replacing caps question

T

tempus fugit

Guest
Hey all;

I'm working on repairing a vintage (ca. 1970s) keyboard, and I'm wondering -
should I replace all the electrolytic caps while I'm in there (and putting
in a parts order)? There aren't a ton of them or anything, and I was kind of
thinking if they haven't failed already they are due to soon. Also, does the
same thing go for the tantalums?

Thanks
 
If it ain't broke, don't fix it. Wholesale change-out of parts can
introduce new problems if everything doesn't go right.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
-----------------------


"tempus fugit" <toccata@no.spam.ciaccess.com> wrote in message
news:RTi6c.100389$AK5.46942@nntp-post.primus.ca...
Hey all;

I'm working on repairing a vintage (ca. 1970s) keyboard, and I'm
wondering -
should I replace all the electrolytic caps while I'm in there (and putting
in a parts order)? There aren't a ton of them or anything, and I was kind
of
thinking if they haven't failed already they are due to soon. Also, does
the
same thing go for the tantalums?

Thanks
Click to expand...
 
I work on old keyboards on occasion. You may want to get those
tantalum caps out of there. I find they have a tendency to short out,
and get put in the wrong way since they are so little. You can save a
few elephants and replace them with electrolytics. As for the
electrolytics in any audio circuitry - you prbably DO want to replace
them. Caps are generally rated for like 3-5000 hours. An 20 year old
synth probably has seen a lot more use than that, and sample/hold caps
for example might degrade the sound of the synth - like
unintentionally rolling off low end. I would probably also do the caps
in the PS as well while you are at it - you'll lower the noise floor -
and new caps are made way better than the 20 year old ones. As long as
you make sure to pay real close attention to polarity you should not
run into any additional problems. Best of luck - Tim



"tempus fugit" <toccata@no.spam.ciaccess.com> wrote in message news:<RTi6c.100389$AK5.46942@nntp-post.primus.ca>...
Hey all;

I'm working on repairing a vintage (ca. 1970s) keyboard, and I'm wondering -
should I replace all the electrolytic caps while I'm in there (and putting
in a parts order)? There aren't a ton of them or anything, and I was kind of
thinking if they haven't failed already they are due to soon. Also, does the
same thing go for the tantalums?

Thanks
Click to expand...
 
On Thu, 18 Mar 2004 10:14:52 -0500 "tempus fugit"
<toccata@no.spam.ciaccess.com> wrote:

I'm working on repairing a vintage (ca. 1970s) keyboard, and I'm wondering -
should I replace all the electrolytic caps while I'm in there (and putting
in a parts order)? There aren't a ton of them or anything, and I was kind of
thinking if they haven't failed already they are due to soon. Also, does the
same thing go for the tantalums?
Click to expand...
I wouldn't replace anything unless it's bad. There are 2 kinds of Ta
caps: the teardrop ones and the cylindrical ones. The latter will last
FOREVER, but the former kind have both good and poor versions. I think
that in general they all work pretty well if the circuit is well
designed, but cheap teardrop Ta caps in some circuits can be almost as
bad as Al electrolytics.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
 
Thanks Jim - that's interesting to know about the cylindrical tants. They
are all cylindrical, so I guess I'll leave them be.

"Jim Adney" <jadney@vwtype3.org> wrote in message
news:7ipk50129q3brt1po825d7k9suhpq4j4ui@4ax.com...
On Thu, 18 Mar 2004 10:14:52 -0500 "tempus fugit"
toccata@no.spam.ciaccess.com> wrote:

I'm working on repairing a vintage (ca. 1970s) keyboard, and I'm
wondering -
should I replace all the electrolytic caps while I'm in there (and
putting
in a parts order)? There aren't a ton of them or anything, and I was kind
of
thinking if they haven't failed already they are due to soon. Also, does
the
same thing go for the tantalums?

I wouldn't replace anything unless it's bad. There are 2 kinds of Ta
caps: the teardrop ones and the cylindrical ones. The latter will last
FOREVER, but the former kind have both good and poor versions. I think
that in general they all work pretty well if the circuit is well
designed, but cheap teardrop Ta caps in some circuits can be almost as
bad as Al electrolytics.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
Click to expand...
 
