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IOTAVX SA3 Stereo Amplifier Review

maty

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True. But, find me a preamplifier in the $500 and under range that features balanced outputs. Using the MiniDSP HD, I'm pretty much restricted to using unbalanced/RCA plugs as it is, so aside from switching over to a balanced MiniDSP for use with a balanced pre-amplifier, unbalanced is the answer for now. Plus, it's summer. Less time to focus on music. More time to focus on and enjoy the convertible and Harley. :cool::p:cool:

Less dangerous and more pleasant (at least to me), listen to a new vinyl rip:

Tony Bennett / Bill Evans - The Tony Bennett / Bill Evans Album (1975), Vinyl x2, Analogue Productions, Remastered 2006, 45rpm, 180g pressing, US
https://www.diyaudio.com/forums/music/6958-playing-listening-post6229287.html

https://www.discogs.com/Tony-Bennett-Bill-Evans-The-Tony-Bennett-Bill-Evans-Album/release/5351083
https://www.amazon.com/Bill-Evans-Album-180g-45RPM/dp/B001DH46ZY

- End of topic -
 
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wje

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Less dangerous and more pleasant (at least to me), listen to a new vinyl rip:

- End of topic -

I hear you regarding the potentially "less dangerous" part. However, when you're on a bike, cruising at 85 MPH, your mind might not be thinking of balanced connectors on your audio gear at home. ;):cool:
 

maty

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Thisisnotfortears

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Any idea when these are coming back in stock on their website (currently says available for preorder with no further info on a date)? Tried contacting them but no response.
 

theAuditor

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Finally! Thanks Amir. Several members have been waiting for this one. Bypass the built in DAC and use a Topping D10 or similar external DAC, and you've got an even better setup, and still for a good price. Like the VTV Hypex amplifiers, minor issues don't spoil an excellent bargain - especially with free shipping to the U.S. Here's the interior photo from the IOTAVX website.

View attachment 64905

I wouldn't be concerned about the DAC performance, but I'm a bit surprised that it wasn't better. No bragging rights, but it should sound fine. If the same wonky DAC performance exists with the IOTAVX 7.1 4K AVP with HDMI input, I just might keep my Topping DX7s DAC/HA for two-channel music listening. Hopefully someone in the U.S. will buy an IOTAVX AVP and send it to you for measurement.

I paid for the AVP with PayPal, and it took a week for Ian to ship it out via DHL. Good tracking info and updates. It took only four days for it to get to my forwarder in Miami, and looks like it will be about ten days to get from from Miami to Panama. Below is a photo of the AVP back panel. I will report on my impressions of it in a week or so.

View attachment 64906

I think IOTAVZ will be a good, solid line of entry-level audiophile gear, especially if we can get Ian to tweak the DAC section. Their 7-channel AV Amplifier looks good too with about twice the power per channel as the integrated and balanced XLR inputs.

View attachment 64904
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:

View attachment 64883

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:

View attachment 64884

So above average among 89 amplifiers tested so far (!). But not state of the art by any stretch.

Noise performance is good:

View attachment 64885

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:

View attachment 64886

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:

View attachment 64887

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:

View attachment 64888

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:

View attachment 64889

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):

View attachment 64891

Changing the frequency of the test tone hardly bothers the SA3:

View attachment 64892

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:

View attachment 64893

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:

View attachment 64898
Noise performance is decent:
View attachment 64894

Intermodulation+noise test is disappointing:

View attachment 64895

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:

View attachment 64896

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/
IOTA has sent me 2 defective amps in a row. It’s been a week since I received the second defective amp and IOTA customer support is silent. I would avoid this company.
 

ThomasMac

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If one just wanted to use the sa3 as a dedicated pre amplifier... do u hook it up from sa3 pre out to pa3 amp in? Their manual suggest hooking it up from sa3 preout to pa3 preout. I don't quite understand that.
 

Elgrosso

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Just my 2 cents on IOTAVX PA3:
In my quest for lower noise on high mid/tweeters on my active system (not super high but still high sensitivity 98/95db) I wanted to test few amps to replace my hypex 122/252. Tried topping pa3s, didn't work well because of a protection mode issue.
Found 2 used PA3 on the "good corner" for a very good price, and they work perfectly, much lower noise, enough power since I probably don't use more than 5w, and can't find a default in the sound.

I also like the design, very basic/sober.
With the very classic layout I'm sure I could service or get it serviced easily if any problem appears.
So happy I bought one more new for my low mids, power here is still good enough for now, and if I need even more I could get another one and bridge them here.
3 of them don't consume more than the 2 hypex', heat is totally fine, but I don't stack them.
And Ian from IOTAVX responded very fast to my email inquiries.

