1959 GA-20T

[Thndr]

It sounds sweet, nice and bluesy.. I am very impressed with the tone, I can not get the same tone from either of my crates or my mustang III. It is a sound all of its own.

I put a reverb in front of it and it has a sound like Samual Jackson in "Black Snake Moan" dark and bluesy. Then I put a slight distortion on it wow.. very nice. I have a Strat I rebuilt with over wound singles.. my my.. it makes it come alive.


I will post pictures of before and after when I get a chance. I'm a bit backed up on my honey do's at the moment.

Thanks for all the help.

T

[soundmasterg]

It sounds sweet, nice and bluesy.. I am very impressed with the tone, I can not get the same tone from either of my crates or my mustang III. It is a sound all of its own.

I put a reverb in front of it and it has a sound like Samual Jackson in "Black Snake Moan" dark and bluesy. Then I put a slight distortion on it wow.. very nice. I have a Strat I rebuilt with over wound singles.. my my.. it makes it come alive.


I will post pictures of before and after when I get a chance. I'm a bit backed up on my honey do's at the moment.

Thanks for all the help.

T

There is a reason why Crates and Mustang III's are not mentioned as some of the great amps of all time. Most tube amps sound pretty good, and certainly better than 90% of solid state amps, to my ears at least. The vintage Gibsons aren't generally as versatile as the vintage Fenders, but then they are cheaper since they aren't as sought after. They sound plenty good too as you are finding out!

Cheers!

Greg

[Thndr]

As promised... Photos

Ok I cleared my work table this morning and took some photos. Please remember this is my first, so be honest but kind..lol

Before:

If you really look, there are two electrolytic caps reversed, the previous owner, a good friend didn't understand polarity which is part of the reason he smoked the 5Y3. Count the caps.. there is an extra. Why? Not sure.

After:

Cleaned up all the sockets the best I could, there was a bunch of cap guts stuff on them. Replaced the Caps and that pesky resistor, ensured the solder joints were appropriate and fresh set of tubes (yes I kept the old ones .


I've seen cleaner wiring.. I installed an input plug for tremolo foot switch. On the back side of the board, all the bumble bee's have been retired with fresh Caps, one of the bumble bee's legs had detached and didn't want to take a chance. I saved them all in a little baggy.




The control printing is worn off, I'll have to do something about that in time. I kept the original 4 chicken heads in a bag and replaced them with new.

She's a bit beat to heck on the outside, I am told this amp has seen lots of gigs.

I really enjoyed this re-build, yes it was a frustrating at times, yes I was over my head but was up to the challenge with the help of all that replied. Thank you.

OH the TONE this amp has...

Bill

[soundmasterg]

It looks great Bill. Those Gibson amps didn't have the neatest wiring from the factory. The important thing is that it works now. I would bet you that most if not all of the original caps leak DC. You can test it if you want. Temp solder one end of the cap to a spot in the circuit where some high voltage is. Hang the other end free floating in the air, and put the clip lead from your meter on it and the other lead of your meter to ground. Set your meter on DC voltage then turn the amp on and see what you see. The meter will spike up at a higher value and then come to rest after 20-30 seconds or so on whatever its leakage value is. A perfect cap would only pass AC voltage and block all DC voltage, but even modern caps will usually leak a very small amount. Anything leakage over about .3v is probably bad .

Greg

[Bruce / Mission Amps]

Without re-reading all the text... did your replace the caps on the underside of the circuit board?
Many "techs" won't 'cause it's a pain in the ass... but you should if you did not.

[Thndr]

Bruce:

Yes I replaced all the underside caps, that was the first change made and yes it was a pain. I kept them, I was wanting to keep it as close to spec as possible, and one of the leads was found discounted from the bumble bee body during initial examination. I replaced everything that looked or tested suspect.

Greg:

Thanks, I moved 80% of the wires to the underside in an attempt to tiddy it up. I'll check the bumble bees in the coming weeks. I'm finding the tremolo weak to my ear, but it could be just me. All in all I am very satisfied. Played on it for a couple hours yesterday.. It was a blast.

Thinking about building a weber reverb (6v6, 12at7 etc) next... putting together a parts list, I'll compare the cost of parts vs the kit. I have a break to do the chassis at work, and a 2 spring long reverb tank, I should have the impedence today to compare with. Another big learning curve.

Bill

[soundmasterg]

Bruce:

Yes I replaced all the underside caps, that was the first change made and yes it was a pain. I kept them, I was wanting to keep it as close to spec as possible, and one of the leads was found discounted from the bumble bee body during initial examination. I replaced everything that looked or tested suspect.

Greg:

Thanks, I moved 80% of the wires to the underside in an attempt to tiddy it up. I'll check the bumble bees in the coming weeks. I'm finding the tremolo weak to my ear, but it could be just me. All in all I am very satisfied. Played on it for a couple hours yesterday.. It was a blast.

Thinking about building a weber reverb (6v6, 12at7 etc) next... putting together a parts list, I'll compare the cost of parts vs the kit. I have a break to do the chassis at work, and a 2 spring long reverb tank, I should have the impedence today to compare with. Another big learning curve.

Bill

I'm also building a Weber Revibe, though I haven't got very far on it due to other stuff going on. On Weber's site he says the Revibe is among the harder kits to get right....lots of hum issues on the early examples...grounding is very important on these. The quality of the kit is pretty good, though I elected to use my own pots, switches, jacks, and tubes. I plan to build a Torevibe style later, but I will build it all myself and add the Magnatone vibrato to it. I have heard the Fender style outboard reverb units sound better with a 6K6 like the originals rather than a 6V6, so you may want to think about that. It is as simple as swapping the tubes. I used to have access to a great break where I used to work and I sorely miss having access nowadays. I want to get one but want a good one. After you use good tools you can't go back to crap. Enjoy your Revibe or 6G15 project if you decide to do it!

Greg

[Thndr]

Greg,

Good information thanks. Not sure which one to build first the Weber or a Bassman or a Bassman with a reverb in it.. Lots of learning still to do before I make up my mind.

Bill

[soundmasterg]

I too plan to build a 5F6A Bassman clone in the future, since I already have some speakers for one. But for me adding the outboard reverb/trem with a Revibe will make everything more versatile as I can use it with any amp. I'm super busy with work full time and school part tiem for a EE degree so I don't have a lot of time for projects for another year or two, but after that I'll be building more stuff. I would like to get my Revibe done sooner though.

Greg

[Thndr]

I've gotta get some basics down, thankfully there is plenty of information on the net. So the Bassman/Revibe may change. Right now I have a list of Honey-Do's a few pages long... Making a shelving unit for a closet I just finished this weekend. It never ends, thankfully I like woodworking.

Bill

[soundmasterg]

Yeah, getting the basics down helps a lot. The more you the better you get. I've got about 15 amps in the works myself once I get the time to work on them. School and work take precedence at the moment for me though.

I've also been fixing the wood floor in my place lately. I evicted a renter who had some cats that damaged the floor with their urine....even though its woodworking and I enjoy that, I don't much like this particular work...haha.

Greg