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Budget DAC test: ViewHD Prosumer UltraHD HDMI 3x1 switcher

Blumlein 88

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#1
I purchased an HDMI 3 input 1 output switcher a couple weeks back. Price is just below $40. It is a ViewHD PRO 3X1. Now it switches HDMI sources obviously. It also can strip out audio in surround or stereo format via Toslink optical. In addition it has analog two channel output. So I thought, hey why not treat it as a budget DAC. This is not one of Amir's official reviews.


https://www.amazon.com/gp/product/B00U8WBOOG/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1





Now there are some cheap knockoffs out there. Yes, a cheap knockoff of a sub $40 device. Tear down pics show the same board and chips, but severe compromises on the power supply and capacitor decoupling. So if you need one insist on ViewHD, and not other brands that look exactly the same. I kid you not.


As you might expect I was in for some surprises. I fed it signal over the HDMI via my Lenovo laptop with files playing via Foobar 2000 Wasapi (push), as it would not play with WASAPI event. The output was recorded with a Focusrite Forte.


Okay silent noise floor was about -90 db so not bad. Most of it were decreasing tones at 50, 100, 150 and 200 hz all at a bit below 90 db. Odd as I am on 60 hz electricity here. ???


Channel separation was better than 120 db except one channel was 108 db only near 20 khz. Nothing to worry about.


A 1 khz tone had reasonably low distortion, but included all harmonics to 20 khz above the noise floor. Another feature worth noting. See those spurs at 700 and 1300 hz. Here only 80 db down. Apparently jitter. Every tone has those around it, and at 20 khz they reach just over -50 db. This at 44 khz operation. Same situation and same levels, but at 48 khz the spurs are spaced at 100 hz.


ViewHD  1    1 khz.png


Frequency response was flat enough not worry about.

ViewHD 2 FR.png


IMD distortion with 18 khz and 19 khz at full scale was not great however. -48 db below signal level for the 1 khz difference signal and similar levels around the tones themselves. You can still see the 50 hz tones and the 300 hz spurs around the high frequencies.

ViewHD 3 IMD.png



Jitter was pretty high though I didn't put a number on it. The 300 hz spurs above and below were only 67db below a quarter sample rate tone at 44 khz and 100 hz spacing with the same levels at 48 khz. You can also see how wide the spread is and effects the noise floor considerably.


ViewHD 4 jitter.png



Here is a 20 khz tone (red) and -4db white noise (blue) superimposed with 192khz sampling from the 48 khz test. Also shown is the silent no signal noise floor(green). So you can see something of the filtering and imaging. Not great, but not horrible if not for the jitter effects.

ViewHD Jurgen 5 wideband plot.png



Here is one I like to do and show for how filtering handles signals. You are seeing a real time FFT in this case a 128 K FFT meaning it is grabbing 128 k samples to construct this. The signal is a linear sweep of twin tones separated by 1000 hz.

First the spectrogram in this case from 48 khz of the entire twin tone sweep. You see IMD distortion worsens with frequency and some THD evident too. The background goes to gray at -120 db.

ViewHD 6 twin tone sweep.png




These are a few snapshots during the sweep of the twin tones with 96 khz bandwidth. Interesting how the reflections move as the frequencies move. Also notice even in the below 20 khz range the noise floor gets modulated heavily. Good DACs don't do much of this.


ViewHD twin sweep 1.png
ViewHD twin sweep 2.png
ViewHD twin sweep 3.png
ViewHD twin sweep 4.png
ViewHD twin sweep 5.png



For comparison of the last image here is the same result for the old Tact RCS 2.0 I have on hand. Notice the 1 khz difference tone is below -110 db here instead of the near -50 db of the ViewHD. The two tones show some reflection around the sample rate, but at levels down near -120 db with the Tact instead of the much higher levels and jitter side bands of the ViewHD.


Tact RCS2 twin sweep.png



So how does it sound? My subjective impressions (done after measurements were viewed by me). It has a smoothed over sound. Not harsh (which I expected might creep in with the high IMD). It did not image very widely or precisely. So less depth, width and detail with an innocuous sound quality. If you needed it not exactly terrible, but my Nexus 6P smartphone is better and I suspect many phones would be. For TV if you need it okay, but otherwise you can do better. Glad I use the Toslink digital out. Seems fine listened to this way. I haven't checked the jitter via Toslink to see if any of it is slipping thru.


