Motu M4 + Schiit Heretic Configuration

[Audiozen]

Hello!

New member here. I've been browsing these forums for the past month - great source of information! The review posts from @amirm are really helpful. I recently bought some new gear and have some questions about the best way to hook everything up.

My gear

1. Audio Interface: Motu M4
2. Headphone Amp: Schiit Heretic
3. Speakers: iLoud MTM
4. Headphones: Sennheiser HD600
5. Home Computer: PC (self-built)
6. Work Computer: Macbook Pro

My goal

• Switch between home and work computer and speakers and headphones with best sound quality and least fuss

Current Setup

• USB-C connected from PC to M4
• 1/8" out from work laptop to dual 1/4" input on lines 3-4 of M4
• dual 1/4" out from lines 1-2 (monitor) of M4 to iLoud MTM speakers
• dual RCA out from lines 3-4 (line out) of M4 to dual RCA inputs on headphone amp

Challenges

• Because lines 3-4 of M4 are line outs, they only output the USB-C (PC) audio. The 3-4 monitor mix button on the front of the M4 doesn't affect the line outs, so I can't route work laptop audio to the headphones. I can only do so for the speakers.
• Alternatively: If I hook the headphones up to the RCA 1-2 line outs (monitors), then they can monitor inputs 3-4 (work laptop) by pushing the 3-4 button- the problem with this setup is the speakers and headphones mirror each other exactly. This would be fine if the speakers were easy to turn off but they're not - I have to switch them off individually from the back.
• The USB-C output on my computer may not provide enough power for the M4 when it's asleep (haven't tested this yet). If it doesn't I'll need to leave my PC on.

Options

1. Use the front headphone jack of the M4 to connect to the headphone amp - 1/4" to dual RCA. Would this affect the sound quality?
2. Use a USB-C hub/switch to switch M4 USB-C connection from work laptop to home pc. Keep the rest of the current setup the same. This would allow me to use M4 volume for speakers and headphone amp volume for headphones, while changing the source via the USB-C connection rather than the M4.
3. Get a Motu M6 which has A/B speaker switching
4. Any others?

Thanks in advance!

 

[twsecrest]

While the M4 headphone jack can send audio to the Heretic, daisy chaining headphone amplifiers can help make noise in the audio.
Do you use the Audio Interface for audio production with both Win PC and Macbook?

 

[Audiozen]

While the M4 headphone jack can send audio to the Heretic, daisy chaining headphone amplifiers can help make noise in the audio.
Do you use the Audio Interface for audio production with both Win PC and Macbook?

Thanks! That's what I suspected. I don't have any audio production needs - just audio input/output switching for now.

 

[twsecrest]

I'm kind of braindead right now trying to figure out your best options.
You could connect the Heretic's line-output to the iLoud MTM, when the headphones are plugged into the Heretic, it mutes the line-output, but that does put a little more wear and tear with the headphone jack.

 

[AnalogSteph]

Sorry for digging up this thread... the M2/M4 headphone output measures little worse than the regular line-outs, and I see no problems whatsoever in using it to feed a headphone amp. Even if your amp should not accept more than 2 Vrms (and I doubt the Heretic has such hard limits), its dynamic range of 115 dB(A) ref. +12.5 dBu means that more than 112 dB(A) would be left even at correspondingly reduced level, and that's more than enough for anyone. Noise would be a complete non-issue even with some EQ. In fact, you'd likely have considerable leeway in trading off between headphone out volume and Heretic amp volume, which may prove handy if the low gain setting still lands you in poor volume pot channel balance terrain with sensitive IEMs.

 

[kiwifi]

If the laptop & PC share the same network then you should be able to share the PC output connection to the audio interface with the laptop. Casting output from the laptop to the PC for instance.

 

[Audiozen]

Thanks for the suggestions. What I ended up doing is hooking the M4 up to a USB switch that switches between laptop and PC, this way I'm getting a digital connection from both computers. The Motu shuts off temporarily when switching but otherwise it works great!