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Singxer SA-1 Review (Balanced Headphone Amp)

Snoopy

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I couldn't find a switch on the Singxer to change it from 110 volt to 220volt. So I assume I will be fine by using the device as it it?

I'm in the EU and it was delivered by a European retailer with the correct power plug.
 

Roland68

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I couldn't find a switch on the Singxer to change it from 110 volt to 220volt. So I assume I will be fine by using the device as it it?

I'm in the EU and it was delivered by a European retailer with the correct power plug.
There are Mean Well Switching power supplies installed covering the entire voltage range.
You can connect it anywhere without hesitation.
 

Snoopy

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There are Mean Well Switching power supplies installed covering the entire voltage range.
You can connect it anywhere without hesitation.

Nice. Just wanted to be absolutely sure that there is no hidden switch or something somewhere.

Really like the sound. Well not that the amp sounds like something Didn't expect it to be such a improvement over my Cambridge cxa 81 (integrated stereo amp).

The background is just dead silent.

Impressive what we get these days for 500$/€
 
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Hello. How do people turn off their SA-1? I'm a bit confused when I turn it off. Because the switch on the front is designed with 3 steps but HPA and OFF are far apart. When I use HPA and want to turn it off, I have to switch to PRE and then OFF. So I usually use the red switch on the back instead of the one on the front. Will this damage the device?
 

Snoopy

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Hello. How do people turn off their SA-1? I'm a bit confused when I turn it off. Because the switch on the front is designed with 3 steps but HPA and OFF are far apart. When I use HPA and want to turn it off, I have to switch to PRE and then OFF. So I usually use the red switch on the back instead of the one on the front. Will this damage the device?

Just use the front switch.
 

Roland68

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Hello. How do people turn off their SA-1? I'm a bit confused when I turn it off. Because the switch on the front is designed with 3 steps but HPA and OFF are far apart. When I use HPA and want to turn it off, I have to switch to PRE and then OFF. So I usually use the red switch on the back instead of the one on the front. Will this damage the device?
The device is switched to stand-by mode with the toggle switch on the front (OFF). This means that the inputs and outputs are switched off with relays, the power pack is still connected to the mains.
The device is physically disconnected from the power supply with the red power switch on the back.
 
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The device is switched to stand-by mode with the toggle switch on the front (OFF). This means that the inputs and outputs are switched off with relays, the power pack is still connected to the mains.
The device is physically disconnected from the power supply with the red power switch on the back.
So the front or back switch is better? :D
 

godmax

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So the front or back switch is better? :D
The front switch will not turn off the unit completely, the unit will still consume around 2,7W then in front-off position.
 

Snoopy

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The front switch will not turn off the unit completely, the unit will still consume around 2,7W then in front-off position.

But isn't that better for the amp? If you turn it fully off and on it will consume more watts for a short time and put more strain on the circuits?
 
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But isn't that better for the amp? If you turn it fully off and on it will consume more watts for a short time and put more strain on the circuits?
I have a Gustard X16, it only has a switch in the back and the manufacturer says that do so to increase product life because you can turn off the device completely.
 

raif71

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So the front or back switch is better? :D
My SIngxer is connected to a power strip with individual switches for each socket. Whenever I leave the room, I will flip the front switch to off and the switch at the power strip off. The back switch, I leave it on. When I want to use the unit, turn the switch at the power strip on and the flip the front switch to HP or Pre.
 
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My SIngxer is connected to a power strip with individual switches for each socket. Whenever I leave the room, I will flip the front switch to off and the switch at the power strip off. The back switch, I leave it on. When I want to use the unit, turn the switch at the power strip on and the flip the front switch to HP or Pre.
I do so, but because Singxer has designed HPA and OFF far away., I mainly use HPA and don't use PRE. So I'm afraid this long-term will affect the switch. I like the design of the topping A90, HPA is located in the middle, beside OFF. Because SA-1 is an headphones amplifer, so if the HPA mode is placed near OFF is a wiser design.
 

Snoopy

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I do so, but because Singxer has designed HPA and OFF far away., I mainly use HPA and don't use PRE. So I'm afraid this long-term will affect the switch. I like the design of the topping A90, HPA is located in the middle, beside OFF. Because SA-1 is an headphones amplifer, so if the HPA mode is placed near OFF is a wiser design.

You could just leave it switched to HPA in the front and turn it off in the back if that is a issue for you.
 

Snoopy

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So I was over at headfi and asked something about the Singxer SA1 and R2R DACs there.

The result was that someone mentioned the power supply unit in the SA1 would introduce jitter/noise because of the way it's designed. And this would be the case in the Topping A90 as well.

I asked how to get rid of this problem and the answer was:

"All the battle is to keep noise outside. To do it properly, power supplies start to take lot of space and DACs like this (expensive amp linked here) or pre-amps like this use regenerative power supplies. So, my answer is 'yes', power supplies need to be designed different, but as you see on examples, it is expensive. The whole idea is to increase impedance for ground loops that would start flowing inside equipment through a power supply, closing a loop on the mains power outlet.

