Falcon GA19RVT cap job ?

[jpbiker]

Hi there,

I got a 1964 Gibson Falcon GA19RVT amp that I’d like to put back in shape.
It has been in storage for a long time and It looks all original down to the tubes in it.

Now I know it will probably be easy for you guys but for me it’s a challenge, how do I know which capacitors should I be replacing in that amp ?
If you guys give me some pointers...

I’m handy with a soldering iron but less to decipher those old schematics.

This amp have 3x6EU7 and 1x6C4 and 2x6V6GT.
I know that there is a lot of different schematics out there but I do  it’s the Falcon/Maestro M216 one...

If anybody could suggest the caps that I should change it would be great.

And if you know where I could source them it would be icing on the cake. 😁

Thanks

[shooter]

does it still play?

you looking for restoration or just working well?

You really need a good meter, a good sense for schematics, and a good understanding of basic electronics.

If that's a go
I make sure I have fuses for the amp and just go for it AFTER making sure there are no shorts between the B+ and ground, all my ohm readings check close, all the wires look intact, I've "figured out" what all "everyone else" did before me.

THEN I pull power tubes if they are FIXED bias, verify my power rail, verify bias.
powerdown, add PA tubes;
THEN I have enough basic idea of the amp to decide what's best to replace.

[tubenit]

You first need to know how to work safely on your amp. 

Read "Servicing Fender Amps" in Doug's Library of Information.  It will apply to your Gibson Falcon also.

https://el34world.com/schematics.htm#Servicing fender amps

https://el34world.com/charts/fenderservice1.htm

[tubeswell]

Basically, it's a good idea to replace all the electrolytic filter caps in an amp that age (if they haven't already been replaced recently) - see the red circles. Cheaper to replace with new electrolytics than to have to replace those vintage transformers (if you get a reservoir cap short).

Replace with caps of same or higher voltage rating and approximately the same capacitance. Observe the correct polarity.


(You could also replace all the electrolytic bypass caps if you want to be pedantic. They are the smaller electrolytic caps in parallel with the cathode resistors - not circled in the attached schematic)

[jpbiker]

does it still play?

you looking for restoration or just working well?

You really need a good meter, a good sense for schematics, and a good understanding of basic electronics.

If that's a go
I make sure I have fuses for the amp and just go for it AFTER making sure there are no shorts between the B+ and ground, all my ohm readings check close, all the wires look intact, I've "figured out" what all "everyone else" did before me.

THEN I pull power tubes if they are FIXED bias, verify my power rail, verify bias.
powerdown, add PA tubes;
THEN I have enough basic idea of the amp to decide what's best to replace.

Did my college degree in Electronics but that was a long time ago and haven't been working in the sector for quite a while but basics electronics is there.
Built a few basic tube amps but it's as easy as following a plan, never really got into troubleshooting the devices although I definitely have an interest in doing so as all my amps are tube.

When I got the amp it wasn't playing, replaced the power tubes and it now works except that when the Reverb is engaged it produces a loud hum, the reverb wires have been fixed in the past with solder, I guess I should replaced them as well to keep the shielding intact and doing it's job.
The amp has been in storage for a few decades and the I doubt the caps have been recently replaced in at least over 20 years.

So basically looking to make it safe and well working and for an amp of that age I guess recap was a must.

So you think I should check all the resistors for value as well ?

Thanks

[jpbiker]

You first need to know how to work safely on your amp. 

Read "Servicing Fender Amps" in Doug's Library of Information.  It will apply to your Gibson Falcon also.

https://el34world.com/schematics.htm#Servicing fender amps

https://el34world.com/charts/fenderservice1.htm

Allright, done this part. ;)

[jpbiker]

Basically, it's a good idea to replace all the electrolytic filter caps in an amp that age (if they haven't already been replaced recently) - see the red circles. Cheaper to replace with new electrolytics than to have to replace those vintage transformers (if you get a reservoir cap short).

Replace with caps of same or higher voltage rating and approximately the same capacitance. Observe the correct polarity.


(You could also replace all the electrolytic bypass caps if you want to be pedantic. They are the smaller electrolytic caps in parallel with the cathode resistors - not circled in the attached schematic)

Thanks a lot, appreciated.

Should I replace all the electrolytic caps in the amp ?

Thanks

[shooter]

replacing caps is "typical" after ~10yrs
restoration is another issue, I've done a handful of GA5T, some Kalamazoo's,  some want it fixed, others wanted "original".
the big brown cap, I've even gutted out, put small modern in to keep "the look"

nice find btw
 

[jpbiker]

replacing caps is "typical" after ~10yrs
restoration is another issue, I've done a handful of GA5T, some Kalamazoo's,  some want it fixed, others wanted "original".
the big brown cap, I've even gutted out, put small modern in to keep "the look"

nice find btw
 

I don't mind it not being original although if I can find parts that looks like the originals it would be great.

From the infos I have collected it might never had been recapped at all...

Will start by a recap and fix all the little issues and see how it goes.

Do you know of a good place to source those big caps ?

Thanks

Here's the beast, it showing it's age a bit but I do believe it's great little amp in it's own right...

[mresistor]

The brown paper wrapped electrolytic capacitor on the right in your photo is a cap can.  There are replacements out there but some might not fit that original mounting clamp..  what are the values on it ?

[shooter]

I've used something like this for the old brown one's.  I think yours is a 3 cap though, this is a 2 cap

https://www.tubesandmore.com/products/capacitor-ft-450v-3333-f-electrolytic

[sluckey]

I would use this for the brown 2x10µF...

     https://www.tubesandmore.com/products/capacitor-ce-mfg-tubular-450v-1010-f

and this for the black 2x20µF (use the 2x32)...

     https://www.tubesandmore.com/products/capacitor-ft-multi-section-electrolytic