Measurements of Singxer SA-1 Headphone Amp(Preview)

[Mikechw]

Update:
I e-mailed leter and got an immediate reply..

Manual can be found at this link:
http://www.singxer.com/col.jsp?id=108

Hi-Z means output impedance 11.4 ohms (balanced) and Lo-Z means 1.4 ohms (balanced)

Also I noticed my dac is outputing at a very low volume..
I changed my dac back to dac mode.

Everything is fine now.. Volume knob at 9 oclock and it is the loudest I can handle..

 

[Veri]

Awesome! Yeah the DAC output should be correct or you will end up with low gain as you noticed

 

[MediumRare]

Hi-Z means output impedance 11.4 ohms (balanced) and Lo-Z means 1.4 ohms (balanced)

What would be the benefit/use case of high output impedance?

 

[Noodles]

Lower power needed for higher impedance headphones mainly.

 

[Mikechw]

I think flipping the Hi-Z and Low-Z switch just change the output impedance of the headphones jack..
Nothing else is changed..
The volume is lower when I flipped from Low-Z to Hi-Z..

I have brought it from office to home..
Stacking D90 on top of SA-1,
SA-1 is slightly wider and taller.
SA-1 is slightly heavier.
SA-1's volume knob is heavier to steer.
SA-1 has locking mechanisum for XLR input.

D90's gain setting is easier to access. (and more flexible)
SA-1's low gain setting 0db(XLR in->balanced out) = D90's M gain (SE in -> balanced out)
SA-1's high gain 11.5db (XLR in->balanced out)
D90's high gain 15.5db (XLR in->balanced out)

SA-1's USD 100 more expensive..

More specs: (If I am correct)
D90's input impedance 2kohm(BAL), 10kohm(SE)
SA-1's input impedance 20kohm(BAL), 30kohm(SE)
D90's output impedance (LO) 40ohm(BAL), 20ohm(SE)
SA-1's output impedance (LO) 45ohm(BAL), 22.5ohm(SE)
D90's HP output impedance <0.2ohm(BAL), <0.1ohm(SE)
SA-1's HP output impedance(Low-Z) 1.4ohm(BAL), 0.7ohm(SE)
SA-1's HP output impedance(Hi-Z) 11.4ohm(BAL), 10.7ohm(SE)

 

[Noodles]

@Mikechw can you give us any subjective impressions compared to the A90 ? Roll-off in the highs/lows, linear comparatively ?

 

[Mikechw]

@Mikechw can you give us any subjective impressions compared to the A90 ? Roll-off in the highs/lows, linear comparatively ?

I have 2 headphones at home. Hifiman Ananda and Sennheiser HD650.
I tried Ananda this morning and switched to HD650 this afternoon.
I just noticed the bass on the SA-1 is stronger, tighter, more controlled on both headphones. It sounds a little warmer compared with A90.
For the treble, I do not notice any difference. I think both head amp sound very clean. Their performance is on par.

Both my headphones are EQd by Roon. When I applied the bass boost on HD650, I think A90 have trouble keeping up. SA-1 have no trouble with HD650.
Powering the Ananda.. Both amp is running good.. Performance is on par.

One thing I don't like about SA-1 is that the gain setting is on the bottom.
When its not loud enough, on A90's mid gain, I can just flip the switch to high gain.
But for SA-1, some songs its just not loud enough on low gain. I had it on max volume and wonder if I can turn it up just a little bit more..
I will tryout high gain on SA-1 tomorrow.

I am not sure what is the use for Hi-Z and Low-Z switch. I had mine on Low-Z most of the time.
I tried flipping it to Hi-Z with HD650. It just lower the volume a little bit.

 

[Noodles]

High and low gain switches, at the bottom of the chassis, there are a total of 4 toggle
switches; when used, they need to be turned to one side together; near the outside of the
chassis is low gain, and the inside is high gain. The low gain is 0db, that is, the
magnification is 1 times; when the high gain is 11db, that is about 3.8 times. It is
recommended to dial the gain switch when shutting down; when turning, you need to fully
dial to the side, not the middle position .

