I have seen some mixed discussion about the Motu M2 and how well it can power a set of headphones. Right now I have the DT 990’s 250 ohms and volume doesn’t get louder past ~80% of the wheel when Windows + application(s) are @ 100%. I’m upgrading to the 660S’ and they’re only 150 ohms so I figure they’ll get powered better and be louder beyond the current 80% of the Motu M2 rests at.
People who have the Motu M2, do you have a similar problem? Have you added an amp into your setup and continued to use the M2 as a DAC for it?
Second, the M2 has a balanced 1/4" output in the back, the amp I’m prepared to buy, the SMSL HO100, has balanced XLR inputs. Would I be able to go from M2 1/4" out to SMSL HO100 XLR inputs and continue to have a balanced connection if I want/need it or how should I run it to the amp if I end up needing it?
Lastly, any aftermarket cable recommendations to achieve any of this would be appreciated! I was looking at Hart Audio Cables.
This is normal. As an interface, the Motu M2 (and M4) aren’t really designed to drive high impedance headphones that well. Additionally the headphone output isn’t all that clean vs other amps.
The M2 has both balanced TRS and single ended RCA and will output to both simultaneously. If you use balanced, you’ll likely need TRS to XLR for most amps. I’ve got my M2 outputting to a vintage Kenwood KR-3010 via RCA and it has plenty of headroom. In fact, I have to then turn the M2 monitor knob down to about 2/3 for a usable volume range on the kenwood.
Regarding custom cables, the 990 is a fixed single ended cable. You’d need to rewire it to make it balanced.
Regarding amp recommendations, I feel the 990 250 ohm pairs best with a good OTL tube amp like the little dot mkiii (the OG OTL version with 4 tubes). And you don’t need to recable it for that amp. 6AM6S specifically are the tubes I prefer for the 990 250 but also require setting a jumper in the amp board. RCA 6AK5 are also great and will drop in without any jumper setting changes needed.
660s is a completely different sound and there are other amps I recommend for it, primarily the Loxjie P20 with balanced input and using the “DR” variant tubes (from Russia, RIP 2022). See my comments in the P20 thread. This amp is balanced and you should only use balanced input with it imo. RCA works but the power output is very low. Balanced XLR fixes it, even when using single ended headphones. BTW try the Focal ELEX with this amp and tube combo and have your mind blown!
One last note on the M2, check if your music player supports WASAPI push mode. WASAPI event mode is another type but does not work with the M2. WASAPI is also known as bitstreaming. By allowing it to bitstream in push mode, the M2 is directly bypassing the OS and doing the decode work on its own, allowing more volume and clarity. Also keep in mind WASAPI is usually “exclusive,” meaning your other applications won’t output any sound while the music app is bitstreaming to the M2. But some apps do allow you to pick shared or exclusive. YMMV
BTW Tidal unfortunately does not appear to support WASAPI push mode and does not work when trying to bitstream to the M2. The bitstream option is just listed as “Exclusive Mode” - I assume it’s WASAPI event mode since it doesn’t work properly with the M2. Let me know if your experience is different though. FWIW, I think Tidal still sounds pretty good going through the OS.
I meant to reply to you a few days ago when I saw your reply. Tidal does bug out for me when I try the exclusive mode. It allows me to select everything but then when I try to play music it tells me exclusive mode ----
Scratch all of that, as I was in the middle of typing Tidal had an update and now it seems to work? So that’s pretty neat.
@ALANMAN I’ve got an update for you, I ended up returning the 660S and I’m going to get the DCA Aeons Open X because I’ve seen that will fill the gaps that I was missing on the 660S that the DT 990’s had.
Now I’m trying to decide if I should get an amp for the DCA Aeon Open X (on sale btw). I still have my Motu M2 and the Aeons have a low enough impedence that I think it’ll power them cleanly and clearly.
I was looking at the Drop x THX AAA One because it’s also on sale but don’t know if it’d be worthwhile.
Sorry for the late reply also, I took a bit of an internet break last month.
I would recommend trying the Motu headphone output first and see if it does the job well. If not, the THX AAA One is more than adequate, but extremely neutral. Personally I don’t prefer this sound as it’s a little cold and lifeless to me with the headphones that I prefer. However, it should do well for planars like the Aeon and should even have enough juice for the DT 990.
I am assuming you already bought this headphone, so I am curious to hear your thoughts on it.
I also hate these headphones, I had them for about 2 months and I did not like them, I had to change them to another now I have different ones and I am very happy that I liked them
@ALANMAN I did get the Aeon’s and picked up the ifi Zen CAN v2 since it was on sale. Very satisfied with the purchase and I’m in love with the Aeon’s. My setup is feeling very complete with it. I also picked up a used pair of Ovidius Combat Armor TX-901 for cheap, would not recommend them that heavily for gaming or not at all for general audio listening. I posted a review of them over on Linsoul, I gave them 3 stars out of 5.
