$299 Gibson tube amp - Made in USA! - Page 11

Guitarslinger1 · March 9th, 2008, 10:37 PM

Quote:

Originally Posted by Jaybird

When I connect the NFB r to pin 8, There is a horrible squeal that happens as soon as the tubes warm up. I have jumped the 22pF/1 meg low freq filter. I will put in the 2.2M r from #1 input hot to ground and see how it goes.

If I'm not mistaken, you said you had it on pin 7 in a previous post. Pin 8 (the correct pin) should cause no problems. The horrible squeal may be from using a mic with no input resistor.

Jaybird · March 9th, 2008, 10:53 PM

No actually I had it on pin 8 and it sqealed without anything in the input. It began to squeal as soon as the amp warmed up. I did ask about what looked like a resistor going into pin 7 on the pic you posted of the NFB mod. Right now the 22pf ,1 megbypass along with the .1 caps and the amp is sounding pretty sweet. I just finished building a 5F1 tweed clone and they are both a lot alike. I think the 5F1 is a tad better for harp, A little more grit, or honk. The GA-5 has got the juice. Using them with a DD-3 delay and the sound is real full for both amps.

red57strat · March 10th, 2008, 10:34 AM

Earlier in this thread, someone had suggested that these amplifiers were imported.

I asked Gibson and have been told by them, in an e-mail, that these amplifiers were made in North Carolina. Mojotone is in North Carolina. Maybe that's why they have Mojotone components.
I have even heard it said, in this thread, I believe and on other wbsites, that Mojotone built these amplifiers for Gibson.

WallyArms · March 10th, 2008, 12:05 PM

Quote:

Originally Posted by red57strat

Earlier in this thread, someone had suggested that these amplifiers were imported.

I asked Gibson and have been told by them, in an e-mail, that these amplifiers were made in North Carolina. Mojotone is in North Carolina. Maybe that's why they have Mojotone components.
I have even heard it said, in this thread, I believe and on other wbsites, that Mojotone built these amplifiers for Gibson.

Makes sense, as the Mojotone website sells such items as Gibson Goldtone speakers and other components found in the amp. I never believed that they were imported - I even doubt that any of the components are imported.

Guitar_Mc · March 10th, 2008, 12:18 PM

So then....

How much would it cost to build this amp? Cab, speaker, caps, transformers etc.

Rob DiStefano · March 10th, 2008, 12:39 PM

Quote:

Originally Posted by Guitar_Mc

So then....

How much would it cost to build this amp? Cab, speaker, caps, transformers etc.

Buying retail, much more than $300.

Sidney Vicious · March 10th, 2008, 12:43 PM

Quote:

Originally Posted by Guitar_Mc

So then....

How much would it cost to build this amp? Cab, speaker, caps, transformers etc.

My guesstimate?

If you bought the parts individually and assembled it yourself:

$300 - if you are very lucky.

Chassis - 50
Trannys - 50
Speaker 30
Board resisters caps 25

that's 155

find a cabinet for 145 and you are in business . . . .

Or are my numbers above way off?

edit to note that RobDi beat me to it - and confirms that my guess is not as crazy as I thought.

and to fix math - again

red57strat · March 10th, 2008, 12:47 PM

Quote:

Originally Posted by WallyArms

I even doubt that any of the components are imported.

Some components are definitely imported.
The Weber Signature speaker, for instance. I'm pretty sure it's imported.
The input jacks were made in the UK. Eastern European tubes, etc. They used to come with US made Sprague filter caps. Not anymore. Have you priced Sprague Atoms lately? They're not worth what they get for them.

red57strat · March 10th, 2008, 12:49 PM

Quote:

Originally Posted by Rob DiStefano

Buying retail, much more than $300.

Mojotone gets over $500 for a tweed Champ kit. Weber, over $400.

Original '50s GA-5 amps can be had for less than $300, though.

In any case, these amps were a good deal.

WallyArms · March 10th, 2008, 01:18 PM

Quote:

Originally Posted by red57strat

Some components are definitely imported.
The Weber Signature speaker, for instance. I'm pretty sure it's imported.
The input jacks were made in the UK. Eastern European tubes, etc. They used to come with US made Sprague filter caps. Not anymore. Have you priced Sprague Atoms lately? They're not worth what they get for them.

