Singxer SA-1 Review (Balanced Headphone Amp)

[Svperstar]

Just out of intrest…I have Adi, what more sp200 brings to game? In my mind Adis headamp is pretty much perfect.

I owned the SMSL SP200 before I got the RME, I hooked it up XLR cuz why not? One more headphone jack. It has more power then the RME if I ever get an HE6 one day.

 

[Masamune]

These measurements appear relevant to headphones. Am I correct in assuming the impedances measured here affect active speakers via XLR too?

I can hear distortion at high gain when I use the SA-1 as a pre-amp outputting to my JBL 305P MKII active speakers over balanced XLR. I also hear some distortion on them when the volume pot on the speakers to around 3/4 of the way. So I run the SA-1 at low gain and Low-Z, and the 305p speakers to +4dBu with the volume pot at 1/2.

The SA-1 input is via a Topping E50, set to DAC mode (ie volume 100%), outputting over balanced TRS to XLR cables. This means the volume pot on the SA-1 needs to be at around 4-5 O'clock for average listening levels in this setup. With the SA-1 volume pot at full, the sound is louder than I would tolerate while sitting at my desk, so the volume is not a huge problem for me but but I have to remember to turn the volume down a lot when switching to headphones! I'm also just interested in why this may be.

I can't find any details on what the impedance of the speakers are to relate to Amir's distortion measurements here. It's not listed in the manual and somewhere I read that input impedance is not relevant to active speakers. Am I on the right path here or could this be caused by poor quality amplification in the speakers, E50 output voltage being too high for the SA-1, or faulty interconnects somewhere in the chain?

I'm running a similar setup with the addition of the subwoofer LSR310s with the same issues on +4dbv.
I had to change the input sensitivity switch on the the sub to -10dbv.
JBL's manual recommends setting on the speakers to -10dbv anyway when connected via the sub LSR310s.

Here's my setup (loud enough for a small room and no distortion to my ears):
Mac to Grace SDAC Balanced (full volume output) -> XLR ->
Singxer SA-1 (Low gains on bottom, Pre, XLR, Hi or Lo-Z don't make a difference for me on pre-amp, 40%) ->XLR ->
LSR 310s (-10dbv, 80hz, 75%) -> XLR ->
LSR 305 (-10dbv, 75%)

 

[Salt]

Slaven,
why are You shouting that way (or did You use the 'B' just by incident?).
There's no need to.

 

[Emdren]

Might be a dumb question but can I use both preamp outputs at the same time? I'm thinking of using balanced XLR in, balanced XLR out to speakers and single ended RCA to a subwoofer. Will that work?

 

[Snoopy]

No. You select one of the other with the front switch

 

[Roland68]

Might be a dumb question but can I use both preamp outputs at the same time? I'm thinking of using balanced XLR in, balanced XLR out to speakers and single ended RCA to a subwoofer. Will that work?

Unfortunately that's not possible, only either/or.
4 amplifier trains, of which he needs 4 for XLR or 2 for RCA.

 

[Emdren]

Unfortunately that's not possible, only either/or.
4 amplifier trains, of which he needs 4 for XLR or 2 for RCA.

Thank you, makes sense.

 

[Mark_A]

Might be a dumb question but can I use both preamp outputs at the same time? I'm thinking of using balanced XLR in, balanced XLR out to speakers and single ended RCA to a subwoofer. Will that work?

I don't know about the Singxer SA-1. On the Schiit Magnius, I believe that both the balanced XLR balanced headphone output on the front, and the RCA pre-amp outputs on the rear, are active at the same time. However, I use the RCA outputs of my DAC to connect to my sub, and the balanced XLR output of the DAC goes to the headphone amp.

 

[rsoffer]

In the same vein, I'd like to know if it's possible to connect two headphones to the amp at once. Using 4.4 and XLR simultaneously, or even SE & XLR together. Would there be any negative repercussions?

 

[roderickvd]

Impedance will be roughly halved, doubling current draw, and wonky across the frequency spectrum, possibly impacting phase. It will probably work but I don’t recommend it.

 

[JoostE]

Does anyone have good experience pairing a power amplifier with the singxer? I just got a pair of kef ls50 meta on my desk and would to combine the pre-amp of the singxer with a nice power amp.