Yamaha RX-A8A Review

[thin bLue]

람쓰 the member of our community kindly purchased it himself with his own money and asked me to measure it. I fried it. Then Repaired. Further more he just provide another Brand New One!!!
And I made some mistake in measurements that made me to retest them. So he asked to Yamaha Korea lent their Yamaha RX-A8A and provide guide from Yamaha Headquarters in Japan,

With Yamaha RX-A8A I've learned so many things. Some of the insights I learned from that I was able to apply after returning the A8A.
So, I have so many trash data that need more explanation.

I'll pick up and explain a series of mistakes I've made, one by one, for all to see. This will help you avoid making mistakes what I did and give you an idea of what uncertainties are exist doing measurements 'without knowledge' like me.



Let's see what I got at 1st attempt.

The FTT windows are not properly trimmed, and the size is default.
The black line in the middle of the green bar graph indicates the maximum-minimum end of value, so it should be initialized after stabilization to properly show the fluctuation.

Fr seems wrong.
AVR has the decent amount of processing time, and intentional delay according to compensate speaker distance.
Too short Acquisition time cuts the final parts of test tone, so end of signal(highest frequency) look filtered.
If you use too short acquisition time like me, you can see the artifacts that do not exist, very distinctly and repeatedly.

The high-frequency region in multitone proves that the filtering seen above is not really there.


4 Ohm sweeps

If you check the specs of the amp and look at this, you'll see that I've pushed the power too far.
However, at 4 ohms, it was surprisingly alive.

Last gasp with 2 Ohms.
Distortion is low, but it was already overheating, Put 2Ohm and sweep to sky high power was 100% my fault But the protection doesn't stop me from frying the amp.


Even if the amplifier's output is near THD+N 1%, it could still be in the zone of permanent damage.
Watching THD+N ratio is not enough at all. READ THE WATTAGE! and you should Monitor power consumption of the Device Under Test to test products with uncertain output range.
Most of case, measured power near the rated power and load on spec sheet range will be fine I think.. (but believe me. this is not that simple!)

WOW!

What is happening!
Hint : S.Korea uses 220V, 60 Hz AC


AMP

Brand New Yamaha RX-A8A Non GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT -20 dB Front L R OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -20 dB Front L R OUT SINAD 22.4k

Compare the 60 Hz peak!



Pre
Brand New Yamaha RX-A8A Non GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R RCA Pre OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Front L R RCA Pre OUT SINAD 22.4k.PNG

Pre, no word is needed,
Yes, that famous bloody ground loop.
In the first attempt, I tested it with various cables plugged in as much as possible (for convenience), so the XLR terminal among them automatically grounded the AP and AMP.
After the amp was repaired and I retested, it was exposed to severe ground loops because only the necessary cables were connected (Optical and RCA, etc.).

This is why the XLR connector has three pins, while a balanced transmission only requires two wires.
RCA sucks!



As you can see, with XLR, no external grounding is needed for do thing right.
They do have that feature in it as basic!

Brand New Yamaha RX-A8A Non GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R XLR Pre OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R XLR Pre OUT SINAD 22.4k

With XLR, regardless of whether external grounding is connected or not, the result of the two is identical.



Finally, Shielding the analyzer and its surroundings from radiation sources!

with dummy load and 0040 filter connected (ends of dummy load=bananas are exposed)

this to

this

AP do so many automation for me
But they don't cover everything.
Today, unless it is a silent environment exclusively for testing, various radio noises exist, and AP Analyzer is quite wideband, it must be better protected to achieve proper performance.
Poor operators can produce the worst results with top-of-the-line equipment. Of course, it's better than a bad operator and the worst equipment.

And here's the confident world class Anpu tempura(AMP Fry) chef.


Anyway let's see
A8A Filter difference. No significant SINAD difference between filters.

