'76 Marshall 1979B 4x15 Cabinet Restoration
- Thread starter Purgasound
- Start date
Purgasound
Member
At the end of last year I went up north and rescued this 4x15 cabinet. I had never seen the speakers before so I made an offer and went up to grab it. I knew there was going to be some hidden damage. These things were always used and abused. Guys were always trying to blow them up with high wattage modern bass amps so you're lucky if you can find one with all four drivers intact, let alone find one at all. This one has some super rare 15" Celestion speakers in it. T2380's which don't show up anywhere. My best guess is that these were made for Marshall and they were the direct predecessor to the G15/100 which debuted in 1977 to the best of my knowledge. Two of the speakers had date codes from Sept 1975 and Feb 1976.
Originally it didn't look too bad, but I knew that stain on the cloth indicated flood damage.
...and this complete nonsense with the insulation. This was going to have to come out and the integrity of the cab needed to be checked before even plugging it in.
Originally it didn't look too bad, but I knew that stain on the cloth indicated flood damage.
...and this complete nonsense with the insulation. This was going to have to come out and the integrity of the cab needed to be checked before even plugging it in.
Purgasound
Member
The baffle was toast. The speakers were extremely difficult to get out. The bottom ones had the screws rusted in the t-nuts and some even broke off. Same with the screws holding the baffle in. It was not going to come out in one piece. The bottom of the front baffle was rotted but on the bright side, the cabinet frame was still in good shape and didn't exhibit any signs of separation or rot.
I had a prototype front baffle for a 4x15 based on Marshall dimensions in the shop so it fit perfectly.
Installed new t-nuts and painted black... Putting the cloth on sucks. The modern cloth dimensions for checkerboard aren't large enough to wrap the baffle. With a lot of cussing and struggling I did manage to thread the needle and get it to work but it's highly unlikely I'll ever do another one in check. It was way to difficult and there's not enough material to staple all around the baffle without risk of it showing on the face.
I had a prototype front baffle for a 4x15 based on Marshall dimensions in the shop so it fit perfectly.
Installed new t-nuts and painted black... Putting the cloth on sucks. The modern cloth dimensions for checkerboard aren't large enough to wrap the baffle. With a lot of cussing and struggling I did manage to thread the needle and get it to work but it's highly unlikely I'll ever do another one in check. It was way to difficult and there's not enough material to staple all around the baffle without risk of it showing on the face.
Purgasound
Member
Since the baffle was rotted I needed to uncover the entire thing to make sure there was no other damage hidden.
All the ply was in good shape. I did pop some finger joints out and reglue since the bottom ones were loose and did some light gluing where a single ply had separated. Also filled in the screw holes for the glider/caster bases.
All the ply was in good shape. I did pop some finger joints out and reglue since the bottom ones were loose and did some light gluing where a single ply had separated. Also filled in the screw holes for the glider/caster bases.
Purgasound
Member
It was disappointing to find out two of the speakers were reconed at some point and the salt in the wound was that whatever wanker did it used the incorrect voice coil so the impedance didn't match the original speakers. The older G15M with aluminum dust caps were typically 16 ohm speakers but these, and the latter G15-100's have 8 ohm voice coils.
As of today, even Bygone Tones doesn't have a reference for these T-Numbers and I've never come across them anywhere else... but of course being rare doesn't mean good, they have to SOUND good! Later I would find out that they sound amazing....
Original labels intact. Interestingly they display no information like a model number, name, or even the impedance.
As of today, even Bygone Tones doesn't have a reference for these T-Numbers and I've never come across them anywhere else... but of course being rare doesn't mean good, they have to SOUND good! Later I would find out that they sound amazing....
Original labels intact. Interestingly they display no information like a model number, name, or even the impedance.
Purgasound
Member
The tolexing part turned out really well. I only use genuine Marshall parts for vintage restorations. There is "Marshall style" elephant grain available but the black is not color correct. This cabinet did have elephant grain tolex and not levant since it was '76. At some point I'll attempt to straighten out the check cloth where it's uneven in the corner but there's really no play left in the cloth. The available cloth width is the exact dimension of the visible face of the baffle. Cutting it close is an understatement!
Replaced all corner protectors but reused the caster cups since they came out fine and were in good condition.
I even salvaged the serial number badge and hand hammered in two original staples since we can't even get the same size here in the U.S. Closest staple we can get is a 3/16" narrow crown. It's almost correct but I didn't want to shoot anything in and miss the original holes. I did take the liberty of flipping the baffle so the jack is on the top instead of the bottom. I'm a purist about some things but it makes more practical sense to be this way.
Replaced all corner protectors but reused the caster cups since they came out fine and were in good condition.
I even salvaged the serial number badge and hand hammered in two original staples since we can't even get the same size here in the U.S. Closest staple we can get is a 3/16" narrow crown. It's almost correct but I didn't want to shoot anything in and miss the original holes. I did take the liberty of flipping the baffle so the jack is on the top instead of the bottom. I'm a purist about some things but it makes more practical sense to be this way.
Purgasound
Member
Since two of the speakers need to be reconed (again) I put in two of the originals and paired them with Celestion Fullbacks with the correct impedance. They do not sound identical but they blend together nicely. If you know anyone who can find period correct cones and voice coils for these, let me know. I think the closest thing is going to be a G15-100 kit but that will be next to impossible to find I'm sure. I used the original wiring method but did upsize the wire gauge slightly. The stains on the bottom frame look gross but the frame is solid. I sanded everything to make sure it was good before recovering.
Thanks for reading!
Thanks for reading!
Racerxrated
Well-known member
Nice job!
I saw a 4x15 B cab not too many yrs ago at a Music Go Round in the Twin Cities. It was loaded with 15' Greenbacks. They do exist.
I saw a 4x15 B cab not too many yrs ago at a Music Go Round in the Twin Cities. It was loaded with 15' Greenbacks. They do exist.
psychodave
Well-known member
well done!
DanTravis62
Well-known member
Looks super nice!
I'd love to hear some clips of the original 2380s, that's a white whale speaker for sure
I'd love to hear some clips of the original 2380s, that's a white whale speaker for sure
Purgasound
Member
I have a hard time selling anything... I don't want my other four 1979B's to get lonely!
I'll probably sell everything in 15 or 20 years.
Techdeth
RESIDENT ROCK PROFESSOR
Dude ! 5 !?
BesaMoogie
Well-known member
Very nice job!
How did you get rid of the glue residues before tolexing? I once did a 4x12 and this was by far the hardest part of the whole job
How did you get rid of the glue residues before tolexing? I once did a 4x12 and this was by far the hardest part of the whole job
Purgasound
Member
I used an orbital sander. I've done a couple heads and cabs that way.
I spoke to a cabinet builder/carpenter friend of mine about it and he had said there was a better and faster way to do it but I can't remember that was. I'll have to bug him again. It did take a while.