AU-9500 restoration

[kevzep]

Well, it's been awhile. A long while. This summer was insane. Two weddings, a baby on the way (here now ) projects kinda took a back burner. I was finally able to replace all the caps, with the exception of the mains and the other large black one. I just need to order some BP caps and finish assembling, and it'll be done! I chose not to replace ALL of the transistors, mainly some that were in place for others..and all the others that said SONY on them.

I hope I got everything installed correctly, I'll be using a bulb tester to make sure I don't cook anything.

I didn't take much for pictures. I'll have to take some and get them posted.

wow, you have been busy.........
Well let us know how it goes, I am interested in a comparison to your AU999.

 

[tobyj17]

wow, you have been busy.........
Well let us know how it goes, I am interested in a comparison to your AU999.

Busy is an understatement. I also completely assembled a car literally from the ground up in less than three months, including rebuilding the entire drivetrain. Wife wanted it to be our car for the big event..the purse strings loosened so I went with it

I just remembered the preamp mod for the 999 too... I'll order those components as well.

What do you think about the existing transistors in the 9500? should I leave them alone or replace them too?

 

[tobyj17]

Well, got it all hooked up to some test speakers, and it looks like I've got a dead right channel. I also noticed that there's a couple warm resistors at the top of the driver board on the dead channel. feels like R825 and possibly others. I've already done a deoxit job to the pots and switches..actually before I fired it up.

EDIT: I tested the outputs, all tested good.

EDIT AGAIN: Looks like I need to check my work a little better. I had a resistor that I must have accidentally desoldered and never resoldered. I've got both channels now. It's making music! now to hook it up and get it into the main system....

 

[kevzep]

Well, got it all hooked up to some test speakers, and it looks like I've got a dead right channel. I also noticed that there's a couple warm resistors at the top of the driver board on the dead channel. feels like R825 and possibly others. I've already done a deoxit job to the pots and switches..actually before I fired it up.

EDIT: I tested the outputs, all tested good.

EDIT AGAIN: Looks like I need to check my work a little better. I had a resistor that I must have accidentally desoldered and never resoldered. I've got both channels now. It's making music! now to hook it up and get it into the main system....

Oh, right......Good news!!! I was having a think about what the problem could be and was just coming back here with some ideas......and now its running.......

Great stuff, I am interested to see what you think it sounds like.........:yes:

 

[tobyj17]

I ran it about an hour with some bookshelf JBL's and an ipod for a source, and I can tell right away that It's got some deep bass,even with the little 5"woofers. I did notice that the driver boards did get a little warm, but I'm not sure if that's normal or not? Sound seems okay from what I can tell with a crappy ipod source. Before I hook it up to my spendy speakers, should I worry about the warm boards? They're not hot to the touch, but just warm. Outputs are cold....

 

[Hyperion]

I think you should run it a bit more before connecting it to the 'spendy' speakers - make sure the bias is stable first, keep an eye on DC offset too.

When both have settled and are stable, then it will be time to try it out on those speakers.

I don't think you need worry about the driver boards getting warm, from what you say they are only 'warm' - this is normal. If you had components which were so hot you couldn't touch them for more than a couple of seconds - that's too hot.

Dare I say pictures ?

 

[tobyj17]

I think you should run it a bit more before connecting it to the 'spendy' speakers - make sure the bias is stable first, keep an eye on DC offset too.

When both have settled and are stable, then it will be time to try it out on those speakers.

I don't think you need worry about the driver boards getting warm, from what you say they are only 'warm' - this is normal. If you had components which were so hot you couldn't touch them for more than a couple of seconds - that's too hot.

Dare I say pictures ?

Damn, I totally forgot to take pictures. Before completely assembling it though I did remove the face and knobs, and gave it the dish water bath. It was disgusting. A smoker owned it for many years. The water in the sink was totally yellow when I was done. For the boards I used a blend of Nichion "fine gold" "muse" PW and PM caps, along with some poly film and Elna caps. The poly films were used in the driver boards, on the C801 2.2uf spots. I read somewhere on here (maybe even in this thread) that it was a good spot to use one because it was in the signal path.

I took a chance and hooked it up to a pair of original smaller advents, and a CD player. Right off the top i could tell this thing sounded good. I had some jazz type music (Flim & the BB's) and listened to a couple tracks off that. The bass was deep and powerful, and the highs were very sharp yet smooth. It actually gave me goosebumps. I then listened to some Queensryche-silent lucidity (limited on the cd department) and got the same results. I hate to say this, but it sounds better in some ways that my G-33k. Maybe it's just a new amp haze I'm seeing though, time will tell. I'm going to hook it up to my turntable after I type this, I expect to see the same results. Stay tuned for the rest of the story...

 

[tobyj17]

Well, Hooked it up to the SR-929. I listened to some Dire Straits, Police, Pink Floyd, Supertramp and some Stevie Wonder.