Neurochome was a strong option but the PA3 are good enough for now.
So, hypex is not "always" the answer.
Now I just need to find a way to tame the front LED, for now it’s just tapped :p
 

Schlippwhip68

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A IOTAVX PA3 would be great match for the $130 Topping E30 DAC/Pre with it's remote control - unless you still have other analog sourses and a need traditional preamplifier functions with input switching and/or active gain.

Also, expect confusion as both IOTAVX and Topping offer amplifiers with the model number "PA3".
Currently thinking about getting hold of the PA3 from IOTA. I have a couple of questions if you can help. I have Toppings E50 dac which I presume could be used but would that only be possible as a preamp or can I use it as a dac too? I ask because volume control doesn't exist on the PA3 so using the E50 as a DAC may present an issue with volume adjustment, I would be using a Mac Mini as a source for the dac. Also could the pre outs on the PA3 be used for a pair of subs?
 

Elgrosso

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Don’t know the E50 but if there’s no volume control that will be a problem.
You could use the macmini volume but that’s painful, and risky.
Maybe just go with the SA3 that has volume control? and later add a PA3 if you need more.

The PA3 only has 1 output, while the SA3 has 1 stereo out + 1 sub out.
But they don't say anything about the high pass.
 

Schlippwhip68

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I'm not surprised about the DAC. I could not measure it and it sounds good but when you turn the volume way up it is noisier than the line input.
It also switches with relays if the bitrate changes.

A longer press on the volume knob selects the bass/trebble/balance settings. Really long press resets it.

One thing I'm not happy about is the non grounded power supply. It uses a small switching powersupply as standby power, under the metal shield see picture above and it leaks some voltage to the chassis. I grounded it myself with a wire to ground and the phono earth connector.
If could you point out in a picture how you did this and the location of the phono earth connector? I have this amp arriving soon and would prefer to do this rather than not.
 

Schlippwhip68

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Don’t know the E50 but if there’s no volume control that will be a problem.
You could use the macmini volume but that’s painful, and risky.
Maybe just go with the SA3 that has volume control? and later add a PA3 if you need more.

The PA3 only has 1 output, while the SA3 has 1 stereo out + 1 sub out.
But they don't say anything about the high pass.
Agreed. I have gone with the SA3. The new Mission 778x was another choice but found an SA3 2nd hand at half the cost so it will suffice.
 

Schlippwhip68

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If one just wanted to use the sa3 as a dedicated pre amplifier... do u hook it up from sa3 pre out to pa3 amp in? Their manual suggest hooking it up from sa3 preout to pa3 preout. I don't quite understand that.
You could also hook up to an Aiyima A07….
 

gfx_1

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If could you point out in a picture how you did this and the location of the phono earth connector? I have this amp arriving soon and would prefer to do this rather than not.
It is just a yellow/green wire between the chassis earth next to the phono input and the earth of the powerstrip you might not need it.
I used a crimp on spade connector on one side and a 3-prong grounding plug on the other with only the earth connected.
There is probably some code somewhere against grounding a double insulated device but I didn't like the slightly tingly feeling.
Health and safety disclaimer: If you wire your own plug make sure which one is earth or it is 33% chance of instant death.
 

Schlippwhip68

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It is just a yellow/green wire between the chassis earth next to the phono input and the earth of the powerstrip you might not need it.
I used a crimp on spade connector on one side and a 3-prong grounding plug on the other with only the earth connected.
There is probably some code somewhere against grounding a double insulated device but I didn't like the slightly tingly feeling.
Health and safety disclaimer: If you wire your own plug make sure which one is earth or it is 33% chance of instant death.
Thanks for the reply, I bought Denon instead.
 

Larx

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Can someone confirm if the SA3 has any hiss? I want to buy this amp solely for the purpose of no hiss. My current amp has a constant loud hiss, even at lowest volume, and since I'm using a desktop setup, its especially noticeable.

I'm hoping the SA3 won't have any hiss 3 feet away from speakers.
 

quma

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Hi guys

I am (was) a happy user of the SA3 and PA3 (in Mono/Bridge mode) with my old speakers. I recently upgraded the speakers and now the presentation is very airy and transparent, but also sometimes too bright and lacking bass.
I would like to test a tube preamplifier to calm things a bit down. I actually asked IOTAVX Enterprises how to add a preamp to the system and the answer was:
-Connect it to the 'Pre Out' of the PA3.
Can this be correct? I would have thought that the preamp belongs to the SA3, or at least to the 'Amp In' of the PA3 (which is already occupied by the SA3)

Thanks for any suggestions.
 
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