YAMAHA A-S701 - tear-down, thoughts about the internals & few measurements

[MacCali]

The Loxjie A30 seems like a good alternative to the 301 - though my main concern is the sound quality going from class D SMPS to a class AB w/ iron core transformer.

I think that new Aiyima with the same modules as Topping PA5 is probably better. It’s a 175 dollars. It performs well at moderate to a touch higher than the PA5.

If you want to play to maximum potential seems like the PA5 is a winner.

It really just depends what units you are using. The aiyima I speak of has sub out I believe. Something 300.

Also your experience with amps, if you don’t have too much anything is going to sound good to you. Personally don’t like how many class D amps are, I just listened to the bel canto black which was like 15,000. They have the same one in plastic for 8,000 and an even better case for 20.

All in all it did sound very decent and not class D to my ears but look at the price. Honestly very curious about the PA5 as it has rave reviews.

But again I am not suggesting you don’t buy a class D. I am just giving my thoughts based on your level of experience with amps to give you something to think about.

But each and everyday it’s getting better and better and moving away from those old school units which may not have been as pleasant

 

[TheBatsEar]

The Loxjie A30 seems like a good alternative to the 301

I wanted to write a lengthy dossier why it's not and you are basically comparing roller blades to a small car, but then the coffee was ready and i had put toast into the toaster.

Maybe you should gain experience about the differences (there is more than sound) in your home and buy them both? Until then, my experience again:

In terms of features? Lots.
In terms of power? A bit better with harder to drive speakers.
In terms of size? Worse.
Price? Worse until bought used.

I think this is easily won by the Yamaha because it has a a remote, a DAC, a phono preamp and a subwoofer output builtin.

 

[TheBatsEar]

If you cannot put up the budget for AS501 minimum, going for Loxjie A30 is my advice.

What is the difference between A-S301 and A-S501 and why should one consider the A-S501 the absolute minimum?

 

[Kobold]

I chose the Musical Fidelity M2si because it is less massive with a more modern aesthetic for my taste, and also because its design seems to indicate a longer lifespan than class D or many class AB whose ventilation is insufficient.
I think Yamaha amps are excellent (at that price more clean power than M2si, Cambridge, Rotel...), but a little shunned by "audiophiles" because of the name and the bulky aesthetic. Yamaha should offer a "audiophile" version without DAC of the AS-701 with a toroidal transformer (cheaper) and a thinner style. At €700 it would have no competition in class AB category.

 

[Doodski]

Yamaha should offer a "audiophile" version without DAC of the AS-701 with a toroidal transformer (cheaper)

Toroidal transformer usually means more money not less.

 

[Kobold]

Toroidal transformer usually means more money not less.

The debate has been going on for a long time...

EI Transformers vs Toroidal Transformers

But doesn't mean toroidals are better I was only commenting on price: That the idea that toroids are more expensive may no longer be true.

www.audiosciencereview.com

Anyway if i'm wrong about that, without DAC and at the same price it would still have no competition

 

[Overseas]

I have Yamaha as701, rn803d, Denon Heos Amp, Loxjie A30. For normal use, Loxjie is excellent, one of my favourites for 180 euro, with Wharfedale Diamond 9.1.

 

[Overseas]

What is the difference between A-S301 and A-S501 and why should one consider the A-S501 the absolute minimum?

Kind of a rule of thumb among dealers and audiophiles on the forums in my country. Nothing wrong with any Yamaha, but under as501 probably better alternatives.

 

[Doodski]

Kind of a rule of thumb among dealers and audiophiles on the forums in my country. Nothing wrong with any Yamaha, but under as501 probably better alternatives.

Can you spot the differences between a A-S301 and a A-S501? Why avoid a A-S301?

 

[NewbieAudiophileExpert]

At this point in time, the only difference that i can spot between the two amps above is the size of the transformer and decoupling capacitors at the PS.

BTW does anybody know how these Yamahas compare to the Marantz PM6007?

 

[TheBatsEar]

At this point in time, the only difference that i can spot between the two amps above is the size of the transformer and decoupling capacitors at the PS.

BTW does anybody know how these Yamahas compare to the Marantz PM6007?

Not as much power as the A-S301, no loudness, much lighter and smaller.
I would compare it to the Yamaha A-S201 maybe.

I have a Marantz NR-1609 which i would say is a better package than the PM-6007, at around the same price. It has tons more features, like Atmos, 7 channel amp (as weakish as the 6007), pre-out for left/right in case you want to upgrade your power amplifier, a few HDMI inputs, their room compensation stuff with measurement microphone and so on.

