SX-1250 Filter Caps

I I'm wanting 2 1/2 " Diameter and, screw terminals should be around 1 1/8" o.c.
oops, I'll edit the size above. I was thinking about a different amp I've got under the knife right now sitting next to the SX-5580.

You don't need to worry about the spacing. Sure be nice to drop it but you can make a connector out of a chunk of copper from a 10ga wire and make it loop each screw terminal and go up and over the chassis bridge between the caps or just drill bigger, correctly spaced holes in the corroded chunk of metal you have there now, like I did.
 
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OK boys, I just bought 4 of these, E36D101LPN223TDB7M from Mouser. Thanks for pushing me in the right direction. Can anyone tell me more about the DBT?

What size bulb should I use?

What should I be looking for when I plug the 1250 into it?
 
100 watt bulb will lower the voltage and control the current when first powered on and the caps fill up. So you see that current making the bulb bright and then it dims to near nothing since there is little current draw on a receiver just sitting there powered on after the caps fill up. If the bulb does not go dim in a few seconds, especially if it is brightly lit...a short circuit, pulling full line power...but through the bulb limiting current, saved from burning up components. I took out the 10-15 seconds of brightness cause Larry says no in the next post.

google dim bulb tester and I'm sure you will find too much info to read. Vintage tube places do a nice job of discussing these along with AK.
 
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For a 1250 get a 100W incandescent. I wouldn't go 10-15 seconds if the light bulb is staying bright. The whole premise of the DBT is as a visual indicator of a short circuit. The longer you leave it on with a bright bulb, the more damage is done. When you throw the power switch one of two things will happen.

1.) Bulb will go bright for a couple of seconds due to Main filter caps charging and if everything is good (no shorts) will dim down drastically (dim down to less than 1/2 brightness to almost out depending on the unit and it's normal current draw idling). This is GOOD!

2.) BULB will go Bright, and stay bright. This indicates a short circuit, and even tho the bulb is restricting current to the unit, every second left on hurts the unit even more. This is BAD!!! A 3-1000 count from throwing the power switch is sufficient to tell if there is a short or not. If it's bright after a 3-1000 count, TURN IT OFF NOW. Find the short, fix it, and retry.
 
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For a 1250 get a 100W incandescent. I wouldn't go 10-15 seconds if the light bulb is staying bright. The whole premise of the DBT is as a visual indicator of a short circuit. The longer you leave it on with a bright bulb, the more damage is done. When you throw the power switch one of two things will happen.

1.) Bulb will go bright for a couple of seconds due to Main filter caps charging and if everything is good (no shorts) will dim down drastically (dim down to less than 1/2 brightness to almost out depending on the unit and it's normal current draw idling). This is GOOD!

2.) BULB will go Bright, and stay bright. This indicates a short circuit, and even tho the bulb is restricting current to the unit, every second left on hurts the unit even more. This is BAD!!! A 3-1000 count from throwing the power switch is sufficient to tell if there is a short or not. If it's bright after a 3-1000 count, TURN IT OFF NOW. Find the short, fix it, and retry.
Cool man, I'll give it a go when I get the new filter caps installed.
 
Hey dudes, do I need to do anything to the Filter caps prior to installation? I'm seeing youtube videos about charging and discharging caps and it's got me wondering. I assume that the power supply of my receiver would do this upon power up, but it's bad to assume when you don't know squat. As usual any help is appreciated...
 
Nothing to do to the new caps prior to power up.

Make absolutely 100% sure you have them installed correctly. If you are unsure, post photos before powering up. Big caps make big bangs if they are installed reversed.
 
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Nothing to do to the new caps prior to power up.

Make absolutely 100% sure you have them installed correctly. If you are unsure, post photos before powering up. Big caps make big bangs if they are installed reversed.[/QUOT

Great advice. As long as the new caps have the polarity marked, I'll be good.
 
it makes a BIG BANG ;-) i remember one time a fellow tech had a ecap in backwards, applied power and BANG, his beard was full of those inards ;-) he was combing it out for a while. Double,triple check :)
 
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it makes a BIG BANG ;-) i remember one time a fellow tech had a ecap in backwards, applied power and BANG, his beard was full of those inards ;-) he was combing it out for a while. Double,triple check :)
Well, I can only hope that the positive and negative are clearly marked. Is there a simple test that I can do to double check the polarity from the manufacturer?
 
They are clearly marked that is for sure. I would not bother to test that the mfg has the polarities correct, but since you ask, I will guess that you measure leakage current at a certain reverse voltage and possibly capacitance.
 
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... a BIG BANG ;-)

That is just a THEORY

Well, I can only hope that the positive and negative are clearly marked. Is there a simple test that I can do to double check the polarity from the manufacturer?

Go to the site you bought your caps from and look em up. Click the link to the datasheet and see that the manufacturer has more than adequately marked the caps for + and - terminals. We are most concerned about you actually installing them exactly like the ones that were in your unit, that is where any reverse voltage will happen, not from the manufacturer marking them wrong.
 
It's not that the caps aren't marked correctly, its installing them correctly.
Most mistakes occur buy mixing up the leads to the terminals.
I use masking tape to mark the (+) (-) on the chassis in the locations where the caps terminals coincide. Mark the leads if they can get mixed up.
Mark them, is my best advice.

Below is a Spec 4 I started this week:
I always mark it up, no matter how many I've done.

DSC04664.JPG
 
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A fairly/medium bright DBT is a result of improperly installed Filter caps.
 
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It's not that the caps aren't marked correctly, its installing them correctly.
Most mistakes occur buy mixing up the leads to the terminals.
I use masking tape to mark the (+) (-) on the chassis in the locations where the caps terminals coincide. Mark the leads if they can get mixed up.
Mark them, is my best advice.

Below is a Spec 4 I started this week:
I always mark it up, no matter how many I've done.

View attachment 1146418
Here's what the Pioneer looks like. It'll be hard to mess it up...
 

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Taking an image is a great way to document the work.
The black paint over the negative terminals attaching rivet identifies the (-) terminals.
The new caps will have a (+)(-) engraved in the base near the terminals.
 
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Sad to say that after all of this the damn thing don't work. I'll put the old caps back in tomorrow and see if they still work. I only replaced them due to leakage on two of them.
When I plug in the unit, with new Fc's, bulb shines bright and no lights or sound from the amp.
Woe is me!
 
First double check your cap replacement making sure there are no wires pinched and all harness leads are isolated and routed correctly.
Disconnect the +- DC feeds from the rectifier on the main filter caps, leaving the negative buss connected on the big filter caps. Make sure they are isolated from any grounds. Power up on the DBT. This removes the outputs unregulated supply. If the bulb dims, an output(s) is shorted. If bight. Something in the set is shorted. Maybe a PS or one of the boards has a short.
 
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