2. amps-preamps
  3. 137144-116067

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?

------------------------------------------------------------------
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
dlcockrum's avatar
dlcockrum
2,190 posts
 
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
helomech
1,694 posts
 
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)


mesch
3,509 posts
 
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.
tls49's avatar
tls49
1,351 posts
 

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.

rafapb OP
5 posts
 
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.



More to discover