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PreSonus Studio 68c for 2.1 listening - a painful experience

neRok

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I have been using the aforementioned device for a couple of months. I got it because it was the cheapest device with decent specs (on paper) that also ticked the following boxes;
  • Has 3 or 4 discrete channel outputs that I could use for a 2.1 setup
  • Has balanced outputs, because my sub is susceptible to ground loops, and my monitors pick up noise from my OLED monitor over RCA too.
  • Was a singular device, which would hopefully allow for;
    • A single volume knob to control all volume levels
    • Simple routing of streams to outputs, and DSP etc in Win10
Once I got my hands on the Studio 68c, I realised it does not achieve any of my "singular device" goals. It presents itself in windows as 2 separate playback devices; "Main Out 1/2" and "Line Out 3/4", and the "Universal Control" driver software has no routing or DSP capability. Thus I had to use VoiceMeeter Banana and Equaliser APO.

Additionally, the "Main" volume knob on the front of the 68c only controls the volume of the 2 main outputs, and not the 2 line outs. This means anything connected to the line outs is full volume, and because I wanted to play on all 4 outputs at once, I effectively have to keep the main volume knob at full (for level match). This means I have to use VoiceMeeter's volume slider to control the volume.

And unforunately I have a problem with regular pops/clicks coming through the speakers whilst listening to music, but this may be because I am driving all 4 outputs at once? There is quite a lot of people on the internet having pop/click problem with PreSonus interfaces, and it often seems to be latency related. I tried many suggested remedies like reinstalling drivers/devices, different USB ports, different process affinity settings, different combinations of sample rates and block sizes, etc. This was with WASAPI Shared, but lately I have been trying WASAPI Exclusive, which has reduced but not fixed the problem. But I am giving up on fixing this because I feel it is the devices fault, not my PC's, because before I got the 68c I was using VM-B and EqAPO to output via a Topping DAC and the PC soundcard, and that worked fine. My PC is also top end, not some budget laptop having latency problems because it has a slow 4 core CPU.

And just this morning I have discovered a new "flaw" in the devices usefulness. I went to use the headphone output and realised that it does not appear in windows as its own device, and so the headphone amps source is only controlled by a button on the front of the device to switch between Main1/2 and Line3/4. BUT, there is no way to "turn off" the speakers that are also connected to those outputs, so you either have to turn off the speakers or turn down the Main volume knob to -80dB (that's its lowest setting) and listen on Main1/2 ouput only (because if you switch to Line3/4, those speakers will get full blast music as they don't have a volume knob). BUT ALSO, I then have to go in to EqAPO and change the DSP settings from speakers to headphones (this point isn't too bad, because I think I had to do the same with my Topping DX3 Pro+ too).

So, all those quirks make this device painful to use. I did only pay $340 AUD for it though, whilst a MiniDSP Flex with balanced outputs would have cost me ~$850 AUD. A Flex Eight may not suit considering it has RCA outputs only. Are there any other devices to consider? I know there is the Okto DAC8 and a similar Topping unit now, which might work. On the interface side, I think the RME's don't have 4 proper outputs like the 68c, because I read of people having to use the headphone out (through its amp) to get 4 individual channels (but maybe things have changed now?). And there is the Motu UltradLite Mk5, but does it function any different to the 68c? I might just resort to getting 2 relatively cheap Topping D10's, but will running mutliple of these on the same machine cause driver issues?

Edit: I think the Studio 68c could be great with a few simple design tweaks;
1) A physical or software switch to swap the volume knobs function from controlling 1/2 or 3/4 or both.
2a) A physical or software switch to swap the headphone playback from 1/2 or 3/4 or it's own channel (5/6).
2b) Or at least a toggle for "headphone only".
3) Some very simple routing options in the drivers so that I can take 2 channel stereo in, and have 4 channels out (that I can then DSP with EqAPO).
And for some bonus features;
4) Some 12v trigger outputs
5) Ability to change the outputs from -10 dBV to +4 dBu
 
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studio7

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Pops/clicks can be very annoying. I had a similar issue last year, but figured out it was a live view graphic equalizer, taxing the integrated GPU. Have you tried minimizing all software GUI's to the taskbar? Sometimes your graphics card and the USB you connect the audio interface to share the same IRQ.
 
