GBX 8x10 cab, vintage treasure or crap?

[JoshuaEdge]

Hey guys, a while ago I picked up a GBX 8x10 cab. Originally it had a black grill cloth but the previous owner was in a noise/punk band so they covered it in green spray paint. Since then I've made it white and basically just more aesthetically pleasing...but I can't find any information on this cab! Year, wattage, anything!

Any opinions or help is appreciated.

[Thornton Davis]

GBX amps were made in Toronto during the late 60's through the mid 70's. Their piggy back rigs were all based on the power module being housed in the cabinet with the preamp sitting on the top of the cab(s).

Growing up in Toronto, I was very aware of their amps. They never marketed a 810 cabinet. Perhaps the one you have is a prototype, because i've never one before.

Because their amps were modular based, you could have up to and including 4 cabinets connected to one preamp. But you could also daisy chain cabinets together to exceed the 4 cabinets and still controlled by a single preamp. Again that's because each cabinet housed its own solid state power amp in it.

The standard bass cabinet was a 410 cab, with the 90 watt power amp module in it. GBX users would have 2 of these stacked creating a 810 rig with 180 watts output, which for the time was more than enough power.

I'd be interested in seeing a photo of the back of the cabinet to see if it has ever had a power module in it? And with all due respect i'd question its authenticity at this point although the front of the cab (excluding the logos) does look like a GBX cab.

Here's a single GBX 410 cab with the preamp. Imagine 4-8 of these linked together to create a huge rig.



TD

[megadan]

All though I don't know much about the GBX amps, I do remember seeing an 8x10 for sale locally once. Never saw it in person.

Also the logo and the black wood sides look very similar in the above two pictures.

[Thornton Davis]

Well according to Wikipedia, GBX did offer a 810 cabinet. Although this isn't the most accurate site for information it's something.

I'd still like to see a photo of the back of the cabinet if you've got one.

http://en.wikipedia.org/wiki/Ahed

TD

[BassmanPaul]

Crap!

[alfaBAT9]

The very first bass amp I ever played was one that was left in a friend's basement, and belonged to a friend of a friend's dad. It was a GBX, just like the one in the pic with the 4x10's, only the one I played was either a horizontal 2x10 or 2x12. The cab was HEAVY. Sounded really good though.

[Thornton Davis]

Originally Posted by alfaBAT9

The very first bass amp I ever played was one that was left in a friend's basement, and belonged to a friend of a friend's dad. It was a GBX, just like the one in the pic with the 4x10's, only the one I played was either a horizontal 2x10 or 2x12. The cab was HEAVY. Sounded really good though.

The GBX vertical bass cabinet was a 215. Here's a photo of mine from 1971.


TD

[korngold]

Looks a bit like a Traynor 2x15 that I just sold a few weeks back. Were Traynors and GBX made in the same place? I seem to recall that Traynors were made in Canada...

[BassmanPaul]

As were GBX. They were not the same company however.

Paul

[JoshuaEdge]

The front doesn't look similar because the original diamond grill cloth was covered in green spray paint so I changed it out. The GBX and BASS badges have also been repainted with gold lettering on black because they too had been covered in green spray paint.

I'll post a picture of the back of it tomorrow, but basically it just looks like a massive piece of wood with a single jack in the middle.

If it is a prototype, I'll probably hang on to it. I waited years to be able to buy an 8x10, I'm glad I got this one. Character.

[JoshuaEdge]

Here are some more photos.

[will33]

The single chunk of flat black painted plywood on the back with the single jack in it is an obvious patch that someone down the line made to replace whatever used to be there....actual jack plate or whatever. That part may have also carried a label and possibly serial #?

Try unscrewing that piece and lift it off gently. May not even have to disconnect any wires if there's enough extra and get a pic of the inside backs of the speakers. Some of these GBX guys in the know may be able to help you then.

Just because that piece of wood with the jack in it is there means somebody did that to make if work after something else failed. Doesn't , mean the whole thing's bad in any way, just check that out.

[JoshuaEdge]

Originally Posted by will33

The single chunk of flat black painted plywood on the back with the single jack in it is an obvious patch that someone down the line made to replace whatever used to be there....actual jack plate or whatever. That part may have also carried a label and possibly serial #?

Try unscrewing that piece and lift it off gently. May not even have to disconnect any wires if there's enough extra and get a pic of the inside backs of the speakers. Some of these GBX guys in the know may be able to help you then.

Just because that piece of wood with the jack in it is there means somebody did that to make if work after something else failed. Doesn't , mean the whole thing's bad in any way, just check that out.

Cant sleep, going to do this now.

[JoshuaEdge]

(removed back panel)


(Serial? The only thing printed on the speakers)


(The bottom two speakers do not match the rest of them, here they are side by side, the left being one of the bottom two, the right being one of the uniform speakers in the cab. The replacement speaker says "Trio" on it. I'm not familiar with this brand but...maybe I'm just new to speakers.

[Thornton Davis]

The patch on the back of the cabinet is where the internal power amp was originally mounted. Seeing the Peavey sitting on top of the cab, I assumed that someone had either removed the power amp or bypassed it. In doing so they would also rewire the speakers. Do you know what the ohmage of the cabinet currently is?

The top six speakers are originals, while the Trio's are replacements as you correctly assumed. Is there a code stamped on the basket frame of the original speakers? Unfortunately the code stamped on the paper cone can't be tracked, but one on the metal speaker basket can be.

TD

PS - This is obviously an original GBX cabinet and a rare find. Too bad someone felt the need to alter it.

[JoshuaEdge]

You'll have to excuse me for my lack of knowledge on the subject of how these cabs are built, but when I opened up the back, the wood above where the power amp used to be was blackened, not with paint, it looked like it had be singed. I'm not familiar with how it was put together originally but would it be a possibility that it overheated and thats why it needed to be taken out?

I'll open it up again later tonight to see if I can find a code stamped onto the speaker.

I've got no idea about any specs of the cab, ohms or anything. I bought it from a guy who lived without electricity in a barn in western Vermont for $100. He didn't know anything about it either. Something tells me its seen quite a bit in its lifetime.

[Thornton Davis]

Originally Posted by JoshuaEdge

You'll have to excuse me for my lack of knowledge on the subject of how these cabs are built, but when I opened up the back, the wood above where the power amp used to be was blackened, not with paint, it looked like it had be singed. I'm not familiar with how it was put together originally but would it be a possibility that it overheated and thats why it needed to be taken out?

I'll open it up again later tonight to see if I can find a code stamped onto the speaker.

If you can provide a speaker code we should be able to track down the maker and its specs.

GBX were the only amp manufacturer back then to mount their power amp modules on the back of the cabinet. I think they did that in order to allow the heat to dissipate through the heat sinks that were part of the power module and exposed to the outer back side of the cabinet.

I've personally never seen a GBX cabinet where the power module has over heated and blackened the inside of the cabinet. GBX gear was well built and sounded great, so I'm surprised to hear this, but at the same time I can understand why it might happen.

Acoustic, Vox Series 90 and others during this time period who made similar style amps with the Solid State power module housed inside the speaker cabinet with the preamp sitting on top, placed their power modules either mounted to the floor of the cabinet, or to the side of it. These cabinets would have either vents or direct air intake access ports designed into the cabinet to reduce heat build up. The GBX designed cabinets had no porting.

Question, how does this cabinet sound?

TD

[JoshuaEdge]

Originally Posted by Thornton Davis

If you can provide a speaker code we should be able to track down the maker and its specs.

GBX were the only amp manufacturer back then to mount their power amp modules on the back of the cabinet. I think they did that in order to allow the heat to dissipate through the heat sinks that were part of the power module and exposed to the outer back side of the cabinet.

I've personally never seen a GBX cabinet where the power module has over heated and blackened the inside of the cabinet. GBX gear was well built and sounded great, so I'm surprised to hear this, but at the same time I can understand why it might happen.

Acoustic, Vox Series 90 and others during this time period who made similar style amps with the Solid State power module housed inside the speaker cabinet with the preamp sitting on top, placed their power modules either mounted to the floor of the cabinet, or to the side of it. These cabinets would have either vents or direct air intake access ports designed into the cabinet to reduce heat build up. The GBX designed cabinets had no porting.

Question, how does this cabinet sound?

TD

It sounds good for the most part, obviously it isn't running all 8 speakers as the two bottom ones have been disconnected since they're blown. It can get a little fuzzy but I give it a bit of slack because its older, as long as I'm not pushing the volume up to 9/10 from the Peavey, the cab handles well.

[Thornton Davis]

Here's what the back of a GBX rig looks like. You can clearly see the power amp mounted to the inside back of the cabinet and how the preamp above is connected for both A/C power and tone control.

Notice the heat sink bars running vertically just above the connection bay.



TD

[Ukiah Bass]

That sucker looks like it weighs a ton. How's it sound?