Would you REMOVE GOOD working filter caps on 1950s Fenders?

[jelle]

Replace them all!!!! Save them in a bag in case some corksniffer wants to buy it later.

+1!

Also, how would you test the old caps? For their ability to filter out (shunt) ripple in circuit, as seen with a scope? Because that is the only real test out there....

[Toppscore]

Replace them all!!!! Save them in a bag in case some corksniffer wants to buy it later.

All done. The six were surgically removed
and replaced with six Sprague Atom filter caps.

You should have seen the big freakin' grin on my face
when we turned on the 1954 Bassman.
I have NEVER heard my amp sound as good in so many ways.
Tone, Volume, Clean, Cranked with Presence, Loudness,
Four 10" 1950s Jensen P10Rs in fine tune.

So, it is what it is ~ all original six filter caps.
The next buyer will get a bag full of ORIGINAL 1954 Filter Caps.
Most are still good.

ANYBODY WANT TO BUY some Original 1954 Filter Caps
Got a good deal
Toppscore





.

[Toppscore]

If this was your main amp, it's gonna sound constipated at first, and so much punchier and dynamic that it might throw you as you were likely very comfortable with old softer sound and feel. Let the caps break in, the constipated will pass and you'll forget about the old soft sound and groove on the new liveliness.

DANG! You mean the Honeymoon will END!!!
That sucks!

I LIKE IT RIGHT NOW!

[rp]

Also, how would you test the old caps? For their ability to filter out (shunt) ripple in circuit, as seen with a scope? Because that is the only real test out there....

Or by swapping them out and hearing the amp come alive Though not quantifiable it's validly qualifiable.

DANG! You mean the Honeymoon will END!!! That sucks! I LIKE IT RIGHT NOW!

Then your tech loves you. Some people freak when their amp suddenly springs to life. Pay attention, just in the first 1 hr, then over the next few hrs you will hear it loosing up, like a girl after a few glasses of wine, without giving up any of the qualities you just heard. As it loosens up it'll get bigger, more 3D, and warmer. Takes a few weeks but 90% is in the first few days. Have fun, it's been years since I had something old and nice to play around with, it's all too much $$$ these days.

edit: btw don't forget all the 25/25 bypass caps after 60 years they are shot too even if they look good and test ok. Those won't just wake your amp up but make it dance around the room.

[Toppscore]

Also, how would you test the old caps? For their ability to filter out (shunt) ripple in circuit, as seen with a scope? Because that is the only real test out there....

Or by swapping them out and hearing the amp come alive Though not quantifiable it's validly qualifiable.

DANG! You mean the Honeymoon will END!!! That sucks! I LIKE IT RIGHT NOW!

Then your tech loves you. Some people freak when their amp suddenly springs to life. Pay attention, just in the first 1 hr, then over the next few hrs you will hear it loosing up, like a girl after a few glasses of wine, without giving up any of the qualities you just heard. As it loosens up it'll get bigger, more 3D, and warmer. Takes a few weeks but 90% is in the first few days. Have fun, it's been years since I had something old and nice to play around with, it's all too much $$$ these days.

edit: btw don't forget all the 25/25 bypass caps after 60 years they are shot too even if they look good and test ok. Those won't just wake your amp up but make it dance around the room.

Not sure about 25/25 bypass caps.
Two years ago during my first visit to the doctor with the 5D6 Bassman,
the Amp Lab tech noted that during the past:
one uf phase inverter, two coupling caps,
and one cathode cap had been changed before.
The original 1954 Astron Filter caps were all there.
It had two 5A4R Groove Tube rectifiers which I later changed to NOS 1954 GE-5Y3GT tubes.

Not bad for a 58 year old Bassman, right?


My tech checks out everything, so I am sure the bypass caps are right.




.

[FUCHSAUDIO]

I deal with the manufacturers of the actual parts all the time.

I spoke recently with Nichicon, who was kind enough to help me decipher the date code on an old Mesa amp. The tech support guy said "we assume 10-15 years of service in a perfect world for those caps". Most component manufacturers agree with that, as do I. Mesa actually argued with me and told me "it wasn't necessary to recap a MK-II". The caps "last for years". They also don't like bias pots...lol.

Sorry, but a guitar amp is hardly a perfect environment: With amps left in cold trunks, then they heat up to very hi temps (without fans anyway), and the audible differences with new caps can be stunning. Sloppy bass leaves and punchiness appears....hum is reduced, and when we recap an old Fender, we do bias caps, filter caps, cathode caps, and clean all sockets top and bottom, as well as treating the sockets and pots with cleaner and preservative....we leave audio caps alone unless they are realyl leaky. Most don't leak, other than known trouble caps like red Astron's in Ampeg's. Honestly the blue tubulars rarely fail. Too many tech replace all those with orange drops and ignore bias and/or cathode caps.

The collector types who want 2-prong cords and original parts need a serious beating....we had a brownface Fender amp with a non working pitch bender tremolo....the caps in the oscillator got leaky. The guy "hoped we could only change the bad ones"....no...sorry dude....

[Toppscore]

I deal with the manufacturers of the actual parts all the time.

