Sonic Frontiers SFS-40 capacitors

[zaphod42]

I am working on a Sonic Frontiers SFS-40 and need to replace the main capacitors.
Someone had the bright idea of putting a jumper wire across the negative terminals, they connect in series (+ to -)
Of course, they are damaged...

The only marking on the cap is a part number (of sorts) 658-9324-321
The value is on the board as 1700uf 300V
It has pos neg and dummy pins.
There are no clamps on the cover, held only by the board.
The board has traces on both sides.
Approx. 45mm wide x 85mm high (can be taller or shorter)

I am unable to find a replacement with the same configuration...
Most have the pos/neg terminals across the center.

Has anyone replaced these before?
Any suggestions on what could be used? Modified?

Thanks in advance...

 

[Dswankey]

Having had a SF, I can tell you there customer service was outstanding!!! my understanding that a lot of SF folks are now working for Paradigm

If it were me contact them directly, they respond quickly and should be able to assist you.

High Performance Audio - Crafted in Canada

Canadian manufacturer of premium high-performance loudspeakers for music and home theater, Crafted in Canada.

www.paradigm.com

 

[gadget73]

so someone basically jumped across one of the caps so the 300v part was being forced to operate in a circuit expecting 600v worth of caps? Little wonder its damaged.

maybe something like this, and cut the extra leg off?

E93E401VND182MBA0U | DigiKey Electronics

Order today, ships today. E93E401VND182MBA0U – 1.8 mF 400 V Aluminum Electrolytic Capacitors Radial, Can - Snap-In - 4 Lead 51mOhm @ 120Hz 5000 Hrs @ 105°C from Chemi-Con. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

 

[zaphod42]

so someone basically jumped across one of the caps so the 300v part was being forced to operate in a circuit expecting 600v worth of caps? Little wonder its damaged.

maybe something like this, and cut the extra leg off?

E93E401VND182MBA0U | DigiKey Electronics

Order today, ships today. E93E401VND182MBA0U – 1.8 mF 400 V Aluminum Electrolytic Capacitors Radial, Can - Snap-In - 4 Lead 51mOhm @ 120Hz 5000 Hrs @ 105°C from Chemi-Con. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

I looked at those types of caps (and others), but the pos/neg legs are across the center.
The holes on the board are offset, so it would not go through the hole in the cover.
Maybe there is some way the add something to the legs?
The issue I see with that is physically securing the cap.
Thanks

 

[zaphod42]

Having had a SF, I can tell you there customer service was outstanding!!! my understanding that a lot of SF folks are now working for Paradigm

If it were me contact them directly, they respond quickly and should be able to assist you.

High Performance Audio - Crafted in Canada

Canadian manufacturer of premium high-performance loudspeakers for music and home theater, Crafted in Canada.

www.paradigm.com

View attachment 3263597

I contacted them yesterday through their form, will see if/when they reply.
Will follow up with a call if necessary...
Thanks

 

[Chubba]

I recomend Parts Connexion Canada. That is where the original Sonic Frontiers guys are. Cheers

 

[zaphod42]

I recomend Parts Connexion Canada. That is where the original Sonic Frontiers guys are. Cheers

I did not see any listed on their site, but sent them an email anyway...
Will see what they say.
Thanks

 

[gadget73]

I looked at those types of caps (and others), but the pos/neg legs are across the center.
The holes on the board are offset, so it would not go through the hole in the cover.
Maybe there is some way the add something to the legs?
The issue I see with that is physically securing the cap.
Thanks

figures that would be too easy.

I guess you could attach a clamp to the top of the chassis and just run short leads to the board but that would look pretty hacky.

 

[Lavane]

figures that would be too easy.

I guess you could attach a clamp to the top of the chassis and just run short leads to the board but that would look pretty hacky.

I guess if all else fails, you coukd put the clamp through the cap hole, securing the clamp to the chassis from the underside? It would hide the mounting tabs at leased.
Also paint the clamps whatever color you want. You could mount the clamps so the side screw that tightens the clamp to the rear so it isn't seen as easily from the front. But you would need to drill mounting holes in the chassis to mount the clamps. Whenever I have to make modifications for caps I try to make it look as clean as possible. Especially with those big dual filter caps they used in 70's SS gear since two modern individual caps would have to be made to fit.

 

[zaphod42]

I guess if all else fails, you coukd put the clamp through the cap hole, securing the clamp to the chassis from the underside? It would hide the mounting tabs at leased.
Also paint the clamps whatever color you want. You could mount the clamps so the side screw that tightens the clamp to the rear so it isn't seen as easily from the front. But you would need to drill mounting holes in the chassis to mount the clamps. Whenever I have to make modifications for caps I try to make it look as clean as possible. Especially with those big dual filter caps they used in 70's SS gear since two modern individual caps would have to be made to fit.

