Leestereo's Restoration/Upgrade Of A Sansui AU-717

Congratulations with things going so well with the AU-717.

I'm a semi-newbie at this, so how do you measure old filter capacitors to determine if they're in good, keepable condition? All mine in my vintage stuff at least look good, except for the ones in my Marantz 2270. One is leaking and the other one has a + shaped crack, both on the terminal sides. I got a couple of Nichicon caps on order to replace them.
 
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Thanks for the kind words, everybody.



I'm a semi-newbie at this, so how do you measure old filter capacitors to determine if they're in good, keepable condition?

Assuming that the capacitor appears to be in good physical condition, and you have a capacitance meter which can measure large capacitors, you can confirm that the capacitance is within the stated tolerance. If you only have a DMM, you can confirm that the rail voltages are as per the service manual and do not fluctuate; also the AC ripple should be quite low (typically <30mV for capacitors >10,000µF).
 
These upgrades could be classified as the type R version of AU-717. Well explaination & documented:yes:

Would probably be trying out power supply F-2663 board for the revision. But the problems lies in sourcing for the 820uf/63v caps locally cos the oly options avail is 100v which might be a little big to accomodate.

Aft some thoughts, the oly way is to insulate wire leads to it & secure nearby main filter caps tiewrap.
 
These upgrades could be classified as the type R version of AU-717. Well explaination & documented:yes:

Would probably be trying out power supply F-2663 board for the revision. But the problems lies in sourcing for the 820uf/63v caps locally cos the oly options avail is 100v which might be a little big to accomodate.

Aft some thoughts, the oly way is to insulate wire leads to it & secure nearby main filter caps tiewrap.

I recommend you don't do that, it would be better to fit the standard value/voltage, if 100v is the only voltage you can get for the increased value capacitor.
 
Great stuff and excellent read! This will be very valuable when I get around to doing mine later in the year.
 
I recommend you don't do that, it would be better to fit the standard value/voltage, if 100v is the only voltage you can get for the increased value capacitor.

For the above mentioned i actually referring to C05,06,07 & 08 on F-2663 as listed on pg1 of this thread.

Origin listed value as 220uf/63v to be upgraded to 820uf/63v accordingly.

All the others value are obtainable locally but except for the 820uf which oly avail in 50v or 100v.

Looks like the oly options is to install back the origin value of 220uf/63v of low esr type in this case.
 
For the above mentioned i actually referring to C05,06,07 & 08 on F-2663 as listed on pg1 of this thread.

Origin listed value as 220uf/63v to be upgraded to 820uf/63v accordingly.

All the others value are obtainable locally but except for the 820uf which oly avail in 50v or 100v.

Looks like the oly options is to install back the origin value of 220uf/63v of low esr type in this case.

There is nothing magical about using a 820µF/63V capacitor for C05-C08; in this particular case it was chosen since it provided a worthwhile increase in capacitance and the physical size was smaller than the original 220µ/63V (to allow better air cooling on the F-2663 board). If you can obtain a 470µF, 560µF or 680µF capacitor that physically fits well, that would be preferred over the original 220µF/63V.
 
There is nothing magical about using a 820µF/63V capacitor for C05-C08; in this particular case it was chosen since it provided a worthwhile increase in capacitance and the physical size was smaller than the original 220µ/63V (to allow better air cooling on the F-2663 board). If you can obtain a 470µF, 560µF or 680µF capacitor that physically fits well, that would be preferred over the original 220µF/63V.

As always thumbs up:thmbsp: for the advices shared.

I try to source out the next step-up capacitance value over 220uf/63v during my offday.
 
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There is nothing magical about using a 820µF/63V capacitor for C05-C08; in this particular case it was chosen since it provided a worthwhile increase in capacitance and the physical size was smaller than the original 220µ/63V (to allow better air cooling on the F-2663 board). If you can obtain a 470µF, 560µF or 680µF capacitor that physically fits well, that would be preferred over the original 220µF/63V.

Well i hav gotten some 1000uf/63v for C05-08.
Will they comply as well?

Tq
 
Nice build.
To me this is the real gem though---

"Capacitor Sound article by Cyril Bateman "

May have to rethink my affection for Nicichon Muse bipolars :)

-Lee
 
Message from the owner of the Sansui AU-717

I have just done a headphones listening of the new amp and I gotta tell you, LeeStereo, this couldn't wait...

