S64AMI power amplifier

[Eugen T]

Hi all,

I have JBL PSW-D112 amplified subwoofer. Recently 2A fuse got blown. I
couldn't find any bad parts on 2 small PCBs inside. The only thing which may
be broken is S64AMI power amplifier module. That piece is filled with epoxy,
so I cannot open it. Looks like I'll need to find replacement for this
module.

I found this message on one of HAM user forums:
The CK-72 germanium transistor made by Raytheon was a direct replacement for
this module <S64AMI>, it is however no longer made. Try using a Phillips
6CA7, it should just drop right in. But in all honesty, you would have
better luck posting in an audiophile forum.

I cannot find any references to either CK-72 or 6CA7 online.

Did anybody have experience fixing these subs or this particular amp module?
Would Philips 6CA7 really replace S64AMI? Where can I find datasheets for
above components?

Thank you very much!

viperz (at) mail (dot) com

Stupid Sympatico in Canada dropped support for sci.electronisc.repair
((((((((

 

[Mike]

Hi all,

I have JBL PSW-D112 amplified subwoofer. Recently 2A fuse got blown. I
couldn't find any bad parts on 2 small PCBs inside. The only thing which may
be broken is S64AMI power amplifier module. That piece is filled with epoxy,
so I cannot open it. Looks like I'll need to find replacement for this
module.

I found this message on one of HAM user forums:
The CK-72 germanium transistor made by Raytheon was a direct replacement for
this module <S64AMI>, it is however no longer made. Try using a Phillips
6CA7, it should just drop right in. But in all honesty, you would have
better luck posting in an audiophile forum.

I cannot find any references to either CK-72 or 6CA7 online.

Did anybody have experience fixing these subs or this particular amp module?
Would Philips 6CA7 really replace S64AMI? Where can I find datasheets for
above components?

The S64AMI is a CUSTOM Harman/JBL potted hybrid thingy which i regard
with the same reverence i hold for Sanken 1050s and root canal
procedures. Only available from manufacturers reps. Note that a very
common fault in subs that use these things is blowing up a squitty
little bipolar cap (10uf) across the speaker terminals (it is usually
found spread evenly around the entire interior of the sub).
Replacement with something decent often restores these subs to their
former crappy glory.
The 6CA7 is a (rather nice) power pentode thermionic tube AKA EL34 and
almost certainly won't help this problem.
cheers
M