ChitChat:
Streamers are becoming increasingly popular nowadays, and I’m very glad that’s the case.
Personally, I think that a beefy gaming PC is literally THE worst possible thing you can have in an audio chain, and getting away from that, even just to something basic like a raspberry pi, can bring a surprising improvement to setups regardless of price or performance level.
A PC is horrifically noisy from an electrical standpoint, and also typically has poor to awful jitter and scheduling on SPDIF and USB.
A dedicated device, such as this zen stream, is a fantastic way to get a nice bump in sound quality which applies to any chain.
For those who just want to plug and play and have everything done though, without configuring a pi themselves, ifi has released the Zen Stream.
A full review of this unit is coming, and it will be VERY positive cause this is a great bit of kit.
But for now, here’s some measurements to compare to other streamers and DDCs like the pi2aes, DI20HE and Singxer SU-6.
Test Setup:
– Audio Precision APx555 B-Series Analyzer
– AudioQuest Carbon SPDIF Cable (1.5m)
– ifi iPower 15v PSU
– Netgear network switch, CAT7 Ethernet cable
– 44.1khz and 48khz white noise played through device during measurement
Measurements:
Jitter:
To measure jitter, the device is connected to the digital input of the APx555, and the analyzer is set to analyze jitter, not audio content.
These measurements do not show audio/analog info, but instead show the spectrum of jitter, ie: time-domain inconsistencies.
This is the primary factor that a good streamer or DDC will seek to improve.
I’ll be posting some measurements of other DDCs/Streamers shortly, so if you’re not sure what to compare this to yet, you won’t have to wait too long!
Electrical Noise:
The second issue that a good DDC or Streamer will seek to address is electrical noise. You don’t want noise from your source causing your DAC to perform poorly. Noise can have a direct, audible effect, such as hearing GPU-whine through your headphones/speakers, or it can have indirectly-audible effects. For example, causing clocks in your dac, or other circuitry, to perform sub-optimally.
Some dacs are more immune to this, and some will even have full galvanic isolation to in theory prevent any noise getting through entirely. But many smaller dacs are much more susceptible to it.
The Zen-Stream comes with a high quality iPower PSU, and ifi says it has Active-noise-cancellation tech on the outputs.
As the measurements show, clearly whatever ifi is doing is working:
This is seriously fantastic noise levels, absolutely nothing here that anyone could possibly consider anything but fantastic. Well done ifi!
Even if for some reason your dac was so horribly designed that it just put all of this noise directly through to the output, it’d be at -107dB relative to 4v (in the 20hz-20khz band).
Also worth noting that the zen stream disables the SPDIF output when nothing is playing, so noise measurement must be taken whilst something is being put through the streamer.
Very good practice. How comes that noise in the plot is in nano and micro range, depending on frequency, and then the RMS is in millivolt range? There seems to be something wrong. Thanks
The RMS is integrated over the audio bandwidth so to get from the noise versus freq plot to a single RMS number you need to multiply it with the square root of the bandwidth, which is about 142 for a 20kHz band.
Jan
Ok, good. Do you have any measurement for the usb output? Thank you
Antonio, it seems you ask me, but I’m just an interested guy, not the one doing the measurements 😉
Hi from Germany, is there any chance to see differences in measurements while beeing powered by 12V battery? By the way, mine was delivered with an IFI 9V power supply in the Box. I wondered why you used a 15V IFI?
The unit has a variable voltage power supply that automatically adjusts based on the voltage coming from the adapter. It doesn’t matter whether you use 9, 12 or 15 volts, the power that emerges from the device’s internal power supply will be the same.
Will you be reviewing Pro Ican/DSD , galvanic 3.0 or micro iusb ? 🙂
Nice review, would have liked USB jitter tests at higher bandwidths, but this is a helpful start. Bit confused about what noise you’re referring to though, other than maybe a ground loop, for a device that exists wholly in the digital domain. The ZS doesn’t even have an internal DAC—it’s transporting ones and zeros from a network. In the unusual event that any errors occurred in that process they would manifest as stutters, glitches or dropouts, not a degradation in sound quality or any rise in the noise floor. Can you please explain?
Hi. Nice tests, would be anyway even nicer to have something more compete now . I would like to share my experiences: I have this device which is powered by an IPower Elite 15V and was connected via an Audioquest Coffee usb cable to a relatively old Lector Digitube S192 DAC . I use the word “was” as few days ago , after months of pain from harsh sound , I decided to try to use the spdif using an old good analog rca cable as I don’t have a coax digital cable at home : I resolved the harshness, now I have a much more natural, rich and analog sound . This make me think that the usb doesn’t work so well in my hardware combination, may be because the DAC hasn’t a very good usb interface or because the Zen Stream spdif output has much better performances.
Your opinion would be really appreciated.
Thanks !!!!
Hi! I am a litle bit confused. Should I buy the ifi streamer or the Gustard U-16 to connect to my Gungnir ? I should buy both, but wich one first ? What is best ? The ifi streamer connected to the dac or the Gustard between the iMac and dac? Hifi dilema… Not to mention what would be best, the Gustard or the Iris? Any comments ? Thanks !!!
how does this device compare with the Bluesound Node with the PDCreative PSU upgrade meseaurements posted on their website?