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G-9000db - it's OCCRD recap time!
- Thread starter w1jim
- Start date
kevzep
Its all about the Music
As Casey says, you cannot get these capacitors (ovals) anymore, but there is a service, one of the AK members here, scottrt pulls them apart and retrofits them with new caps......You just send him the complete ovals and he does the rest.....
If you look under Sansui G on the Bay and scroll way down you will find his service there......
Those big caps are just as, if not the most important caps in the amplifier.....I think its worth doing.......
Ive seen the results and well if it weren't so far I would sent mine to him in a heartbeat.......but I will have to do mine myself..
Something to consider anyway......
But hey, what an in depth and thorough job you are doing in this amp.....its giving me a bit of much needed motivation to get mine finished....:thmbsp:
Nice job Jim :thmbsp:
If you look under Sansui G on the Bay and scroll way down you will find his service there......
Those big caps are just as, if not the most important caps in the amplifier.....I think its worth doing.......
Ive seen the results and well if it weren't so far I would sent mine to him in a heartbeat.......but I will have to do mine myself..
Something to consider anyway......
But hey, what an in depth and thorough job you are doing in this amp.....its giving me a bit of much needed motivation to get mine finished....:thmbsp:
Nice job Jim :thmbsp:
: )
That's seriously impressive though. BUT- you still have to put it all back together again! Muahaha...
Okay, I shouldn't talk as I'm currently too afraid to take apart my Yamaha anymore than I have to in order to fix the damn dB meter and adjust the bias, etc!
Do you just somehow remember how it all goes back together, or do you go off of a (well written) service manual?
That's seriously impressive though. BUT- you still have to put it all back together again! Muahaha...
Okay, I shouldn't talk as I'm currently too afraid to take apart my Yamaha anymore than I have to in order to fix the damn dB meter and adjust the bias, etc!
Do you just somehow remember how it all goes back together, or do you go off of a (well written) service manual?
Moving along
The big Mouser tractor-trailer came to the house yesterday and today so progress is being made - the underside is reassembled except for the tuner power supply board - which I left floating to make the tuner more maneuverable.
You can see here the new speaker relays I used on the power supply board. I erroneously got the ones with the wire solder tabs instead of the PCB mount models. I used a Dremel tool to enlarge the mounting holes on the PCB to make them fit.
The PS PCB also had a 3.3uf/63v cap mounted close to a large resistor and heatsink. I left about 0.75" of extra lead, covered them in teflon tubing and positioned it away from the heat. You can't see it in the picture - it's off to the right of the rightmost silver heatsink - by the white plug.
I decided not to bother with replacing the two 0.068uf/35v tantalums - they're for the microphone input - which I'll surely never use.
Next decision is whether to recap the FM Dolby board - again likely never to be used.
Next up is that (maybe) and the tuner PCB (which you can see the underside of in the picture).
Here are some more parts lists:
2 - F2814 - Driver connection circuit boards (green boards to either side of the PS PCB)
F2795 Microphone amp circuit board (with selector switches)
F2799 Tone control circuit board
The big Mouser tractor-trailer came to the house yesterday and today so progress is being made - the underside is reassembled except for the tuner power supply board - which I left floating to make the tuner more maneuverable.
You can see here the new speaker relays I used on the power supply board. I erroneously got the ones with the wire solder tabs instead of the PCB mount models. I used a Dremel tool to enlarge the mounting holes on the PCB to make them fit.
The PS PCB also had a 3.3uf/63v cap mounted close to a large resistor and heatsink. I left about 0.75" of extra lead, covered them in teflon tubing and positioned it away from the heat. You can't see it in the picture - it's off to the right of the rightmost silver heatsink - by the white plug.
I decided not to bother with replacing the two 0.068uf/35v tantalums - they're for the microphone input - which I'll surely never use.
Next decision is whether to recap the FM Dolby board - again likely never to be used.
Next up is that (maybe) and the tuner PCB (which you can see the underside of in the picture).