Pre

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Front L R RCA Pre OUT SINAD 20k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Front L R RCA Pre OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Front L R RCA Pre OUT SINAD 40k

Official Yamaha RX-A8A GNDed Opti 0 dBFS IN Sharp Roll-off STRAIGHT 0 dB XLR Pre L R SINAD 20k Firmware Ver.1.96 Temp 27.3 Humi 42

Official Yamaha RX-A8A GNDed Opti 0 dBFS IN Sharp Roll-off STRAIGHT 0 dB XLR Pre L R SINAD 22.4k Firmware Ver.1.96 Temp 27.3 Humi 42

Official Yamaha RX-A8A GNDed Opti 0 dBFS IN Sharp Roll-off STRAIGHT 0 dB XLR Pre L R SINAD 40k Firmware Ver.1.96 Temp 27.3 Humi 42.PNG

Official Yamaha RX-A8A GNDed Opti -6 dBFS IN Sharp Roll-off STRAIGHT 0 dB XLR Pre L R SINAD 22.4k Firmware Ver.1.96 Temp 27.3 Humi 42.PNG

Official Yamaha RX-A8A GNDed Opti 0 dBFS IN Sharp Roll-off STRAIGHT 0 dB XLR Pre L R Gain Firmware Ver.1.96 Temp 27.3 Humi 42

Official Yamaha RX-A8A GNDed Opti 0 dBFS IN Sharp Roll-off STRAIGHT 0 dB XLR Pre L R Fr wrong Firmware Ver.1.96 Temp 27.3 Humi 42 <- For compare

Official Yamaha RX-A8A GNDed Opti 0 dBFS IN Sharp Roll-off STRAIGHT 0 dB XLR Pre L R Fr Firmware Ver.1.96 Temp 27.3 Humi 42.PNG

Official Yamaha RX-A8A GNDed Opti 0 dBFS IN Sharp Roll-off STRAIGHT 0 dB XLR Pre L R Multitone Firmware Ver.1.96 Temp 27.3 Humi 42.PNG

Due to image limit up to 35, continued in the next post.

 

[thin bLue]

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Center Front R RCA Pre OUT SINAD 22.4k.PNG

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Surround L R RCA Pre OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Surround Back L R RCA Pre OUT SINAD 22.4k.PNG

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Front Presence L R RCA Pre OUT SINAD 22.4k.PNG

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Rear Presence L R RCA Pre OUT SINAD 22.4k.PNG

AMP


Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) PURE DIRECT -20 dB Front L R OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -20 dB Front L R OUT Multitone

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT -5dB Front L R OUT Power sweep 4 Ohms

Did not fired at ALL!

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -17 dB Center OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -17 dB Center OUT Multitone

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -17 dB Surround L R OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -17 dB Surround L R OUT Multitone

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -11 dB Surround Back L R OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -11 dB Surround Back L R OUT Multitone

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -11 dB Extra Sp1 L R OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -11 dB Extra Sp1 L R OUT Multitone

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -11 dB Extra Sp2 L R OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -11 dB Extra Sp2 L R OUT Multitone.PNG

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo -5 dB Power sweep 4 Ohms

Main claim is 150 W in 2 ch driven, No 4 Ohm rating, so It appears to fit that.


I tested Pre and AMP Pure direct, straight, 2ch stereo and All-Channel Stereo but there was no significant SINAD changes.
It's a pity that it's not a perfect review, but I think the minimum key elements are still here.

 

[GXAlan]

Lots of data, but do you have a SINAD versus output voltage under these types of shielded testing? This SINAD is top of its class…

 

[thin bLue]

View attachment 304195

Lots of data, but do you have a SINAD versus output voltage under these types of shielded testing? This SINAD is top of its class…

It's kind of a loop back (in fact not a loop-back, just test loop)

So, APx525B and 0040 filters and etc in my environment shows max 108~109 dB @ 22.4.

So. DUTs bout 90 dB could be "Accurate"
DUTs have performance above 100 dB are "heavily affected by test tools and environment"


If analyser is upgraded like Amirs APx555 with some option, It can go further high SINAD. But the cost....

 

[GXAlan]

It's kind of a loop back (in fact not a loop-back, just test loop)

So, APx525B and 0040 filters and etc in my environment shows max 108~109 dB @ 22.4.