This amp personally is the best sounding amp that I ever listened to in my lifetime. These precious recordings that I have - and I have a lot of audiophile recordings - sound more incredible now than ever before.

Also, the "separation" is extremely good and balanced - and, you were right again - it sounds like live music. So, what more can I ask for?

You were also right about my expensive headphones - the reason I thought I maybe got ripped off is because I was listening to crappy amps - period.

Great job LeeStereo - best amp I ever heard. Plus, you were the one who told me to buy it - another bonus for you.

As a concluding note for anyone out there seeking a great sounding audio system, I can testify having purchased 18 pairs of great speakers over the past 90 days...as a conclusion to my observations thus far, searching for that elusive great sound....

Unless you have a killer amp - top of the line - extremely good amp...

then you will never achieve the great sound you are searching for.

You must start off knowing that your amp is flawless - otherwise you will never hit the great sound.

So, I would say make sure your amp is top-of-the-line in performance and sound, before you check out all the stuff that goes with it. Since I have been dealing primarily with vintage audio, then it becomes critical to have a technician (such as the one I have - LeeStereo) who can provide you with the latest technology to replace the worn and out-dated components of your amplifier or receiver. Honestly, if it wasn't for LeeStereo, I would still be sitting here with tons of equipment, and not able to enjoy my listening experience.

The newly restored AU-717 is the backbone and engine of my audio system. I will never part with it. I feel I now have a piece of equipment that is truly unique and functioning to its maximum potential. I and my family can now start to enjoy the benefits listening to great music.

As a layperson with no technical knowledge, you made it easy for me to understand many of the things that came up along the way, and this is also a very important thing. You were like a "Dr. Phil" at times, and I value that a lot. As well, you were extremely honest, even when you knew it's not what I wanted to hear - but the truth hurts sometimes - and you knew I wanted great sound, so you did not waiver from that goal of mine.

Bravo LeeStereo...many thanks...it is a pleasure discussing all things audio with you. You are a true lover of vintage audio and extremely knowledgeable technically and it shows in the way you approach a restoration project.

- Owner (Sansui AU-717)
 
Awesome true story.

Its like reading the original owner of a vintage mustang just give their track impressions after taking delivery of a restore mod by the Ring Brothers.

One question : does the headphone jack on the au717 have a dead silent noise floor? My g6700 is completely dead quiet on all the aux and tape1/2 on the speaker outs, but there is a noise floor on the headphone jack that is noticible in comparison.

Please update us when you decide on speakers and what audiophile recordings you use and what you listen for!!
 
Also, did u hear your au717 before ben restored it? If so, what differences are you able to pick out post a restoration?
 
Concluding Reply from Owner of Sansui AU-717

Q1-
Does the headphone jack on the au717 have a dead silent noise floor?

The headphones work perfectly. Prior to receiving my AU-717 restored amp, I was comparing the sound between 2 Marantz receivers through the headphones, and I was able to hear notable differences in sound between the 2. So, headphones are great for many circumstances, including comparing “sounds” or even comparing recordings of the same track – which one sounds better, etc. I have been doing quite a bit of this.

Well, when I got back my AU-717, my headphones sounded much, much better. It’s like I bought a new pair of headphones. So, I knew at that time the amp was very good.

Q2-
Please update us when you decide on speakers?

The next day, I first plugged in my JBL 4311B speakers (I am familiar with these and know that they are excellent speakers – studio monitor sound) and whoa!! Incredible sound. A perfect match with the Sansui Au-717.

"I have experience with and I have owned all kinds of JBL's, and without a doubt, my all time favorite speaker is the 4311. I call it the giant killer. Pound for pound, dollar for dollar and sound for sound, I don't think ANY speaker beats it." - Steve Barnes (Huntley Audio)

I then plugged in my newly acquired Tannoy Arden speakers, and again – incredible sound. I just acquired the Tannoys, so I haven’t been able to have my speaker tech go through them yet, but I can say these speakers are top-of-the-line in class and sound. Incredibly good sound. There is something special about these Tannoy Arden. So now I know I have 2 pairs of excellent speakers.

Clash magazine editor, Simon Harper, recently interviewed former Beatle Sir Paul McCartney about the behind the scenes stories of some of their classic songs. Amid rumors of the Beatles back catalogue finally appearing on the iTunes store, the launch of the Rock Band: The Beatles console game and the extensive album re-issue campaign, McCartney shared memories of the stories behind some of their famous songs.

