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.

 

[raif71]

https://www.audiophonics.fr/en/desktop-hp-amplifiers/singxer-sa-1-v2-p-18558.html - singxer sa-1 v2 revealed, got this news initially from the singxer sa-1 thread in head-fi

 

[Veri]

https://www.audiophonics.fr/en/desktop-hp-amplifiers/singxer-sa-1-v2-p-18558.html - singxer sa-1 v2 revealed, got this news initially from the singxer sa-1 thread in head-fi

What exactly would be different in the v2? Is the logarithmic volume knob maybe changed? I found that quite weird in use..

 

[raif71]

What exactly would be different in the v2? Is the logarithmic volume knob maybe changed? I found that quite weird in use..

That's from the site however when I look at the pictures, couldn't find any gain switch on the front panel. Well, could be an old picture of the SA-1?

 

[Monsieurétourdi]

View attachment 333787
That's from the site however when I look at the pictures, couldn't find any gain switch on the front panel. Well, could be an old picture of the SA-1?

Version 1 already had a switch for gain, switch 1 starting from the right (Hi or Low).
Physically, I don't see any difference in the photos, nothing in the descriptions, the power announced depending on the impedance of the headphones changes a little, but apart from that, I don't see any difference, and no information on the official singxer website?

 

[Roland68]

View attachment 334310
Version 1 already had a switch for gain, switch 1 starting from the right (Hi or Low).
Physically, I don't see any difference in the photos, nothing in the descriptions, the power announced depending on the impedance of the headphones changes a little, but apart from that, I don't see any difference, and no information on the official singxer website?

Hi-Z and Low-Z is the impedance switching for the headphones, not gain. Gain is switched underneath the device.

There is no picture with a gain switch on the front and the pictures on the Audiophonics site already show the V2 version.
Probably just a wrong description or translation error.
It would also be a stupid idea to lay the gain switching traces from all 4 channels to the front and back.

 

[raif71]

View attachment 334310
Version 1 already had a switch for gain, switch 1 starting from the right (Hi or Low).
Physically, I don't see any difference in the photos, nothing in the descriptions, the power announced depending on the impedance of the headphones changes a little, but apart from that, I don't see any difference, and no information on the official singxer website?

The Hi-Z and Low-Z are the impedances for the headphones used. Not for gain. Gain switches are at the bottom and I guess the V2 still has the same gain setup as the current SA-1.

 

[roderickvd]

Hi-Z and Low-Z is the impedance switching for the headphones, not gain. Gain is switched underneath the device.

There is no picture with a gain switch on the front and the pictures on the Audiophonics site already show the V2 version.
Probably just a wrong description or translation error.
It would also be a stupid idea to lay the gain switching traces from all 4 channels to the front and back.

Could do it another way though, like relays or multiplexer controlled by a front panel button. If they paid attention to the reviews, it would make total sense.

Like with the SDA-6 refresh, it seems that none of the new pictures are available yet.

 

[Roland68]

Could do it another way though, like relays or multiplexer controlled by a front panel button. If they paid attention to the reviews, it would make total sense.

Like with the SDA-6 refresh, it seems that none of the new pictures are available yet.

As I wrote, you can see the pictures of the SA-1 V2 on the Audiophonics site, including the circuit board.
These pictures of the SA-1 V2 version should leave no questions unanswered.
https://www.audiophonics.fr/en/desktop-hp-amplifiers/singxer-sa-1-v2-p-18558.html
There are no pictures of the SINGXER SDA-6 PRO2 yet because it is not yet available/in stock.

The gain switches are located in a very sensitive part of the amplifier circuit and the conductor tracks should be kept as short as possible. I understand every developer who doesn't want to use a relay in this sensitive circuit. It doesn't always make sense to sacrifice the quality of a device for comfort.
But that's just my personal opinion that no one has to share.

What I find much worse is that the potentiometer was not replaced with a cheaper and better version with SMD resistors, or a relay-based volume control.

 

[roderickvd]

As I wrote, you can see the pictures of the SA-1 V2 on the Audiophonics site, including the circuit board.

The gain switches are located in a very sensitive part of the amplifier circuit and the conductor tracks should be kept as short as possible. I understand every developer who doesn't want to use a relay in this sensitive circuit. It doesn't always make sense to sacrifice the quality of a device for comfort.

You seem to be right on the pictures, had not spotted the V2.0 on the PCB.

Your arguments about relays make no sense. Relays do not influence signals (other than either passing them, or not) and do not require to extend traces of signals they switch.

What I find much worse is that the potentiometer was not replaced with a cheaper and better version with SMD resistors, or a relay-based volume control.

…which is a case in point.