The main speaker page at Weber's site says "Proudly Made In The USA", and he states that his speakers are hand built to order, so I never suspected that the speaker was imported - unless it is not actually a Weber product. I have always figured that the Epi version for the Valve Junior was a copy made in Asia. Mere speculation on all of this on my part - I don't really know

Rob DiStefano · March 10th, 2008, 01:22 PM

Quote:

Originally Posted by WallyArms

The main speaker page at Weber's site says "Proudly Made In The USA", and he states that his speakers are hand built to order, so I never suspected that the speaker was imported - unless it is not actually a Weber product. I have always figured that the Epi version for the Valve Junior was a copy made in Asia. Mere speculation on all of this on my part - I don't really know

It's the Weber Signature speakers that are imports - all the other Weber speakers are home built in their shop.

red57strat · March 10th, 2008, 01:34 PM

Quote:

Originally Posted by Rob DiStefano

It's the Weber Signature speakers that are imports

Sounds good, though...

boris bubbanov · March 10th, 2008, 03:57 PM

Get a load of this, MF has abandoned the six digit code that matches this product. That leads me to believe that when a new version arrives, it'll be a Mark II or whatever. And anyone's guess as to price.

Kinda mind boggling to ask for $ 699 and not bother to put a US source speaker in the amp. I guess people's awareness on this subject has changed a lot in the last 2 years.

red57strat · March 10th, 2008, 04:41 PM

Quote:

Originally Posted by boris bubbanov

Kinda mind boggling to ask for $ 699 and not bother to put a US source speaker in the amp.

My Mesa/Boogie cost twice that and has a Celestion speaker that was made in China. Very Few speakers are made here and when they are, they're too expensive to put in $699 amps.

Guitarslinger1 · March 10th, 2008, 06:37 PM

Quote:

Originally Posted by Jaybird

No actually I had it on pin 8 and it sqealed without anything in the input. It began to squeal as soon as the amp warmed up. I did ask about what looked like a resistor going into pin 7 on the pic you posted of the NFB mod. Right now the 22pf ,1 megbypass along with the .1 caps and the amp is sounding pretty sweet. I just finished building a 5F1 tweed clone and they are both a lot alike. I think the 5F1 is a tad better for harp, A little more grit, or honk. The GA-5 has got the juice. Using them with a DD-3 delay and the sound is real full for both amps.

Yeah, that's the weirdest thing. It's a 1.5k resistor, that was installed by the factory. I haven't read where anyone else's GA5 has this. The only thing I can figure is that it was a mod they did, possibly due to instability caused by that high pass filter they're installing on these. Maybe some individual amps gave them trouble, and they installed this mod if needed. But I really don't know.

I removed the resistor, and the amp is louder (as expected) and a bit brighter, but still stable.

red57strat · March 10th, 2008, 06:57 PM

Quote:

Originally Posted by specialty guitars

Yeah, that's the weirdest thing. It's a 1.5k resistor, that was installed by the factory. I haven't read where anyone else's GA5 has this. The only thing I can figure is that it was a mod they did, possibly due to instability caused by that high pass filter they're installing on these. Maybe some individual amps gave them trouble, and they installed this mod if needed. But I really don't know.

I removed the resistor, and the amp is louder (as expected) and a bit brighter, but still stable.

Mine has that 1.5k resistor on pin 7 too. I was surprised to see it there. It's not on the schematic that Gibson sent me.

So I can try it without it?

Jaybird · March 10th, 2008, 07:31 PM

After playing my amp a while today, I decided that I like it better stock, so I reverted all the mods. I was never able to get that NFB resistor to function properly, The 25uf cap "leglift" just made the amp sound spotty and gargley, so now everything is stock except I left in the .1 coupling caps, I am really likeing the amp again. I sort of ABed it with my new 5F1 and they both are pretty sweet. I must say that I believe the 5F1 is a little richer sounding though. This is a great thread with some good ideas and timely responses.

red57strat · March 10th, 2008, 07:37 PM

Quote:

Originally Posted by red57strat

Mine has that 1.5k resistor on pin 7 too. I was surprised to see it there. It's not on the schematic that Gibson sent me.

So I can try it without it?

I guess I can because I just did. It sounds fine, even cranked.

It's very slightly brighter and more open.

red57strat · March 10th, 2008, 07:39 PM

Quote:

Originally Posted by Jaybird

I sort of ABed it with my new 5F1 and they both are pretty sweet.

Sort of???

Jaybird · March 10th, 2008, 07:58 PM

"Sort of", being a lazy way of saying aA/B'd. Sorry for the laxity. I ran them side by side , same mic, same setting, same song, same player. What can I say? To my ears, the 5F1 is a bit richer and has more body. The GA-5 has more muscle and volume, but not that suble little soul that is produced by a 6V6. The El84 is in my opinion a more volatile, dangerous, sound. I also used the line out in my 5F1 and ran them both together. Very cool. Mars and Venus holding hands.

