RCA's as 'tonearm exit' cables with no issues at all (they do a slimmer pro Patch version as well with similar results).

Selected Mogami cables work well too, as do Klotz and Linn use the Mogame 2549 mic cables in their hideously expensive (for what it is) tonearm 'T' Cable (I believe both inners are used as hot and return, with the outer screen connected at one end only, or left floating and coupled to the turntable chassis in this case.

I don't trust Kimber at all I'm afraid and the electrical characteristics may also not be suitable despite hum rejection (subject to proper testing of capacitance).

 

[WDeranged]

@Thorsten Loesch Is there any kind of clip prevention circuit in the Zen Phono? I'm chatting with a user with a high output (8.5mV) cartridge and they're hearing "compression like" sounds during loud bass.

 

[audioeclectic]

Mr Thorsten Loesch
I have this setup, Audio Technica AT-LP7 turntable, AT-OC9XSL MC Phonocaptor and the ifi ZEN Phono, the ifi ZEN Phono caught my attention because of the design of the subsonic filter, I have it connected via XLR to my Schiit Freya S preamplifier, the The first question I have, and it seems the answer may be obvious, but I don't know, is does the subsonic filter work for both RAC Single Ended and XLR outputs? I have some discs where I do notice that it effectively mitigates the subsonic frequencies due to disc undulations, but I have some others that seem to be in the same condition, and on those discs I still notice abrupt movement of the cones, could it be that they are undulations that do they go beyond the threshold of the filter? The record I took as an example is one of Lee Retinour's GRP - Rio which I really like and comes from a digital master. What else could you tell us about it?

 

[mike70]

Mr Thorsten Loesch
I have this setup, Audio Technica AT-LP7 turntable, AT-OC9XSL MC Phonocaptor and the ifi ZEN Phono, the ifi ZEN Phono caught my attention because of the design of the subsonic filter, I have it connected via XLR to my Schiit Freya S preamplifier, the The first question I have, and it seems the answer may be obvious, but I don't know, is does the subsonic filter work for both RAC Single Ended and XLR outputs? I have some discs where I do notice that it effectively mitigates the subsonic frequencies due to disc undulations, but I have some others that seem to be in the same condition, and on those discs I still notice abrupt movement of the cones, could it be that they are undulations that do they go beyond the threshold of the filter? The record I took as an example is one of Lee Retinour's GRP - Rio which I really like and comes from a digital master. What else could you tell us about it?

Something I see ... that turntable comes with a VM series cartridge, that cartridges have a dynamic compliance of about 10 (at 100Hz).
You replaced by a cartridge in the oc9 series that have a dynamic compliance of about 16 (at 100Hz).

I think that cartridge is not the best partner with that tonearm, you can use the original cartridge to check with the same tracks if the resonances (cone movements) are lesser.

I don't use a filter and with the right cartridge I don't see badly cone movements with reasonably warped records.

 

[audioeclectic]

Something I see ... that turntable comes with a VM series cartridge, that cartridges have a dynamic compliance of about 10 (at 100Hz).
You replaced by a cartridge in the oc9 series that have a dynamic compliance of about 16 (at 100Hz).

I think that cartridge is not the best partner with that tonearm, you can use the original cartridge to check with the same tracks if the resonances (cone movements) are lesser.

I don't use a filter and with the right cartridge I don't see badly cone movements with reasonably warped records.

Thank yo for your response, befor to purchase the cartridge and the headshell, I asked to Audio Technica technical support if that could be compatible with this tonearm, and they answer yes it it’s compatible and works fine, in fact they use in their web page, a picture with that cartridge installed on this tonearm, and for your advices, when I used the original MM cartridge and with its own headshell, it happened the same thing using with ifi zen phono with subsonic filter on, but as I tell you, with some records I don’t see this badly cone movements, it just happens with some records, but with the majority of them, in fact I noted the same movement with both cartridges, I guess some warping records overpassed the filter capacity or something like that, but I just wanted to know your opinion.

 

[mike70]

Thank yo for your response, befor to purchase the cartridge and the headshell, I asked to Audio Technica technical support if that could be compatible with this tonearm, and they answer yes it it’s compatible and works fine, in fact they use in their web page, a picture with that cartridge installed on this tonearm, and for your advices, when I used the original MM cartridge and with its own headshell, it happened the same thing using with ifi zen phono with subsonic filter on, but as I tell you, with some records I don’t see this badly cone movements, it just happens with some records, but with the majority of them, in fact I noted the same movement with both cartridges, I guess some warping records overpassed the filter capacity or something like that, but I just wanted to know your opinion.

Maybe you can get another preamp with filter on loan with some friend and test it.

 

[audioeclectic]

Maybe you can get another preamp with filter on loan with some friend and test it.

I am noticing a detail that seems very favorable to me, and apart from that it makes me correct a possible error that I had, with this Audio Technical cartridge AT-OC9XSL with 100 ohms recommended load impedance, I had it configured in Ifi ZEN Phono with the gain of low MC Low: 1K Ohms, and I changed it to MC V Low: 110 Ohms,and now I notice that the subsonic filter works much better and I don't notice the abrupt movements in the driver cones, and everting sounds much better, regardless of the higher gain, could you confirm if this is correct?

 

[dougi]

As I mentioned before, it is location and system dependent. If your house or locale have a lot of electrical noise or if there are high energy systems or transmitters nearby, you may have no choice but to use a screened cable.

Personally, I'd rather use a quality screened cable from Belden, Canare or Mogami with some reliable connectors.

I compared noise and hum measurements with a different Kimber cable used for phono and with shielded cables. While I could not hear any hum or noise with the Kimber, through shielded cables I could definately measure an improvement. I have stuck with cheap but effective RG6 style cables since (which also have quite low capacitance).

 

[WDeranged]

The biggest hum reduction I got with my Zen Phono was to move all mains cables far from the turntable and wire the ground lug directly to the earth connection in my house. I went on a mad mission moving my turntable setup around the room to narrow down my noise issue. It was always a mains cable running near the turntable.

 

[mike70]

The biggest hum reduction I got with my Zen Phono was to move all mains cables far from the turntable and wire the ground lug directly to the earth connection in my house. I went on a mad mission moving my turntable setup around the room to narrow down my noise issue. It was always a mains cable running near the turntable.

What's your TT?

 

[WDeranged]

Rega Planar 1. Which has a reputation due to Rega's non standard grounding method.

 

[mike70]

Rega Planar 1. Which has a reputation due to Rega's non standard grounding method.

Yes ... I never had a problem with hum (even using MC step-up transformers) side by side to my Technics.

 

[WDeranged]

Yes ... I never had a problem with hum (even using MC step-up transformers) side by side to my Technics.

Have you ever compared the two turntables with the same cartridge? I'm more than satisfied with my budget TT but I often wonder what a Technics might sound like.

 

[mike70]

Have you ever compared the two turntables with the same cartridge? I'm more than satisfied with my budget TT but I often wonder what a Technics might sound like.

After some "medium quality" .... I don't think TTs sounds much different.

The Rega P1 is a basic device, a Rega P3 or Technics MK7 are good stuff above the P1. Then a Rega P6 or Technics GR have better construction, materials, ... but ... will "sound" better? I don't think so.

That's my opinion. You can have some improvements above P1 ... but, after that "medium quality" ... I doubt it.