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neRok

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Pops/clicks can be very annoying. I had a similar issue last year, but figured out it was a live view graphic equalizer, taxing the integrated GPU. Have you tried minimizing all software GUI's to the taskbar? Sometimes your graphics card and the USB you connect the audio interface to share the same IRQ.
I have also thought that it could be GPU related. I often have a game and web browsers going whilst listening to music, and I feel like the issue can be worse the more I have going sometimes (this is what led me to try WASAP Exclusive). I haven't investigated it thoroughly though. I also "feel" like the errors don't happen on "cold start", but after a while (software errors piling up or something?). But again, that's just a feel because I haven't kept a proper log or anything.

Also, when I was researching presonus latency issues I did come across people talking about the shared IRQ problem, and I looked into it but found no error (my Nvidia 2080ti was on its own channel). I also used LatencyMon to test for errors but found none in particular, except on 1 occasion the error discussed here did appear: Discussion: NVIDIA Display Driver (nvlddmkm.sys) DPC Latency | NTLite Forums
 

studio7

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I have also thought that it could be GPU related. I often have a game and web browsers going whilst listening to music, and I feel like the issue can be worse the more I have going sometimes (this is what led me to try WASAP Exclusive). I haven't investigated it thoroughly though. I also "feel" like the errors don't happen on "cold start", but after a while (software errors piling up or something?). But again, that's just a feel because I haven't kept a proper log or anything.

Also, when I was researching presonus latency issues I did come across people talking about the shared IRQ problem, and I looked into it but found no error (my Nvidia 2080ti was on its own channel). I also used LatencyMon to test for errors but found none in particular, except on 1 occasion the error discussed here did appear: Discussion: NVIDIA Display Driver (nvlddmkm.sys) DPC Latency | NTLite Forums

Hm, why are you using WASAPI, and not the dedicated Presonus ASIO driver? I would personally first try the ASIO driver, and as a second option the DirectSound driver. Both with a buffer size of 1024 samples or more.
 
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neRok

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the "Universal Control" driver software has no routing or DSP capability.
I was just clicking around trying out some different things and discovered what appears to be routing options when using ASIO output. The following is a screenshot from MusicBee interface, so I'm not 100% sure where this config is coming from (and if it is available in every audio-source program), but it seems to have the right options.
asio_on_68c.jpg
Edit: Well that was a quick fail. Turns out Eqalizer APO can't configure those ASIO channels.

Hm, why are you using WASAPI, and not the dedicated Presonus ASIO driver? I would personally first try the ASIO driver, and as a second option the DirectSound driver. Both with a buffer size of 1024 samples or more.
I did switch to ASIO driver (through VoiceMeeter Banana) and it did seem to be more stable, but there has still been a rare glitch. Perhaps this isn't as good as using Presonus ASIO driver directly, but until just now I didn't know that had routing options, so it wasn't a possibility.

I was using WASAPI because sometimes I'm playing games and listening to music at the same time and like to have the game sound come through the speakers too. But lately I've just been doing the music through ASIO/speakers and games through WASAPI+monitors speakers, and that seems ok.
 
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Trell

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Get a RME device with the required number of outputs, and you can buy an old second-hand RME devices as well as they're still supported.

Perhaps you've seen this thread where the OP bought a RME Fireface UC audio interface released in 2006? He seemed quite happy with the result.

 

studio7

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Edit: I just noticed that you have DPC latency spikes, caused by your Graphics Driver. Ideally your DPC should be under 100 us, even when using ASIO.
 
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