Power Rating: Onkyo vs Yamaha


Hi, everyone!

I am browsing for an integrated amplifier and I stumbled upon the Onkyo A-9150, that meets all my requirements (budget, good sound, discreet class AB design, internal DAC, pre-out, phono, the whole package), but I am really curious by its power rating.

Looking at the specs, it is rated as 60W/4-ohm and 30W/8-ohm with 0.08% THD from 20 to 20,000Hz. Okay, but the manual also states that it weighs 9.2 Kg, almost the same (even heavier) as the Yamaha A-S301, that weighs 9.0 Kg. Only the Yamaha is rated as 60W/8-ohm and 70W/4-ohm with 0.019 THD from 20 to 20,000Hz. Upon inspection of pictures over the internet, their transformers are pretty much identical, just like their chassis, and 

How come is this difference in power so big? Any ideas?

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PS.: If you look in their service manuals, I guess you will find that their topology is the same and that the Onkyo A-9150 amplifier transistors are even more powerful than the Yamaha A-S301's.
rafapb
Oh, and the Onkyo has two 10,000 uF capacitors, and the Yamaha two 6,800 uF caps.
The Onkyo will double the power at 4 ohms. It also has a bigger power supply. It looks like the Onkyo would be a better choice!
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My experience with Yamaha is that they have the weakest "watts" of anything I’ve ever owned. I avoid at all costs now. Coincidentally, I bought an Onkyo 9110...the littlest brother of their line...for a budget system for my wife. The thing sounds better that it has any right to at anywhere near the price,
Sorry, I made a mistake! Actually the Yamaha is not rated for minimum RMS power for 4-ohm, but for 6-ohm (and 0.038% THD).The numbers for 8-ohm are alright.

The lower capacitance reserve in the power supply may be justified if it’s being regulated in some fashion. The significantly lower distortion does suggest a better engineered power suppy. They Yamaha clearly operates higher voltage rails and provides more current.

I am definitely no expert, but for what I have seen in the service manual (very superficially), the power supplies seemed very similar to me. And the voltages indicated in the power amplifier section were 40 V for the Yamaha A-301 and 37.5 V for the Onkyo A-9150. I don't know if that difference is significant to that point.

Is it possible that the Onkyo has some kind of gain adjustment to leave current headroom on purpose?

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PS: I also noticed that the idling current adjustments are different: the Yamaha asks for 1-10mV on the emitter resistor, while the Onkyo asks for 20-30mV. Maybe there's something in that, but I just don't know enough to make something of this.
What speakers are you going to pair this integrated with? I suspect that these integrateds are similar in there ability to drive speakers, and neither are meant for speakers difficult to drive. I am not familiar with the Onkyo, only the Yamaha which I think to be very good at it's price point. Both are full function integrateds.
What speakers are you going to pair this integrated with?

I intend to pair them with Tekton Lore References. They should work great, but knowing they can handle so much more power, it is tempting to try and squeeze something more out of this Onkyo unit. I feel it should be able to output more than that, but I don't know why it can't.

I have only one problem with the whole Yamaha line: no pre-amp output!
" I have only one problem with the whole Yamaha line: no pre-amp output!"

Assuming you are speaking about the digital equipped Yamaha integrateds.  I agree at least the upper models(701 and 801) of the A-S#01 line should have right/left preouts.  The higher end line analog only(A-S1000, A-S1100, A-S2000, A-S2100, A-S3000) all do have stereo preouts.

Bill
rafapb

Sorry, but I think you're splitting hairs with the amps. For practical considerations, one is not any more powerful than the other. Also, with THD specs that low, the difference is meaningless. Years ago, some amps were manufactured with THD lower than these two, however there was an issue. They sounded horrible. One thing that is a negative for me about the Yamaha is that it uses an impedance switch when using 4 ohm speakers. This results in some type of limiting to prevent damage to the amp with a more difficult load. The Onkyo is built to be 4 ohm stable without the need for a switch. I would choose the Onkyo. I thinking it is likely the better sounding amp.

The difference is in the power supply. The Onkyo is rated into 4 ohms and the Yamaha is not. The latter is a tell-tale sign of a weak power supply (at least for a Class A/B amps).

Onkyo products have always had more robust power supplies and deliver more headroom at the same wattage rating than their competitors, thus earning merit for a strong recommendation in this class of equipment.