Clash: On the end of ‘Hey Jude’ you can quite clearly hear someone swearing. Why did you decide not to remove that?

Paul McCartney: I don’t think we noticed until later. We recorded it in Trident Studios, which is in Soho, which is a studio that we used if we couldn’t get in Abbey Road. So, we were all there and we did ‘Hey Jude’, and we were listening back on these six-foot tall Tannoy speakers, and there were four of them in the room so it was like living in the song, which is how you can impair your hearing! So we just whacked it up real loud and listened to it. It was more of an experience than anything. Then we took it back to Abbey Road, and we were more preoccupied with the thing that we’d fooled ourselves with the sound - it sounded great on these great big speakers, but when we put it on the naff speakers that we always tested everything on, which was just a couple of very ordinary JBLs, it sounded crap. We had to put in like full bass and full treble; the engineers really had to load it back up, cos we’d fooled ourselves on the sound. I think we were so preoccupied with that, that we didn’t really listen to it until it was too late, and then we listened to it very carefully on headphones and sort of thought, ‘Oh, shit!’ Because there were a lot of vocal part harmonies, you know: [sings] “And any time you feel the... Aaaahhhhhh...” A lot of long notes, and I think probably someone made a mistake and went, ‘Aw, **** it!’ or whatever, and that just found itself in the mix. It wasn’t intentional.

Q3-
What audiophile recordings you use and what you listen for!!

For me, most any quality 24 bit digital transfer from Vinyl to FLAC file, is audiophile. The sound is exactly like listening to the vinyl LP, without having to turn on the turntable. I have been interested in making digital copies of my vinyl for a while now. I have a large collection already.

Some of it is upgraded stuff, like MFSL vinyl, and similar stuff like that. I have The Beatles Box Set MFSL vinyl, as recorded by Dr. Robert, as well as the Led Zeppelin collection (200g Classic Records version). Awesome sound on both. There is a lot of amazing recordings out there.

I am using a Rega RP6 Turntable (with an Ortofon 2M Black cartridge) – going through a USB phono box device Furutech ADLGT-40a. This converts the vinyl to a digital signal, which goes into my MacBook Pro Laptop, and Audacity Software converts to 24 bit FLAC files, ready for playback through the Sansui Amp.

The ADLGT-40a Phono Stage is available at the Canadian distributor: AUDIYO.COM - Simon - Markham, ON.

My playback device is the new SONY HAP-Z1ES hi res audio player. It plays back most all digital music using my iPad as the remote. I make “playlists” along the way, as I listen, I keep adding albums, or tracks, to the various playlists I have created. It is like having a high definition “jukebox” for easy playback of all the songs - your entire library in fact.

Q4-
Also, did you hear your au717 before it was restored?
If so, what differences are you able to pick out post-restoration?

I was fortunate to find an original owner 5 minutes away from my house who listed his au-717 on local classifieds. I bought it as is because it was in mint condition (cosmetic physical condition) but the sound had a constant humming sound. Original manuals came with it. Nice home – well-kept units. The only reason I searched for a sansui au-717 was on the advice of my technician, LeeStereo. I knew I had bought a good one, even though it had internal electronics issues.

LeeStereo restored it and upgraded it, and the sound now blares out “on all cylinders”. The amp now sounds “like new” or “better than new”.

Every time I listen to music, it’s a listening “experience” now – it’s an event…almost like live music. Today I played Let It Be Naked (vinyl) and Get Back, The Long and Winding Road, were excellent. I concluded with Let It Be, and we were left speechless. It was that good.

As I say, everything pretty much sounds amazing now. None of this is possible without a very good (new or) well-restored amp. Make sure your amp is very high quality.

Best regards to everyone.

- Owner (restored Sansui AU-717)
 
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What a great read . I have to do this to the AU 717 I have. The filter cans have arrived and my BOM is almost complete .
I have a question on this " The capacitors C05 and C06, on the RIAA equalization."
You changed from polarize to non polarize ,can you always do this in the signal path ?
I've seen this done before but with smaller value caps.
 
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There should be no issues replacing polarized capacitors in the signal path with modern construction bi-polar types (i.e., dual anode foil), or film types. Some older bi-polar capacitors actually consisted of two polarized capacitors in series within the same capsule and with this type it was not recommended that they be installed in positions with significant DC voltage.

Note that in this particular case, there is very little, if any, DC voltage on C05 and C06.
 
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