So. DUTs bout 90 dB could be "Accurate"
DUTs have performance above 100 dB are "heavily affected by test tools and environment"


If analyser is upgraded like Amirs APx555 with some option, It can go further high SINAD. But the cost....

Got it. I didn’t appreciate that it was just a loopback equivalent as opposed to a measurement once you shielded everything.

 

[thin bLue]

Got it. I didn’t appreciate that it was just a loopback equivalent as opposed to a measurement once you shielded everything.

I mean, like loop back, it shows limit performance of device! not It is loopback.

It is measurement once you shielded everything. Yes it is.

Sorry for my English.

 

[Deleted member 21219]

Thank you for the clarification and all the work, @thin bLue .

Jim

 

[thin bLue]

Thank you for the clarification and all the work, @thin bLue .

Jim

Thank you for watching!

 

[delta76]

Appreciate time and effort you have put into this, but if I may give a suggestion - even on this forum there are many "less technical" people (like me). a lot of graphs can be overwhelming. I am biased but I found format by @amirm to be easy to follow and understand (DAC/Amp performance, SINAD and power). other graphs can be put in <spoiler> tags which a description of what they are, how the AVR performs, and maybe with your comment.

Just a suggestion - hope to see more reviews from you.

 

[sweetchaos]

Yes, consider adding a summary or TLDR section.

Thanks for another set of measurements.

 

[thin bLue]

Appreciate time and effort you have put into this, but if I may give a suggestion - even on this forum there are many "less technical" people (like me). a lot of graphs can be overwhelming. I am biased but I found format by @amirm to be easy to follow and understand (DAC/Amp performance, SINAD and power). other graphs can be put in <spoiler> tags which a description of what they are, how the AVR performs, and maybe with your comment.

Just a suggestion - hope to see more reviews from you.

Yes, consider adding a summary or TLDR section.

Thanks for another set of measurements.

Actually, in this time, I was going to try something like that.

But... I was burnt out...Physically, I am on various medications, including antibiotics now.

I'll try some after I rrecover!

 

[NOAMattD]

So if I am understanding these right (a lot of data here, hoping smarter minds than I can comment), your measurements are similar to what Audioholics measured on the RX-A6A for the equivalent tests, yes?

Yamaha RX-A6A 9.2CH 8K AV Receiver Bench Test Results!

We bench tested the Yamaha RX-A6A 9.2CH 8K 150watt/ch Atmos/DTS:X Receiver to gauge power output and uncover performance issues we discovered. We discuss the proper settings for best power delivery.

www.audioholics.com

 

[thin bLue]

So if I am understanding these right (a lot of data here, hoping smarter minds than I can comment), your measurements are similar to what Audioholics measured on the RX-A6A for the equivalent tests, yes?

Yamaha RX-A6A 9.2CH 8K AV Receiver Bench Test Results!

We bench tested the Yamaha RX-A6A 9.2CH 8K 150watt/ch Atmos/DTS:X Receiver to gauge power output and uncover performance issues we discovered. We discuss the proper settings for best power delivery.

www.audioholics.com

Hard to answer.

It is the same that they want to provide information, so do I, but it is difficult to say that they are mutually direct comparable. It would be nice to see wide trends with large tolerance. Since this was done with different measuring instruments and under measurement conditions, it is better not to accept the figures as absolute values, but to compare them as relative values.

 

[GXAlan]

I am still confused about what the 108 dB SINAD result is showing.

Is that analog out of the A8A into your analyzer? Or is that with a different signal generator to show you the quality of your analyzer?

It may be helpful to "show your work" using the spoiler tag, and focus on the end results on the findings.

 

[thin bLue]

I am still confused about what the 108 dB SINAD result is showing.

Is that analog out of the A8A into your analyzer? Or is that with a different signal generator to show you the quality of your analyzer?

It may be helpful to "show your work" using the spoiler tag, and focus on the end results on the findings.

That's Ap Out - Ap In with filters, load, cables. Not A8A's!