Oh, and as an HDMI switcher it is pretty nice. With a 12 foot cable straight from the satellite source I would sometimes get minor momentary picture tearing effects as if the signal was iffy to my projector. Don't get those with blu-ray or computer sourced HDMI. I chalked it up to satellite. Since getting this switcher and now using a 35 ft HDMI cable to my projector I no longer get those artifacts. So it seems an improvement in that one sense. Switches well with the supplied remote. My only complaint is the remote is too tiny. Smaller than a credit card. Has good range though. The LEDs on front are just right, lit enough you can see them, yet not so bright as to distract during low light viewing.

As an HDMI switcher/digital audio extractor.........

Thumbs up.png



As a low buck DAC........................................................................................................

Thumbs down.png
 
Last edited:

RayDunzl

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#2
I read all the results.

I like the two-tone sweep in Audacity. I'll try that here.

---

But now I'm looking that the thumbs above.

I can make my hand do the thumbs-up. It's easy, a left-handed gesture.

The thumbs-down, visually, is harder to comfortably duplicate.
 
OP
Blumlein 88

Blumlein 88

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I read all the results.

I like the two-tone sweep in Audacity. I'll try that here.

---

But now I'm looking that the thumbs above.

I can make my hand do the thumbs-up. It's easy, a left-handed gesture.

The thumbs-down, visually, is harder to comfortably duplicate.
Actually I haven't liked it since I posted it, the thumbs up that is. So I think I will change one of them. I marginally prefer the lower one rotated so it is both up and down. I do think I will replace them.

The sweep in Audacity just to save time I create a chirp, from 2 to 19,000 hz and another over the same period from 1002 to 20,000 hz. Then combine them.

I have also sometimes ferreted out odd behaviour with two sweeps one going upward and one going downward concurrently.
 

Thomas savage

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#4
I purchased an HDMI 3 input 1 output switcher a couple weeks back. Price is just below $40. It is a ViewHD PRO 3X1. Now it switches HDMI sources obviously. It also can strip out audio in surround or stereo format via Toslink optical. In addition it has analog two channel output. So I thought, hey why not treat it as a budget DAC. This is not one of Amir's official reviews.


https://www.amazon.com/gp/product/B00U8WBOOG/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1





Now there are some cheap knockoffs out there. Yes, a cheap knockoff of a sub $40 device. Tear down pics show the same board and chips, but severe compromises on the power supply and capacitor decoupling. So if you need one insist on ViewHD, and not other brands that look exactly the same. I kid you not.



As you might expect I was in for some surprises. I fed it signal over the HDMI via my Lenovo laptop with files playing via Foobar 2000 Wasapi (push), as it would not play with WASAPI event. The output was recorded with a Focusrite Forte.



Okay silent noise floor was about -90 db so not bad. Most of it were decreasing tones at 50, 100, 150 and 200 hz all at a bit below 90 db. Odd as I am on 60 hz electricity here. ???



Channel separation was better than 120 db except one channel was 108 db only near 20 khz. Nothing to worry about.



A 1 khz tone had reasonably low distortion, but included all harmonics to 20 khz above the noise floor. Another feature worth noting. See those spurs at 700 and 1300 hz. Here only 80 db down. Apparently jitter. Every tone has those around it, and at 20 khz they reach just over -50 db. This at 44 khz operation. Same situation and same levels, but at 48 khz the spurs are spaced at 100 hz.



View attachment 6359



Frequency response was flat enough not worry about.

View attachment 6360

IMD distortion with 18 khz and 19 khz at full scale was not great however. -48 db below signal level for the 1 khz difference signal and similar levels around the tones themselves. You can still see the 50 hz tones and the 300 hz spurs around the high frequencies.

View attachment 6361


Jitter was pretty high though I didn't put a number on it. The 300 hz spurs above and below were only 67db below a quarter sample rate tone at 44 khz and 100 hz spacing with the same levels at 48 khz. You can also see how wide the spread is and effects the noise floor considerably.


View attachment 6362


Here is a 20 khz tone (red) and -4db white noise (blue) superimposed with 192khz sampling from the 48 khz test. Also shown is the silent no signal noise floor(green). So you can see something of the filtering and aliasing. Not great, but not horrible if not for the jitter effects.

