Yamaha A-1 Vintage Amplifier Review

[audioeclectic]

It would be interesting if you measure the Yamaha A-S801 maybe the equivalent of this A-1, and compare both, the 801 include a delta sigma DAC with USB input.

 

[GrimSurfer]

It likely won't measure well, if Yamaha's specs are correct. Combining the THD and Noise figures that Yamaha publishes orresponds toa SINAD of about -73.8, which is mediocre.

 

[Willem]

This review suggests you may well be wrong: https://www.avhub.com.au/product-re...grated-amplifier-review-and-test-page3-393552

 

[GrimSurfer]

This review suggests you may well be wrong: https://www.avhub.com.au/product-re...grated-amplifier-review-and-test-page3-393552

Wrong about what? Your link was for an A-S700. I was talking about the A-S800. Different product.

And let's not forget... I was using specs provided by the manufacturer. So was my math wrong? If so, what do you get when you add -99 dB and -74 dB?

 

[pma]

Amir, I am missing THD (+N) vs. frequency plots in your set of measurements, or CCIF 19+20kHz twin tone measurement. These old amplifiers from seventies were often good in THD 1kHz, however not so good in THD 10kHz or high frequency CCIF IMD. THD 1kHz or SINAD 1kHz does not tell a big story. They also often had TIM/DIM issues. Would not you consider to broaden your measurements, for the readers to get more complete view of the amplifier tested?

 

[GrimSurfer]

Not to answer for Amir but measurement at 1 kHz has become accepted practice. It is, therefore, likely that manufacturers would do anything they can to minimize THD+N at this frequency.

This might be seen as "gaming the system" but it has a practical dimension because 1 kHz is where human hearing crosses the 0 dB point for pure tones.

 

[saturnaal]

I've always been fond of this older Yamaha audio equipment, and it's always nice to see some external data-based validation of your opinions. I'm still using a Yamaha A-1000 (1982-1984) as the centerpiece of my loudspeaker / home theater system. Published specs show 120 watts per channel into 8Ω, 0.005% THD.

Alas, just recently it started intermittently tripping into protection so it's time for a refurb. Fortunately, service manuals for equipment of this era are widely available. When is the last time you saw a service manual for a piece of modern gear? This, paired with the low cost and high availability of modern diagnostic and repair tools will keep this sort of gear relevant for a long time.

I've been waiting for an excuse to buy an oscilloscope anyway

 

[pma]

Not to answer for Amir but measurement at 1 kHz has become accepted practice. It is, therefore, likely that manufacturers would do anything they can to minimize THD+N at this frequency.

Yes it has become "accepted practice", but all of us who work a bit deeper in this field know how insufficient measurement it is and how poor is a correlation with listening results. So in times of AP systems available and especially APx555 there is no reason and no excuse why not to use more revealing test.

 

[Willem]

The AS 801 is the same as the AS 701 apart from an additional usb input. The AS 701 is virtually the same as the AS 700 apart from the optical and coaxial inputs that the AS 700 lacks. Hence, the measurements of the AS 700 are likely to be quite representative of analogue amplifier performance compared to those for the AS 801.

 

[Timbo2]

AU-9900 , AU-11000 , AU-20000 , AU-X1 , AU-777A they're my favorites. But there are many more. I would like a review of anyone.

Have you seen this series?

By the time I got into HiFi the Sansui brand had been trashed. The TU-X1 was quite a beast!

 

[GrimSurfer]

The AS 801 is the same as the AS 701 apart from an additional usb input. The AS 701 is virtually the same as the AS 700 apart from the optical and coaxial inputs that the AS 700 lacks. Hence, the measurements of the AS 700 are likely to be quite representative of analogue amplifier performance compared to those for the AS 801.

But I used Yamaha specs from my calculations for the A-S800. So do you have reason to believe that Yamaha's specs are incorrect?

 

[Willem]

I don't understand how you calculated, let alone how that would compare to the extremely good Australian numbers. Anyway, we can only be sure of really comparable numbers if Amir tests one.

 

[GrimSurfer]

I don't understand how you calculated, let alone how that would compare to the extremely good Australian numbers. Anyway, we can only be sure of really comparable numbers if Amir tests one.

Call me old fashioned, but I'd rather stick with the factory specs for the actual model than use measurements for another model.

I do, however, agree that an independent test of the actual model would be best. TBH, I don't have high hopes for any consumer amps, integrated in this price segment.

 

[restorer-john]

They were designed by Peter Walker's team that way, to be sold and to match as a pair for their speakers. Why he chose those electrical parameters I can't say. Maybe it was typical for British components of the era?

Don't forget, all the Quad gear initially came with European spec DIN connectors for inputs and outputs on the preamps and inputs on the power amps. The DIN spec was much higher sensitivity (lower level) than RCAs. (100mV in/ 500mV out for the Quads)

The 34/405-2/FM-4 stack I had was all DIN connections to all components- no RCAs.

It was only in later years (through the 34 and 405-2 years) where they changed over to RCAs. What changes to sensitivities they made, if any, I'm not sure.

 

[Willem]

I don't think the Quad 0.5 Volt output and input level were ever changed. My late model 405-2 and 606-2 with RCA connectors still had that level. Both were and still are very fine power amplifiers of a brilliant design. If anyone in the US would care to send one to Amir it would be great.

 

[restorer-john]

I don't think the Quad 0.5 Volt output and input level were ever changed.

The sensitivities on the 34 were able to be specified (when ordering- note the *) and were different for the Tuner/Aux and the Tape input- 100mV and 300mV.

This is the 34 style I had:

Quad always did their own thing- they used a combination of 5 pin 180 degree DINs and 4 pin DINs. No fun making up leads...

 

[LTig]

Amir, I am missing THD (+N) vs. frequency plots in your set of measurements, or CCIF 19+20kHz twin tone measurement. These old amplifiers from seventies were often good in THD 1kHz, however not so good in THD 10kHz or high frequency CCIF IMD.

I don't care about THD at 10 khz since I cannot hear any of those distortion components - and I'm pretty sure this holds true for everybody.

 

[Willem]

Continuing about Quad. Those were the input sensitivities and as the table shows, other specifications were indeed available on demand, such as for the Shure V15iii. Peter Walker was eminently aware of the importance of accurate matching. As soon as CD came onto the market (Peter Walker was a great fan), CD specific boards became available as well. This service included the older and by then discontinued Quad 33 pre amplifier.

 

[AudioSceptic]

Have you seen this series?

By the time I got into HiFi the Sansui brand had been trashed. The TU-X1 was quite a beast!

The pinnacle of Sansui electronics?

 

[AudioSceptic]

Don't forget, all the Quad gear initially came with European spec DIN connectors for inputs and outputs on the preamps and inputs on the power amps. The DIN spec was much higher sensitivity (lower level) than RCAs. (100mV in/ 500mV out for the Quads)

The 34/405-2/FM-4 stack I had was all DIN connections to all components- no RCAs.

It was only in later years (through the 34 and 405-2 years) where they changed over to RCAs. What changes to sensitivities they made, if any, I'm not sure.

Excellent point. I had forgotten that. In the 70s Brit-fi tended to adhere to (Euro) DIN standards and only later changed to using RCAs. Bad in one way, though because RCA commits the cardinal sin of connecting signal before ground.