# Switching inputs on Discrete DAC not working **URL:** \ **Category:** Support\ **Created:** [February 27, 2026, 11:50pm UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125 "2026-02-27T23:50:45Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![BTHartman](https://avatars.discourse-cdn.com/v4/letter/b/ce73a5/32.png) [@BTHartman](https://forum.msbtechnology.com/u/BTHartman)\ **Post date:** [February 27, 2026, 11:50pm UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/1 "2026-02-27T23:50:45Z")
I just picked up a used Discrete DAC yesterday, with two power supplies and both the Network Renderer V2 and the Pro-ISL input modules. I’m trying to compare the sound quality of the two input options today but ran into an issue. My source is a Roon Core running on a NUC computer, feeding a Wiim Ultra streamer for USB input, and of course directly through my home network to the Renderer. I have Roon set up with a group to both the Wiim and to the Discrete. I just checked, and updated the Discrete firmware to 27.14, and have the Switch option set to “ManuaL”. I selected the ISL input (actually now says “USB” on the display), but every time I start playback from Roon the Discrete switches to the Renderer. I can certainly either ungroup in Roon, or unplug the ethernet cable from the Renderer, but I was under the impression that when in Manual mode I could force the input selection. Not a long term issue, as I plan to at some point replace with the Renderer or the Pro ISL module with the I2S module to allow playback from an SACD transport, but for now I want to evaluate the sound quality between the two and would be easier if I could just switch the input on the fly with the remote. Have I missed something, or will it always automatically switch to the Renderer? Thanks! ---
**Author:** ![Dustin\_Symanski](https://yyz1.discourse-cdn.com/flex003/user_avatar/forum.msbtechnology.com/dustin_symanski/32/680_2.png) [@Dustin\_Symanski](https://forum.msbtechnology.com/u/Dustin_Symanski)\ **Post date:** [February 28, 2026, 4:42am UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/2 "2026-02-28T04:42:04Z")
Roon requires that a renderer always takes priority if we want to be Roon certified. Sorry. ---
**Author:** ![BTHartman](https://avatars.discourse-cdn.com/v4/letter/b/ce73a5/32.png) [@BTHartman](https://forum.msbtechnology.com/u/BTHartman)\ **Post date:** [February 28, 2026, 5:21am UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/3 "2026-02-28T05:21:05Z")
OK - thanks for the response. I would have thought that setting to manual would allow me to force the input. As I stated, this is a minor hiccough in what I’m trying to do in assessing which input I prefer. My workaround is to set my Roon to the USB streamer, and then either switch to the Discrete Renderer for comparison or, more likely, add it to a Roon group to preserve the playback queue. This is only temporary anyway, and once I determine which input I think is better I’ll eventually replace the other input module with the I2S module. Brett ---
**Author:** ![Nous](https://avatars.discourse-cdn.com/v4/letter/n/ecc23a/32.png) [@Nous](https://forum.msbtechnology.com/u/Nous)\ **Post date:** [April 15, 2026, 6:36am UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/4 "2026-04-15T06:36:39Z")
Hi Brett, do you mind share what’s the result f the comparison? I have been using Renderer V2 and I like it, but I am curious whether ProISL combined with cheap streamer can bear that. I think moving digital processing outside of the chassis might be a good idea in principle, and sometimes I feel my SACD transport connected through I2S sounds better than Renderer V2. Thanks! ---
**Author:** ![BTHartman](https://avatars.discourse-cdn.com/v4/letter/b/ce73a5/32.png) [@BTHartman](https://forum.msbtechnology.com/u/BTHartman)\ **Post date:** [April 15, 2026, 3:47pm UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/5 "2026-04-15T15:47:37Z")
Honestly, I didn’t feel there was any significant difference. Bear in mind, however, that everyone’s ears are different, and each system is different. In my case I’m using a Wiim Ultra as the streamer, though the USB cable is a fairly expensive one from Transparent. As they sounded (to me, in my system) to be equivalent in sound quality I prefer having the album art displayed on the streamer’s screen. It’s a shame if you don’t have a way to give a demo of the ProISL module so you can decide for yourself before buying it outright. ---
**Author:** ![Nous](https://avatars.discourse-cdn.com/v4/letter/n/ecc23a/32.png) [@Nous](https://forum.msbtechnology.com/u/Nous)\ **Post date:** [April 16, 2026, 3:07am UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/6 "2026-04-16T03:07:50Z")
Thanks! Presumably, the theory is that the processing of Renderer V2 itself inside the chassis generates some kind of noise right next to the core DAC architecture, while Pro USB/ISL removes that entire digital processing outside of the chassis. But I guess it might really be system dependent or just marginal difference. I have only used Renderer V2, never tried the Pro USB/ISL path. @Daniel_Francis Any thoughts? Would really appreciate it! ---
**Author:** ![Daniel\_Francis](https://yyz1.discourse-cdn.com/flex003/user_avatar/forum.msbtechnology.com/daniel_francis/32/681_2.png) [@Daniel\_Francis](https://forum.msbtechnology.com/u/Daniel_Francis)\ **Post date:** [April 16, 2026, 7:03pm UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/7 "2026-04-16T19:03:34Z")
> [@Nous](#): > > Renderer V2 itself inside the chassis generates some kind of noise right next to the core DAC architecture This is correct for the Discrete and Premier. Not a concern if there is a Digital Director in the system. BUT, this is still only a small performance difference and you may want to use the Renderer for the convienience/connection even still. ---
**Author:** ![Nous](https://avatars.discourse-cdn.com/v4/letter/n/ecc23a/32.png) [@Nous](https://forum.msbtechnology.com/u/Nous)\ **Post date:** [April 16, 2026, 7:18pm UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/8 "2026-04-16T19:18:16Z")
Thanks, Daniel! Makes total sense — definitely love the convenience of the Renderer and won’t lose sleep for marginal theoretical difference haha. 😄 ---
**Author:** ![Daniel\_Francis](https://yyz1.discourse-cdn.com/flex003/user_avatar/forum.msbtechnology.com/daniel_francis/32/681_2.png) [@Daniel\_Francis](https://forum.msbtechnology.com/u/Daniel_Francis)\ **Post date:** [April 16, 2026, 8:38pm UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/9 "2026-04-16T20:38:43Z")
Plus! Check out this new post: [https://forum.msbtechnology.com/t/renderer-update-qobuz-connect-is-here-and-its-fantastic](https://forum.msbtechnology.com/t/renderer-update-qobuz-connect-is-here-and-its-fantastic) A nice update to the Renderer! ---
**Author:** ![Nous](https://avatars.discourse-cdn.com/v4/letter/n/ecc23a/32.png) [@Nous](https://forum.msbtechnology.com/u/Nous)\ **Post date:** [April 16, 2026, 9:06pm UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/10 "2026-04-16T21:06:41Z")
Truly great news! Saves those of us who get frustrated by Roon’s slowness (despite its superb library function). ---
**Author:** ![Daniel\_Francis](https://yyz1.discourse-cdn.com/flex003/user_avatar/forum.msbtechnology.com/daniel_francis/32/681_2.png) [@Daniel\_Francis](https://forum.msbtechnology.com/u/Daniel_Francis)\ **Post date:** [April 16, 2026, 9:21pm UTC](https://forum.msbtechnology.com/t/switching-inputs-on-discrete-dac-not-working/1125/11 "2026-04-16T21:21:40Z")
I am over the moon about it. The sonic performance is SO GOOD as well. It suits my minimal system sensabilities. All wins as far as I am concerned.