View attachment 6378




Here is one I like to do and show for how filtering handles signals. You are seeing a real time FFT in this case a 128 K FFT meaning it is grabbing 128 k samples to construct this. The signal is a linear sweep of twin tones separated by 1000 hz.

First the spectrogram in this case from 48 khz of the entire twin tone sweep. You see IMD distortion worsens with frequency and some THD evident too. The background goes to gray at -120 db.


View attachment 6364



These are a few snapshots during the sweep of the twin tones with 96 khz bandwidth. Interesting how the reflections move as the frequencies move. Also notice even in the below 20 khz range the noise floor gets modulated heavily. Good DACs don't do much of this.


View attachment 6369 View attachment 6368 View attachment 6367 View attachment 6366 View attachment 6365



For comparison of the last image here is the same result for the old Tact RCS 2.0 I have on hand. Notice the 1 khz difference tone is below -110 db here instead of the near -50 db of the ViewHD. The two tones show some reflection around the sample rate, but at levels down near -120 db with the Tact instead of the much higher levels and jitter side bands of the ViewHD.


View attachment 6370


So how does it sound? My subjective impressions (done after measurements were viewed by me). It has a smoothed over sound. Not harsh (which I expected might creep in with the high IMD). It did not image very widely or precisely. So less depth, width and detail with an innocuous sound quality. If you needed it not exactly terrible, but my Nexus 6P smartphone is better and I suspect many phones would be. For TV if you need it okay, but otherwise you can do better. Glad I use the Toslink digital out. Seems fine listened to this way. I haven't checked the jitter via Toslink to see if any of it is slipping thru.


Oh, and as an HDMI switcher it is pretty nice. With a 12 foot cable straight from the satellite source I would sometimes get minor momentary picture tearing effects as if the signal was iffy to my projector. Don't get those with blu-ray or computer sourced HDMI. I chalked it up to satellite. Since getting this switcher and now using a 35 ft HDMI cable to my projector I no longer get those artifacts. So it seems an improvement in that one sense. Switches well with the supplied remote. My only complaint is the remote is too tiny. Smaller than a credit card. Has good range though. The LEDs on front are just right, lit enough you can see them, yet not so bright as to distract during low light viewing.

As an HDMI switcher/digital audio extractor.........

View attachment 6374


As a low buck DAC........................................................................................................

View attachment 6377
@amirm member @Blumlein 88 has both shamed you and schooled you with his excellent review post..
 

amirm

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#5
OP
Blumlein 88

Blumlein 88

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@amirm member @Blumlein 88 has both shamed you and schooled you with his excellent review post..
Come on now Thomas. No attempt at shame. I had pestered Amir about the DAC reviews and it occurred to me I could do one of my own with this device. Besides, Amir was able to attend Axpona and has been filing beautiful show reports, and I didn't get to go. :(

I have read published articles by Amir too so I don't think there was any schooling involved. Heck I even forgot the Dirac pulse results to tell us what kind of filter was in use.
 
OP
Blumlein 88

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The question came up later on about how the ViewHD device worked if you feed the Toslink output form it to another DAC. This is how I use it in my video system.

So in the following measurements, the red is the ViewHD Toslink feeding a Tact RCS 2.0. The green is the same Tact RCS 2.0 being fed over Toslink using a Musical Fidelity V-link USB to SPDIF converter. Even over Toslink the ViewHD is not as clean. And 44 khz rates are much worse than 48 khz rates. I attribute much of this to the fact you can only feed the ViewHD digital audio via an HDMI connection. HDMI connections are usually poor in terms of jitter performance. I doubt the result at 48 khz is audible or not obviously so. Worst case is IMD is around -72 db for 48 khz. Some artifacts using 44 khz rates get high enough to cause some concern.


First up is 1 khz at 44 khz sampling rates. After that is the same signal at 48 khz sampling rates. You'll notice the 48 khz rates are cleaner though both are dirtier than the Vlink Toslink feed.

1 khz 44.png


48 khz 1 khz tone.

1khz 48.png


Next the Jtest. Again notice the 44 khz from the ViewHD Toslink is much dirtier than the 48 khz version. Both are worse than the V-link device.

jtest 44.png


48 khz Jtest.

jtest 48.png


Finally the twin tone IMD test 44 khz and 48 khz. This is not a good result from the ViewHD. Still I don't notice real issues watching movies with this device.

twin tone imd 44.png


48 khz ViewHD

twin tone imd 48.png
 
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