Filter Capacitor help

[socrates75]

I have a Clairtone CT-101B stereo receiver and i just need help identifying the amount of tabs on the giant filter caps and what i would use to replace them?
Its got a very low hum coming from the receiver itself and i have read its most likely the filter caps, there are 4 large cans, 3 of them have 2 tabs and then 4 outside tabs that im assuming are grounds and the 4 large can has 3 tabs and then 4 on the outside for ground again, does that mean for the 2 tabs with ground tabs i would look for a 2 tab can or a 3 tab can? same with the 3 tab one, do i look for a 4 tab cause of the ground tabs?......tab lol
The picture shows the rats nest, the 3 circled in blue have 2 tabs and then the ground tabs on the outside well the one circled in red has 3 plus ground tabs, if someone could post a link from digikey or mouser for the right one to pick to replace all 4 that would be very helpful
The 3 cans with 2 tabs are as follows
1000mfd 50v (also says 60 volts)
1000mfd 35v (also says 40 volts)
1000mfd 35v (also says 40 volts)

The 1 can with 3 tabs plus ground is
500mfd 50v 75v surge

 

[whoaru99]

Probably should look at the transforner mounting and maybe the transforner through bolts if there are, before worrying about the caps if you're hearing a hum from the unit itself.

 

[TPettenati]

Some say "Can Isolated" so I wouldn't consider the 4 tabs around the outside to be a negative. They are probably mounting tabs that are part of the case.

On three I see "Negative △ " so look for that symbol on the top to identify which pin is negative.

The multi-section cap looks like
500MFD 50V
500MFD 50V
???MFD 50V
Something else faded and illegible.
(check for matching symbols near lugs)

Also, don't confuse Negative and Ground, two completely different things.

 

[socrates75]

Probably should look at the transforner mounting and maybe the transforner through bolts if there are, before worrying about the caps if you're hearing a hum from the unit itself.

Actually that was the first thing i did lol i tightened the transformer down as tight as possible, still humming

 

[socrates75]

Some say "Can Isolated" so I wouldn't consider the 4 tabs around the outside to be a negative. They are probably mounting tabs that are part of the case.

On three I see "Negative △ " so look for that symbol on the top to identify which pin is negative.

The multi-section cap looks like
500MFD 50V
500MFD 50V
???MFD 50V
Something else faded and illegible.
(check for matching symbols near lugs)

Also, don't confuse Negative and Ground, two completely different things.

Ok this is extremely helpful! thank you! i didnt know what the symbols on the 3 tab one meant, so triangle is negative, what would the square and half circle be?
So i had asked a while ago about finding new cans but i kept running into cost and availability and also that it would be very hard to remove the old cans due to the grounding tabs, so i was told to just buy regular less expensive caps and cut the wires from under the old cans and wire in the new caps under neath all the mess of wires and leave the old unconnected cans in place, i can figure out the 2 tab one, buy a regular polarized cap with matching mf and matching or greater volts and just solder onto the wires after being clipped from the old can, but do i still need to use the ground from the 4 tabs on the large can? and how would i hook up the 3 tabs one to a new cap?
again thank you for any and all advice given, i have already replaced a lot of the axial caps that had barfed out there guts and it sounds better but that hum is driving me nuts cause i know its not good lol

 

[whoaru99]

Actually that was the first thing i did lol i tightened the transformer down as tight as possible, still humming

If there isn't hum in the audio I have doubts the caps will fix.

 

[socrates75]

If there isn't hum in the audio I have doubts the caps will fix.

If its not the filter caps and the transformer isnt lose could it be dirt and grime on the boards? cause this sucker lived with me growing up as a kid and my dad smoked cigars and pipes and its sticky looking lol

 

[whoaru99]

Sometimes transformers just make/get a little noisy without any other cause than the transformer.

 

[socrates75]

Sometimes transformers just make/get a little noisy.

Im gonna pick at it again tonight and see if i can hear the hum in the speakers at all, if not then i will take the bolts out that hold the transformer down and drive them back in again and see what happens lol

 

[whoaru99]

Some have crafted rubber isolator mounts. If the screws are already cranked down making them tighter is unlikely to help.

 

[socrates75]

Some have crafted rubber isolator mounts. If the screws are already cranked down making them tighter is unlikely to help.

i think i might have some rubber washers,i could try it and see what helps, anythings better then having to replace the filter caps, thanks man i will update tonight

 

[whoaru99]

If you try something with isolation bear in mind putting something only between the transformer mounts and chassis may not help much if the screws are still in contact with transformer. If the transformer mounts by "feet" then rubber on both sides and try to avoid the screws touching the transforner feet at all.

 

[socrates75]

If you try something with isolation bear in mind putting something only between the transformer mounts and chassis may not help much if the screws are still in contact with transformer. If the transformer mounts by "feet" then rubber on both sides and try to avoid the screws touching the transforner feet at all.

Thanks man i will make sure to use on both sides of the screw heads and the chassis

 

[socrates75]

If you try something with isolation bear in mind putting something only between the transformer mounts and chassis may not help much if the screws are still in contact with transformer. If the transformer mounts by "feet" then rubber on both sides and try to avoid the screws touching the transforner feet at all.

Ok plugged speakers in and the hum is coming from both speakers as well and now the left channel is completely out sop i got some more work to do it seems

 

[mbz]

Is hum mains 50/60Hz or rectified 100/120Hz, use scope/phone ap spectroid or.../pc freeware audacity or...
If 50/60Hz then wont be main caps

 

[socrates75]

Is hum mains 50/60Hz or rectified 100/120Hz, use scope/phone ap spectroid or.../pc freeware audacity or...
If 50/60Hz then wont be main caps

it sounds like the 60hz hum, also i just set my multimeter to 20volts DC and im getting 17volts from both speaker terminals :O

 

[socrates75]

So no audio out of left channel yet i get 17 volts showing out of both channels?

 

[whoaru99]

So no audio out of left channel yet i get 17 volts showing out of both channels?

I don't know the unit, but if it is capacitor coupled output I think it's normal to see voltage. Need a load on if so.

 

[socrates75]

I don't know the unit, but if it is capacitor coupled output I think it's normal to see voltage. Need a load on if so.

I tried radio and aux and same thing, both channels were working before but one was always kind of hit or miss and now its off completly, i did replace a bunch of caps but couldnt find the 80uf one i needed for cheap so im wondering if thats the one thats failed completly now

 

[TPettenati]

what would the square and half circle be

The printing on the side of the cap shows which symbol is equal to which spec. Unique to each cap. Need to look at each one individually.
I don't think the triangle is neg on the three tab you have. Hard to read but looks like half circle = 500/50 , square = 500/50 , triangle =???/50 and cant' read the 4th.