517 much better than a 317?

[JimEGR]

Hi there, bumping this thread as I have the exact same question.

I have 317 which I love, used for listening to vinyl and driving B&W CM8 s2 speakers. I had the 317 refurbished and recapped a few years back and it sounds great.

Now I have the chance to pick up a recapped 517. Has anyone auditioned both of these? Or could comment on if it is a worthy jump in sound quality?

Thanks

Look like pretty reasonable specs.




I own the entire AU-*17 series. Sansui really knocked it out with this branch of the family tree. All really good. Not sure if I would spend the money to go from the AU-317 to AU-517 though - not much if any sonic improvements. Not a big gain in power. If you want another Sansui, like @Filip I suggested, you might consider trying a Sansui from another series. Try an X-Balanced Alpha like an AU-a607i (or all the way for any Alpha 907), or earlier with an AU-999 or something else cap coupled. Or go all three - AU-999 / AU-317 / AU-a607i - this would cover really well the Sansui Sonic Arc.

And welcome!

Keep us posted on your Sansui adventures.

 

[Pouakai]

Ah thanks this is great advice. Yes I do love the 317, but would make the jump if it was a big improvement with the 517/717. Glad the hear the 317 is in the same ballpark.

It had a full clean up removing glue etc about 8 years ago, and it the drives the CM8s just fine. The CM8 has four inputs for high and low frequencies, so I have the A channel driving the highs and the B channel driving the lows.

Was the AU-999 better than the later x17 series?

 

[JimEGR]

Was the AU-999 better than the later x17 series?

That is really subjective. Different family and different sonic characteristics. Some might say the AU-x17 sounds “better” than the AU-xxx, and some might say the reverse.

If you want to learn more before pulling the trigger on a AU-xxx series unit, you should start a new thread. Would be a good discussion. “Is the AU-999 better than the AU-317?”. Should be interesting reading the comparisons.

 

[Hyperion]

Was the AU-999 better than the later x17 series?

In unmodified form - no chance, however after the AK developed modifications an AU-999 vs AU-717 (restored) comparison would definitely be interesting.

I thought the AU-317 was just a little bit less resolving when compared to the AU-517, both in fully restored form. I've seen about 3 AU-317's (all Mk1) and about 5 AU-517's.

 

[Bright_Star]

The AU-317 is a fine amp. Every model upward could be considered "better", basically, its what we can all see that is easy to agree on, so if having extra tape jacks and two phono inputs is "better" on the 517/717, then sure, it is superior, as reflected in the price tag, along with various other things having to do with its circuitry and extra wattage.

However, as opposed to what we can all 'see', there is also what we 'hear'- what our ears perceive when listening to an amp, but with your own particular pair of speakers, listening to the music you like, in the acoustics of your room, and via the format you prefer (vinyl, tape, cd, streaming...)

Thus, seeing is one thing, hearing, well.......... You can ask for opinions, but the only way to really know if a 517 or 717 is a big upgrade in performance with your speakers, is to actually listen to one. Some folks might hear it as very noticeable improvement, others not so much. Not surprising, as I mentioned- we're all listening to our music, and especially thru our speakers which will be a major factor in the overall sound quality, and of course- the AU itself at 45 years old- which has to take into account the extent of its servicing/restoration when doing an evaluation of it.

In a nutshell, if someone is very happy with their AU-317, I dont see a compelling reason to change it, unless you're just curious and dont mind buying another amp to try it out and experiment.

Actually, an interesting comparison would be the AU-317 vs an 80's model of similar size/wattage, such as AU-D55X.

 

[GJ Kasdorp]

My 317 does not get used much, I have too many nicer toys. But I can imagine a situation where I do not have the space and need money. I might end up with the 317 as my only amp and I would be perfectly happy with it. It is cheap, moderately sized and sounds just great.

 

[mcgjohn]

AU-517 much better than an AU-317?

I've got a pair of AU 317 amps, and love the size and look of them.

But am wondering how much of an upgrade a 517 would be.

Anyone own both? Have opinions?

I know the 517 is about 12 lbs heavier, with dual power supplies, and about 15wpc more. Features are close, with the 317 getting the nod for having a high-pass filter and mic-in imputs, while the 517 features dual phono imputs. No big deal (to me). The phono stage is slightly improved in the 517- 8x2 low-noise transistors in it, vs. the 317's 6x2.

Am I really going to gain much in sonic headroom with those 15 extra watts per channel? Enough to notice? Will the dual power supply dramatically clean up the sound of my amp? Enough for me to tell? Will the phono section be that noticeably improved? Enough for me to hear?

Or am I better off just sticking with the simplicity of the delightful 317?

Some specs on the models, if you're interested-

The 317 is 50wpc vs. the 517 at 65wpc.

There's a 12 pound difference between the two models, most likely due to the twin power supply and case, which is nearly twice as tall, 6 5/8" vs 4 3/8".

The 317 is a single power source (with a twin power relay, detection curcuit and output transistors).

The 517 is a dual power supply.


Both ar DC connected.

The 317 Phono stage has an 6-low noise transistors per channel and a Class A amp buffer, while the 517 Phono stage has 8-low noise transistors per channel, and active loaded Class A amp buffer in a SEPP output utilizing metallized film resistors and polypropylene caps.

The 317's phono feature allows for single TT hookup, while the 517 allows for two turntables to be connected.

Now, both feature a Subsonic Filter, Loudness, Treble and Bass controls, and tone defeat. The 317 adds a high-pass filter.

Now, I dunno how different the amp setup is, but here's what I pulled from literature (there may be items missing, left out by the type creators)-

"The 317 features a Darlington Arranged power output, w/ a current differential push-pull driver, and a transistor differential of dual-FET construction. The 517 literature reads it's a Dual-FET imput differential, followed by a mirror loaded cascade connection arrangement, followed by a push-pull differential amp arrangement, followed by a 3-stage Darlington connected power stage followed by a SEPP (Single-Ended-Push-Pull design) final Power Output stage."

In the amplifier design, the 317 features 51 Transistors vs. the 517's 63 Transistors, the 317 features 25 Diodes vs the 517s 40 Diodes and 10 Zener Diodes, and the 317 has 2 FETs vs the 517s 1 LED and 2 FETs.

The 317 has no more than 0.03% total harmonic distortion, vs. the 517's .025%. For intermodulation distortion, it's 0.03% for the 317, and 0.01% for the 517.

Damping factor is (at 1,000 Hz, both channels driven) 70 into 8 Ohms for the 317 vs. 60 into 8 ohms for the 517.

I have both as well as the 717. The 417 is dual mono, a lowered powered version of the 717, I doubt you would hear much difference due to the 15 watts of increased power.

the phono stage is better in the 517 but if phono is a primary source you would be better off going with the EAR clone phono stage and running it into an AUX input on either amp.