It is always more effective to fight a noise at the source. The amp in question is violating a fundamental design rule of using single grounding point. These two sealed SMPS's have a grounding point on a negative power rail. When there are connected in series, one grounding point is located properly on the system ground, but the other one is on the negative (-) power rail and it creates a current noise flow through the entire internal electronics. The same 'invention' had been implemented on a Topping A90 and in a result RCA inputs are unusable on many systems. XLR inputs are more immune to the noise, you can't hear a hum, but a ground a shield wires transfer internal noise to the associated equipment. Besides, SMPS noise is mostly high frequency, it is not normally heard as a hum, but spreads around much easier than a typical mains hum."
 

JohnYang1997

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So I was over at headfi and asked something about the Singxer SA1 and R2R DACs there.

The result was that someone mentioned the power supply unit in the SA1 would introduce jitter/noise because of the way it's designed. And this would be the case in the Topping A90 as well.

I asked how to get rid of this problem and the answer was:

"All the battle is to keep noise outside. To do it properly, power supplies start to take lot of space and DACs like this (expensive amp linked here) or pre-amps like this use regenerative power supplies. So, my answer is 'yes', power supplies need to be designed different, but as you see on examples, it is expensive. The whole idea is to increase impedance for ground loops that would start flowing inside equipment through a power supply, closing a loop on the mains power outlet.

It is always more effective to fight a noise at the source. The amp in question is violating a fundamental design rule of using single grounding point. These two sealed SMPS's have a grounding point on a negative power rail. When there are connected in series, one grounding point is located properly on the system ground, but the other one is on the negative (-) power rail and it creates a current noise flow through the entire internal electronics. The same 'invention' had been implemented on a Topping A90 and in a result RCA inputs are unusable on many systems. XLR inputs are more immune to the noise, you can't hear a hum, but a ground a shield wires transfer internal noise to the associated equipment. Besides, SMPS noise is mostly high frequency, it is not normally heard as a hum, but spreads around much easier than a typical mains hum."
That person is totally inaccurate about the cause of A90's RCA input noise. If you have a ground loop it will of course have noise issue with A90 if one uses RCA input. It's by design. One can use RCA to XLR cable to connect to XLR's on A90 to eliminate noise.

If there's no ground loop then the RCA input will even have less noise than the XLR input. This condition is not usual in real world. But if the DAC is isolated from earth, there will be very low noise.
 

Snoopy

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That person is totally inaccurate about the cause of A90's RCA input noise. If you have a ground loop it will of course have noise issue with A90 if one uses RCA input. It's by design. One can use RCA to XLR cable to connect to XLR's on A90 to eliminate noise.

If there's no ground loop then the RCA input will even have less noise than the XLR input. This condition is not usual in real world. But if the DAC is isolated from earth, there will be very low noise.


And the part about the power supply unit being designed bad?

(I'm just assuming this person is probably using a linear power supply and power filters etc )
 

JohnYang1997

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And the part about the power supply unit being designed bad?

(I'm just assuming this person is probably using a linear power supply and power filters etc )
Both SA-1 and A90 are well designed. You can certainly get nasty ground loop issue with transformer based devices too. It's irrelevant. He just has no clue about what he's talking about.
 

nobody

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That person is totally inaccurate about the cause of A90's RCA input noise. If you have a ground loop it will of course have noise issue with A90 if one uses RCA input. It's by design. One can use RCA to XLR cable to connect to XLR's on A90 to eliminate noise.

If there's no ground loop then the RCA input will even have less noise than the XLR input. This condition is not usual in real world. But if the DAC is isolated from earth, there will be very low noise.

I had problems with unbalanced line out on my A90 with power amps. High amount of noise on Nakamichi PA5 or Usher R1.5 even without any source connected. What's worst, the noise was there even with the A90 powered off with front switch. Only solution to get rid of the noise was to disable A90 with rear switch.
Balanced out with my NC500 monoblocks was ok.
And the switching supply developed high pitch mechanical noise after one year of use.
I sold the A90.
 

Kahntraband

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I purchased the sa-1 about a week ago and it still hasn’t come in (and likely won’t for several weeks since I’m in the US) and I was wondering if anyone has purchased one recently that can confirm whether the amp still has the jumper pins. I know SingXer said they would remove the pins in a future revision, but I would like to know if they are still present on current models. If not I am going to either return it or cancel my order and just go with the Jotunheim 2.
 
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Veri

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I purchased the sa-1 about a week ago and it still hasn’t come in (and likely won’t for several weeks since I’m in the US) and I was wondering if anyone has purchased one recently that can confirm whether the amp still has the jumper pins. I know SingXer said they would remove the pins in a future revision, but I would like to know if they are still present on current models.
They mean future products, they won't suddenly revise the current SA-1. Mine had everything as normal. I wouldn't worry.
I don't believe the jumpers give actual benefit but if you wanna try, pins should be there..
 
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