Here are some more parts lists:
2 - F2814 - Driver connection circuit boards (green boards to either side of the PS PCB)
4 - 4.7uf/80v bipolar
F2795 Microphone amp circuit board (with selector switches)
F2799 Tone control circuit board
8 – 220uf/35v
3 – 100uf/35v
4 – 47uf/25v
1 – 47uf/6.3v
4 – 4.7uf/25v
2 – 3.3uf/25v
4 – 10uf5v LR
2 – 1.0uf/25v LR
2 – 0.068uf/35v Tantalum – replace with poly film
2 – 100uf/6.3v Bipolar
2 – 47uf/25v Bipolar
3 – 100uf/35v
4 – 47uf/25v
1 – 47uf/6.3v
4 – 4.7uf/25v
2 – 3.3uf/25v
4 – 10uf5v LR
2 – 1.0uf/25v LR
2 – 0.068uf/35v Tantalum – replace with poly film
2 – 100uf/6.3v Bipolar
2 – 47uf/25v Bipolar
Attachments
I decided not to recap the Dolby FM board / F-2688 but wanted to document the caps nonetheless:
F-2688 Dolby circuit board:
The PCB is mounted vertically between the faceplate and the tuner PCB. It is held in place with 4 plastic pins.
F-2688 Dolby circuit board:
2 - 2200uf/16v
6 - 10uf/16v
2 - 3.3uf/50v LR
2 - 1.0uf/50v LR
2 - 100uf/16v
6 - 10uf/16v
2 - 3.3uf/50v LR
2 - 1.0uf/50v LR
2 - 100uf/16v
The PCB is mounted vertically between the faceplate and the tuner PCB. It is held in place with 4 plastic pins.
Attachments
Getting close to the end 
.
Recapped the tuner board today. Don't forget to DeOxit the slide switch and then leave in the 75us position (for the USA anyway).
F-2920 Tuner circuit board:
.Recapped the tuner board today. Don't forget to DeOxit the slide switch and then leave in the 75us position (for the USA anyway).
F-2920 Tuner circuit board:
2 - 220uf/16v
3 - 47uf/16v
1 - 220uf/6.3v
12 - 10uf/16v
1 - 47uf/6.3v
1 - 4.7uf/50v
1 - 1.0uf/50v
1 - 3.3v/35v
1 - 3.3uf/50v
1 - 4.7/25v
2 - 10uf/25v LR
1 - 0.47uf/50v LR
3 - 2.2uf/50v LR
3 - 1.0uf/50v LR
1 - 1.0uf/50v Bipolar
1 - 10uf/16v Bipolar
1 - 0.22/35v Tantalum - replace with poly film!
1 - 1.0/35v Tantalum - replace with poly film!
1 - 3.3/35v Tantalum - replace with poly film!
3 - 47uf/16v
1 - 220uf/6.3v
12 - 10uf/16v
1 - 47uf/6.3v
1 - 4.7uf/50v
1 - 1.0uf/50v
1 - 3.3v/35v
1 - 3.3uf/50v
1 - 4.7/25v
2 - 10uf/25v LR
1 - 0.47uf/50v LR
3 - 2.2uf/50v LR
3 - 1.0uf/50v LR
1 - 1.0uf/50v Bipolar
1 - 10uf/16v Bipolar
1 - 0.22/35v Tantalum - replace with poly film!
1 - 1.0/35v Tantalum - replace with poly film!
1 - 3.3/35v Tantalum - replace with poly film!
Attachments
kevzep
Its all about the Music
Getting close to the end
Recapped the tuner board today. Don't forget to DeOxit the slide switch and then leave in the 75us position (for the USA anyway).
F-2920 Tuner circuit board:2 - 220uf/16v
3 - 47uf/16v
1 - 220uf/6.3v
12 - 10uf/16v
1 - 47uf/6.3v
1 - 4.7uf/50v
1 - 1.0uf/50v
1 - 3.3v/35v
1 - 3.3uf/50v
1 - 4.7/25v
2 - 10uf/25v LR
1 - 0.47uf/50v LR
3 - 2.2uf/50v LR
3 - 1.0uf/50v LR
1 - 1.0uf/50v Bipolar
1 - 10uf/16v Bipolar
1 - 0.22/35v Tantalum - replace with poly film!
1 - 1.0/35v Tantalum - replace with poly film!
1 - 3.3/35v Tantalum - replace with poly film!
Some would say you would need a Tuner alignment after re-capping the tuner, but I guess you could just see how she runs.......
I will be interested in seeing how that goes...
Let us know.....
Actually, I've never needed an alignment as long as I stay away from the tuning circuit caps - basically the ceramics.
And finally the last 2 caps - the ones on the F-2807 Pre-Main switch PCB. There are 2 - 1.0uf/50v Bipolars in there for one of the 3 switchable options for connecting the pre output to the power amp input. I replaced the 2 old caps (circled) with some poly films (pointed to with the arrow).