Dave
At the Onkyo’s retail price of $499, Yamaha’s contender is the A-S501, not the 301.

The A-S501 has the stronger power supply - two 12000μf capacitors and it’s rated to 220 watts at 2Ω for dynamic peaks. It’s "minimum" RMS power at 8Ωs is 85 watts/Ch - both channels driven.

The following review includes some measurements for ths A-S500 (501 sans DAC). It actually outputs more power than its spec sheet suggests.

https://www.avhub.com.au/product-reviews/hi-fi/yamaha-a-s3000-amplifier-review-and-test-395562

(Click on "Review and Test" link)


Somehow I was thinking both amps were in the $350 price range. Yes, the Yamaha A-S501 is more robust than the 301, and also a good buy.

I'm still curious as to how Onkyo can build a 4 ohm stable amp for $500 and it takes Yamaha $2500, their lesser priced amps using a speaker impedance switch. I can't remember when this switch first appeared on an amp, but I don't believe it was on what was considered to be a quality amp.

Sorry, but I think you’re splitting hairs with the amps. For practical considerations, one is not any more powerful than the other.

I know it is silly to be concerned with such a difference, but I really want to invest my money on the best possible piece of equipment, one that could be useful to me, and that I could enjoy, and even be proud of, for decades to come. This, along with my natural curiosity, makes for a hell of a treasure hunt.

At the Onkyo’s retail price of $499, Yamaha’s contender is the A-S501, not the 301.

It seemed to me that, as fas as power is concerned, the A-S301 would be the most fair contender. If we compare the Onkyo A-9150 to the A-S501, then the power difference is even bigger, but for the price it seems a very nice amp.

The A-S501 has the stronger power supply

By the way, I think the transformer of the A-S301 is rated for 6A, and the A-S501’s is rated for 8A. I couldn’t find anything on the Onkyo A-9150, but it is really similar to the 301’s. As for topology and regulation and other more technical stuff, they also seem similar to me, but I am no expert.



It seemed to me that, as fas as power is concerned, the A-S301 would be the most fair contender. If we compare the Onkyo A-9150 to the A-S501, then the power difference is even bigger, but for the price it seems a very nice amp.
As far as power is concerned, but most folks compare what they can afford under a specific budget. Dollar for dollar, the Yamaha has more grunt.

Comparing the 9150 to the 301 is akin to comparing a Toyota Camry to a Honda Civic.


I'm still curious as to how Onkyo can build a 4 ohm stable amp for $500 and it takes Yamaha $2500, their lesser priced amps using a speaker impedance switch. I can't remember when this switch first appeared on an amp, but I don't believe it was on what was considered to be a quality amp.

The Onkyo just has a built-in power limiter. These switches/devices are not reflective of an amp quality. They exist solely to sacrifice the speakers instead of the amp in case some idiot does something like attempting to drive 2 ohm loads to 120db. They are simply idiot-proofing. It allows the manufacturer to stamp a UL or similar rating on the amp. If these switches are left in 8 ohms they can still drive 4 ohm loads without detriment, it only makes it more likely that the amp will also suffer damage if overdriven. Speaking from personal experience, the $500 Yamaha integrateds can drive <4 ohm loads to high SPLs without breaking a sweat. As for amps that double on power as impedance halves, point to any new-production product that does that for <$500. 


A little late but I thought I would add my experience with the Onkyo 9150 . I have Dynaudio Audience 52 4 ohm speakers. I contacted Dynaudio before purchase and asked them what power was required . They said that they recommend 65 watts for a medium sized room .Larger room more and small or nearfield less. I bought the Onkyo mainly for the pre-amp section and new technologies figuring I could always buy a seperate power amp if I needed it as the amp is configured to be used as a pre amp if wanted. I have not needed to do that as the amp delivers clean power and wonderful sound at good volume. I listen to mostly Classical and jazz with no problem. Music is either streamed from qobuz hi-res,downloaded cd in alac or cd from Onkyo dx 7555 cd player. I also run all music thru my Rega dac though the onkyo onboard dac is very good but brighter than the Rega. Besides the Dynaudio speakers I use AKG K712 phones. I would Highly recommend this amp to people who like music .
Has anyone compared the sound quality of the Onkyo A-9150 with the Yamaha A-S501, 701, or 801?