Working down the list, I found that Dire Straits brothers in arms sounded very warm, musical and clear. The deep bass was still there, and that's when I noticed a design flaw to this unit. No subsonic filter! Sure, you can cut everything below 50hz, but you lose a lot. It should cut below 20hz..why they chose 50 is beyond me. I chose DSOTM half speed master for the next album. The results were impressive. Now I don't know a lot of these fancy terms, but the soundstage is huge and prominent, the speakers seem to disappear into the room. Things like footsteps and all the other things you barely notice on that album came alive. Seemed to be just a tad too much midrange for some songs, but my 33k is the same way in that aspect. probably just the pressing.

Now for Supertramp. I also chose a half speed. Crime of the century. This album presented a whole different story altogether. I didn't paticularly like it going through this system, which his a disappointment, because it is my all time favorite album. It sounded good, don't get me wrong, but just not what I was expecting. I always expect the vocals and the saxophone to stand out on this one, and they didn't.


Kev was dying to know what I thought of it in comparison to my 999. Well, I can say that the 9500 is a LOT more powerful, but it's also rated for twice the wattage. Certain albums sound good on each system. The 999 lacks the deep bass whic h I like, but it's still a great system.

So, in conclusion, I really don't know what to think of it yet. I'm not totally sold yet. It's a hell of a powerful amp, and a nice one at that, but the jury is still out. We'll see what happens when I hook it up to the KEF's and give it some time to break the caps in.

 

[Hyperion]

Thanks for that Toby - an interesting read

 

[tobyj17]

Thanks for that Toby - an interesting read

Thanks John,
I tried to describe what I heard, but it's difficult for me. I did try the KEF's, listened to some Styx and Supertramp again. The midrange is also quiet and subtle, but you hear a lot of the weird things they hide in the music, unlike the 33k. The G-33 is a better match for the KEF's hands down. The AU-999 with the Kef's is pretty lifeless. They take gobs of power to run though...dual 10" woofers, three mids and a tweet.

I'd be interested to hear others impressions. John, Do you own one? I'd also like to hear from Kev on what he didn't like about his.

 

[Hyperion]

Thanks John,
I tried to describe what I heard, but it's difficult for me. I did try the KEF's, listened to some Styx and Supertramp again. The midrange is also quiet and subtle, but you hear a lot of the weird things they hide in the music, unlike the 33k. The G-33 is a better match for the KEF's hands down. The AU-999 with the Kef's is pretty lifeless. They take gobs of power to run though...dual 10" woofers, three mids and a tweet.

I'd be interested to hear others impressions. John, Do you own one? I'd also like to hear from Kev on what he didn't like about his.

I am sorry to say, no..... I have an AU-717, AU-D11 II, AU-X701, and an AU-919, they are all just a little different and I love them all

 

[kevzep]

Well, Hooked it up to the SR-929. I listened to some Dire Straits, Police, Pink Floyd, Supertramp and some Stevie Wonder.

Working down the list, I found that Dire Straits brothers in arms sounded very warm, musical and clear. The deep bass was still there, and that's when I noticed a design flaw to this unit. No subsonic filter! Sure, you can cut everything below 50hz, but you lose a lot. It should cut below 20hz..why they chose 50 is beyond me. I chose DSOTM half speed master for the next album. The results were impressive. Now I don't know a lot of these fancy terms, but the soundstage is huge and prominent, the speakers seem to disappear into the room. Things like footsteps and all the other things you barely notice on that album came alive. Seemed to be just a tad too much midrange for some songs, but my 33k is the same way in that aspect. probably just the pressing.

Now for Supertramp. I also chose a half speed. Crime of the century. This album presented a whole different story altogether. I didn't paticularly like it going through this system, which his a disappointment, because it is my all time favorite album. It sounded good, don't get me wrong, but just not what I was expecting. I always expect the vocals and the saxophone to stand out on this one, and they didn't.


Kev was dying to know what I thought of it in comparison to my 999. Well, I can say that the 9500 is a LOT more powerful, but it's also rated for twice the wattage. Certain albums sound good on each system. The 999 lacks the deep bass whic h I like, but it's still a great system.

So, in conclusion, I really don't know what to think of it yet. I'm not totally sold yet. It's a hell of a powerful amp, and a nice one at that, but the jury is still out. We'll see what happens when I hook it up to the KEF's and give it some time to break the caps in.

Have you done the pre-amp mod to your AU999, the clincher is the EQ mod, if you like deep bass, as I do, then you have to do the EQ mod.....I cant remember if you did or not.....
Its a tough call without the mods, but with those mods, the AU999 is a completely different amp...
My AU999 sound powerful now where as before it had a weak sound.....like someone running out of breath...

But essentially, thats what I found, I would play something and think "wow this is cool" then the next album comes on and I thought "oh, whats going on here".....

I found the thing which really annoyed me was the top end, it doesnt sound as even and as linear with the same clarity as the Big G's, and the AU999 after the Mods blows it away in that department.....

But even then for some music the AU9500 really works, I think its really dependent on what sort of music you listen to, and the speakers its paired up with....

