I think you mean 22.5k and 45k ohms input impedance !More details, from Singxer's Taobao:
At the front stage output, the single-ended impedance is 22.5 ohms, and the balanced impedance is 45 ohms.
Tom, can you provide me with details on the jumpers to bypass the AC input coupling caps ?In fact, I am the designer of SA-1 from Singxer.
I am very happy that everyone is interested in SA1.
The design ideas of SA1 are different from other manufacturers;
Balance the input and output for maximum performance.
SA1 is based on a fully balanced design, from input to volume control (quadruple ALPS RK27 volume potentiometer), 4 identical amplifier circuits.
The potentiometer is manually selected to ensure channel balance at low volume.
Other manufacturers may convert the balanced input to single-ended, and the volume potentiometer just uses a clean 2-connect potentiometer.
thanks
In all honesty? Likely absolutely none, the 789 is very good already. It has a knob that can get noisy, and it hasn't got the best crosstalk in lowest gain; both of which might be better on SA-1. On the other hand, 789 will have less of a performance loss at lowest impedance loads. Not a problem with SA-1 in lower gain though, but can become troublesome at high gain and high driving power. 789 also handles BAL in SE out, SE in BAL out better. SA-1 is optimal with balanced out as mentioned earlier in the thread. SE in SE out as measured by Amir seems fine from the looks of it, while with BAL in SE out Amir noticed more grounding noise. So all of this are things to keep in mind!If i have an SMSL SU-9 and Drop THX 789 what differences should i expect if i replace the amp for the Singxer sa-1?
Great review. I was waiting for it.
If i have an SMSL SU-9 and Drop THX 789 what differences should i expect if i replace the amp for the Singxer sa-1?
Damn you!
I said NOTHING about "measures better"Quite the statement. I'm pretty sure the A90 measures slightly better SE.
@tom.chen Which opamp does the SA-1 use on its input stage?
Thank you for your encouragement, we will work hard to design more new products. Thank you all for your attention.Thank you for this information and congratulations for your amp very appreciated in several reviews
Tom, can you provide me with details on the jumpers to bypass the AC input coupling caps ?
My source (Oppo UDP-205) is also AC coupled at the output (0.0mv dc).
Also is the 6.5mm output just in parallel to the positive out on the 4 pin balanced connector ?
Love the amp so far and have some 4 pin Neutrik XLR connectors on the way to convert one or more of my headphones !
While you're at removing DC sockets in the future, bring the gain switch to the front of the unit, will yaIn any case, we don't recommend to use internal DC coupling, this is only for our test. We will consider removing this DC socket in the future.
There are only 4 amplifiers inside, and the three output sockets 6.35 4.4 XLR are all connected together.
Pretty sure your KEYBOARD is ACTING UP. Please check the CAPS LOCK key.I said NOTHING about "measures better"
I DID say it is BUILT better, and SOUNDS better.
I dont use BAL in SE out.
I have other amps that I prefer for my Single Ended needs.
Maybe even some low SCORING amps
If Single Ended MEASUREMENTS are important, there are many higher SCORING amps on "the chart"
Always best to have no AC coupling caps in the circuit path !In any case, we don't recommend to use internal DC coupling, this is only for our test. We will consider removing this DC socket in the future.
There are only 4 amplifiers inside, and the three output sockets 6.35 4.4 XLR are all connected together.
Did you activate high gain by flipping all the switches underneath the unit?Well, for me the SA-1 just did not work as expected and it will be sent back to Shenzhenaudio (unless someone in the UK wants to take it off my hands).
Although I trust Amir's measurements, I just can't understand why it drives even my Q701 with little to no headroom left. In all honesty I did not expect this even from my Arya but that is what I experience. My Violectric V200 which this might have replaced has A LOT of spare headroom left. For example I listen the Arya with volume set at 12.30 o'clock while on the SA-1 am at 5. I just do not get it: how can it have 3.6W into 50 ohm?
On the subjective side, which I realise isn't that suited to this forum, the SA-1 does sound good. Fed balanced by an SU-1 the sound of the Violectric is a bit crisper than the smoother SA-1 and the soundstage is narrower than the SA-1. To my ears of course.
Have you set the SA-1 to high gain mode? The 4 switches are at the bottom of the amp. It's a weird way of switching to high gain but I guess Singxer has their reason for doing so.Well, for me the SA-1 just did not work as expected and it will be sent back to Shenzhenaudio (unless someone in the UK wants to take it off my hands).
Although I trust Amir's measurements, I just can't understand why it drives even my Q701 with little to no headroom left. In all honesty I did not expect this even from my Arya but that is what I experience. My Violectric V200 which this might have replaced has A LOT of spare headroom left. For example, see photo, I listen the Arya with volume set at 12.30 o'clock while on the SA-1 am at 5. I just do not get it: how can it have 3.6W into 50 ohm?
On the subjective side, which I realise isn't that suited to this forum, the SA-1 does sound good. Fed balanced by an SU-1 the sound of the Violectric is a bit crisper than the smoother SA-1 and the soundstage is narrower than the SA-1. To my ears of course.
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