My 9500 coming back to me with FINAL mods,and the BEST possible sound .
- Thread starter quadklipsh
- Start date
quadklipsh
Super Member
Ill definitely have the work documented .coz he will forget .
Also if guys like leestereo are online me or my tech wont have any problems getting it back to specs in case we dont prefer the changes now.
Also if guys like leestereo are online me or my tech wont have any problems getting it back to specs in case we dont prefer the changes now.
quadklipsh
Super Member
Conrad , my strong feeling is that he hasnt done anything more than just replacing the 2 bad capacitors which he thinks filter the sound before entering the power amp section for amplification( which may be the sole cause of booming sonic signature.)and the other thing he did was recapping with polyprops on the pre amp stage as directed by leestereo.
He must have brought it back to original sound signature of the 9500 and really liked the improvement in sonics of this perfect machine.
He must have brought it back to original sound signature of the 9500 and really liked the improvement in sonics of this perfect machine.
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Ronald.C
Active Member
What a coincidence, my AU-9500 also returns tomorrow !!! changed 20 transistors, 2 jfets and the two rectifying bridges!
quadklipsh
Super Member
Ronald , this surely is a coincidence.
Although 9500 is not super rare but it still occurs rarely .
Of the 20 transistors you mentioned i believe theose are the small ones . The small black one half a pea sized. Well mine were also changed 4 yrs ago by the first tech . But i have seen so many fakes in the market here . I know that my first tech used only top notch components coz he cannot deal with fakes repeatedly he says.
Do these small transistors have to do with signal path? Sorry dumb question
Although 9500 is not super rare but it still occurs rarely .
Of the 20 transistors you mentioned i believe theose are the small ones . The small black one half a pea sized. Well mine were also changed 4 yrs ago by the first tech . But i have seen so many fakes in the market here . I know that my first tech used only top notch components coz he cannot deal with fakes repeatedly he says.
Do these small transistors have to do with signal path? Sorry dumb question
quadklipsh
Super Member
Kevzep , if you are reading this id like to add that my tech strongly felt the same about the bass of the 9500 being fat as you did . Although it was not that much bothersome to me but definitely it did have a bad impact on the overall sound making me think why would a two time restored 9500 be sounding this bad that i cannot keep it for music .
But after rectifying this issue this time around he says the 9500 has a very nice flat responce and you will keep it
But after rectifying this issue this time around he says the 9500 has a very nice flat responce and you will keep it
quadklipsh
Super Member
Guys .
I received it yesterday . Was very happy to see it .very excited.
I took it to my friends place where a pair of klipsch rp280s awaited as mains.
We played the bang olufsen 1700 amplifier with some audio nirvana music and smooth jazz . for 20 min and registered the sound . Then we hooked up the 9500.
The immediate impressions :
A very relaxed and laid back responce came up as i rolled up the volume gradually settling it at 9 o'clock.
We were astonished with immediate improvement in highs and expansive soundstage . IT felt like a new amp. It was like lifting up an elephants foot off a mans chest and he could breath again.
The congestion we felt before was all gone . It was scary detailed . I could find a lot of improvement in the details of the instruments and feeble and missed out instruments were now quite audible.
The best part was the modded bass responce . It was extremely well welcomed by both of us . We loved the bass . It was detailed. The lows that were boomy and veiled had now details and ripples that did goose bumps all over my skin. . I cant describe it but it now felt like the camera had been blurred taking hazy pictures earlier and now the lens is replaced with a new one from carl zeiss.
Awesome my friend said .
I will post later as my session with my amp lasted 1hr only .and the bang olufsen sounded lesser in clarity n detail.
I received it yesterday . Was very happy to see it .very excited.
I took it to my friends place where a pair of klipsch rp280s awaited as mains.
We played the bang olufsen 1700 amplifier with some audio nirvana music and smooth jazz . for 20 min and registered the sound . Then we hooked up the 9500.
The immediate impressions :
A very relaxed and laid back responce came up as i rolled up the volume gradually settling it at 9 o'clock.
We were astonished with immediate improvement in highs and expansive soundstage . IT felt like a new amp. It was like lifting up an elephants foot off a mans chest and he could breath again.
The congestion we felt before was all gone . It was scary detailed . I could find a lot of improvement in the details of the instruments and feeble and missed out instruments were now quite audible.
