• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

SCH-REMOTE Digital VU/Spectrum Meter Review

Rate this VU/Spectrum Meter

  • 1. Poor (headless panther)

    Votes: 3 2.2%
  • 2. Not terrible (postman panther)

    Votes: 6 4.3%
  • 3. Fine (happy panther)

    Votes: 66 47.5%
  • 4. Great (golfing panther)

    Votes: 64 46.0%

  • Total voters
    139

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
45,235
Likes
247,881
Location
Seattle Area
This is a review and measurements of the Sch-remote EVOR04-slim LCD based audio VU/Spectrum/Visualization module. It was sent to me by the company and costs US $78 ($72 in volume).
EVOR04 VU Meter Spectrum Analyzer Review.jpg

This is a two-board sandwich with the display in the front as you see. On the right there is a USB jack for power or a standard barrel connector for the same. Two analog stereo 3.5mm jacks are provided which you can select from the menu. Screen is touch sensitive. I think it is resistive though as it requires some pressure and has a delay before it detects your touch. To the extent you don't need to touch it often, it is fine.

The unit is hugely configurable through the menu system allowing you to set such things as sensitivity, etc. Here is a shot of the back where the guts are:
EVOR04 VU Meter Spectrum Analyzer CPU board.jpg


The display in person looks very good. There is a bit of dancing/sequencing pixel going on at times which I suspect is due to refresh rate. There are not only stereo and mono graphs but also differential (X-Y) displays as well. I like the simulated VU meter of which there are 4 or 5:

EVOR04 VU Meter Review.jpg


This one has peak detection. Here is a shot of it with my mobile phone:
EVOR04 VU Meter Spectrum Analyzer Review Meter.jpg


Company also sent me a compact black plastic case for the unit to make it freestanding.

EVORO4-Slim Measurements
All the VU meters we have tested in the back have had poor front-ends, loading the input down causing severe distortion. So that was the first test I went for by first measuring my Audio Precision analyzer by itself:

APx555 Loopback Measurement.png


I set the output voltage to 250 millivolts as by default the VU meter is setup for 20 dB gain. I then plugged the EVOR04 in parallel to the signal connection above:

EVOR04 VU Meter Spectrum Analyzer Distortion and Noise Measurement.png

As you see the impact is basically non-existent indicating a nice buffer in the front-end of the meter.

Not that it matters a ton but I wanted to see how flat the frequency response of the meter was. I used its own display to show the dB value while I selected four different frequencies (calibrated to 1 KHz):
EVOR04 VU Meter Spectrum Analyzer Frequency Response Measurement.png


As you see, there is a bit of drooping at both ends of the spectrum, dropping by 1 dB at 20 Hz and 1.4 dB at 20 kHz.

Last bit was frequency resolution when using the spectrum analyzer:
EVOR04 VU Meter Spectrum Analyzer Frequency Resolution Measurement.png


The meter was fed a pure sine wave at 100 Hz which should just create a vertical bar. It does that at higher frequencies but as you go down, it widens as you see. It would have been nicer to make this much narrower. Unfortunately that sharply increases the computational requirement (and slows down the response some). Not sure if there are spare CPU cycles to throw at it.

Finally, I connected the meter to my DAC and enjoyed beautiful dancing bar graphs with low latency:
EVOR04 Spectrum Analyzer Review.jpg


What I wished the device had was IR remote. Then you could cycle through the visualizations in non-desktop applications.

Conclusions
I got into hi-fi in 1970s when VU meters and spectrum analyzers were often sign of status of the audio device. The larger the VU meter, the more high-end the unit was! Our sources were spinning devices whether we were talking cassette tapes, LP or reel to reel. Today, we have lost all of that with digital. Yes, software visualizations exist but they are too far removed from where the audio samples come out so they don't seem very connected to the music. And at any rate, they are not where they should be -- in our audio rack. I really like to see audio companies innovate in this domain and bring back attractive front panels sporting informative and beautiful displays. Modules like EVOR04 enable this as they seem to be built for OEMs to include in their audio devices.

I was pleasantly surprised how capable and flexible this meter is. I did not remotely do justice to its level of programmability in this write up. It does everything you wish and then some. I mean it even has two stereo audio inputs! And two ways of powering it.

