Melting Jupiters

for the DIY ST35, the Dynakit and every other PP EL84

Melting Jupiters

Postby spamer » Tue Jan 25, 2011 5:31 pm

Hi,

I have been enjoying my Stereo 35 for over 4 years now and the other day it
started to make a squealing sound so I had to shut it down.

After letting it sit for awhile, I opened it up and noticed that my Jupiter coupling caps have been melting.

Here is a picture that I took:

http://www.flickr.com/photos/31146530@N06/sets/72157625906536096/with/5388838620/


As a result I have a couple of questions and I understand these are asking for opinions so I am not trying to start any back-and-forth.

Could this be the source of the squealing or is something else going on?
Any opinions on replacements? If I remember correctly, I spent about $20 dollars each for those caps so I dont want to waste another $80 USD and honestly I had more money to spend at that time.
I have 4 unused Astron's and 4 unused West-Cap's that were given to me. Are they worth trying? I also have some K42Y2 PIO's that I purchased online. I dont want to do alot of swapping around for fear of screwing up my PCB.

Has anyone else experienced this? Did Jupiter provide any relief?

Thanks

Steve
spamer
 
Posts: 20
Joined: Wed Sep 30, 2009 6:39 pm
Location: Boston, MA

Postby TomMcNally » Tue Jan 25, 2011 8:59 pm

Steve -

I would say, yeah, those melted caps are probably the source of
the noise. You can always snip the existing cap leads about
3/8" from the board, and connect the replacements to the
tails. Put little loops on the ends of the news ones and
you can make a nice job. Back in the day, Sprague
capacitors had little spring looking things which were wire
coated with solder, and you stuck the ends of the new
and old in and hit it with a soldering iron and it made a
neat connection. They were called "squigs" I think.

Personally, I don't think anyone can really hear the
difference between a plain old Orange Drop cap and the
expensive ones. I've used some Auricaps and Musicaps
in Single Ended amps, because they were only about $ 8
and I only needed two.

... tom
User avatar
TomMcNally
Darling du Jour
 
Posts: 2729
Joined: Sat Nov 19, 2005 2:19 pm
Location: Northfield, NJ

Postby EWBrown » Tue Jan 25, 2011 10:48 pm

The old-fashioned beeswax and paper caps are very sensitive to excess temperature, even holding one in hand for a while will start to melt the outsie wax. These are reportedly good sounding, but unless measures are made to keep them as cool as possible, they also do not last for very long in a tube amp.

/ed
Real Radios Glow in the Dark
User avatar
EWBrown
Insulator & Iron Magnate
 
Posts: 6389
Joined: Wed Mar 19, 2003 6:03 am
Location: Now located in Clay County, NC !


Return to stereo 35

Who is online

Users browsing this forum: No registered users and 18 guests