How to connect 2 Pioneer SA-8500 II

[QSilver]

If your doing the rest of it, you probably should. But you might struggle to find ones that have the original dimensions. They'll work just fine, but you might need to pad out the original capacitor clamps or get new ones.

They are the AC filter capacitors for the main power supply for the amplifier so they are quite important. There are four because the Mk2 is a dual power supply model. Two per power supply (positive and negative) if that makes sense...

 

[pioneerhip]

If your doing the rest of it, you probably should. But you might struggle to find ones that have the original dimensions. They'll work just fine, but you might need to pad out the original capacitor clamps or get new ones.

They are the AC filter capacitors for the main power supply for the amplifier so they are quite important. There are four because the Mk2 is a dual power supply model. Two per power supply (positive and negative) if that makes sense...

You think it's a bad idea to buy some used ones off of the bay, or go with the new replacements? If replacements does anyone have a part number they used?

 

[QSilver]

Buying capacitors out of another old unit is a bad idea. They're as old as yours and could be worse. Any new electrolytic capacitor that is 10,000uF at 50V and over with similar or smaller dimensions will be fine. But second hand capacitors is a definite no. If you find one you could post a link here and we can check it for you.

 

[pioneerhip]

Well initially i felt that way about buying used capacitors, but i kept thinking since there wasn't a direct replacement maybe it made sense to go with the original. Since i have this thing open i would rather replace with a newer part as long as it does not change the sound.

I talked with mouser this morning. Here is the list they gave. I really don't want to mess this up. Would you mind taking a quick look at this list, and tell me the one to go with.

http://www.mouser.com/Passive-Compo...0Zscv7?P=1yzxs5sZ1yztzazZ1yx4avv&Ns=Pricing|0

 

[pioneerhip]

Looking at the list i think these will work.

http://www.mouser.com/ProductDetail...Ev19YinWt8YVHLrlvHl0j3%2bSEi0NbYFvEb1GXBZPw==

Im curious what you think....

 

[QSilver]

Yes, they should work fine. You might want to just check that the clamps will hold the new ones as the diameter of the new capacitors might be less than the old ones.

 

[pioneerhip]

Well........ flipped the switch and blew the fuse.... Where do i start with the volt meter? Somehow i knew there would be some issues. HELP!!

 

[jheu02]

Before you do any more work, build a Dim Bulb Tester, it may save the unobtanium outputs. The large filter caps are probably still ok to leave be until you get the amp running again. You now need to give the boards a good look to see scorch marks, bulging caps, etc. make sure you check for proper polarity...hopefully you took lots of pictures.

 

[petehall347]

is this after changing the capacitors ? if so be sure they are right ways round

 

[pioneerhip]

All caps have been changed. Im pretty sure they are right ways round. I double checked before installing, but im sure its possible that one is backwards. I did take lots of pics. Im going to build a Dim Bulb Tester. Until i get the materials for it any other advice of items to check before I can get to the hardware store?

 

[QSilver]

You should have powered up with a DBT (Dim Bulb Tester) make one of these first before you continue. If nothing else it will save fuses! It's been known that the (+) marks on the circuit board can be wrong on some boards. Do you have photographs of the amp before you started working on it? Is it the main fuse?

 

[pioneerhip]

You should have powered up with a DBT (Dim Bulb Tester) make one of these first before you continue. If nothing else it will save fuses! It's been known that the (+) marks on the circuit board can be wrong on some boards. Do you have photographs of the amp before you started working on it? Is it the main fuse?

I have photos. I also purchased a second amp that is identical. I'm opening it up tonight to compare. It is the main fuse on the back of the unit. I'm building a dbt tomorrow.

 

[QSilver]

It could be that you've put a transistor in backwards around the driver or current stages of the amplifier so checking the leads of the transistors are in the right places would be a good place to start too.

 

[pioneerhip]

It could be that you've put a transistor in backwards around the driver or current stages of the amplifier so checking the leads of the transistors are in the right places would be a good place to start too.

Is there a way to test without removing them?

 

[QSilver]

Usualy the board has the symbol for transistor printed on it. The leads of the transistor go through the legs of the symbol which indicates where emitter,collector and base go. You can look at that and double check the correct legs of the transistor match with the legs on the boards symbol.

Some transistor WILL have different leg arrangements than the originals so its best to check vs the datasheet of the new transistor.

I think ive said the word "transistor" too much... Hope that makes sense!

 

[pioneerhip]

Usualy the board has the symbol for transistor printed on it. The leads of the transistor go through the legs of the symbol which indicates where emitter,collector and base go. You can look at that and double check the correct legs of the transistor match with the legs on the boards symbol.

Some transistor WILL have different leg arrangements than the originals so its best to check vs the datasheet of the new transistor.

I think ive said the word "transistor" too much... Hope that makes sense!

I got to take a look at the other amp. I think I may have found my problem. I want a second opinion before I make the change. The 10000 uf capacitors look like they are wired opposite every other cap. Am I looking at this correctly?

 

[pioneerhip]

I got to take a look at the other amp. I think I may have found my problem. I want a second opinion before I make the change. The 10000 uf capacitors look like they are wired opposite every other cap. Am I looking at this correctly?

This is the other amp I have that is next in line for a recap.

 

[petehall347]

i would say the pic looks correct .. need to see the other amp really to be certain .

 

[pioneerhip]

i would say the pic looks correct .. need to see the other amp really to be certain .

When I installed the new capacitors on the other amp I connected negatives together and positives together. On the previous post the picture shows negative connected to positive.

 

[QSilver]

When I installed the new capacitors on the other amp I connected negatives together and positives together. On the previous post the picture shows negative connected to positive.

That's why you blew the fuse. The capacitors are energy reserves of DC power for the amplifier as well as AC filters. One is for positive energy (+) and the other is for negative energy (-). So one must connect to the wire with a + so it can load with positive energy and the other must connect with the negative on the wire and the positive grounded. So it can build up negative energy - think of it as telling it what sort of energy to expect. You need to check on the one you haven't recapped yet, which is positive and which is negative. You might have to replace the capacitors too, as a reverse voltage (positive when it was expecting negative or vice versa) of that magnitude might have damaged it - especially with no DBT.