ifi Zen CAN Review (Headphone Amp)

[staticV3]

Hi all! I have this amp. How it work wit LCD 2 classic? Thanks

The LDC-2 Classics is a very easy to drive headphone. The Zen Can will have no problems with it.

 

[odyo]

Anyone have any idea why balanced connection causing a ground loop ?

 

[cheapmessiah]

Anyone have any idea why balanced connection causing a ground loop ?

I'm no electronic engineer, but how can a device powered by a 2 prong wall wart be grounded? Or in other words how can an appliance that's not connected to ground be grounded?

My understanding is that this device has a common ground in the 0v rail, but the device isn't really grounded.

I grounded mine connecting a 3.5mm double male cable between my computer and it (there's other ways equally cumbersome), and I don't know how that works or why it works, since 3.5mm isn't grounded connection either, but it does.

 

[odyo]

I'm no electronic engineer, but how can a device powered by a 2 prong wall wart be grounded? Or in other words how can an appliance that's not connected to ground be grounded?

My understanding is that this device has a common ground in the 0v rail, but the device isn't really grounded.

I grounded mine connecting a 3.5mm double male cable between my computer and it (there's other ways equally cumbersome), and I don't know how that works or why it works, since 3.5mm isn't grounded connection either, but it does.

I use RCA cables between zen dac and zen can too. It dissipates the 4.4mm bal interconnect buzz. I find it weird that RCA has no issues but BAL has issues. It should be reverse lol. I bought this 4.4mm bal cable from aliexpress. Can it be the cable ?

 

[Veri]

I use RCA cables between zen dac and zen can too. It dissipates the 4.4mm bal interconnect buzz. I find it weird that RCA has no issues but BAL has issues. It should be reverse lol. I bought this 4.4mm bal cable from aliexpress. Can it be the cable ?

Definitely weird. And no, I doubt it.

 

[cheapmessiah]

I use RCA cables between zen dac and zen can too. It dissipates the 4.4mm bal interconnect buzz. I find it weird that RCA has no issues but BAL has issues. It should be reverse lol. I bought this 4.4mm bal cable from aliexpress. Can it be the cable ?

Don't think so, you could buy the ifi 4.4mm interconnect on Amazon if available, and return it if it doesn't solve the problem, or even if it does since its price is outrageous.

Also, did you notice any output volume increase going from RCA to bal? I bought a topping d10bal thinking I would get some more output volume but I got the same I had from RCA.

 

[Veri]

Also, did you notice any output volume increase going from RCA to bal? I bought a topping d10bal thinking I would get some more output volume but I got the same I had from RCA.

That is.. also weird. These Zen CANs seem to have some seriously odd design

 

[odyo]

Don't think so, you could buy the ifi 4.4mm interconnect on Amazon if available, and return it if it doesn't solve the problem, or even if it does since its price is outrageous.

Also, did you notice any output volume increase going from RCA to bal? I bought a topping d10bal thinking I would get some more output volume but I got the same I had from RCA.

Yep no volume increase. That surprised me too. RCA and BAL same loudness despite being 2v vs 4v. I guess they are both 0db unity gain.

This is what they say in product page:

Inputs

4.4mm Pentacon BAL RCA L/R Socket SE 3.5mm Jack SE

4.0V nominal @ 0dBFS, 24 kOhm Zin 2.0V nominal @ 0dBFS, 1 MegOhm Zin 1.0V nominal @ 0dBFS, 1 MegOhm Zin

I'm no expert but maybe input impedance causing this ? But 3.5mm jack is 0dbfs too.

Edit: They also say this maybe relevant:

• SE inputs (1M Ohm) ensures loading of the source so always in Class A operation

 

[Veri]

Yep no volume increase. That surprised me too. RCA and BAL same loudness despite being 2v vs 4v. I guess they are both 0db unity gain.

Actually, it would mean that SE in has +6dB gain to be equal to BAL's double voltage input. Either that, or the balanced input ignores half of the signal which would be false advertising and dishonest.

Unity gain would have the balanced be louder than the single ended input..

 

[odyo]

Actually, it would mean that SE in has +6dB gain to be equal to BAL's double voltage input. Either that, or the balanced input ignores half of the signal which would be false advertising and dishonest.

Unity gain would have the balanced be louder than the single ended input..

It should have some kind of mechanism to match all the inputs at output level. I don't know if this makes sense lol i'm confused.
In Amir's test at 300ohm 0db gain, SE out have 13mw, BAL out have 52mw. This should mean 2x2=4/300=13, 4x4=16/300=52 but the loudness is same?

 

[cheapmessiah]

It should have some kind of mechanism to match all the inputs at output level. I don't know if this makes sense lol i'm confused.
In Amir's test at 300ohm 0db gain, SE out have 13mw, BAL out have 52mw. This should mean 2x2=4/300=13, 4x4=16/300=52 but the loudness is same?

