Sansui 9090DB Protection Board Fused Resistor

[Skywatcher]

Yes they are soldered in with no other changes. Look at the photo I uploaded. You can see them as they came from the factory in mine. The tubing is dark brown-ish because Sansui coated things with rosin and it has aged a bit. I have some spare fuses and tubing I removed from one of my units where I installed remote fuse holders instead. Just in case any of them blew I wouldn't need to perform surgery to replace them. But I have never had any of the fuses blow yet, even in 40 years of abuse. lol. However in some cases the fuse resistors have "blown" *after* the damage was done. That's why Sansui made the change.

 

[danrclem]

Do you have any pictures of your remote fuse holders and where they are attached? That sounds like something I might be interested in doing.

 

[Skywatcher]

Do you have any pictures of your remote fuse holders and where they are attached? That sounds like something I might be interested in doing.

I made the bracket out of some aluminum I had laying around. And had some thumb screws and nylon spacers so I can easily remove the bracket in case I need to remove the tuner again.

 

[danrclem]

I really didn't expect something like that. Very nice!

 

[Skywatcher]

I really didn't expect something like that. Very nice!

Thank you.

 

[danrclem]

I didn't realize that I had this 9090db this long. I finally got to work on it and I changed all 14 fusible resistors in the driver board. It came out of protection but I could barely hear one channel unless I put it in mono. I got my Deoxit out and went to work on the switches. Everything worked like it should but when I didn't have a signal running through it I could hear a hum. I changed the three fusible resistors in the power supply board. The hum is gone and it sounds great. I took it to my listening room and am ready to hook it up and see how it sounds in there.

Thanks for all replies.

 

[Skywatcher]

I didn't realize that I had this 9090db this long. I finally got to work on it and I changed all 14 fusible resistors in the driver board. It came out of protection but I could barely hear one channel unless I put it in mono. I got my Deoxit out and went to work on the switches. Everything worked like it should but when I didn't have a signal running through it I could hear a hum. I changed the three fusible resistors in the power supply board. The hum is gone and it sounds great. I took it to my listening room and am ready to hook it up and see how it sounds in there.

Thanks for all replies.

I changed every fusible resistor I could find and replaced them with 1% Metal film resistors. *EXCEPT* where those 1 Ohm are in the early models as mentioned above. I also just installed Noah Schumacher's BA312 "upgrade" in my one unit's tone board. Yes, I can definitely hear a difference in depth and clarity. The lows are much cleaner and is more linear throughout the frequency range. I am considering the upgrade for the RIAA as well in the EQ board.

 

[danrclem]

I changed every fusible resistor I could find and replaced them with 1% Metal film resistors. *EXCEPT* where those 1 Ohm are in the early models as mentioned above. I also just installed Noah Schumacher's BA312 "upgrade" in my one unit's tone board. Yes, I can definitely hear a difference in depth and clarity. The lows are much cleaner and is more linear throughout the frequency range. I am considering the upgrade for the RIAA as well in the EQ board.

I had forgotten all about the fuses that you put in the PSB until I went back and reread this thread. If Sansui thought it was important enough to do it then it should be done so I think I need to do that soon.

I didn't know anything about the BA312 upgrade but I'll have to check into it and maybe do it. I'm all about better sound and the 9090db sounds good already.

 

[Skywatcher]

I had forgotten all about the fuses that you put in the PSB until I went back and reread this thread. If Sansui thought it was important enough to do it then it should be done so I think I need to do that soon.

I didn't know anything about the BA312 upgrade but I'll have to check into it and maybe do it. I'm all about better sound and the 9090db sounds good already.

Here is his website and then the link to his eBay store. The prices on Ebay are better. ;-)
https://analogesoteric.com/collections/all
https://www.ebay.com/itm/Vintage-Sa...990-990DB-9090-9090DB/182964283347?rmvSB=true

Noah is very attentive as well and will work with you should there be any problems. I installed the 2 resistors in the MIC amp first, then went onto the Tone board to install the modules. Note the modules must be slightly angled before you solder them on simply because of the size of the boards, and how close the 2 original BA312 modules are mounted. It's no problem really. Plus you have to "scooch" two caps to the side a bit for clearance.

 

[danrclem]

Thanks for the links Skywatcher.