In the process of testing the A8As, I became aware of the effect of the surrounding environment on the analyzer. I thought It was self bullet proof and immune for things like that. I thought It was self bulletproof and immune for things like that. But it wasn't. That's why it's written here (as part of my failure), and A8A is the first instance where that improvement was applied.

Value from A8A has marked with measurement conditions. (What input, gain, output etc)

Sorry if I've confused you.

 

[GXAlan]

No need to apologize. I see the file names then.

So,this is the highest measurement at a relaxed “1.6V balanced”

 

[thin bLue]

No need to apologize. I see the file names then.

So,this is the highest measurement at a relaxed “1.6V balanced”
View attachment 307126

This is RCA out!

Brand New Yamaha RX-A8A Non GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R RCA Pre OUT SINAD 22.4k
->

Brand New Yamaha RX-A8A : 3rd sample, after 1st one(fried) and 2nd one(=repaired 1st one))

Non GNDed : No ground connection, so we can see the loop on signal (60Hz and It's Harmonics)

Opti 0 dBFS IN : Digital Optical connection AP(OUT) -> (IN)RX-A8A, Volume as 0 dBFS, full <- AP's output setting, test signal that RX-A8A received

IN Short Latency (default) : RX-A8A's digital filters set as default

STRAIGHT 0 dB : At RX-A8A's STRAIGHT Mode, and RX-A8A's volume set at 0 dB

Front L R RCA Pre OUT : Tested channel = front L R, RCA Pre out of RX-A8A

SINAD 22.4k : SINAD test. filter set to 22.4 kHz (ASR standard)




Brand New Yamaha RX-A8A Non GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R RCA Pre OUT SINAD 22.4k

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R RCA Pre OUT SINAD 22.4k.PNG

Comparing the difference caused by the ground connection in original post, it appears that I accidentally uploaded less meaningful file. I'm so sorry again.
These images will provide a better comparison!

 

[peng]

No need to apologize. I see the file names then.

So,this is the highest measurement at a relaxed “1.6V balanced”
View attachment 307126

That's 3.2 V balanced, XLR, not bad at all!

 

[FrantzM]

Actually, in this time, I was going to try something like that.

But... I was burnt out...Physically, I am on various medications, including antibiotics now.

I'll try some after I rrecover!

Focus on your health and recovery .. Please..
We'll wait for the TLDR and whatnot ...

to your health!

Peace.

 

[thin bLue]

That's 3.2 V balanced, XLR, not bad at all!

You can see the left side 'Signal Path setup' - 'Input Configuration' - 'Connection : Analog Unbalanced'
Unbalanced = RCA


XLR and modes

Brand New Yamaha RX-A8A Non GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R XLR Pre OUT SINAD 22.4k.PNG

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R XLR Pre OUT SINAD 22.4k.PNG

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) PURE DIRECT 0 dB Front L R XLR Pre OUT SINAD 22.4k.PNG

Brand New Yamaha RX-A8A GNDed Opti 0 dBFS IN Short Latency (default) All-Channel Stereo 0 dB Front L R XLR Pre OUT SINAD 22.4k.PNG

Optical signal -3 dBFS
Brand New Yamaha RX-A8A GNDed Opti -3 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R XLR Pre OUT SINAD 22.4k.PNG

Optical signal -5 dBFS
Brand New Yamaha RX-A8A GNDed Opti -5 dBFS IN Short Latency (default) STRAIGHT 0 dB Front L R XLR Pre OUT SINAD 22.4k.PNG

Filters (RCA IN - XLR OUT)

Brand New Yamaha RX-A8A GNDed RCA 2 Vrms IN Short Latency (default) STRAIGHT 0 dB Front L R XLR Pre OUT SINAD 22.4k.PNG

Brand New Yamaha RX-A8A GNDed RCA 2 Vrms IN Slow Roll-off STRAIGHT 0 dB Front L R XLR Pre OUT SINAD 22.4k.PNG

Brand New Yamaha RX-A8A GNDed RCA 2 Vrms IN Sharp Roll-off STRAIGHT 0 dB Front L R XLR Pre OUT SINAD 22.4k.PNG