@32ohm both channels have the same output, I only have low impedance headphones ATM, so maybe with 300ohm HP the output difference is noticeable. I wonder if IFI limits the potential of the amp to such extent to keep it in class A mode.

 

[odyo]

@32ohm both channels have the same output, I only have low impedance headphones ATM, so maybe with 300ohm HP the output difference is noticeable. I wonder if IFI limits the potential of the amp to such extent to keep it in class A mode.

Yeah same but at 33 ohm at 0db gain, the difference is same. SE: 116mw BAL: 463mw. Their max power output is same but SE reaches that at 12db gain, BAL at 6db gain.
I don't know if this mean BAL have more power at same loudness ? which makes it better ?

 

[staticV3]

doesn't it just mean that the Zen Can has strong voltage capabilities but weak current supply?
At high impedances it can take advantage of a "hotter" input signal and extract the full +6dB advantage.
At low impedance it runs into current limits regardless of which output you use, so the advantage is gone.

 

[staticV3]

here's a graph to explain what I mean:


In yellow is Amir's single-ended 33/300Ω data, red the balanced 33/300Ω data, and in blue his balanced load sweep data.
In all three cases I added a fake 150Ω data point which just mirrors the 300Ω results he got. It's unlikely that voltage will drop going from 300 to 150 and leaving that out would've presented unrealistic graphs due to linear interpolation.
Still, take that with a grain of salt as that 150Ω data point does not represent measused values!

Also unfortunate is that Amir's 33/300Ω power data does not match his load vs Vrms vs distortion data. That's because he does his load sweeps at a really low resolution (high step size).

Nonetheless, you can see that at ~32Ω and below you won't get any more volume out of Bal than out of SE. It's only at higher impedances that the Zen Can's Bal out can stretch its legs.

 

[odyo]

here's a graph to explain what I mean:
View attachment 196255

In yellow is Amir's single-ended 33/300Ω data, red the balanced 33/300Ω data, and in blue his balanced load sweep data.
In all three cases I added a fake 150Ω data point which just mirrors the 300Ω results he got. It's unlikely that voltage will drop going from 300 to 150 and leaving that out would've presented unrealistic graphs due to linear interpolation.
Still, take that with a grain of salt as that 150Ω data point does not represent measused values!

Also unfortunate is that Amir's 33/300Ω power data does not match his load vs Vrms vs distortion data. That's because he does his load sweeps at a really low resolution (high step size).

Nonetheless, you can see that at ~32Ω and below you won't get any more volume out of Bal than out of SE. It's only at higher impedances that the Zen Can's Bal out can stretch its legs.

Discussion is around the loudness/gain, not max capability i think. Unfortunately i don't have any headphone to try balanced right now but
RCA in SE out and BAL in SE out has the same loudness (same gain and volume knob position). From my memory, with my balanced Ananda, they were still same.

 

[staticV3]

You're right. I'm sorry
Checking gain across all inputs and outputs can actually be done pretty easily with a multimeter and some adapters.
Maybe at some point a Zen Can owner will be curious enough to do it.

 

[LaL]

I just switched back and forth from 2Volt SE input and 4Volt Balanced input and yes, both are the same volume with balanced output.
But if I use the headphone jack on my phone as source - it's louder when I use the 3.5mm input on the back of the Zen-Can compared to feeding my phone into RCA on the Zen-Can.

 

[Makafuni]

Yep no volume increase. That surprised me too. RCA and BAL same loudness despite being 2v vs 4v. I guess they are both 0db unity gain.

This is what they say in product page:

I'm no expert but maybe input impedance causing this ? But 3.5mm jack is 0dbfs too.

Edit: They also say this maybe relevant:

• SE inputs (1M Ohm) ensures loading of the source so always in Class A operation

Don't know if this has anything to do with anything. Guess you know this, but the RCA of the Zen dac outputs 2.1V in fixed and 3.2V in variable mode. Switching to the variable mode it gets louder by a margin.
Is this because of the higher voltage going in to the Can? I would guess so but if the CAN's input RCA is nominated at 2V should this be avoided?
And why would it be louder with higher voltage in RCA SE and not from the BAL 4.4mm.

 

[odyo]

Is this because of the higher voltage going in to the Can?

Yes.

I would guess so but if the CAN's input RCA is nominated at 2V should this be avoided?

Max. Input

Balanced RCA 3.5mm

7.4V RMS 3.8V RMS 1.92V RMS

This is max input voltage so you can increase it.

And why would it be louder with higher voltage in RCA SE and not from the BAL 4.4mm.

It should be louder with BAL too. Use 4.4mm interconnect and try variable mode.

 

[Makafuni]

Yes.

Max. Input

Balanced RCA 3.5mm

7.4V RMS 3.8V RMS 1.92V RMS

This is max input voltage so you can increase it.

It should be louder with BAL too. Use 4.4mm interconnect and try variable mode.

But didn't you say volume was the same from RCA and 4.4mm? Or did I misunderstand something?