Gibson Skylark ga-5t white panel tube question!

[Mrdunkirk]

I recently tried to use a Jan 6x4wa for a rectifier tube replacement.It didn't work(brand new)
Any help out there???

Thanks
Barry

[sgelectric]

Barry , Welcome to the forum.

It's often helpful when posting a question to provide a link to the schematic for your amp.

Here is one for the GA-5t

http://www.webphix.com/schematic%20h...kylarkga5t.pdf

Was your amp working in the recent past?
Do the other tubes in your amp glow when powered up?

What is your skill level in regards to working on vacuum tube amplifiers?

Your problem may be as simple as a defective tube but don't necessarily assume so.

There are many skilled technicians on this site that will help you sort out your problem.

Regards, SG

[Mrdunkirk]

Hi,
Thank you for responding.
I probably don't belong in this forum at all.I'm interested in playing way more than any of the technical aspects
of tube amps.
I have a small collection of old amps that I've had for years and just love the sound of them.
I was told that i could use a 6x4 tube for a rectifier tube and I see sets for sale on line that use them.

The amps works with the old tube thats in it but when i switch it out with either of the brand new jan 6x4wa's that I just got it doesn't work.
I'm assuming that it's not compatible?
I just spent 30 bucks on tubes and shipping and thought I could get an answer here.

Thanks guys.

[Resonator Guy]

Is the old tube you removed a 6X4.? I have a white panel GA-5T that doesn't have a tube rectifier. Gibson amps were subject to change. Mine bears no resemblance to that posted by sgelectric, but his is quite valid.
A 6X4 really can't be substituted for anything but a 6X4.

[Mrdunkirk]

the one thats in there is a 6c4.It's a little tough to see,but I think thats what it says.

[Resonator Guy]

The 6C4 is a preamp tube, not a rectifier. I will bet yours has two EL84s (6BQ5) as power tubes and no tube rectifier.
See if you can post a pic of the amp with the back off.

[Mrdunkirk]

Yes! it has 2 el84's.
I'm not sure if that 6c4 is the right tube in there either. I may have stuck it in there in my younger,more broke days living in the city and it worked so i just went with it as a practice amp.
I'll post a pic of it when I get a chance tonight or tomorrow.
Thank You Mr. Resonator Guy for your response.

[Resonator Guy]

Your amp should look like this, I believe. The tubes are, from your right to left, 6EU7, 6C4, 2xEL84.
None of those have any substitutes that can be used.
I hope that helps.

[Mrdunkirk]

exactly! except for the fender replacement speaker ....Thank you you put on the right track.That 6C4 that i have has seen better days!
i love the sound of this amp...Thank you so much.This was really helpful.

Barry