AV Receiver connected with old integrated amplifier

P

PENG

Audioholic Slumlord
Because it has a lot more RMS power, better bios unit, it can handle 4ohm speakers better too
A lot more? No way, and I just read the specs and the service manual. Based on the info in the service manual, I would say the RX-A1080's power supply is comparable to that of the Sansui amp. For one thing, the AVR has 20% more power supply storage capacitance. The Sanui may do a little better in terms of "continuous" rating, but for real world use, the AVR would do better for sure, especially in terms of dynamic output.

AVRs are not rated for 4 ohms, but for two channel use, the power supply should have no trouble outputting more than it would into 8 ohms. In this case, it would do as good or better than that Sanui.

For two channel into 4 ohm, you can see the actual measured output of the RX-A1080 if you follow the links below to two different bench test sites:

https://audiovision.de/yamaha-rx-a1080-test/ (See that it measured 214 W into 4 ohms, 2 channel driven)

In the ASR review, it measured only 133 W into 4 ohms, but it was at about 0.01% THD+N (SINAD 79), whereas Audiovision.de, being a German site, likely based theirs on DIN, i.e. 1%.

The Sanui's output spec is 100 W into 8 ohms, and only 120 W into 4 ohms, no THD+N spec given, though for the 100 W 8 ohm rating, it does say 20-20,000 Hz at no more than 0.005% THD, even that is very clear. Typically such spec should say something like 20-20,000 Hz, 0.XXX % THD+N at rated output into X ohms.
Also, the 0.005%, while quite good, but it does not include noise. You can have low THD, but if noise is excessively high and is the dominant one then it would still be no good. Being 30 years old, the Sansui would likely not do as well in terms of THD+N.

In your system, I would rather use the AVR for the 4 ohm infinity speakers and let the Sansui drive the center speaker. In theory, the Yamaha should give you cleaner (lower THD+N) among other things because the signal path is simpler. The Sansui does not have input for the Yamaha pre-outs so you have to use the line input, and that means the signal has to go through the preamp/volume control of the integrated amp, no gain there, only deterioration.

People tend to think those old/near vintage amps are more powerful than AVR just because they are heavy and are "integrated amps". That is not true, like cars, older heavy body on frame cars used to do better in crash dummy tests, not the case any more. Instead of trusting the old hearsay and myths, it is better to trust technologies that actually do advance with time, just my two cents, ymmv..
 
D

Danimaimi65

Enthusiast
A lot more? No way, and I just read the specs and the service manual. Based on the info in the service manual, I would say the RX-A1080's power supply is comparable to that of the Sansui amp. For one thing, the AVR has 20% more power supply storage capacitance. The Sanui may do a little better in terms of "continuous" rating, but for real world use, the AVR would do better for sure, especially in terms of dynamic output.

AVRs are not rated for 4 ohms, but for two channel use, the power supply should have no trouble outputting more than it would into 8 ohms. In this case, it would do as good or better than that Sanui.

For two channel into 4 ohm, you can see the actual measured output of the RX-A1080 if you follow the links below to two different bench test sites:

https://audiovision.de/yamaha-rx-a1080-test/ (See that it measured 214 W into 4 ohms, 2 channel driven)

In the ASR review, it measured only 133 W into 4 ohms, but it was at about 0.01% THD+N (SINAD 79), whereas Audiovision.de, being a German site, likely based theirs on DIN, i.e. 1%.

The Sanui's output spec is 100 W into 8 ohms, and only 120 W into 4 ohms, no THD+N spec given, though for the 100 W 8 ohm rating, it does say 20-20,000 Hz at no more than 0.005% THD, even that is very clear. Typically such spec should say something like 20-20,000 Hz, 0.XXX % THD+N at rated output into X ohms.
Also, the 0.005%, while quite good, but it does not include noise. You can have low THD, but if noise is excessively high and is the dominant one then it would still be no good. Being 30 years old, the Sansui would likely not do as well in terms of THD+N.

In your system, I would rather use the AVR for the 4 ohm infinity speakers and let the Sansui drive the center speaker. In theory, the Yamaha should give you cleaner (lower THD+N) among other things because the signal path is simpler. The Sansui does not have input for the Yamaha pre-outs so you have to use the line input, and that means the signal has to go through the preamp/volume control of the integrated amp, no gain there, only deterioration.

People tend to think those old/near vintage amps are more powerful than AVR just because they are heavy and are "integrated amps". That is not true, like cars, older heavy body on frame cars used to do better in crash dummy tests, not the case any more. Instead of trusting the old hearsay and myths, it is better to trust technologies that actually do advance with time, just my two cents, ymmv..
Thank you, this is the first comprehensive answer I was looking for, inthiught I was clear enough in my description and you understood what I was looking for
 
P

PENG

Audioholic Slumlord
Thank you, this is the first comprehensive answer I was looking for, inthiught I was clear enough in my description and you understood what I was looking for
You are welcome. And, to be clear, I am not suggesting that those older amps are bad, just that to assume they are better, or at least more powerful in general is a myth.

I still own an old amp, much older than yours, and I spent good money recapping it just because I treasure it. Not for sound quality, but for other reasons.

