Elna main filter cap polarity

[GytisB]

Hey AKers! Do any of you know how I could determine the main filter cap polarity on these? They are from Sansui AU5900. It’s confusing when they say black negative, while the black dot is on the other side. Or does the black dot indicate the negative?

 

[avionic]

Black dot is Negative..

 

[avionic]

Welcome aboard AK. My brother and sister-in-law live in Norway . There both Icelanders.

 

[GytisB]

Black dot is Negative..

Thank you! That’s what I thought in the beginning, but again, better to ask and be sure.

Welcome aboard AK. My brother and sister-in-law live in Norway . There both Icelanders.

Thank you! Amazing, Norway is a beautiful place to live, altough it rains a lot here.

 

[avionic]

altough it rains a lot here.

Keeps it nice and green..

 

[whoaru99]

Maybe you're already on it, but remember that when it comes to the dual rail power supply that the "ground" is normally one cap positive and the other cap negative. If you connect both negatives to ground one capacitor will be backward.

 

[GytisB]

Soooo... I ended up doing it like this (photo attached). I think it is correct. Although it didn't produce any sound after turn on, relay clicks. Pretty strange, since I have taken photos prior to recapping and making sure that all the polarity is correct. Unless I could place film caps in the preamp section wrong? But aren't they bipolar?
Anyway, right after on button, amp makes a hum type of noise, which wansn't present before. Checking the fuses, it blew F604 and almost F603, which are rated for 160mA. Does anyone know where should I look at?

Update: Short on R71 and R74 on power amp board.Maybe thats normal though.

Update 2: wooops... I found a small mistake I made swapping diodes. Replaced one of the diodes the wrong way... Will check tomorrow and report back if it fixed the problem. Hope it didn’t damage anything else... ahhh

 

[Guest159]

Soooo... I ended up doing it like this (photo attached). I think it is correct. Although it didn't produce any sound after turn on, relay clicks. Pretty strange, since I have taken photos prior to recapping and making sure that all the polarity is correct. Unless I could place film caps in the preamp section wrong? But aren't they bipolar?
Anyway, right after on button, amp makes a hum type of noise, which wansn't present before. Checking the fuses, it blew F604 and almost F603, which are rated for 160mA. Does anyone know where should I look at?

Update: Short on R71 and R74 on power amp board.Maybe thats normal though.

Update 2: wooops... I found a small mistake I made swapping diodes. Replaced one of the diodes the wrong way... Will check tomorrow and report back if it fixed the problem. Hope it didn’t damage anything else... ahhh

It's a little unusual to do it that way. Usually you'd put the ground terminals in the middle to make it more visually and mechanically simpler. Marantz liked to run a piece between the middle that then screwed to the chassis, and that's how I like to build my power supplies too.

 

[GytisB]

A bit late update, but... It did sing again after I rotated the diode. All good!

It's a little unusual to do it that way. Usually you'd put the ground terminals in the middle to make it more visually and mechanically simpler. Marantz liked to run a piece between the middle that then screwed to the chassis, and that's how I like to build my power supplies too.

I see what you mean! But I just left it as it was, but I do agree on that.