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

Showing 2 responses by helomech

helomech
1,829 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)


helomech
1,829 posts
 
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. 


More to discover