I spoke recently with Nichicon, who was kind enough to help me decipher the date code on an old Mesa amp. The tech support guy said "we assume 10-15 years of service in a perfect world for those caps". Most component manufacturers agree with that, as do I. Mesa actually argued with me and told me "it wasn't necessary to recap a MK-II". The caps "last for years". They also don't like bias pots...lol.

Sorry, but a guitar amp is hardly a perfect environment: With amps left in cold trunks, then they heat up to very hi temps (without fans anyway), and the audible differences with new caps can be stunning. Sloppy bass leaves and punchiness appears....hum is reduced, and when we recap an old Fender, we do bias caps, filter caps, cathode caps, and clean all sockets top and bottom, as well as treating the sockets and pots with cleaner and preservative....we leave audio caps alone unless they are realyl leaky. Most don't leak, other than known trouble caps like red Astron's in Ampeg's. Honestly the blue tubulars rarely fail. Too many tech replace all those with orange drops and ignore bias and/or cathode caps.

The collector types who want 2-prong cords and original parts need a serious beating....we had a brownface Fender amp with a non working pitch bender tremolo....the caps in the oscillator got leaky. The guy "hoped we could only change the bad ones"..no..sorry dude..

What is US Patent # 7336165 ?
And why are you "proud" of it?
Anything I should invest in

Thanks for your post. Much appreciated.
I've been told for two years to watch out for amp repair techs who REMOVE EVERYTHING!!!
I have been told to tell the techs to only remove what is necessary and keep all that's working.

That's why I questioned my amp repair tech when we found
two 60 year old filter caps not working and that he chose to replace
all six original Astrons (including four good Astrons) with six new
Sprague Atoms. He told me it was all six or nothing ~ as he could not
do a "half-job". That the other four were ready to fail after sixty years of usage.

Well, the results are incredible. I like to compare to an older 1954 Cadillac car.
Gotta replace the spark plugs, get new tires, new seat covers,
new paint, change the oil, etc etc etc.

WHY ARE FANS of VINTAGE AMPS afraid to change older
caps/resistors, speaker cones, potentiometers ,etc?


Toppscore

[badtweed]

I deal with the manufacturers of the actual parts all the time.

I spoke recently with Nichicon, who was kind enough to help me decipher the date code on an old Mesa amp. The tech support guy said "we assume 10-15 years of service in a perfect world for those caps". Most component manufacturers agree with that, as do I. Mesa actually argued with me and told me "it wasn't necessary to recap a MK-II". The caps "last for years". They also don't like bias pots...lol.

Sorry, but a guitar amp is hardly a perfect environment: With amps left in cold trunks, then they heat up to very hi temps (without fans anyway), and the audible differences with new caps can be stunning. Sloppy bass leaves and punchiness appears....hum is reduced, and when we recap an old Fender, we do bias caps, filter caps, cathode caps, and clean all sockets top and bottom, as well as treating the sockets and pots with cleaner and preservative....we leave audio caps alone unless they are realyl leaky. Most don't leak, other than known trouble caps like red Astron's in Ampeg's. Honestly the blue tubulars rarely fail. Too many tech replace all those with orange drops and ignore bias and/or cathode caps.

The collector types who want 2-prong cords and original parts need a serious beating....we had a brownface Fender amp with a non working pitch bender tremolo....the caps in the oscillator got leaky. The guy "hoped we could only change the bad ones"....no...sorry dude....

Those collector types are not going to change their routine.
That is the nature of collectors to want original components.

Also, no Fender tremolo "pitch bends" but you knew that. right?

[Cygnus X1]

There is also the option of gutting the old filter cap canisters and stuffing the inside with new caps to retain the original appearance.
New filter caps are superior in performance and are small enough to fit easily inside.
Sprague Atoms are small caps placed inside large containers.

This is a Tweed Champ I recapped:

[img683]http://i932.photobucket.com/albums/ad16 ... ure103.jpg[/img]

[cbass]

[Cygnus X1]

Whut?
Did I doo sumpin' rong?

[cbass]

No your amp is sweet I've been wanting to try stuffing caps.I just posted some thing that may be misinformed so I deleted it.

[Toppscore]

Cygnus! Nice amp.
Is that one of the reissue tweed Champs
with PCBoards and "Made in China"?
or a real 1950's tweed Fender?

[Cygnus X1]

Cygnus! Nice amp.
Is that one of the reissue tweed Champs
with PCBoards and "Made in China"?
or a real 1950's tweed Fender?

Real deal.
I believe it was a 1960,IIRC.
I did it for someone else.

cbass...gotcha.
It's cool.
And thanks.

[Phil_S]

LOL, the topic of this tread begs the question. What is old, and what is good? If a filter cap is well past its expected service life, it is no longer considered good and should be replaced [1]. If it is a bank a caps, like under the dog house, I think you'd want to do all or none. Mixing old caps with new caps seems like a bad idea, sorta like changing 3 tires and leaving the 4th because it still has good tread.

[1] I suppose if you live in a developing nation where you can't get parts for love or money the you do what you have to do, but not in a modern country where supplies are plentiful and prices reasonable.