On technical performance, there is no impact on your audio fidelity which is as it should be. The accuracy of the meter itself is not perfect but certainly good enough for fun.

I would like to see a more premium version of it with a stepped up display quality, remote control and better frequency resolution. As it is, what we have is quite compelling.

I am going to put the Sch-remote EVOR04 on my recommended list.

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
Last edited:
First known product for this kind, no other alternative. So, cast vote #4 from me.
Probably can be used to compare between 2 DACs from those 2 3.5mm jack inputs. If you want to compare 10 DACs, it means 5 pairs of comparison.
And next advancement, should be displaying SINAD, THD, SNR, etc so no need to visit ASR anymore.
Also it can input complex load and reacted impedance from speakers bla bla bla… so it can accurately give the performance of input amps
 
Last edited:
Looks really good, has lots of options, and is transparent. The price is okay I guess.

@amirm do you have a picture of the casing?
 
I got into hi-fi in 1970s when VU meters and spectrum analyzers were often sign of status of the audio device. The larger the VU meter, the more high-end the unit was!
It is my impression that this is still the case in the not so scientific HiFi-world, where spinning wheels and glowing tubes in many cases still are the norm.

Besides. Is this DIY-product just for fun, or are there any other reason to use it?
 
Besides. Is this DIY-product just for fun, or are there any other reason to use it?
Within its accuracy range, you can use it to find spectrum of your music, whether a signal is present or not, measure output power, etc. I use my RME ADI Pro spectrum analyzer all the time for first two.
 
At which rms level is the VU 0dB calibrated to?
I've always been disappointed by meters that don't have any real relationship to actual input levels. Especially when a sensitivity trim is provided (see Douk H7, for example).
 
Last edited:
Within its accuracy range, you can use it to find spectrum of your music, whether a signal is present or not, measure output power, etc. I use my RME ADI Pro spectrum analyzer all the time for first two.
Even more, when you use a mix of digital and analog sources, to see how much bandwidth is wasted in the latter case and remember your brain to not fall again in compulsive shopping next time you see a spinning reel...
 
Don't know what to think about it. I would probably play with it one day and then put it in some drawer. A semi-professional analyzer like the TC-Electronics Clarity M (Stereo) is not horribly expensive and just on a different level than this.
 
Looks really good, has lots of options, and is transparent.
Agree, I'm initially impressed. A good video here from the product site showing the case, various modes and functionality;


I like that the company even provides an STL file for 3D printing ones own case as well as a detailed datasheet etc.

This video was interesting I thought where they install one of these in an old DCC player;


Thanks for bringing this to our attention @amirm! :)


JSmith
 
I'm not sure I understand. There are two stereo inputs? Or input/output? So to hook up to an existing setup, you would feed an unused output (example RCA unbalanced from the DAC) to the 3.5 jack?
 
I'm not sure I understand. There are two stereo inputs? Or input/output? So to hook up to an existing setup, you would feed an unused output (example RCA unbalanced from the DAC) to the 3.5 jack?
Probably he wants us to connect this pre-out:
IMG_0536.jpeg
 
Agree, I'm initially impressed. A good video here from the product site showing the case, various modes and functionality;


I like that the company even provides an STL file for 3D printing ones own case as well as a detailed datasheet etc.

This video was interesting I thought where they install one of these in an old DCC player;


Thanks for bringing this to our attention @amirm! :)


JSmith
I want one even though it probably has no practical purpose for me. Something to watch when listening to music!
 
That looks great.

For the "fun visualization" this looks really cool. I'm tempted to get one, but my audio hobby budget was already spent trying out a 300B SET amp. ;)

It's a microphone that moves ferrofluid around:

https://www.amazon.com/Sovenomund-D...mzn1.fos.f5122f16-c3e8-4386-bf32-63e904010ad0
And it's out of band!
I believe this qualifies for the meme:
1682081518497.png


As for the SCH... Looking at that video it makes me miss my Winamp days... Scrolling through /. Listening to Groove Armada.... ahhh nostalgia.
 
Last edited:
Back
Top Bottom