Chorus II JEM Capacitor Kit Installation

[billybob]

Am certain Dean has had alot of bo rds like that under his belt buckle. Can just try and get creative like he told me about a Mills resistor on a Chorus pcb.

Interesting though...

[OO1]

2 hours ago, Dave MacKay said:

The PCB is so crowded with the new components that it sure looks difficult.

 

Just wondering if it might make sense to make new, larger PCBs. They can be drawn up with free tools like KiCAD and made quickly and cheaply by companies like PCBway. That might make the job a whole lot easier without incurring much additional cost.

 

you can , but then you have to  remove all the parts and  rewire extensions since you're working on a larger surface   , and re-solder  . 

 

this  PCB is not so crowded ,  Dean created space by placing 2 caps upright with  wire    , and the PCB  is re-used  .

 

 

[chuckears]

1 hour ago, OO1 said:

you can , but then you have to  remove all the parts and  rewire extensions since you're working on a larger surface   , and re-solder  . 

 

this  PCB is not so crowded ,  Dean created space by placing 2 caps upright with  wire    , and the PCB  is re-used  .

 

 

Actually, the original two caps to which you refer were upright - being radial as opposed to the axial-type that seem to be more ubiquitous currently.  The biggest challenge with this replacement kit - once you get past removal of the board, and assuming some skill with soldering - was that those two replacement caps have to be altered from their horizontal placement to vertical, and soldering on an extra length of wire to run the lead from the now-top end of the cap down through its hole in the PCB, and getting the caps to sit upright.

[OO1]

12 minutes ago, chuckears said:

 run the lead from the now-top end of the cap down through its hole in the PCB, and getting the caps to sit upright.

definitely 

 

[chuckears]

On 1/3/2023 at 5:12 AM, Deang said:

Vertical mounting is a bit of a double edged sword. If you squirt the hot melt under the cap and press down - when you solder, the glue melts and gets pulled through the hole. If you leave the cap somewhat lifted off the board, then it's not as secure - but the soldering looks better. After you solder, go back and squirt the hot melt under the cap. I started by gluing the electrolytic to the low pass coil to stabilize it while I soldered. 

 

Gorilla glue hot melt is the best I've ever used. I also use the small version of the gun and sticks for better control. I normally hit areas where parts are up against each other for reasons I can't remember.

 

 

 

Dean, how critical was it to remove that 20ohm resistor by the two vertical caps?  Was it just for the convenience of a little more space to work in, or do you need to free up the space to physically put the new caps in place?

[tigerwoodKhorns]

On 1/3/2023 at 11:08 AM, Dave MacKay said:

The PCB is so crowded with the new components that it sure looks difficult.

 

Just wondering if it might make sense to make new, larger PCBs. They can be drawn up with free tools like KiCAD and made quickly and cheaply by companies like PCBway. That might make the job a whole lot easier without incurring much additional cost.

 

Take a close look at the board, if it is any bigger it will not fit through the opening in the speaker.  Plus now you have to unsolder and resolder the inductors, transformer and all of the wires, most of which are covered in hot melt.  Sounds like a lot of work even if the board could be made bigger.

 

 

[Deang]

3 hours ago, chuckears said:

 

Dean, how critical was it to remove that 20ohm resistor by the two vertical caps?  Was it just for the convenience of a little more space to work in, or do you need to free up the space to physically put the new caps in place?

It doesn’t need to be removed. 

[001]

@Deang great job on the recap of these chorus 2s.  i am curious though about the electrolytic, why did you use a axial cap instead of the factory radial type?  a radial would obviously drop right into place as the original & not require adding a length of wire.  or is that what is provided with these mylar replacement kits?  & if so, same question, why not use the same type or radial as original?  

 

 

[chuckears]

1 hour ago, 001 said:

@Deang great job on the recap of these chorus 2s.  i am curious though about the electrolytic, why did you use a axial cap instead of the factory radial type?  a radial would obviously drop right into place as the original & not require adding a length of wire.  or is that what is provided with these mylar replacement kits?  & if so, same question, why not use the same type or radial as original?  

 

 

This is what JEM - the Klipsch-authorized replacement cap company - is providing in the replacement kits.  I don’t know if it’s because the same-spec radial is no longer available, but that would be my guess.

[henry4841]

1 hour ago, chuckears said:

This is what JEM - the Klipsch-authorized replacement cap company - is providing in the replacement kits.  I don’t know if it’s because the same-spec radial is no longer available, but that would be my guess.

Possible you take what you can find these days. Terrible electronic part shortages for the last couple of years. 

[Deang]

7 hours ago, henry4841 said:

Possible you take what you can find these days. Terrible electronic part shortages for the last couple of years. 

I couldn’t find radial bipolars in all of the needed values when I started doing this almost 20 years ago - unless I was willing to meet the insane MOQ’s for electrolytics and special order them. 
 

Using a polyester in place of the electrolytic for the midrange was Roy’s suggestion. I can only hope he knows what he’s doing.  ¯\_(ツ)_/¯ 

[Travis In Austin]

Locked per OP’s request