Hello Tony. Real nice work here! :-) I just did a full recap and repair of a Sansui 9090 a year ago. I did not do the full replacement of the outputs but I changed all transistors on left channel and swap a lot of transistors and resistors. I managed to get a full four pair of matched Sanken NOS orginal transistors to the receiver from the US. The owner are very happy with the work. I used mostly Elna SilmicII in the audio and a lot of Nichicon and Panasonic in the power section. I changed the Main Filter capacitors to Nichicon KG Series Gold Tune 10000uF 100V in there. The receiver have been used daily now for the last 12 months without problems. Happy for that!
Hey man. Thank you. Thank you for making specifically this set of how-to. My 9090 needs a ton, and you have just taught a man how to fish. I will forever know this beast inside and out. Thank you.
Love watching your videos of you just going to town on these old vintage recievers restoring them, very smart guy. Looking forward to the next part and more videos to come.
Nice video! Just one comment: - The extra transistors in the SANSUI 9090 DB are not used as overall gain transistors, they are just protection in overdrive conditions of the output transistors. They sense the current in the output transistors, via the emitter resistors, and reduce the drive at the driver transistors. Keep up the good work. Greetings.
What a great amp. It was a work horse that played well at street dances. Rectilinear and Altec Lansing speakers to compliment the sound. This is my brother's amplifier, and my first experience with it led me to the conclusion that you don't just listen to music...you feel it. I believe he still has it, in perfect working order. He has always treated it like gold.
WOW!! You know your stuff with this receiver! I've wanted to get my Sansui9090 restored and I think I've found my man. These are excellent units and sound fantastic! Mine still works, but is needing lots of love..
I bought my 9090DB new in 76 it will never be for sale. Plus, I keep up on the servicing. Send it to a Sansui factory trained tech for servicing about every 10 years and I keep play time under a few hours a week. My daily user is my Pioneer SX1250 which has more top end punch, but in my opinion does not have the warm sound of the 9090DB. The main problem I have had over the years with my 9090DB is output transistors. The original Toshibas are NLA, and finding a matched set of 8 new aftermarket you might need to test 50 or more to find 8 that totally match value.
The materials used in that amp were those which were available in the 70’s. A lot of that stuff was in other consumer electronics from that age are delicate as well. It is my understanding that fusing resistors are basically a bunch of ceramic material doped with metal elements or other types of semi conductive materials and are composed in a way to transfer electrons but will heat up - like your stove - if enough electrons are shoved through. The AMP in the video is of course , creating a set of variably amplified outputs through which the amplification is achieved by creating a ratio of smaller amounts of electrons to a larger amount , which would naturally cause more electrons to flow through. Hence the modification for two diodes , similar provisions would effectively negate the failure of the resistors
cool, maybe that explains why mine has fried twice so easily when outley energy suddenly goes out? i once took it to a "pro" guy and he just changed the main fuse i think, but now i cannot take it to anyone who really knows,,, what type of main fuse can i use?
I don't know if it's the case with this amplifier but like exaggerated power outputs, many amplifier manufactures would give the damping factor with no given frequency or as high as 1khz. A better way would be to give it at say, 40hz. Therefor a true reading of 10 at 40hz would be better than 100 at say 1khz where damping is less important. But members of the public with no understanding on the subject just like big numbers. I sold these all those years ago, I had no issue with reliability, maybe we were lucky but a very powerful and clean sounding they were.
Not my first, but I still have the one I bought new & use it, not as much anymore but I put a few hours on it every week and send it to be serviced (hand delivered) about every 10 years.
bought a sansui 7000, that was the exact model my grandfather had, was looking at murantz, but it seems that sansui models of this era are sort of underrated, on ebay etc., the guy did a nice restoration on the 7000, think I got a decent deal.
Very informative video. I do have a question in regards to the resistors replaced. You discussed in detail replacing R43-46 and 49/50. But in the video it almost seems like some additional ones in between TR12/14 and 11/13 were replaced as well. With this said, I am actually confused about something different . It appears there are 3 installed resistors you have on this board in-between those transistors. On a 9090 I have, there are only 2, with the 3rd having a jumper (R39/40). In the schematic, it does indeed show an R39/40 (10 ohm), but again, it is missing on my board. Do you recommend adding these in, or leave them out?
Very interesting and involved, Tony. Did you just research the web forums to get a consensus of proper mods to be done, or do you have a definitive web source that you go to, that has all the mods listed? Tracking down what needs to be done is a job in itself, but the reward will be worth it!
I have a Sansui 8080 that I bought new in 1975. I have a subtle, scratchy and poppy static noise that comes through both channels and is not affected by manipulation of volume, balance or any of the other switching controls. It doesn't matter if I use A,B or C speaker outputs. Would you have any suggestions on the most likely cause?