Guitarslinger1 · March 10th, 2008, 08:15 PM

Quote:

Originally Posted by red57strat

So I can try it without it?

No. It may kill you!

Seriously, give it a shot. Let me know if anything (good, bad, or ugly) happens.

Like any of this stuff, you can always put it back.

red57strat · March 10th, 2008, 08:40 PM

Quote:

Originally Posted by specialty guitars

No. It may kill you!

Seriously, give it a shot. Let me know if anything (good, bad, or ugly) happens.

Like any of this stuff, you can always put it back.

Good, because I already did it! See post #418!

Guitarslinger1 · March 10th, 2008, 09:25 PM

Quote:

Originally Posted by red57strat

Good, because I already did it! See post #418!

Right on.

I have never seem or heard of that being done with that grid resistor . I'd really like to know the scoop on that one.

March 9th, 2008, 10:53 PM	#402 (permalink)
Jaybird Tele-Meister Join Date: Nov 2006 Location: California Posts: 161 9 Photos	No actually I had it on pin 8 and it sqealed without anything in the input. It began to squeal as soon as the amp warmed up. I did ask about what looked like a resistor going into pin 7 on the pic you posted of the NFB mod. Right now the 22pf ,1 megbypass along with the .1 caps and the amp is sounding pretty sweet. I just finished building a 5F1 tweed clone and they are both a lot alike. I think the 5F1 is a tad better for harp, A little more grit, or honk. The GA-5 has got the juice. Using them with a DD-3 delay and the sound is real full for both amps. __________________ Blaaaa blaaaaa, waaaaa waaaaa, razzle dazzle, do dah, zzzzzzzzzz.

March 10th, 2008, 10:34 AM	#403 (permalink)
red57strat Tele-Holic Join Date: Oct 2003 Location: Massachusetts Posts: 986	Earlier in this thread, someone had suggested that these amplifiers were imported. I asked Gibson and have been told by them, in an e-mail, that these amplifiers were made in North Carolina. Mojotone is in North Carolina. Maybe that's why they have Mojotone components. I have even heard it said, in this thread, I believe and on other wbsites, that Mojotone built these amplifiers for Gibson. __________________ Don

March 10th, 2008, 03:57 PM	#413 (permalink)
boris bubbanov Poster Extraordinaire Join Date: Feb 2007 Location: New Orleans, LA + in the past Posts: 5,126	Get a load of this, MF has abandoned the six digit code that matches this product. That leads me to believe that when a new version arrives, it'll be a Mark II or whatever. And anyone's guess as to price. Kinda mind boggling to ask for $ 699 and not bother to put a US source speaker in the amp. I guess people's awareness on this subject has changed a lot in the last 2 years. __________________ Bubban0v

March 10th, 2008, 07:31 PM	#417 (permalink)
Jaybird Tele-Meister Join Date: Nov 2006 Location: California Posts: 161 9 Photos	After playing my amp a while today, I decided that I like it better stock, so I reverted all the mods. I was never able to get that NFB resistor to function properly, The 25uf cap "leglift" just made the amp sound spotty and gargley, so now everything is stock except I left in the .1 coupling caps, I am really likeing the amp again. I sort of ABed it with my new 5F1 and they both are pretty sweet. I must say that I believe the 5F1 is a little richer sounding though. This is a great thread with some good ideas and timely responses. __________________ Blaaaa blaaaaa, waaaaa waaaaa, razzle dazzle, do dah, zzzzzzzzzz.

March 10th, 2008, 07:58 PM	#420 (permalink)
Jaybird Tele-Meister Join Date: Nov 2006 Location: California Posts: 161 9 Photos	"Sort of", being a lazy way of saying aA/B'd. Sorry for the laxity. I ran them side by side , same mic, same setting, same song, same player. What can I say? To my ears, the 5F1 is a bit richer and has more body. The GA-5 has more muscle and volume, but not that suble little soul that is produced by a 6V6. The El84 is in my opinion a more volatile, dangerous, sound. I also used the line out in my 5F1 and ran them both together. Very cool. Mars and Venus holding hands. __________________ Blaaaa blaaaaa, waaaaa waaaaa, razzle dazzle, do dah, zzzzzzzzzz.

March 10th, 2008, 12:18 PM	#405 (permalink)
Guitar_Mc TDPRI Member Join Date: Dec 2006 Location: Buckeye Country Posts: 23	So then.... How much would it cost to build this amp? Cab, speaker, caps, transformers etc.