That's some weird wording in the manual and a weird position on the switch
Sure they are not the first to do this (AUNE i am looking at you), but the chassis has more than enough space for another switch ...

 

[Mikechw]

Yes, the wording in the manual is difficult to understand..
To switch from low gain to high gain, basically you have to flip all the switches to the other side all together, while unit being switched off.

 

[pimy]

Logically the Ananda (25 Ohm) must be on the "Low-Z" position and the Sennheiser HD650 (300 Ohm) on "High-Z" ?

 

[Veri]

Logically the Ananda (25 Ohm) must be on the "Low-Z" position and the Sennheiser HD650 (300 Ohm) on "High-Z" ?

Yes, but you can totally use higher impedance like the Sennheiser with the Low-Z output, just the opposite is really not recommended.

 

[w1000i]

Yes, but you can totally use higher impedance like the Sennheiser with the Low-Z output, just the opposite is really not recommended.

if I used low impedance (30-60 ohm ) with High-Z does that mean I will draw more current to the headphone ? I think this is good ?

 

[Mikechw]

There are 2 x Meanwell IEM 20-15 inside the SA-1. I think one for the positive rail and one for negative. The max current one can pump out is 1.4A. I suppose spliting L and R and some for the other components. The max current it can pump to each ear pieces should be around 0.5A.

 

[Veri]

if I used low impedance (30-60 ohm ) with High-Z does that mean I will draw more current to the headphone ? I think this is good ?

No, you present a high output impedance to your low impedance headphone which will negatively affect the frequency response, typically it will make the low-end presentation more muddy, which is generally negatively perceived.

 

[Mikechw]

I just read something about headphone impedance...

https://www.headphonesty.com/2019/04/headphone-impedance-demystified/

Quote:
"Pairing a headphone with an impedance of 2.5-8 times higher than the source impedance should yield good results. "

 

[Veri]

I just read something about headphone impedance...

https://www.headphonesty.com/2019/04/headphone-impedance-demystified/

Quote:
"Pairing a headphone with an impedance of 2.5-8 times higher than the source impedance should yield good results. "

Yes the 1:8 "rule", 10ohm Z out to ~80ohm headphone impedance, 20 ohm Z out to ~160ohm impedance etc, but what it really means is 10/20ohm "or lower". Lower will work just as well, so headphone amps with output impedance of say <=1 ohm to be the most universally compatible.

 

[w1000i]

I got mine today.

Note: do not dial the mode selection switch quickly.

 

[SHENZHENAUDIO]

View attachment 104435View attachment 104436View attachment 104437
My SA-1 arrived this morning...
I powered it up immediately, listening to it via balanced XLR with my Meze Classics99 for half an hour.. (low gain, low-Z)
First impression, treble is very clear, bass is tightly controlled.
I had volume at max and its just loud enough.

On the bottom there are a few dip switches, there are no manuals in the box. Any one know how do I set it to higher gain ?

 

[w1000i]

The SA-1 Sound amazing. I don't have now L30 to compare it but for sure I can hear at much higher volume with much ease to my ear than I ever did. And it is the first time I heard Focal Clear with this dynamic and bass control.
I'm impressed how things sound like all over the place, every tone is very very distinguishable.

I start to think that Topping may drive constant load like planer better than dynamic driver with changing impedance and phase. My frend is trying L30 against Audio gd Master 9 and Gustard H20 and he liked L30 sooo much with headphone like HE1000se and other planner but he said HD800 and Akg k712 didn't sound as dynamic with L30 compare to Master 9 and H20

 

[Mikechw]

The SA-1 Sound amazing. I don't have now L30 to compare it but for sure I can hear at much higher volume with much ease to my ear than I ever did. And it is the first time I heard Focal Clear with this dynamic and bass control.
I'm impressed how things sound like all over the place, every tone is very very distinguishable.

I start to think that Topping may drive constant load like planer better than dynamic driver with changing impedance and phase. My frend is trying L30 against Audio gd Master 9 and Gustard H20 and he liked L30 sooo much with headphone like HE1000se and other planner but he said HD800 and Akg k712 didn't sound as dynamic with L30 compare to Master 9 and H20

Yes, My HD650 sound much better on SA-1.