I just finished my Sansui G-8000 about to have a video review on it , it has A massive transformer SANSUI started out a radio parts supplier they speacialized in transformers ! Review coming soon thanks for the video
Hi Tony. Happy New Years. Gosh I love these pieces you do on receiver and amplifier refurbs. Now you’re creating an itch to investigate into the Sansui line which I had read a bit into and always seen positive reviews of their sound. Did they make an equivalent integrated amp with the same design ? Thank you for your always interesting videos packed with many bits useful information and insights.
Good evening I just purchased a couple weeks ago a Pioneer sx838.I'm new to vintage audio My question is is that a good unit and what are some of the problem areas on that unit that you would check or modify
I own a Sansui 9090 that I purchased new circa 1974 (?). It works fine but I would like to have it cleaned and updated...overhauled, so to speak. I live on the central Florida coast near Daytona Beach. Can you recommend a technician who I can contact for this work? They don't make them like this anymore and I want to keep it dancing.
You are definately right about replacing those lousy pots in the output stage. I usually replace them with 20 turn models if there is enough room to put them on the desired spot. 20-turn pots are very convenient to adjust, spot on to one mV. BTW, damping factor is not really that important, any figure starting at 10 is plenty.
One thing is for sure, those old receivers were elegant. I hate this age of charcoal lettering on black anodized aluminum. Are you going to have to recap all electrolytics? Quite a few, if so.
Thank you, Thank you, Thank you...I have a 9090 I bought a few years ago and it's in pretty sad shape, stays in protection mode as I remember. I downloaded the manual from hifi-engine but I ran into a lot of things that didn't match the schematic and after awhile I got disgusted and put it back together and sat it on a shelf. Your video clears up a lot of questions I had, as you said I thought somebody had been re-engineering it. I was a Magnavox tech in the 1970's and a retired district engineer for the Missouri Highway Patrol communications division. I'd really like to make this beast work. Are any of your schematics with the modifications available for purchase? Thanks again...
I have one of these, it's been broken for some time. The light just blinks red. Is it worth fixing? It was in our house growing up. How expensive can it get?
When I was 16 next to the pizza shop I worked at was a pawn shop and they sold me a Sansui 7000 when I yold yehm I wanted something loud for 50 bucks. I bought a Radio Shack watt meter that measrued to 200 watts and that Receiver would bury that watt meter at 1/3 volume and it would go full volume perfectly will no hearable distortion. When I left home I left it at home My mom married and moved a few times and it disappeared.. I had steady volume increase all the way to max.. Was the best receiver I have ever owned. Now I can't afford one for what they go for .. I really miss it..cry...
I have an Pioneer SX-980. Tell me what you think of this receiver it's 1979 Model only had it cleaned once. Paid only 100.00 from and friend. I'm and Technician from DeVry, and Re-Tired I/T Professional. Thank you for your time.
Instead of putting the two fuses on the input why don't you put a X Y capacitors instead in a triad formation this will help with smoothing filtering the input and added protection.
Hello Tony. Real nice work here! :-) I just did a full recap and repair of a Sansui 9090 a year ago. I did not do the full replacement of the outputs but I changed all transistors on left channel and swap a lot of transistors and resistors. I managed to get a full four pair of matched Sanken NOS orginal transistors to the receiver from the US. The owner are very happy with the work. I used mostly Elna SilmicII in the audio and a lot of Nichicon and Panasonic in the power section. I changed the Main Filter capacitors to Nichicon KG Series Gold Tune 10000uF 100V in there. The receiver have been used daily now for the last 12 months without problems. Happy for that!
I have a 9090. I bought it when I was 18. The speakers I bought for it are Cerwin Vega Hard Rockers. Awesome bass and high end!
Hey man. Thank you. Thank you for making specifically this set of how-to. My 9090 needs a ton, and you have just taught a man how to fish. I will forever know this beast inside and out. Thank you.
Love watching your videos of you just going to town on these old vintage recievers restoring them, very smart guy. Looking forward to the next part and more videos to come.
Nice video! Just one comment:
- The extra transistors in the SANSUI 9090 DB are not used as overall gain transistors, they are just protection in overdrive conditions of the output transistors. They sense the current in the output transistors, via the emitter resistors, and reduce the drive at the driver transistors.
Keep up the good work. Greetings.
Thank you for the correction! I'll try to remember to mention this on the next video. Thanks for watching!
What a great amp. It was a work horse that played well at street dances. Rectilinear and Altec Lansing speakers to compliment the sound. This is my brother's amplifier, and my first experience with it led me to the conclusion that you don't just listen to music...you feel it. I believe he still has it, in perfect working order. He has always treated it like gold.
WOW!! You know your stuff with this receiver! I've wanted to get my Sansui9090 restored and I think I've found my man. These are excellent units and sound fantastic! Mine still works, but is needing lots of love..