Now this is all just from the looks of it, it might do well in a regular room with regular speakers. But to be honest, for 550€ you can do better.

I have to say however, Marantz has a very atractive design. Not as smooth and universal as the silver Yamahas, but it looks cool.

 

[Overseas]

Usually size of the transformer is a big deal among audiphiles. Depending on the speakers, from the price point, I would go for Loxjie.

However, it would worth a stretch, includind credit card, for a RN803D if you can find one.

 

[WDeranged]

Looooooove my A-S301. I got it so cheap and it's in such good condition. I have a pair of Dali Spektor 2s so I don't need a ton of drive. If I decided to upgrade to the A-S501 do you think there would be much of a change in tone?

 

[restorer-john]

Looooooove my A-S301. I got it so cheap and it's in such good condition. I have a pair of Dali Spektor 2s so I don't need a ton of drive. If I decided to upgrade to the A-S501 do you think there would be much of a change in tone?

No significant change. The amplifiers are basically the same, except for a higher voltage rail for the power stage with a larger transformer, more filter capacitance and another paralleled pair of output devices to give a bit more continuous power. Minor other changes not worth bothering about.

The front end, tone controls, switching circuitry and the power stage are essentially identical, using all the same components and PCBs. To give you an idea, the service manual for both the 301 and the 501 is a single document...

 

[WDeranged]

No significant change. The amplifiers are basically the same, except for a higher voltage rail for the power stage with a larger transformer, more filter capacitance and another paralleled pair of output devices to give a bit more continuous power. Minor other changes not worth bothering about.

The front end, tone controls, switching circuitry and the power stage are essentially identical, using all the same components and PCBs. To give you an idea, the service manual for both the 301 and the 501 is a single document...

View attachment 208868

That's what I hoped, cheers!

 

[restorer-john]

The 701 is another scaled up version of the 301 and 501. It gets more output devices and a beefier power supply. The 501 is really just a slightly scaled up 301.

Nothing wrong with that- Yamaha has been doing just that for many decades very successfully. Often the best buy was the 50-75wpc integrated or 40-50wpc receiver back in the day. Their designs have been solid since the early 1990s and to be honest, nothing much has changed apart from frills like a D/A converter.

 

[TheBatsEar]

Looooooove my A-S301. I got it so cheap and it's in such good condition. I have a pair of Dali Spektor 2s so I don't need a ton of drive. If I decided to upgrade to the A-S501 do you think there would be much of a change in tone?

Don't think there will be any meaningful difference either, like @restorer-john wrote. The Spector 2 seems to be easy enough to drive.

If you want an upgrade that makes an impact, consider a subwoofer. I'm not talking about boomyness, but finesse. The SVS SB-1000 is well regarded and you will not make a mistake buying it. Next upgrade should be some form of DSP, like a RPi with Moode and CamillaDSP, or a MiniDSP 2x4HD. In any case, you need a calibrated microphone to get information about how the Spectors are doing in your room.

So the chain of future upgrades could be this:

1. A subwoofer like the SVS SB-1000
2. Microphone (UMIK1) and the freeware REW
3. DSP: MiniDSP 2x4HD or Flex or RPi/CamillaDSP or any of the other free solutions

There is a thread you should be able to find, called "inside Yamaha amps", it offers a good overview about what Yamaha offered and offers.

 

[NewbieAudiophileExpert]

Yeah, based on my understanding the Yamaha A-S301 is just the lowest wattage variant of their entry level stereo amplifiers - it's the same design as the A-S501/A-S701/A-S801, but with a smaller power supply and no USB DAC.

I've heard really good things about this amplifier, and in fact one youtuber who opened one up has stated that the build quality is so high that he's surprised that could sell it for so cheap - i.e. the components are all 'Made in Nippon', etc.

The 301 is 'only' rated for 60 watts per channel, but in reality you wouldn't even need 10 watts per channel to drive some speakers loud enough to fill your room.

 

[restorer-john]

it's the same design as the A-S501/A-S701/A-S801, but with a smaller power supply and no USB DAC.

The AS-301 does indeed have an onboard D/A converter. The AS-300 (discontinued) was identical except with no onboard D/A converter.

I have an AS-300 floating around here- it's got some very good points as well as some not so good points, but for the money, they are a bargain.

 

[NewbieAudiophileExpert]

The AS-301 does indeed have an onboard D/A converter. The AS-300 (discontinued) was identical except with no onboard D/A converter.

I have an AS-300 floating around here- it's got some very good points as well as some not so good points, but for the money, they are a bargain.

Yeah, the A-S801 (which is sadly not available in Australia) has an actual USB-B input, where as the lower models only have optical and coaxial.