This is a review and detailed measurements of the IOTAVX SA3 integrated stereo amplifier with built-in DAC and subwoofer output. It was kindly purchased by a member and drop shipped to me. It costs £399.00 (on sale from £449.00) on company's website. Hard to find it on sale in US but found one ebay listing for $498.
SA3 nails the industry design with svelte chassis, dot matrix display and judicious use of backlighting for the logo:
I left the plastic on the display as otherwise it looks nicer than it does in the picture. A reassuring power button is the left and a nice feeling rotary control handles the volume. If you press it, it becomes an input selector. Very nicely done.
Back panel shows a lot of inputs:
There is phono input which I did not test. I did test both analog input and Toslink digital input. Sadly there is no USB input. There is bluetooth but no streaming support over network.
Let's get started by using the line in (analog) input to the power amp and work our way out to the DAC section.
Amplifier Audio Measurements
With integrated amplifiers with volume controls, I adjust that to produce roughly 29 dB of gain which is a THX "standard." That gives us this dashboard:
Distortion dominates with second harmonic telling the full story. Wish channel 2 was as good as channel 1 but this is typical. Averaging the two we get this kind of ranking:
So above average among 89 amplifiers tested so far (!). But not state of the art by any stretch.
Noise performance is good:
You almost clear the CD's 16-bit dynamic range at 96 dB at 5 watts output.
Typical of class AB designs, bandwidth is abundant:
Should the zombie apocalypse come, you can hook up a few hundred yards of wire to the speaker wire and have yourself an AM transmitter power amp!!! A microphone and simple modulator and you could be talking to people thousands of miles away at night....
Crosstalk is surprisingly good:
If you look inside the chassis, you realize why. A toroidal transformer is in the middle with each amplifier nicely separated from each other by good 8 to 10 inches.
Power output at 4 ohms falls a bit short of the spec:
And I am not too happy about the constant rise in distortion from just 1 watt, ending worse than one of our worse performing Audio Video Receiver (the NAD T758).
It is a bit happier driving an 8 ohm load:
That's not a lot of power though so best get an efficient speaker is 8 ohm is the language it speaks.
Fortunately burst power is quite decent (only 4 ohm shown):
Changing the frequency of the test tone hardly bothers the SA3:
Other topologies such as Class D make a mess out of this measurement.
DAC Audio Measurements
Taking advantage of the pre-amp output, I fired off a few DAC tests to get an idea of how good that subsystem is starting with our digital dashboard:
OK, this is a bit disappointing. You want a SINAD here that is 10 dB better than the amp for it to be transparent. Here it is actually a couple of dB worse then the amplifier which means the combo will drag down the performance of the amplifier some.
As a DAC, it falls in the failing (red) category of all DACs tested to date:
Noise performance is decent:
Intermodulation+noise test is disappointing:
The upper line in orange is a phone dongle! The SA3 hugs that performs like it is related to it which it should not be.
Jitter performance looks better than it is due to high noise floor potentially hiding other spurious tones:
So overall the DAC portion is barely a match for the amplifier. If the amp gets the grade B, the DAC gets a C+.
Conclusions
It is nice to see a fresh take on the integrated stereo amplifier from IOTAVIX. The SA3 looks attractive, has good feature set including many inputs from digital to analog and takes up little space. You can nicely put it under your monitor, add a couple of speakers and be in business.
You don't get to brag its measured performance but what is there "is not broken" which is often an accomplishment in world of audio. Performance is solid across the board with the DAC trailing a bit. I would happily use it in a secondary system.
Overall, I am going to recommend the IOTAVIX SA2 amplifier.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Every day I am in the garden, digging holes, removing rocks and weed and planting until my back can't take it anymore. Then I come inside and do these reviews. I am thinking this definitely qualifies for overtime. So even if you have donated before, you owe me an extra 50% in donations : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
SA3 nails the industry design with svelte chassis, dot matrix display and judicious use of backlighting for the logo:
I left the plastic on the display as otherwise it looks nicer than it does in the picture. A reassuring power button is the left and a nice feeling rotary control handles the volume. If you press it, it becomes an input selector. Very nicely done.
Back panel shows a lot of inputs:
There is phono input which I did not test. I did test both analog input and Toslink digital input. Sadly there is no USB input. There is bluetooth but no streaming support over network.
Let's get started by using the line in (analog) input to the power amp and work our way out to the DAC section.
Amplifier Audio Measurements
With integrated amplifiers with volume controls, I adjust that to produce roughly 29 dB of gain which is a THX "standard." That gives us this dashboard:
Distortion dominates with second harmonic telling the full story. Wish channel 2 was as good as channel 1 but this is typical. Averaging the two we get this kind of ranking:
So above average among 89 amplifiers tested so far (!). But not state of the art by any stretch.
Noise performance is good:
You almost clear the CD's 16-bit dynamic range at 96 dB at 5 watts output.
Typical of class AB designs, bandwidth is abundant:
Should the zombie apocalypse come, you can hook up a few hundred yards of wire to the speaker wire and have yourself an AM transmitter power amp!!! A microphone and simple modulator and you could be talking to people thousands of miles away at night....
Crosstalk is surprisingly good:
If you look inside the chassis, you realize why. A toroidal transformer is in the middle with each amplifier nicely separated from each other by good 8 to 10 inches.
Power output at 4 ohms falls a bit short of the spec:
And I am not too happy about the constant rise in distortion from just 1 watt, ending worse than one of our worse performing Audio Video Receiver (the NAD T758).
It is a bit happier driving an 8 ohm load:
That's not a lot of power though so best get an efficient speaker is 8 ohm is the language it speaks.
Fortunately burst power is quite decent (only 4 ohm shown):
Changing the frequency of the test tone hardly bothers the SA3:
Other topologies such as Class D make a mess out of this measurement.
DAC Audio Measurements
Taking advantage of the pre-amp output, I fired off a few DAC tests to get an idea of how good that subsystem is starting with our digital dashboard:
OK, this is a bit disappointing. You want a SINAD here that is 10 dB better than the amp for it to be transparent. Here it is actually a couple of dB worse then the amplifier which means the combo will drag down the performance of the amplifier some.
As a DAC, it falls in the failing (red) category of all DACs tested to date:
Noise performance is decent:
Intermodulation+noise test is disappointing:
The upper line in orange is a phone dongle! The SA3 hugs that performs like it is related to it which it should not be.
Jitter performance looks better than it is due to high noise floor potentially hiding other spurious tones:
So overall the DAC portion is barely a match for the amplifier. If the amp gets the grade B, the DAC gets a C+.
Conclusions
It is nice to see a fresh take on the integrated stereo amplifier from IOTAVIX. The SA3 looks attractive, has good feature set including many inputs from digital to analog and takes up little space. You can nicely put it under your monitor, add a couple of speakers and be in business.
You don't get to brag its measured performance but what is there "is not broken" which is often an accomplishment in world of audio. Performance is solid across the board with the DAC trailing a bit. I would happily use it in a secondary system.
Overall, I am going to recommend the IOTAVIX SA2 amplifier.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Every day I am in the garden, digging holes, removing rocks and weed and planting until my back can't take it anymore. Then I come inside and do these reviews. I am thinking this definitely qualifies for overtime. So even if you have donated before, you owe me an extra 50% in donations : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