Working my way through an 890, great tutorial! And thanks for giving the part number of the leaded fuses.
Best tuner ever made been playing mine for 40 years
I bought my 9090DB new in 76 it will never be for sale. Plus, I keep up on the servicing. Send it to a Sansui factory trained tech for servicing about every 10 years and I keep play time under a few hours a week. My daily user is my Pioneer SX1250 which has more top end punch, but in my opinion does not have the warm sound of the 9090DB. The main problem I have had over the years with my 9090DB is output transistors. The original Toshibas are NLA, and finding a matched set of 8 new aftermarket you might need to test 50 or more to find 8 that totally match value.
You really know your stuff so great to see you do this, Thanks for sharing
The materials used in that amp were those which were available in the 70’s. A lot of that stuff was in other consumer electronics from that age are delicate as well. It is my understanding that fusing resistors are basically a bunch of ceramic material doped with metal elements or other types of semi conductive materials and are composed in a way to transfer electrons but will heat up - like your stove - if enough electrons are shoved through. The AMP in the video is of course , creating a set of variably amplified outputs through which the amplification is achieved by creating a ratio of smaller amounts of electrons to a larger amount , which would naturally cause more electrons to flow through. Hence the modification for two diodes , similar provisions would effectively negate the failure of the resistors
cool, maybe that explains why mine has fried twice so easily when outley energy suddenly goes out? i once took it to a "pro" guy and he just changed the main fuse i think, but now i cannot take it to anyone who really knows,,, what type of main fuse can i use?
I sent a Sansui 4000 home when I left the Philippines when I was in the Navy. Its still going...I use it almost every day in my shop.
I don't know if it's the case with this amplifier but like exaggerated power outputs, many amplifier manufactures would give the damping factor with no given frequency or as high as 1khz. A better way would be to give it at say, 40hz. Therefor a true reading of 10 at 40hz would be better than 100 at say 1khz where damping is less important. But members of the public with no understanding on the subject just like big numbers.
I sold these all those years ago, I had no issue with reliability, maybe we were lucky but a very powerful and clean sounding they were.
Very informative. Thanks so much.
Hi, watching and learning. Greetings from the Philippines
Really enjoyed the 9090 videos. I'm starting to work on a 990DB. Wish you could upload some video of a DB version.
Sansui 9090DB was my first receiver back in 1977.
Not my first, but I still have the one I bought new & use it, not as much anymore but I put a few hours on it every week and send it to be serviced (hand delivered) about every 10 years.
bought a sansui 7000, that was the exact model my grandfather had, was looking at murantz, but it seems that sansui models of this era are sort of underrated, on ebay etc., the guy did a nice restoration on the 7000, think I got a decent deal.
Very informative video. I do have a question in regards to the resistors replaced. You discussed in detail replacing R43-46 and 49/50. But in the video it almost seems like some additional ones in between TR12/14 and 11/13 were replaced as well. With this said, I am actually confused about something different . It appears there are 3 installed resistors you have on this board in-between those transistors. On a 9090 I have, there are only 2, with the 3rd having a jumper (R39/40). In the schematic, it does indeed show an R39/40 (10 ohm), but again, it is missing on my board. Do you recommend adding these in, or leave them out?
Very interesting and involved, Tony. Did you just research the web forums to get a consensus of proper mods to be done, or do you have a definitive web source that you go to, that has all the mods listed? Tracking down what needs to be done is a job in itself, but the reward will be worth it!
I have a Sansui 8080 that I bought new in 1975. I have a subtle, scratchy and poppy static noise that comes through both channels and is not affected by manipulation of volume, balance or any of the other switching controls. It doesn't matter if I use A,B or C speaker outputs. Would you have any suggestions on the most likely cause?
I just finished my Sansui G-8000 about to have a video review on it , it has A massive transformer SANSUI started out a radio parts supplier they speacialized in transformers ! Review coming soon thanks for the video
Yet another great video
Thanks Tony
Hi Tony. Happy New Years. Gosh I love these pieces you do on receiver and amplifier refurbs. Now you’re creating an itch to investigate into the Sansui line which I had read a bit into and always seen positive reviews of their sound. Did they make an equivalent integrated amp with the same design ? Thank you for your always interesting videos packed with many bits useful information and insights.
Happy New Year, Thomas! Good to hear from you. Stay tuned and we'll see how this one turns out!
xraytonyb
Oh oh. Hope you don’t light a stick of dynamite to it 😵.
Good evening I just purchased a couple weeks ago a Pioneer sx838.I'm new to vintage audio My question is is that a good unit and what are some of the problem areas on that unit that you would check or modify
I own a Sansui 9090 that I purchased new circa 1974 (?). It works fine but I would like to have it cleaned and updated...overhauled, so to speak. I live on the central Florida coast near Daytona Beach. Can you recommend a technician who I can contact for this work? They don't make them like this anymore and I want to keep it dancing.