What kind of keyboard is this? I am still not sold on the don't fix it
unless its broke line of thought for this particular application - if
this were the case, why do people spend a fortune and hours and hours
recaping old recording consoles? They do this to renew the sound -
even though the channels were working. You still might want to
consider giving this thing some love, especially if there are
electrolytics involved. - Tim


"tempus fugit" <toccata@no.spam.ciaccess.com> wrote in message news:<7Xu6c.102889$W65.96808@nntp-post.primus.ca>...
Thanks Jim - that's interesting to know about the cylindrical tants. They
are all cylindrical, so I guess I'll leave them be.

"Jim Adney" <jadney@vwtype3.org> wrote in message
news:7ipk50129q3brt1po825d7k9suhpq4j4ui@4ax.com...
On Thu, 18 Mar 2004 10:14:52 -0500 "tempus fugit"
toccata@no.spam.ciaccess.com> wrote:

I'm working on repairing a vintage (ca. 1970s) keyboard, and I'm
wondering -
should I replace all the electrolytic caps while I'm in there (and
putting
in a parts order)? There aren't a ton of them or anything, and I was kind
of
thinking if they haven't failed already they are due to soon. Also, does
the
same thing go for the tantalums?

I wouldn't replace anything unless it's bad. There are 2 kinds of Ta
caps: the teardrop ones and the cylindrical ones. The latter will last
FOREVER, but the former kind have both good and poor versions. I think
that in general they all work pretty well if the circuit is well
designed, but cheap teardrop Ta caps in some circuits can be almost as
bad as Al electrolytics.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
Click to expand...
 
Tim Marcus wrote:
What kind of keyboard is this? I am still not sold on the don't fix it
unless its broke line of thought for this particular application - if
this were the case, why do people spend a fortune and hours and hours
recaping old recording consoles? They do this to renew the sound -
even though the channels were working. You still might want to
consider giving this thing some love, especially if there are
electrolytics involved. - Tim
Click to expand...
When it comes to old caps affecting the sound it is in effect "broke".

-Bill M
 
On Thu, 18 Mar 2004 23:55:31 -0500 "tempus fugit"
<toccata@no.spam.ciaccess.com> wrote:

Thanks Jim - that's interesting to know about the cylindrical tants. They
are all cylindrical, so I guess I'll leave them be.
Click to expand...
Of those in the metal cans with the glass seals, I've never seen one
which has gone bad, and I have a lot of HP test gear that's 25 years
old with those in them. I also use them to replace Al electrolytics
when possible (I buy them at swap meets) and I've never had one of my
replacements go bad, either.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
 
Thanks Tim;
It's an old Moog keyboard - so it's dfinitely worth taking care of. I was
thinking more in terms of putting in only 1 order, rather than ordering some
stuff, finding that some caps needed replacing later, etc. I don't think
there are that many electros in the signal chain, but you bring up a good
point about old consoles.

THanks


"Tim Marcus" <timfromsirius@hotmail.com> wrote in message
news:a3a12184.0403192345.6584214e@posting.google.com...
What kind of keyboard is this? I am still not sold on the don't fix it
unless its broke line of thought for this particular application - if
this were the case, why do people spend a fortune and hours and hours
recaping old recording consoles? They do this to renew the sound -
even though the channels were working. You still might want to
consider giving this thing some love, especially if there are
electrolytics involved. - Tim


"tempus fugit" <toccata@no.spam.ciaccess.com> wrote in message
news:<7Xu6c.102889$W65.96808@nntp-post.primus.ca>...
Thanks Jim - that's interesting to know about the cylindrical tants.
They
are all cylindrical, so I guess I'll leave them be.

"Jim Adney" <jadney@vwtype3.org> wrote in message
news:7ipk50129q3brt1po825d7k9suhpq4j4ui@4ax.com...
On Thu, 18 Mar 2004 10:14:52 -0500 "tempus fugit"
toccata@no.spam.ciaccess.com> wrote:

I'm working on repairing a vintage (ca. 1970s) keyboard, and I'm
wondering -
should I replace all the electrolytic caps while I'm in there (and
putting
in a parts order)? There aren't a ton of them or anything, and I was
kind
of
thinking if they haven't failed already they are due to soon. Also,
does
the
same thing go for the tantalums?

I wouldn't replace anything unless it's bad. There are 2 kinds of Ta
caps: the teardrop ones and the cylindrical ones. The latter will last
FOREVER, but the former kind have both good and poor versions. I think
that in general they all work pretty well if the circuit is well
designed, but cheap teardrop Ta caps in some circuits can be almost as
bad as Al electrolytics.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
Click to expand...
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top