That is an interesting idea...
There is only about 1 inch of clearance between the main chassis and the board, would just have to be sure nothing is close enough to short or arc.
Screw terminal capacitors may give me some flexibility with that method?
Thanks

 

[Lavane]

The thickness of the clamp metal is pretty thin. And you should be able to find screws and nuts that will be short enough to clear the board.
I'm building a guitar amp kit for my son right now and there weren't any sheilds for the signal tubes or spring clamps for the power tubes included.
The PCB mounts about 3/4" below the chassis. I used some 3/8"" screws that once through the chassis and clamp mounting holes leaves plenty of space. I may go with 1/4" screws if needed when I fit the PCB.

 

[gadget73]

The other thing thats a possible but also not super kosher is to use a one of those multi-pin caps with the terminals in the wrong place and just use jumper wires. The board has holes directly across from one another for the dead pins or the plastic nubs, but neither have a trace going to them. Would still need some means of securing the caps, maybe glue, but thats also kind of a lame way of doing it.

 

[zaphod42]

The thickness of the clamp metal is pretty thin. And you should be able to find screws and nuts that will be short enough to clear the board.
I'm building a guitar amp kit for my son right now and there weren't any sheilds for the signal tubes or spring clamps for the power tubes included.
The PCB mounts about 3/4" below the chassis. I used some 3/8"" screws that once through the chassis and clamp mounting holes leaves plenty of space. I may go with 1/4" screws if needed when I fit the PCB.

I was referring to the height of the clamp, which is about 3/4" (the ones I have that would fit the cap).
Not sure if 1/8" is enough of a gap for safety from arcs/shorts.
(component leads stick up a little bit on the board)

Curious what the "Sky" and "Earth" pots do on the amp you are building...

 

[zaphod42]

The other thing thats a possible but also not super kosher is to use a one of those multi-pin caps with the terminals in the wrong place and just use jumper wires. The board has holes directly across from one another for the dead pins or the plastic nubs, but neither have a trace going to them. Would still need some means of securing the caps, maybe glue, but thats also kind of a lame way of doing it.

Yep, though about that, too.
Came to the same conclusion about the lameness of just glue.
Asking for future trouble...
Thanks

 

[Lavane]

One is for presence, I'm not sure what earth is. This chassis is made to fit 6 different amp kits. The vinyl face plate cover that came with this kit covers the earth control hole.

 

[zaphod42]

Having had a SF, I can tell you there customer service was outstanding!!! my understanding that a lot of SF folks are now working for Paradigm

If it were me contact them directly, they respond quickly and should be able to assist you.

High Performance Audio - Crafted in Canada

Canadian manufacturer of premium high-performance loudspeakers for music and home theater, Crafted in Canada.

www.paradigm.com

View attachment 3263597

I heard back from Paradigm, they recommended contacting Parts Connexion
Spoke to them this morning, waiting for a call back... fingers crossed.
Thanks

 

[Lavane]

I heard back from Paradigm, they recommended contacting Parts Connexion
Spoke to them this morning, waiting for a call back... fingers crossed.
Thanks

The folks at Partsconnexion are great to deal with. I hope they can help.
They've been the only option for me several time when it came to odd value electrolytic capacitors no one else carried.

 

[gadget73]

One is for presence, I'm not sure what earth is.

I think it was Fender that had those but it might be someone else I'm thinking of. The ones I've seen looked like a pot in the negative feedback loop to adjust the feedback level.

The earth switch might be to lift the earth ground from chassis to fix a ground loop problem. I've also seen a setup with death caps, and a DPDT switch that switches which power lead the death cap is connected to, also for some hum reduction purpose.

 

[Lavane]

I think it was Fender that had those but it might be someone else I'm thinking of. The ones I've seen looked like a pot in the negative feedback loop to adjust the feedback level.

The earth switch might be to lift the earth ground from chassis to fix a ground loop problem. I've also seen a setup with death caps, and a DPDT switch that switches which power lead the death cap is connected to, also for some hum reduction purpose.

It very well could be. The amp kits that can be used in this chassis range from Marshall, Fender, Vox, Matchless, etc. The funny thing is there is a US maker for the chassis. It costs the same as the one that comes with the amp kits if ordered along with the kits. But the US made chassis is unpainted steel and no lettering decals. Both chassis cost the same.
It doesn't cost any more for shipping if you add the finished chassis with the kit order. Most of the builders I've seen use the blank US chassis.
It made way more sense to me to order the factory chassis that comes with the face plate decal for the amp kit bought.

 

[zaphod42]

The folks at Partsconnexion are great to deal with. I hope they can help.
They've been the only option for me several time when it came to odd value electrolytic capacitors no one else carried.

Heard back from Chris at Parts Connexion:
"Sorry to say, we have no original parts ….long gone, 20 years ago (CAPACITOR TECHNOLOGY custom made them for us – 30 years ago…they were bought out, 25 years ago.)
Any 1000uf+ 300V cap will do…we find something that will fit thru hole….drill out holes for the connection pins, affix caps with a clamp or double sided tape….and then hardwire connection to the bottom of the pc board. (1700uf isn’t critical)"

So... I think I can use one leg through an original hole, drill for the other one, then run some wires to connect.
Maybe use hot glue or silicone glue to attach the caps to the board?

Hopefully, this will help someone out in the future as well...
Thanks