Now I put this away until tomorrow when I look over everything with fresh eyes and then get ready to power it up and adjust the amp settings.
2 - 1.0uf/50v Bipolar
And finally the last 2 caps - the ones on the F-2807 Pre-Main switch PCB. There are 2 - 1.0uf/50v Bipolars in there for one of the 3 switchable options for connecting the pre output to the power amp input. I replaced the 2 old caps (circled) with some poly films (pointed to with the arrow).
Now I put this away until tomorrow when I look over everything with fresh eyes and then get ready to power it up and adjust the amp settings.
2 - 1.0uf/50v Bipolar
Attachments
I had to put this aside for a while but I got the opportunity to do some upgrades and get this back on track.
I replaced the trim pots on the two amplifier driver PCBs with some Bournes multi turn units. Even with these the bias and idle adjustments are touchy so this is a good upgrade.
One lesson learned was that the bias adjustment needs to be turned all the clockwise before the initial adjustment or the current draw will be substantial and draw down the power supply.
I also replaced the small signal transistors, the two 22 volt zeners and the various power and fuse-resistors. The resistors were spaced off the board with some Teflon tubing. Those resistors on the bottom of the board may look small compared to the originals but in fact they're 1 watt parts.
Getting ready to do the final bias & idle adjustments and a few other tweaks.
I replaced the trim pots on the two amplifier driver PCBs with some Bournes multi turn units. Even with these the bias and idle adjustments are touchy so this is a good upgrade.
One lesson learned was that the bias adjustment needs to be turned all the clockwise before the initial adjustment or the current draw will be substantial and draw down the power supply.
I also replaced the small signal transistors, the two 22 volt zeners and the various power and fuse-resistors. The resistors were spaced off the board with some Teflon tubing. Those resistors on the bottom of the board may look small compared to the originals but in fact they're 1 watt parts.
Getting ready to do the final bias & idle adjustments and a few other tweaks.
Attachments
kevzep
Its all about the Music
I had to put this aside for a while but I got the opportunity to do some upgrades and get this back on track.
I replaced the trim pots on the two amplifier driver PCBs with some Bournes multi turn units. Even with these the bias and idle adjustments are touchy so this is a good upgrade.
One lesson learned was that the bias adjustment needs to be turned all the clockwise before the initial adjustment or the current draw will be substantial and draw down the power supply.
I also replaced the small signal transistors, the two 22 volt zeners and the various power and fuse-resistors. The resistors were spaced off the board with some Teflon tubing. Those resistors on the bottom of the board may look small compared to the originals but in fact they're 1 watt parts.
Getting ready to do the final bias & idle adjustments and a few other tweaks.
Nice Jim, You probably only needed to go multiturn on the 100ohm and not the 2K on the DC offset, because one is a coarse and the 100ohm is the fine........
The bias is the same on mine, it does end up being close to 3/4, it all happens in the last 30% of the adjustment....
A fine job indeed, I must finish mine now..........
Well, one of the bias pots was open (which was my real motivation to replace them) and they only cost $0.98 each so what the heck.
I also found that the two 4-pin connectors on the phono EQ PCB are interchangeable - guess who got them backwards, resulting in no phono? An easy fix (after some constructive self criticism).
I always enjoy a little customizing of my gear - I changed the Phono LEDs to green and the AM one to amber - just because.
All done and singing beautifully with a new Monk LP I scored the other day
!Bedtime now, I have to leave for the track tomorrow (pace car duty) at 6AM
.
kevzep
Its all about the Music
Well, one of the bias pots was open (which was my real motivation to replace them) and they only cost $0.98 each so what the heck.
I also found that the two 4-pin connectors on the phono EQ PCB are interchangeable - guess who got them backwards, resulting in no phono? An easy fix (after some constructive self criticism).
I always enjoy a little customizing of my gear - I changed the Phono LEDs to green and the AM one to amber - just because.
All done and singing beautifully with a new Monk LP I scored the other day
Bedtime now, I have to leave for the track tomorrow (pace car duty) at 6AM
At 98 cents each yeah what the hey..........
I will remember that about the phono board....
Yeah why not change the colour of the LED's, Im a bit of an aqua blue fan myself...........You are giving me ideas Jim....:yes:
Oh no dont say that Casey, look what happened when you told me about the AU-9500....:sigh:
You guys arent gonna believe what Ive been doing with my Sansui's today!!!!! there will be a thread coming....and pics......Its all to do with getting some punch out of my system.....:scratch2: