NCD: educate me on my Marshall 412 jcm800 1960a

[Jimbilly]

this popped up on Craigslist for a impulse purchase type price, - and I'm a sucker for the jcm800 stuff, probably because of my age.  It has G12T 75s, my local expert told me those are some of his favorite speakers, but with a Fender type amp, not as much with a Marshall, they do sound a little buzzy (?) with my '79 2204, and better with my tiny bassman pre champ power head.  

Is this a reissue?, what's the story on the JCM800 1960a with the stereo switching?

[Dave Scepter]

On 3/10/2024 at 3:55 PM, Jimbilly said:

this popped up on Craigslist for a impulse purchase type price, - and I'm a sucker for the jcm800 stuff, probably because of my age.  It has G12T 75s, my local expert told me those are some of his favorite speakers, but with a Fender type amp, not as much with a Marshall, they do sound a little buzzy (?) with my '79 2204, and better with my tiny bassman pre champ power head.  

Is this a reissue?, what's the story on the JCM800 1960a with the stereo switching?

The older 80's 1960 cabs did not have that switch... my 1990 cab have the same switch but with G12-65 speakers 

[Jimbilly]

it might be a 'mutt', or just re badged

[crunchee]

I don't think the jack panel for Marshall cabs in the '80s ever had the 'CE' logo or the X'd out trash bin mark, though I could be wrong...either that or somebody replaced the plastic jack panel housing with a newer one (it's just mounted onto the cab back with screws).  However, the metal data badge below the jack looks a lot to me like a dead ringer for the ones Marshall used back in the late '80's/'90's.  It's the little details that make or break figuring out the age of gear sometimes.  What do the labels on the speakers look like?

[Dave Scepter]

Oh, I might add that I completely bypassed the whole switch running it mono, as I don't trust it being a kinda cheap plastic switch mounted on a PC board... "I didn't want to risk having an open circuit "on a tube amp" even for a second...

[Jimbilly]

here's some inside photos.  I had a early/mid '90s 2x12 (I think it was an 8222, and I think it's current fs on my local CL) with a sort of similar plastic input plug, that automatically switched to stereo with when 2 plugs were in. 

[Cboss]

Quick easy mod; on both my 4x12s I got rid of those switch panels, put in Mojotone jacks, ohfc solid core wire soldered everywhere, and the difference was massive.. probably a half hour of work

[crunchee]

Those speakers look like late '80's/early '90's vintage to me, I had a few '80's Marshalls in the past with the same type of labels on the speaker magnets.

[Biz Prof]

Definitely mid-1980s-and-up Celestions. The earlier '80s cabs tended to have -65 or -70 Celestions as OEM.

[Biz Prof]

Quick question:  Is the back panel made of plywood or MDF?

[Jimbilly]

I think the speakers date '87 (if I'm reading it all correctly), and they were supposedly spec'd in that model cab from about '86 to '89, so that lines up.  The remaining question is: when did that switchable input jack plate appear? It's clean enough that I'm suspecting that it is pretty much an original '87.  

[Jimbilly]

6 minutes ago, Biz Prof said:

Quick question:  Is the back panel made of plywood or MDF?

looks to be particle board from the photo I took, - it put it back together after shooting the speaker photos.

[Biz Prof]

My memory might be failing me here, but I recall that the mono/stereo jack debuted with the JCM 900 cabinets.  None of my 800-series cabs (2x12 or 4x12) have anything like it, for sure.

[Jimbilly]

If the output jack plate is not original, that's not a very big deal, I'm happy that the speakers seem to match the bulk of the cabinet.

These speakers do sound a little bit bright to me, I can see why some find them too bright, I had a '70s 50w Marshall jmp combo that was so very bright sounding, I imagine it would not pair well with this cabinet.  Maybe these speakers are ideal for players with a lot of hearing damage, - or just with a darker sounding amp.

[crunchee]

2 hours ago, Jimbilly said:

These speakers do sound a little bit bright to me, I can see why some find them too bright, I had a '70s 50w Marshall jmp combo that was so very bright sounding, I imagine it would not pair well with this cabinet.  Maybe these speakers are ideal for players with a lot of hearing damage, - or just with a darker sounding amp.

You mean players with a lot of hearing damage, or players who want a lot of hearing damage?  Or both?  

[Dutchman]

I use 1 of those speakers in my home made Leslie paired with a creamback on the top speaker. It's a great blend with a Bandmaster.