SU8v2 user reporting back too, zero issues here except the occasional light pop when turning on. I've had the unit almost since release of the v2 version, probably 2 years now? Granted I have mine at fixed bitrate since I don't care for anything beyond 16/44. Here's hoping that it lasts me 20 years because I see absolutely zero reasons to change it.
Editing post to add that I use mine exclusively via the XLR outputs via a professionaly made (NOT expensive but made by a professional) Y splitter on Mogami Multi cable (which is designed for balanced Y splitting) and Neutrik connectors, one split going to my SP200, another one to my JBL LSR305 Mk1 monitors.
Hi I would like to add to this,
I also report zero issues for years using XLR outputs of SU-8 V2.
Setup: Source (constant Bit/Sample rate) > Optical cable > SMSL SU-8 V2 > XLR cables > Studio Monitors
I have noticed a very quiet pop when changing the "filter" and "sound color" settings, but I only changed these settings in the beginning when testing them.
I leave the settings to default: "Fast Linear" Filter + "Standard" Sound color, and for years now I only control "volume" (no pops) and "on/off" (no pops) (Sequence: SU-8 is first on and last off).
It has been a flawless device,
until I recently tried the RCA outputs for the first time.
Setup 2: Source (constant Bit/Sample rate) > Optical cable > SMSL SU-8 V2 > RCA cables > Monoblock Power Amplifiers > Speakers
Everything in the chain is identical to first setup except from RCA cables and after.
So this is the issue which happens only on RCA outputs.
1. "Power on" the SU-8, it takes a second to remember/show last used input (optical), and then shows volume when it is ready.
2. "Power on" the Monoblock Amplifiers
--At this point before anything is played from the source there is no noise in the signal (same silence as XLR output)--
3. "Play" audio (song) from source (optical), then after song ends or I stop the audio
--At this point there is constant audible noise in the signal, I can hear it from the listening position after the song ends, and I can even hear it in quiet passages of songs--
The best way I can describe the noise is high pitched "coil whine". Keep in mind it is quiet from listening position, so with busy loud songs I can sometimes forget it is there, but I can hear it in quiet/silent passages.
Adjusting the volume up or down has
no effect on the level of the noise, it is always constant and same level of noise.
Summary:
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XLR outputs: controlling only "volume" and "on/off" sequence, the SU-8 is silent and works as expected.
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RCA outputs: same conditions as XLR. Before source is "played" the signal is silent, but after source audio is played there is constant audible "whining" noise in signal.
I can power cycle everything to reproduce the issue.
I am using optical input connection so that should rule out any noise from the source.
Edit: just now I considered it may be ground loop related since noise is on RCA outputs but not XLR.
I will do more troubleshooting tomorrow...
The
SU-8 V2 "XLR output" is great (no pops when adjusting volume and correct on/off sequence), but the
SU-8 V2 "RCA output" has noise issues.
I did not realize until I used the RCA outputs for the first time.
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V1 Measurement (RCA 60hz/120hz noise, XLR shows same noise)
As noted, I powered the D50 using a Samsung charger I had laying around. Let's compare that to SMSL SU-8 using its unbalanced output:
We see fair bit of power supply noise at 120 Hz and other harmonics of mains 60 Hz. We take a 4 to 5 dB hit in SINAD (signal above distortion+noise).
There is fair bit of interest in balanced outputs of the unit so let's see how that did:
Distortion climbs unfortunately reducing SINAD to 86 dB.
V2 Measurement (RCA 60hz/120hz noise, XLR No Power-supply noise)
Measurements
Let's start with our unbalanced dashboard:
This is some 8 dB improvement in SINAD/distortion relative to original review sample! Let's see how our previously problematic balanced output performs: