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SONCOZ SGP1 Stereo Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 6 1.8%
  • 2. Not terrible (postman panther)

    Votes: 8 2.4%
  • 3. Fine (happy panther)

    Votes: 62 18.9%
  • 4. Great (golfing panther)

    Votes: 252 76.8%

  • Total voters
    328

amirm

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This is a review and detailed measurements of the SONCOZ stereo class AB power amplifier. It was sent to me by the company about 5 or 6 months ago and costs US $1099.
Soncoz SGP1 Stereo Power Amplifier Balanced class AB review.jpg

As you see, the unit comes in gorgeous packaging with custom and VU meters befitting of some of the highest end audio products of 1980s when such feature was popular. The meters also seem to have acceleration and autoscaling as they seem very responsive during my testing. But as you see, one is pegged to max. This only happened when there was no cable attached to that input (it only affected the meter, I measured and nothing comes out of the amp that way). Company says this problem was found and is fixed.

The unit feels extremely sturdy and heavy for its size (medium). Back panel sports high quality connectors and a trigger input:

Soncoz SGP1 Stereo Power Amplifier Balanced class AB back panel review.jpg


Notice the rounded over heatsinks so they don't tear your skin open as you lift the unit. Really, this is A+ execution.

In use, the unit only got warm despite me pushing it a lot. It may get warmer if you left it on longer though.

If you are new to these reviews, please watch my video on understanding amplifier measurements.

SONCOZ SGP1 Amplifier Measurements
As usual we start with our dashboard:
Soncoz SGP1 Stereo Power Amplifier Balanced Measurement.png

I like the sensible gain of not too high, not too low (you need 2.5 volt for max power). SINAD of 106 dB easily lands in our top tier category of all amps tested:
best stereo amplifier review 2023.png

top amplifier stereo review.png


Dynamic range is superb:
Soncoz SGP1 Stereo Power Amplifier Balanced SNR Measurement.png


As is distortion with multitone:
Soncoz SGP1 Stereo Power Amplifier Balanced Multitone Measurement.png


Same for 19 and 20 kHz:
Soncoz SGP1 Stereo Power Amplifier Balanced 19 20 kHz Measurement.png


Frequency response is one of the flattest I have seen:
Soncoz SGP1 Stereo Power Amplifier Balanced Freqency response Measurement.png


Crosstalk was excellent:
Soncoz SGP1 Stereo Power Amplifier Balanced Crosstalk Measurement.png


Unlike some other compact amplifiers, we have plenty of power, matching company spec:
Soncoz SGP1 Stereo Power Amplifier Balanced Power 4 ohm Measurement.png

Soncoz SGP1 Stereo Power Amplifier Balanced Max and Peak Power 4 ohm Measurement.png


Soncoz SGP1 Stereo Power Amplifier Balanced Power 8 ohm Measurement.png


Finally, here is our sweep vs frequency:
Soncoz SGP1 Stereo Power Amplifier Balanced Power 4 ohm vs frequency Measurement.png


I asked the company about the 20 Hz response and I am told this was an issue with the loading of the switchmode power supply and it has since been fixed. Otherwise, performance is once again superb.

The amp was essentially ready to go on power up:
Soncoz SGP1 Stereo Power Amplifier Balanced Warm up Measurement.png


I like to see less than 1 mv pop on/off noise:
Soncoz SGP1 Stereo Power Amplifier Balanced Pop Noise Power On Off Measurement.png


Conclusions
What a delightful product from SONCOZ: it nails both aesthetics and performance at the same time. The gorgeous VU meters give the SGP1 style and functionality while the traditional class AB delivers extremely low noise and distortion with lots of power. We have had amplifiers with such performance characteristics but not with this much power. I feel regret in not testing this amplifier sooner. :(

It is my pleasure to recommend SONCOZ SGP1 amplifier. It is a model of how you deliver a product to both please the ear and the heart!

Manufacturer PRODUCT SPECIFICATIONS:​

Dimensions 350*260*125mm
Weight 8 Kg
Rated Out Power 240Wx2@4,120Wx2@8
SNR 130 dB, A-Wt., 20 ~ 20k Hz
THD+N < -110 dB (< 0.0003%), A-Wt., 20 ~ 20k Hz
Output Current 8.5A Peak Output Current per Channel
Output Voltage 95 Vpp Peak -to-Peak Output per Channel
Output Configuration Bipolar 4-Parallel Push-Pull per Channel
Frequency Response +0.12dB @82; +0.13dB @42,@20~20kHz
Crosstalk -145~-120dB
Input Sensitivity 2.5Vrmsor28dB
Input Impedance 20kΩ
Environmental 0C to 50 "C Ambient Temperature; Up to 80% Humidity, Non-condensing

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levimax

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Nice review. The final chart is a repeat of the "warm up" chart instead of the "power on and power off" chart.
 

617

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200w class ab with that level of refinement and the nice casework for that price? Very impressive.

Let's see under the hood.
 

Anthony T

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Hi Amir, do you know if the unit you tested is a revision of the first SGP1 released some time ago? I’m sure the amplifier was pulled from sale due to one or two issues so have they fixed those issues and now have a bulletproof design?

I have been using a SGD1 for around three years now and it has been rock solid, so much so I purchased a second one for a little headphone setup so this power amplifier would be a perfect fit:)
Thank you for the review.
 
OP
amirm

amirm

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Hi Amir, do you know if the unit you tested is a revision of the first SGP1 released some time ago?
Yes, I noted that in the review that the couple of issues I found are now fixed.
 

thewas

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Very nice design and implementation, only pity for me is that it doesn't have the 430 mm standard Hifi width to be used together with other classical components.
 

Dougey_Jones

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SimpleTheater

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Can't seem to find the same enthusiasm as Amir. A meter that doesn't work, an issue with the loading of the switchmode power supply and audible "popping" on power up and off. All for over $1,000? And I have to hope this thing lasts, while NAD and Benchmark have proven track records of support. Not thrilled. I gave it a "fine" rating.
 

staticV3

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Can't seem to find the same enthusiasm as Amir. A meter that doesn't work
Read carefully:
The meters also seem to have acceleration and autoscaling as they seem very responsive during my testing. But as you see, one is pegged to max. This only happened when there was no cable attached to that input

Both meters work as expected when listening to audio.
Only when nothing is connected to the Amp's inputs, one meter is pegged at max.
Furthermore, the company has since identified the issue and fixed it.
 

restorer-john

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Most likely will be faulty after a few months and with of course no after sale services.

The power stages look to be beautifully made and they have incorporated a shielded custom SMPS. So the problems of hum and mains noise are virtually absent. The mains artifacts are at least 30dB below a decent performing traditional linear supply.

I would expect this amplifier to have an excellent life.

I would be putting it on my list if I wanted a real, compact, high performance and serviceable amplifier. I would scrap the two output LEDs and make them Clip LEDs instead. And get rid of the silly tagline and arrows on the meters, along with the unnecessary second SONCOZ- it's already engraved directly above. Other than that, it looks really nice.
 
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