You are definately right about replacing those lousy pots in the output stage. I usually replace them with 20 turn models if there is enough room to put them on the desired spot. 20-turn pots are very convenient to adjust, spot on to one mV. BTW, damping factor is not really that important, any figure starting at 10 is plenty.
greetings from the Philippines!
So in the power supply board are you keeping the same value caps the-same?
I’ve got a Sansui 33000 that became slower & slower to clear the protector and come on.
Is this power circuit board issue also exist in the 33000...?
One thing is for sure, those old receivers were elegant. I hate this age of charcoal lettering on black anodized aluminum. Are you going to have to recap all electrolytics? Quite a few, if so.
Thank you, Thank you, Thank you...I have a 9090 I bought a few years ago and it's in pretty sad shape, stays in protection mode as I remember. I downloaded the manual from hifi-engine but I ran into a lot of things that didn't match the schematic and after awhile I got disgusted and put it back together and sat it on a shelf. Your video clears up a lot of questions I had, as you said I thought somebody had been re-engineering it. I was a Magnavox tech in the 1970's and a retired district engineer for the Missouri Highway Patrol communications division. I'd really like to make this beast work. Are any of your schematics with the modifications available for purchase? Thanks again...
could anyone tell me what the upgraded R-49 and R50 resisters should be?
That's high praise!
I have one of these, it's been broken for some time. The light just blinks red. Is it worth fixing? It was in our house growing up. How expensive can it get?
Hi Michael. That’s a pretty common issue and reasonably easy to fix. Where are you?
@@briant8 In Minnesota!
Hello. I have a 9090. Do you still service and upgrade this type of receiver?
Do you have the specs that your cousin did to his 9090bd?
Hi my 9090db no sound to spearker
But i Can use pre out
How can i check it
Thank you
9090 Is better for no other reason is that the DB section of tbe 9090DB is fragile and a pain.
Still really prefer the 881.
can i send mine to you for a recap/clean-up?
very informative!!!
Hi Tony, thanks for the precise explanations of these mods. Am I correct in thinking they can be applied to the 8080 in the same way?
Jelcke de Boer. Yes, pretty much. The differences between the 8080 and 9090 are pretty minor. The maintenance manual is the same.
When I was 16 next to the pizza shop I worked at was a pawn shop and they sold me a Sansui 7000 when I yold yehm I wanted something loud for 50 bucks. I bought a Radio Shack watt meter that measrued to 200 watts and that Receiver would bury that watt meter at 1/3 volume and it would go full volume perfectly will no hearable distortion. When I left home I left it at home
My mom married and moved a few times and it disappeared.. I had steady volume increase all the way to max.. Was the best receiver I have ever owned. Now I can't afford one for what they go for .. I really miss it..cry...
I have a 9090db, would you be interested in taking a look at mine? Looking for a good service tech
We all are. My factory trained Sansui tech I used for decades just passed away from Covid, NOT GOOD !.
Sansui 9090 DB + JBL L-100 Century. from 1976/77.
I have an Pioneer SX-980. Tell me what you think of this receiver it's 1979 Model only had it cleaned once. Paid only 100.00 from and friend. I'm and Technician from DeVry, and Re-Tired I/T Professional. Thank you for your time.
I love every well maintained SX receiver I have ever heard from the era. My model is an sx 750.
Hola amigo, estoy reparando uno igual pero no tengo el diagrama sería tan amable de facilitarme el diagrama de servicio.soy de colombia
Maybe this receiver sound great but, the engineers had no clue what they were doing!.
Nice
Nice!
nd The way you Read The Schematics ........Im Begging That You Be My Repair Man????????
just a quick question. What is your source for the main filter caps?
thanks
Digikey seems to have the best selection. I think I covered how to find the correct ones in one of my Viewer Questions Videos. Thanks for watching!
I use these from Parts Connexion: www.partsconnexion.com/capacitor_ele_nichicon_kg.html
xraytonyb please help with my 9090 no DB when I turn on power it keep red flashing so please help what wrong .thx for help.
hey there, whats a good replacement for the main fuse?
I here in Amazon north of Brazil
Why can't you put a 15000 and a thermistor and upgrade the switch this would be alright
Would it be better to change the electrolytic on the output power board for polymer like orange drop's
What about if you instead of replacing it with a fuse put a 40w candescent bulb? Wouldn't this gives some smoothing from the transistors???
Instead of putting the two fuses on the input why don't you put a X Y capacitors instead in a triad formation this will help with smoothing filtering the input and added protection.
what a mess That's a Lot of freaking mod work they must of rushed that receiver in to production and tried to cheep out. it definitely needed more R&D
And that's just it. As good as they can be, this was a trend sansui continued into the 80s and ended up cheeping themselves out of the market.
That was back in 85..lol