Yeah, I thought the High and Low pass filters were a bit of a joke on the AU9500 too, I remember thinking "what could you possibly use these for?".

Hmmm interesting......

 

[tobyj17]

I haven't done any mods yet, other than removing the subsonic filter. Right now it's playing kid music, it's small platform works well in a bedroom. I'll get to it.. I want to.. when time permits. Hopefully sooner than later.

On the 9500...that's what I found on it too.. one album was great, the other one left some things to be desired. The top end is okay, but I'm a fan of the tingly highs, and this didn't have it. The filters bother me. I have no idea what they would be for either. It does well with CD's, but the phono stage could use some improving.

 

[canuckaudiog]

Just curious toby, how much of a difference in sonics did you notice with it recapped vs. it not?

 

[kevzep]

I haven't done any mods yet, other than removing the subsonic filter. Right now it's playing kid music, it's small platform works well in a bedroom. I'll get to it.. I want to.. when time permits. Hopefully sooner than later.

On the 9500...that's what I found on it too.. one album was great, the other one left some things to be desired. The top end is okay, but I'm a fan of the tingly highs, and this didn't have it. The filters bother me. I have no idea what they would be for either. It does well with CD's, but the phono stage could use some improving.

Oh yes, right well when you do, the AU999 will rise above the AU9500 for sure, I think you will really like it.....
I will be very interested to hear your opinion once you do those things......
Yeah those filters are ridiculous arent they....not sure what they were thinking there.....

"The top end is okay, but I'm a fan of the tingly highs, and this didn't have it"

Yes, I think I know what you mean, I felt the same way......

 

[tobyj17]

Just curious toby, how much of a difference in sonics did you notice with it recapped vs. it not?

I actually bought this DOA. It was missing transistors, others were burnt..etc..so I have no idea how it sounded before. I did a clean sweep when I was in there, replacing all the caps (except mains) and 80% of the transistors.

I see that you just bought one. I don't want to scare you away from it, It is a really nice amp, and it does a lot of things very well. It's just that compared to what I already own, it lacks in some places. It would take a lot to knock my current stuff off it's pedestal.

I'll most likely keep it though, put it in the living room and replace a crappy preamp/equalizer thing I'm ashamed to own. I'll use the preamp side to run my power amp that powers my CV's.

 

[tobyj17]

Oh yes, right well when you do, the AU999 will rise above the AU9500 for sure, I think you will really like it.....
I will be very interested to hear your opinion once you do those things......

I will certainly get it done. I've got the thread bookmarked.. sounds like we both look for the same things as far as listening interests are concerned..so i need to do it.

 

[canuckaudiog]

I actually bought this DOA. It was missing transistors, others were burnt..etc..so I have no idea how it sounded before. I did a clean sweep when I was in there, replacing all the caps (except mains) and 80% of the transistors.

I see that you just bought one. I don't want to scare you away from it, It is a really nice amp, and it does a lot of things very well. It's just that compared to what I already own, it lacks in some places. It would take a lot to knock my current stuff off it's pedestal.

I'll most likely keep it though, put it in the living room and replace a crappy preamp/equalizer thing I'm ashamed to own. I'll use the preamp side to run my power amp that powers my CV's.

Oh no worries, you aren't scaring me in any way I love my AU-9500. Everyone has their own tastes and synergy plays a big role too. You could tell me this AU-9500 was junk and I'd still enjoy it.

That's too bad it was DOA, well, good thing you got it working then! Was the job fairly challenging? I am going to be doing it to mine, for sure. How long would you say the entire job took you, for the recap? How long I'll hold on to it is hard to say but, it's a lovely sounding machine so I want to ensure it lasts a long time.

 

[tobyj17]

Oh no worries, you aren't scaring me in any way I love my AU-9500. Everyone has their own tastes and synergy plays a big role too. You could tell me this AU-9500 was junk and I'd still enjoy it.

That's too bad it was DOA, well, good thing you got it working then! Was the job fairly challenging? I am going to be doing it to mine, for sure. How long would you say the entire job took you, for the recap? How long I'll hold on to it is hard to say but, it's a lovely sounding machine so I want to ensure it lasts a long time.

The most challenging part was the board situated in the center of the chassis that had 10 or so wires soldered onto it. Not burning the wires was a huge pain. The rest of it was easy...just your basic desolder/resolder. No glue in this one.Time wise i have almost a year into it..haha. Over that year I had a wedding to plan..then found out we were expecting..just a bad time to work on it..so it got put to the side. Really though probably only around 10 hours tops.

 

[kevzep]

The most challenging part was the board situated in the center of the chassis that had 10 or so wires soldered onto it. Not burning the wires was a huge pain. The rest of it was easy...just your basic desolder/resolder. No glue in this one.Time wise i have almost a year into it..haha. Over that year I had a wedding to plan..then found out we were expecting..just a bad time to work on it..so it got put to the side. Really though probably only around 10 hours tops.

That board you are talking about is the F2019 board which is the one where the transistors usually go noisy.....it is a real PIA to get to.....