Hanging by a thread, aka restoring a Sansui AU-717 the Leestereo way!

[AmbientNoise]

Good Day,
+1 on Output transistors. Also if driver transistors are intact leave them alone and do not use MJE15032/33 (they are also slower). Best replacement for those driver transistors which are currently in production are Sanken 2SC4883A/2SA1859A . But those have isolated tab and will require creativity when installing them (you can see my "Another Sansui AU-717 restoration") Also if you do it for yourself look at my thread and see about Rubycon MU series film caps. Good Luck with the resto.
Here is the link to my resto https://audiokarma.org/forums/index.php?threads/another-sansui-au-717-rebuild.932752/

@TupolevFan,
Thank you! I've looked up the Sanken units and will go over your build again as I get to that part of the resto! I can't thank you gentlemen enough for your wisdom and kind words!

 

[Uncle Bambi]

So I'm still waiting on a couple of pieces to arrive, in the meantime I've decided to crack open the case and take a look inside.
Woof, I know it hasn't been submerged but wow look at that grime!

Similar to the one I did a few years ago. It looked like it came from the wreck of the Titanic. Cleaned up pretty well, though:

 

[AmbientNoise]

Good Day,
+1 on Output transistors. Also if driver transistors are intact leave them alone and do not use MJE15032/33 (they are also slower). Best replacement for those driver transistors which are currently in production are Sanken 2SC4883A/2SA1859A . But those have isolated tab and will require creativity when installing them (you can see my "Another Sansui AU-717 restoration") Also if you do it for yourself look at my thread and see about Rubycon MU series film caps. Good Luck with the resto.
Here is the link to my resto https://audiokarma.org/forums/index.php?threads/another-sansui-au-717-rebuild.932752/

Hi @TupolevFan,

I'm a bit apprehensive to try and modify the isolated tab on the Sanken units, is there another set of Transistors that will perform as good or better than the stock units that are plug and play? I read someone on your thread suggested I believe the Sanyo 2sc2344/2sa1011 transistors. What are your thoughts? I'm reading your's and SuperNoob's build and trying to find a good list of all transistors to replace minus the driver and output units, though I may buy a new set of those just to use until I get everything together and voltages set in an effort to keep from destroying them. My budget for parts is decent as I only want to do this once hopefully, so if a better transistor cost 10 dollar per unit to get the best that fits, I'll gladly do that.

 

[AmbientNoise]

I just wanted to take a moment and thank you all for all of your help and kind words! I really appreciate the fact that so many of you are willing to share your builds and thoughts on best practices/parts/etc. Please understand that I was never classically trained in electronics repair. I do understand what each component is and variables within each component group, I just don't know theory/rules behind circuit design. I'm basically a parts swapper that's had a fair amount of success changing like for like parts. I've also set hall effect sensors, rebuilt guitar control sections, and rebuilt/aligned CRT/LCD projectors. Additionally I've spend a few years doing high end home audio/theater installations and programming control systems and wired electric within new home builds and remodels. I'm a jack of all trades king of none. So thank you everyone, I can't say it enough!

 

[Leestereo]

As others have mentioned, keep the original transistors unless they are faulty. Wholesale replacement of the transistors is not necessary and invites potential issues wrt matching original specs, e.g., speed and gain. Note that using a DBT for testing post board work will typically avoid damage to the installed transistors.

 

[AmbientNoise]

As others have mentioned, keep the original transistors unless they are faulty. Wholesale replacement of the transistors is not necessary and invites potential issues wrt matching original specs, e.g., speed and gain. Note that using a DBT for testing post board work will typically avoid damage to the installed transistors.

Thank you sir! I've got a DBT built and ready to go once I get everything done and will certainly be using it. Hopefully my ocd nature will keep me from making any mistakes.

 

[TupolevFan]

Hi @TupolevFan,

I'm a bit apprehensive to try and modify the isolated tab on the Sanken units, is there another set of Transistors that will perform as good or better than the stock units that are plug and play? I read someone on your thread suggested I believe the Sanyo 2sc2344/2sa1011 transistors. What are your thoughts? I'm reading your's and SuperNoob's build and trying to find a good list of all transistors to replace minus the driver and output units, though I may buy a new set of those just to use until I get everything together and voltages set in an effort to keep from destroying them. My budget for parts is decent as I only want to do this once hopefully, so if a better transistor cost 10 dollar per unit to get the best that fits, I'll gladly do that.

Hi,
First of all just explain again why you want to replace the original drivers ? Currently the only suitable replacement transistors ( in terms how they fit in place of originals) are MJE 15032/33.
Sanyo 2sc2344/2sa1011 are NOT in production anymore and you have to get them from the reputable source like B&D Enterprise otherwise your choice is isolated TAB devices.

There is another thread about AU-5900 and i was going to help the person to troubleshoot it. If anybody could pick up please Thanks you and god bless you all...

 

[AmbientNoise]

Hi,
First of all just explain again why you want to replace the original drivers ? Currently the only suitable replacement transistors ( in terms how they fit in place of originals) are MJE 15032/33.
Sanyo 2sc2344/2sa1011 are NOT in production anymore and you have to get them from the reputable source like B&D Enterprise otherwise your choice is isolated TAB devices.

Guys with a very heavy heart I have to say that I will be out for a while as i have huge personal tragedy as my older son is not with me anymore. There is another thread about AU-5900 and i was going to help the person to troubleshoot it. If anybody could pick up please Thanks you and god bless you all...

I'm so sorry to hear that TupolevFan, your family is in my thoughts. Thank you for your generous time, I can't thank you enough!

 

[AmbientNoise]

Update, still waiting on parts to come in... In the mean time I snagged another AU-717 with a right channel issue, so I'll have a back up in case everything goes to hell and I let the smoke out.

 

[AmbientNoise]

Quick update everyone. I've had a lot to consume with the new job(still do) and just this week got everything I needed to start to work properly on my build. Between replacing a water heater and having a good friends mother pass, I've been quite busy. I'm currently in the process of testing all the parts to confirm they're within tolerance and working on ironing out a few kinks that are tripping me up. I promise I'll have tasty photos of board work soon. Please understand I'm OCD and will likely be going over each board and re-flowing all solder joints as well as cleaning all heat sink contact points. Thank you all for your patience, I don't think I could have picked a busier time of year to start...