How to Connect Headphones to a SMSL DAC

Here’s my system.  I have a NODE N130, but I’m bypassing the internal DAC.  A USB cable connects the NODE to a SMSL M400 DAC.  The M400 has 2 RCA outputs, these are connected to my 2 powered B&O speakers.  The 2 balanced outputs on my M400 each connect to one of my powered subs.  There’s no more outputs available.

So say I bought a Singxer, I would install interconnects between the balanced outputs on my M400, and the Singxer balanced inputs.  Having unplugged the 2 subs, I don’t know where I would reconnect them.

‘Right now I’m using my iPad to control the NODE, but volume is controlled by a remote for the M400.  You mentioned that the Singxer would control volume.  I would be using my system for both headphones and my speakers.  I don’t understand if my speakers/subs need to all connect to the Singxer, or if those stay connected to the M400.  And then, how do I switch between listening via the headphones and the speakers.

‘All this does point to the utility of the NODE, where everything is in one box and controlled by one controller.

Well, I wish I was aware of the rest of your setup going into this because it changes a lot. Here’s what I’d do if I was you. If I’m listening to home audio just leave things as they are if it’s working for you. To switch to headphones just unplug the cables that go into the subs and plug them into the Singxer and switch the DAC from variable to fixed output (so only the Singxer’s volume control is operative). And if you go this route use a good balanced headphone cable into your headphones if you don’t already have one to preserve the balanced connection. It’s not the most elegant or seamless solution, but it’s not really hard to do and it’ll work and you’ll get all the goodness of the SA1 (and your DAC) into your ‘phones. I have a balanced headphone cable recommendation if you’re interested. Sorry for the convoluted answer (it sounds worse in words than it would be in practice and would only take a minute to change over), but I didn’t know all the other stuff you had going on here. You’ve got good headphones and they’ll reward you for the effort, and if you decide to upgrade headphones in the future your electronics will scale up nicely and let them sing.

Thx @soix  I have a better understanding.  I’ll give it more thought.  Often when I want to use headphones it’s late and I’m tired.  I don’t know if I would opt to switch connections.  I can see how some people end up with a separate headphone system.  I am interested in your balanced cable recommendation.

This has gotten more complicated than I anticipated. Perhaps the best thing you can do is use RCA splitters to drive your B&O speakers off one of your DAC’s outputs and the drive your subs off the other set of RCA outs. Then you can run the balanced outputs from the DAC into a dedicated balanced headphone amp of your choosing — one that doesn’t have a preamp/volume control — then you can use the DAC to control everything. As far as a balanced headphone cable, I’d recommend this one with the AECO XLR plugs as it’s a great performer and a great value for what you get. Hope this helps, and best of luck.

https://www.lavricables.com/cables/reference-silver-headphone-upgrade-cable/

Update - thanks to everyone who chimed in answers!  I bought an RME ADI-2 DAC fs, which has a headphone amp with 2 outlets, one for IEM’s.  I also bought the Sennheiser HD600’s.  They sound great together.  This gives me the option to listen late at night without having to turn down the volume very low.

I chose this to avoid having another box and wires, as well as giving me a wide variety of controls including parametric EQ.  I also bought a UMIK 1, so I can do some room testing and perhaps adjust the sound for further improvements.  Since I don’t have a preamp, I had no adjustments before.  Enjoying the upgrade!