Sansui G-9000 - Yet another 'Protector won't come off' thread
- Thread starter djbono
- Start date
So I went ahead and added a quarter inch thick isulating/padding underneath the cap boards, even with their pins cut - I was afraid the cap's pins would contact the metal frame (which for half of them wouldn't be bad I guess)
I tidied up the rest as much as I could, rerouted wires in their holders, zip-ties,etc. before putting back the bottom cover.
Top view of the new 'cans', with one new F2806 board. A very 'modernized' unit this G9000 ! Again thanks to the folks who designed & printed those @Hyperion !
I've made final adjustments to the Bias & Offset as best I could.
I've since then put back the heat sinks (with new thermal paste), all metal covers on boards F2806/7/8
There's only one thing to do now... (two..if you count 'finding the top cover screws I removed 4 years ago...)
CLEAN !
A friend has suggested I applied 'Renaissance Wax Polish' to the wood parts (and even Metal.. but I doubt it would do a good job on this heavily brushed metal)
Anyhow.. thanks again a million @mrk229 - I couldn't would have done it without you
I tidied up the rest as much as I could, rerouted wires in their holders, zip-ties,etc. before putting back the bottom cover.
Top view of the new 'cans', with one new F2806 board. A very 'modernized' unit this G9000 ! Again thanks to the folks who designed & printed those @Hyperion !
I've made final adjustments to the Bias & Offset as best I could.
I've since then put back the heat sinks (with new thermal paste), all metal covers on boards F2806/7/8
There's only one thing to do now... (two..if you count 'finding the top cover screws I removed 4 years ago...)
CLEAN !
A friend has suggested I applied 'Renaissance Wax Polish' to the wood parts (and even Metal.. but I doubt it would do a good job on this heavily brushed metal)
Anyhow.. thanks again a million @mrk229 - I couldn't would have done it without you
Attachments
That was someone else - not me - but thanks anyway. It might have been 'TupolevFan' or 'Hippocrates'
Well Done! on getting it working.
....and I thought I'd be done..
(The cleaning part is, it really looks stellar now)
So.. for a week, operated in my basement office - all was well.
Over the week-end, climbed it up for a party upstairs - we didn't even abuse of it; more of a background listening.
Brought it back downstairs yesterday - there is now a very perceptible humm as soon as I open the speakers; while on 'Pre-amp connected' even with the volume knob down at 0 precisely.
Looks like a 60hz cycle to me
Doesn't matter if there is something connected to the AUX in or not, or if that cable is connected to a source or not. Still humm.
Doesn't matter if there's an FM antenna connected or not.
I swear I didn't hear that humm last week in the very same conditions. (BUT... I may very well be crazy and was too happy being able to massage my brains with massive sound waves that I didn't perceive the humm during silences.)
Things that could have changed, electrically that I tried
- Heated flooring (on or off, still a hum)
- Heat pump active or not, still a hum
- electric Car charger active or nto, still a hum
(all of these three were likely off during the first week of audition bliss; that's why I tried.)
One thing though - if I go 'Pre-amp disconnected, Power amp Capacitor coupled' - then it flat lines and I don't hear a peep.
What is the Sansui's pre-amp picking up, and how ?
I know it doesn't seem like much, but when listening to classical, jazz ensemble or piano - it really drives me nut because I know these recordings to be stellar and almost noise-free but alas..here's the noise.
I'll go with my cambridge pre-amp for now, but I'll miss the 'loudness' feeling
any thoughts appreciated... (or let me know if I'm simply chasing ghosts and that a few years from now I'll likely won't hear that humm anyway)
Pierre
(The cleaning part is, it really looks stellar now)
So.. for a week, operated in my basement office - all was well.
Over the week-end, climbed it up for a party upstairs - we didn't even abuse of it; more of a background listening.
Brought it back downstairs yesterday - there is now a very perceptible humm as soon as I open the speakers; while on 'Pre-amp connected' even with the volume knob down at 0 precisely.
Looks like a 60hz cycle to me
Doesn't matter if there is something connected to the AUX in or not, or if that cable is connected to a source or not. Still humm.
Doesn't matter if there's an FM antenna connected or not.
I swear I didn't hear that humm last week in the very same conditions. (BUT... I may very well be crazy and was too happy being able to massage my brains with massive sound waves that I didn't perceive the humm during silences.)
Things that could have changed, electrically that I tried
- Heated flooring (on or off, still a hum)
- Heat pump active or not, still a hum
- electric Car charger active or nto, still a hum
(all of these three were likely off during the first week of audition bliss; that's why I tried.)
One thing though - if I go 'Pre-amp disconnected, Power amp Capacitor coupled' - then it flat lines and I don't hear a peep.
What is the Sansui's pre-amp picking up, and how ?
I know it doesn't seem like much, but when listening to classical, jazz ensemble or piano - it really drives me nut because I know these recordings to be stellar and almost noise-free but alas..here's the noise.
I'll go with my cambridge pre-amp for now, but I'll miss the 'loudness' feeling
any thoughts appreciated... (or let me know if I'm simply chasing ghosts and that a few years from now I'll likely won't hear that humm anyway)
Pierre
Attachments
I know I've already drained alot of your resources on this ... but I still need help;
If you have any clues..
While I can't 100% rule out external factors; no matter what I try (other outlets on another phase; disconnecting pretty much everything; trying other rooms..) I still have that very audible hum as soon as I open up the speaker switches.
Again _feels_ a bit worse when using the built in Pre-Amp ... but as soon as I connect anything to power amp; the same kind of hum appears, albeit a bit fainter it seems.
---
Could I have revived it, abused of it a bit, which pushed some old other parts (caps?) to their death ?
any thoughts appreciated because I'm going nuts now !
If you have any clues..
While I can't 100% rule out external factors; no matter what I try (other outlets on another phase; disconnecting pretty much everything; trying other rooms..) I still have that very audible hum as soon as I open up the speaker switches.
Again _feels_ a bit worse when using the built in Pre-Amp ... but as soon as I connect anything to power amp; the same kind of hum appears, albeit a bit fainter it seems.
---
Could I have revived it, abused of it a bit, which pushed some old other parts (caps?) to their death ?
any thoughts appreciated because I'm going nuts now !
One of the series regulators in the PSU for the preamp may have failed thus causing ripple (hum) on the supply lines which modulates the output signal. It could be a lot of other things - but a PSU voltage and regulator functionality test should be first I think.
I'll let the Big G experts take it from here...
I'll let the Big G experts take it from here...
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Still here. Have not had a chance to look this over yet, sorry.