The best part was the modded bass responce . It was extremely well welcomed by both of us . We loved the bass . It was detailed. The lows that were boomy and veiled had now details and ripples that did goose bumps all over my skin. . I cant describe it but it now felt like the camera had been blurred taking hazy pictures earlier and now the lens is replaced with a new one from carl zeiss.
Awesome my friend said .
I will post later as my session with my amp lasted 1hr only .and the bang olufsen sounded lesser in clarity n detail.
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quadklipsh
Super Member
Thankyou and i asked my tech .He said Fusible resistors didnt play bad a role in worsening the sound in this set . They must be fine he didnt check for their integrity. Major problem was the bass filtering capacitors . He replaced the 4.7 with 2.2 uf on the inputs of the power amp section. Those who have the schematics can check n correct me(maybe they were 3.3 if im wrong) but 2.2 uf caps DID it . Bass is now boom n bloat free .Others should try it . It doesnot change the vocals the mids or the other range . It doesnot shape the bass into something else . It simply lowered the amplitude of the bass to levels that suit me n to his ears . And i can assure you its lost that boomy hangover and you will embrace it .
The highs got better with the recapping with the polyprops in the pre amp section . Im loving it. Those tone controls also seldomly used here have now more effect .Crisp highs flow in if you will.
One thing he left undone was the decoupling caps that lie underneath the amp near the 4 main caps . It has 120uf electrolytics (originals were 3.3uf only) and we followed leestereos 120uf suggestion .
Now my tech suggested to just try with 4.7 uf polyprops there .
I wanna know what this might bring ????
Any ideas plz
The highs got better with the recapping with the polyprops in the pre amp section . Im loving it. Those tone controls also seldomly used here have now more effect .Crisp highs flow in if you will.
One thing he left undone was the decoupling caps that lie underneath the amp near the 4 main caps . It has 120uf electrolytics (originals were 3.3uf only) and we followed leestereos 120uf suggestion .
Now my tech suggested to just try with 4.7 uf polyprops there .
I wanna know what this might bring ????
Any ideas plz
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quadklipsh
Super Member
quadklipsh
Super Member
These are leestereos caps image. Mine were nichicons 120uf caps . And larger due to higher voltage. Ill post images when ill bring the polyprops
quadklipsh
Super Member
quadklipsh
Super Member
For comparison another amp . The pioneer c200 
quadklipsh
Super Member
WHERE IS EVERYBODY
quadklipsh
Super Member
Is that all kev ???
What about playing with those input caps that are now 2.2 uf allowing signal into the power amp section.
What about playing with those input caps that are now 2.2 uf allowing signal into the power amp section.
kevzep
Its all about the Music
Use the standard values unless you have a FFT Spectum analyser to check and asses the performance.
I am not one to "play" with cap values, I use the Maths to figure it out.
Leestereo
Super Member
The published input impedance of the AU-9500 power amplifier stage is 50kohm and the circuit consists of the R801/R802 (82kohm) followed by C801/C802 (2.2µF) and then the differential input pairs (TR801/TR803 and TR802/TR804). Hence, the high pass filter impedance is ~128kohm and with a 2.2µF capacitor, the F3 is 0.57Hz.
quadklipsh
Super Member
Please elaborate in english for me .
Is the 2.2 uf capacitor rightfully there in my amp.
Does it mean that what im listening to is now the original state of 9500 as factory settings (with ofcourse the addition of polyprops)..and not any mods to the topology ?
Is the 2.2 uf capacitor rightfully there in my amp.
Does it mean that what im listening to is now the original state of 9500 as factory settings (with ofcourse the addition of polyprops)..and not any mods to the topology ?
It means that you won't achieve anything by 'playing' with the value of the 2.2µF capacitors, except maybe mess up the frequency response of the amplifier.
This would also be the case with many other capacitors scattered around the AU-9500, I suggest you don't monkey with the values, and please don't fit ridiculously large film capacitors chasing that sonic 'rainbow's end' you are always in search of.
But hey, it's yours so you can do what you want with it - just don't ask us if it sounds good afterwards.
This would also be the case with many other capacitors scattered around the AU-9500, I suggest you don't monkey with the values, and please don't fit ridiculously large film capacitors chasing that sonic 'rainbow's end' you are always in search of.
But hey, it's yours so you can do what you want with it - just don't ask us if it sounds good afterwards.
