Hi,
2nd owner of a G9000 - Had it for the best part of the last 20 years, but it has been in my life for 30 years at least. The original owner still asks me about it from time to time. Clearly these units mark for life
I've enjoyed it thoroughly for the first 10 years of my ownership, then it went into phases of storage and then some use. 10 Years ago I had charactized it in the lab at the university and it still was impressively within (or above) specs; up to a ridiculous (and inaubible) 50khz. I cleaned it every few years - though nothing serious; I only opened it a few times.
A few years ago I sent it to "the shop" to get it cleaned & looked after. Noisy pots, starting to lose left channel sporadically at low volumes. Tech was in awe, as he showed me a poster of it in his very shop and mentioned he rarely had the "chance" to work on Sansui gear. (Guess Sansui weren't too popular around Montreal?)
The tech didn't want to do the "real work" and so suggested to stop using the pre-amp, thankfully as you know the G9000 has a power amp in.
I had already a cambrige pre-amp, so that's fine - though would defeat some of the warmth of the vintage sansui preamp. So the Sansui, the pre-amp & I continued our life.
Fast forward to last year - after a year or so of storage (to my dismay, renovations...) - when I plugged it in- it woulnd't go out of "Protection". There were , at that time, other priorities (I know, it's hard to believe) - and so I said to myself it's a problem for my future self.
Future is now. I've been prepping some space in my office, dusting off my scope, testers & soldereing iron in view of a few weeks of fun.
blimey. I plugged it in - and the ****** went out of protection to its beautiful green "power" - albeit took a lot longer than memory serves (like , a good 30 s) - but it did get out. Hooked up a pre amp and speakers... and it plays. Volume looks pretty similar on both sides, I haven't found it to clip at high volumes or demanding musical passages - sound is spectacular at any volumes.
Sorry for the life history - here's the real question bits
1) Left channel still sometimes quits, mostly after long silences or lower volume parts. The good old trick of cranking the volume up and then back wakes it up flawlessly each time. But then again, so does switching from Direct to Capacitor coupled. (I leave it at Capacitor coupled). I would have expected the left channel to crap out at higher volume, but it holds up like its right peer. I may be hearing more sybillance but not sure.
--- I've read interesting threads on this - foremost (https://audiokarma.org/forums/index.php?threads/sansui-9090db-main-amp-left-channel-dead.849701/) - but bear in mind I'm tapping into the power amp directly; so none of them pots/switches seem to be at play.
2) Protector takes a while when its been off for a few days. I suspect some capacitor is taking its sweet little j* time to juice up. Would you recommend I try and play with the driver boards?
3) THe unit is 45 years old - though it still sounds marvellous - I can't imagine it's still as pristine as it was.
Would you recommend changing most caps, diodes, transistors (I see loads of packages of "high quality parts" on eBay to change most components.) ? I'm trying to weight the risk of potentially making it worse/damaging the unit - or then making it alot better (?) Is the pre-amp on its own valuable enough to salvage ?
While I do know (a bit) what I'm doing in this field - I haven't played with discrete electronics for a few years. Then again the components are dinosaur sized compared to today's - so I should be able to manage.
So, knowing I have basic skills and comprehension - do you guys recommend overhauling the whole thing - or simply trying to address the protector's long time / left channel issue ?
Sorry for the novel-like length of this post, I do need to work on being more concise and precise.
2nd owner of a G9000 - Had it for the best part of the last 20 years, but it has been in my life for 30 years at least. The original owner still asks me about it from time to time. Clearly these units mark for life
I've enjoyed it thoroughly for the first 10 years of my ownership, then it went into phases of storage and then some use. 10 Years ago I had charactized it in the lab at the university and it still was impressively within (or above) specs; up to a ridiculous (and inaubible) 50khz. I cleaned it every few years - though nothing serious; I only opened it a few times.
A few years ago I sent it to "the shop" to get it cleaned & looked after. Noisy pots, starting to lose left channel sporadically at low volumes. Tech was in awe, as he showed me a poster of it in his very shop and mentioned he rarely had the "chance" to work on Sansui gear. (Guess Sansui weren't too popular around Montreal?)
The tech didn't want to do the "real work" and so suggested to stop using the pre-amp, thankfully as you know the G9000 has a power amp in.
I had already a cambrige pre-amp, so that's fine - though would defeat some of the warmth of the vintage sansui preamp. So the Sansui, the pre-amp & I continued our life.
Fast forward to last year - after a year or so of storage (to my dismay, renovations...) - when I plugged it in- it woulnd't go out of "Protection". There were , at that time, other priorities (I know, it's hard to believe) - and so I said to myself it's a problem for my future self.
Future is now. I've been prepping some space in my office, dusting off my scope, testers & soldereing iron in view of a few weeks of fun.
blimey. I plugged it in - and the ****** went out of protection to its beautiful green "power" - albeit took a lot longer than memory serves (like , a good 30 s) - but it did get out. Hooked up a pre amp and speakers... and it plays. Volume looks pretty similar on both sides, I haven't found it to clip at high volumes or demanding musical passages - sound is spectacular at any volumes.
Sorry for the life history - here's the real question bits
1) Left channel still sometimes quits, mostly after long silences or lower volume parts. The good old trick of cranking the volume up and then back wakes it up flawlessly each time. But then again, so does switching from Direct to Capacitor coupled. (I leave it at Capacitor coupled). I would have expected the left channel to crap out at higher volume, but it holds up like its right peer. I may be hearing more sybillance but not sure.
--- I've read interesting threads on this - foremost (https://audiokarma.org/forums/index.php?threads/sansui-9090db-main-amp-left-channel-dead.849701/) - but bear in mind I'm tapping into the power amp directly; so none of them pots/switches seem to be at play.
2) Protector takes a while when its been off for a few days. I suspect some capacitor is taking its sweet little j* time to juice up. Would you recommend I try and play with the driver boards?
3) THe unit is 45 years old - though it still sounds marvellous - I can't imagine it's still as pristine as it was.
Would you recommend changing most caps, diodes, transistors (I see loads of packages of "high quality parts" on eBay to change most components.) ? I'm trying to weight the risk of potentially making it worse/damaging the unit - or then making it alot better (?) Is the pre-amp on its own valuable enough to salvage ?
While I do know (a bit) what I'm doing in this field - I haven't played with discrete electronics for a few years. Then again the components are dinosaur sized compared to today's - so I should be able to manage.
So, knowing I have basic skills and comprehension - do you guys recommend overhauling the whole thing - or simply trying to address the protector's long time / left channel issue ?
Sorry for the novel-like length of this post, I do need to work on being more concise and precise.