That Sansui of yours is a nice one, but make sure it is good shape if you plan on using it for a long time. For example, if the volume knob is noisy, try getting it cleaned. If you do a search, you can find and download the service manual. Also, be careful if you have the volume control at maximum. That is one thing I don't like about using an integrated amp or AVR that does not have a bypass, may be its just me..
 
D

Danimaimi65

Enthusiast
You are welcome. And, to be clear, I am not suggesting that those older amps are bad, just that to assume they are better, or at least more powerful in general is a myth.

I still own an old amp, much older than yours, and I spent good money recapping it just because I treasure it. Not for sound quality, but for other reasons.

That Sansui of yours is a nice one, but make sure it is good shape if you plan on using it for a long time. For example, if the volume knob is noisy, try getting it cleaned. If you do a search, you can find and download the service manual. Also, be careful if you have the volume control at maximum. That is one thing I don't like about using an integrated amp or AVR that does not have a bypass, may be its just me..
I had it fully serviced and recapped. The guy that did the job, who is one of the best in this business, was impressed by the way it sounded. Priori to posting my question, I did several tests (audio, not instrument measurements) and I am a skeptical and advocate of blind tests. Yet the Sansui gave audible depth and body to the front speakers that the Yamaha could not deliver
 
Pogre

Pogre

Audioholic Warlord
I had it fully serviced and recapped. The guy that did the job, who is one of the best in this business, was impressed by the way it sounded. Priori to posting my question, I did several tests (audio, not instrument measurements) and I am a skeptical and advocate of blind tests. Yet the Sansui gave audible depth and body to the front speakers that the Yamaha could not deliver
So you performed a DBT between them and determined that?
 
D

Danimaimi65

Enthusiast
I did. Bear in mind that the Sansui was not even under my consideration until a good friend who is a big audiophile, asked me why I wasn’t using it anymore. Got it back in perfect shape, tied it out, and it made me smile. I used to have JBL 880 as front speakers, when I switched to JBL L 100 the change was even more noticeable
 
P

PENG

Audioholic Slumlord
I had it fully serviced and recapped. The guy that did the job, who is one of the best in this business, was impressed by the way it sounded. Priori to posting my question, I did several tests (audio, not instrument measurements) and I am a skeptical and advocate of blind tests. Yet the Sansui gave audible depth and body to the front speakers that the Yamaha could not deliver
That puzzles me and can't help but think may be the Sansui now has audible distortions. The fact is, the two has similar power output, and the Yamaha both, if in top shape, should have distortions below the threshold of audibility, so if you can hear it a difference in a blind test, then one must have distortions risen above the threshold. It is more likely the one that has developed much higher THD is the 30 years old one and the fact that the signal has to go through 2 pre-amps.

The good thing is, it sounds better to you and that's all that matters. It could just mean that you happen to (by chance) prefer that particular sort of distortions.
 
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Pogre

Pogre

Audioholic Warlord
That puzzles me and can't help but think may be the Sansui now has audible distortions. The fact is, the two has similar power output, and the Yamaha both, if in top shape, should have distortions below the threshold of audibility, so if you can hear it a difference in a blind test, then one must have distortions risen above the threshold. It is more likely the one that has developed much higher THD is the 30 years old one and the fact that the signal has to go through 2 pre-amps.

The good thing is, it sounds better to you and that's all that matters. It could just mean that you happen to (by chance) prefer that particular sort of distortions.
That's exactly what I said in a previous post, well not exactly. I said "no longer accurate", because they really should sound the same.

If the distortion somehow makes it sound more pleasant and he's happy with it... I guess it's a win. Personally I'd just use the Yamaha and have a separate music only system with the Sansui.
 
P

PENG

Audioholic Slumlord
That's exactly what I said in a previous post, well not exactly. I said "no longer accurate", because they really should sound the same.

If the distortion somehow makes it sound more pleasant and he's happy with it... I guess it's a win. Personally I'd just use the Yamaha and have a separate music only system with the Sansui.
I didn't read all the earlier posts. Here's an easy to read article on THD vs subjectivists vs rationists. Like me, he's an EE in the related field but he has a master's degree and have written other articles related to harmonic distortions.

.
 
lovinthehd

lovinthehd

Seriously, I have no life.
Only one, other than phono, tape 1 and 2, CD, tuner, 4 digital
Sorry, yes, see one labeled line now in the spec section, the manual copy of the back panel is poor resolution (at least the hifiengine copy). Phono isn't really a line input since there's a special pre-amp/eq circuit on that input....fwiw. In any case the Yamaha pre-out level should be sufficient for the input sensitivity on the Sansui.
 
P

PENG

Audioholic Slumlord
In any case the Yamaha pre-out level should be sufficient for the input sensitivity on the Sansui.
Agreed, but there should be no question about that because he would be feeding the pre-out signal to another pre-amp, i.e. from source to the AVR preamp and then to the Sansui preamp and finally the Sansui power amp. The signal will get distorted, with noise added, twice before being power amplified.:D
 
lovinthehd

lovinthehd

Seriously, I have no life.
Agreed, but there should be no question about that because he would be feeding the pre-out signal to another pre-amp, i.e. from source to the AVR preamp and then to the Sansui preamp and finally the Sansui power amp. The signal will get distorted, with noise added, twice before being power amplified.:D
Definitely not something I'd do.
 

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