Gibson GA-8 1962 Discoverer

[vampwizzard]

Y'all,

Went to my annual wrestling crawfish boil in Birmingham this weekend then made the trip north to Nashville to see Mama. Like a good son. Did my usual FB marketplace search and this popped up. Picked it up on the way into town.

Ill go back through the circuit to check against a schematic but this is the GA8 with the parallel* 6v6's. It was serviced at some point and the tech did a decent job. The three prong chord appears to have been installed correctly and has its own ground screw. Filter caps replaced as well as the first tube socket. Sounds tremendous. Im in love.

[octal]

That looks like it must the parallel single ended version rather than push pull?  The tube count doesn't seem high enough otherwise to include a PI and enough gain stages to make a useable amp. (Barring using a transformer for the PI.)


Anyway, you love the way it sounds and that's what matters!

[octal]

This is the schematic I'm thinking it might be. Which, because of the way they drew it looks a bit like a push pull amp, but it isn't!


https://el34world.com/charts/Schematics/files/Gibson/Gibson_ga_8_6v6.pdf

[vampwizzard]

This is the schematic I'm thinking it might be. Which, because of the way they drew it looks a bit like a push pull amp, but it isn't!


https://el34world.com/charts/Schematics/files/Gibson/Gibson_ga_8_6v6.pdf

Parallel single ended. http://www.0rigami.com/gg/gibsonette_schematic.jpg

[tubeswell]

There's GA8s that are parallel SE and there's a GA8 which is self-split PP with a 6SJ7 preamp. Depends which one you've got

[vampwizzard]

this particular model ive only seen as paralleled SE.. the crestline version went to the PP config.

 https://www.vintageguitar.com/39002/gibsons-ga-8-discoverer/

VG just did an article on them too.. been looking for one of these for 2-3 years now.

[bmccowan]

Nice find. I have one of those. Love that era of Gibson amps. The GA-8 has a nice growl to it. And even if it didn't, the handle with a piece of the cab covering in it is cool enough to seal the deal. Although I like his books, I always thought it funny that Dave Hunter claimed credit for "designing" the Two-Stroke as the circuit is just about identical.

[thetragichero]

I always thought it funny that Dave Hunter claimed credit for "designing" the Two-Stroke as the circuit is just about identical.

my overall theory on folks thinking/claiming they've "created something new" wrt tube guitar amps is that they're either delusional or liars. it's all been done before, possibly ripped directly from example circuits published by the tube manufacturers almost 100 years ago. and that's all okay because we know it will likely sound good

[bmccowan]

it's all been done before

I think that is true regarding the building blocks. And the GA-8 is certainly a building block amp. But I do think that folks do come up with new creative ways to expand upon those baselines. They get credit for that in my book.

[vampwizzard]

it's all been done before

I think that is true regarding the building blocks. And the GA-8 is certainly a building block amp. But I do think that folks do come up with new creative ways to expand upon those baselines. They get credit for that in my book.

I think both are true. I did get this based on some recommendations for solo acoustic/electric blended gig amps. If someone improved on this it would make a great amp.

As far as builders experimenting with designs and truly innovating, Benson and Milkman are doing some cool things. Benson has a 6v6 based voltage regulator/attenuator which is pretty neat. Milkman has done a bunch of interesting things in his attenuator, plus the amp in a pedal stuff. Theres still room for innovation.

[shooter]

builders experimenting with designs and truly innovating

i'm at the engineer, bookwork, steal others work stage, taking a forklift motor and attaching it where the jeep motor was
will it still be a Jeep? 

[echuta13]

I think innovation is more a marketing word these days.  Not saying it doesn't happen, just not so much.  More novelty in most spaces less innovation.

[vampwizzard]

Tested everything. Nothing seemed too far out of whack but still went ahead and ordered new caps. Thought about it a bit more and got a replacement speaker. G12Q from WGS. It was cheap, but backordered and it finally came in yesterday.

Problem solved. I really like this amp!

the previous owner put the spades on the speaker wires and used the wrong size. They then cut down the original speaker tab to force fit them in. I opened up the spade a little bit and it went on perfectly fine and tight. I hate people sometimes.

I might test some speakers out. I still may replace the cathode bypass and tone cap. But otherwise, this is a sweet amp.