9090 Power Supply and BA312 Upgrades

[sajjad amer]

I have recapped this receiver and am looking for further tweaks. I have found following 2 and would like your advice if it is worth it ?
1- Power supply: http://marantzhallo-fi.blogspot.co.uk/2017/09/tommys-sansui-9090db-w-dual-ba312.html
Although the link posted above is for DB version but looking at power supply board, Axial silicon diodes are there on 9090. Can I use this tweak? would it help? Being a novice I need to know what Schottky TO-220 to use?
2- BA312 : https://analogesoteric.com/products/copy-of-pioneer-ta7136-upgrade-module-kit-available-soon
What are your thoughts on this upgrade ? I will be buying it directly from the seller in above link, is it worth the price as its almost 1/3rd the price of an average 9090 on eBay.

 

[Hipocrates]

I've seen those board rectifiers here
http://www.partsconnexion.com/product26998.html, no idea of the improvement

Regarding the BA312 upgrade, I don't think many have tried that.For 50 bucks I guess I would, $135.... mmmm don't think so.

On my 9090, replacing ceramics for C0G and Mylars for P.P and C0G and replacing all resistors for metal film 1% on F-2436 and F-2547 had a nice effect on the unit.
Off course this is just a subjective observation made on a basket case unit.

 

[sajjad amer]

Makes sense, thank you

 

[Hipocrates]

Makes sense, thank you

this is this the correct link
http://www.partsconnexion.com/kits_sub_assemblies.html
I think I'll order some of those boards to experiment.
I've been replacing those with mur1620 for a while... just in case

 

[sajjad amer]

so will you put 4 MUR 1620 in this board ? I look forward to see how your experiment goes.

 

[Hipocrates]

so will you put 4 MUR 1620 in this board ? I look forward to see how your experiment goes.

Not exactly
On the 9090 you will have just D01 which is a 10DC2 and where replaced with MUR1620CTG.
On the 9090DB you will have D01 and D02 10DC2 and 10DC2-R and where replaced with MUR1620CTG-R.

https://www.mouser.com/productdetail/on-semiconductor/mur1620ctg?qs=Gev%2bmEvV0ibn2O5QQL3OzQ==

This are 3 legs devices so they are a drop in replacements. 1 on the 9090 and 2 on the 9090db.

Remember than the 9090 and the 9090db, besides the F-2544 board, are different animals.
Regarding the sonic improvements, well... hard to tell.

 

[tarior]

First off, avoid Hallo-Fi.
http://audiokarma.org/forums/index.php?threads/hallo-fi-electronics.711282/

Secondly, if it's not broken, don't fix it.
BA312 isn't an opamp, it's just a transistor array. If it works, leave it alone. Same for the rectifiers in the P/S. If they work, leave them be.

 

[Hipocrates]

Just to clarify
Again, my parts replacements were performed in basket cases... So I took the liberty to try some stuff, check what others do to their units, and have some fun. (usually that is not a good practice)
About '' tweaks" : Please just be cautious on what are you doing to your unit. Try to gather a lot of info about it, their circuits, parts and expect no dramatic improvements.

Just in case, I just wanted to let the OP knows what parts where used on this case, in order to satisfy his curiosity, not to endorse hallo-fi and his practices.
Finally, regarding the comments like ''if not broken don't fix'' or "don't mess with this or with that", have the intention to save you headaches y errors and it is in fact a good advice.

 

[sajjad amer]

@Hipocrates @tarior thank you both of you for guiding me, I appreciate it. I will leave it well alone.

 

[Hipocrates]

thank you both of you for guiding me

No problem, and keep asking a lot very good teachers around, it is amazing what you can extract from this fellows.
Cheers!