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Unread 04-04-2012, 07:34 AM   #211 (permalink)
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Re: my '79 JMP 2203 project




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Unread 04-04-2012, 09:53 PM   #212 (permalink)
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Re: my '79 JMP 2203 project

damn that Tolex work zaps all the fun out of this project!
Cut and glued the back, still have a little cleanup to do. I'm happy with the results so far!


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Unread 04-05-2012, 05:20 PM   #213 (permalink)
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Re: my '79 JMP 2203 project

Quote:
Originally Posted by smashedguitars View Post
hey, top, bottom and baffle are 3/4" sides and back panel are 1/2"
braces trim etc are pine... a bit of experimenting I guess, wanted the baffle stiff and since I was doing a rabbet joint to join the sides, top and bottom seemed to make sense to go with 3/4" for the top and bottom... guess i'll see then it's done... dimensions are approx 33 1/2" tall, 14 13/16" deep at the bottom, 11" deep at the top. It's nice birch plywood from home depot, hardly any knots but not sure how it compares to a real Marshall...
You`ll be fine.

You`ll be able to,should you choose to,...LOL,.... push it out the back door of a moving Ryder Moving van,.....or pound on the sides with a 12 lb sledge hammer,....you won`t do anything to it,....although I don`t really suggest you do this,.....just don`t be worried that it will get hurt if it gets abused a little,....all you`ll have to do is protect the speakers from pointy,teary,rippie things.

When you wire the speaker cable input jack,.....make sure you give yourself lots of length for taking the back off,.....without pulling your wiring off the speakers.

What are you putting in for speakers? What ohm rating are you going to use?
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Unread 04-05-2012, 05:26 PM   #214 (permalink)
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Re: my '79 JMP 2203 project

That looks good.

One of these days I`ll be asking you for some tips,....as I want to cover mine ,...after 32 years,...LOL

Maybe a funky color,.....and maybe not.
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Unread 04-05-2012, 06:48 PM   #215 (permalink)
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Re: my '79 JMP 2203 project

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That looks good.

One of these days I`ll be asking you for some tips,....as I want to cover mine ,...after 32 years,...LOL

Maybe a funky color,.....and maybe not.
thanks! I hope to be playing it this weekend if everything goes right... Tolex is the hardest, most boring part so far but I think I'm getting the hang of it. My corners are ok on the back but not perfect. I think the front corners will be better... Best tip I have is to use really sharp knives and scissors when doing any cuts

Last edited by smashedguitars; 04-05-2012 at 08:42 PM.
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Unread 04-05-2012, 08:40 PM   #216 (permalink)
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Re: my '79 JMP 2203 project

pretty happy with the front!




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Unread 04-06-2012, 07:11 PM   #217 (permalink)
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Re: my '79 JMP 2203 project

So if you are a newbie "do it yourself" person like me, you probably realize by now its much easier to just buy one lol...

got the excess tolex cleaned up and I'm mounting the baffle now.... I bought some white piping/wetting or whatever you call it, but I got 1/8" and it won;t bend the corner properly without showing a gap... So I'm skipping the piping on this project....

Last edited by smashedguitars; 04-06-2012 at 10:17 PM.
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Unread 04-06-2012, 07:32 PM   #218 (permalink)
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Re: my '79 JMP 2203 project

not bad! not bad at all...


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Unread 04-06-2012, 10:19 PM   #219 (permalink)
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Re: my '79 JMP 2203 project

Got the feet and handles on... Just have the brace, back and speakers... Hope to be playing through it sunday


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Unread 04-07-2012, 11:58 AM   #220 (permalink)
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Re: my '79 JMP 2203 project

should be rocking soon...


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Unread 04-07-2012, 12:01 PM   #221 (permalink)
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Re: my '79 JMP 2203 project

I've been away for a while, and I am surprised by the tolex/grill work you've done during this time! It looks really really really nice, man! Awesome work! Now, I've got some questions:

1) In a previous picture I noticed you mounted a speaker from the inside. Isn't this wrong? Also is it possible to mount them from the outside now that the grill is nailed? Is the grill nailed the same way on original Marshall cabinets?

2) What is this brace you're referring to? (Don't know much about cabinet parts.)

3) Will you make a badge with your name or something for it? I saw you screwed a wooden part behind the grill for that purpose. If so how will it be made?

4) From what I know, I think cabinets have some sound anti-reflective material inside, which looks like cotton wool or something. Am I correct and is this necessary?

5) How you will you judge the cabinet using cheap speakers to decide if you'll buy expensive ones or not?

Hope that's not too much I'm asking. Thanks!
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Unread 04-07-2012, 03:53 PM   #222 (permalink)
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Re: my '79 JMP 2203 project

pic of the brace I was talking about its cut about 1/8" longer so that when you tighten the back up it squeezes the cab together... worked out good!

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Unread 04-07-2012, 03:59 PM   #223 (permalink)
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Re: my '79 JMP 2203 project

1) In a previous picture I noticed you mounted a speaker from the inside. Isn't this wrong? Also is it possible to mount them from the outside now that the grill is nailed? Is the grill nailed the same way on original Marshall cabinets?

No they mount from the rear based on my research, the baffle screws in from the back....

2) What is this brace you're referring to? (Don't know much about cabinet parts.)

see pic above

3) Will you make a badge with your name or something for it? I saw you screwed a wooden part behind the grill for that purpose. If so how will it be made?

not sure yet, I was planning on making a "smashed" badge but i kind of like it the way it is... looks real clean...

4) From what I know, I think cabinets have some sound anti-reflective material inside, which looks like cotton wool or something. Am I correct and is this necessary?

there is tons of info on the web, from my research its mostly used on bass cabs. i dont know much about it

5) How you will you judge the cabinet using cheap speakers to decide if you'll buy expensive ones or not?

if the cheap speakers sound pretty good, then the expensive ones will sound better
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Unread 04-07-2012, 04:01 PM   #224 (permalink)
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Re: my '79 JMP 2203 project

Wired it series/parallel for 8 ohms.

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Unread 04-07-2012, 04:03 PM   #225 (permalink)
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Re: my '79 JMP 2203 project

Some pics of the finished cab. (I may tolex the back panel later....)






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Unread 04-07-2012, 04:05 PM   #226 (permalink)
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Re: my '79 JMP 2203 project

The END! I have about $430 in the cab with the speakers. Not too bad I guess...
It sounds pretty damn good! much tighter than my 2 x 12, loud as hell! I'll get some recordings tomorrow.... shew I need a beer, I have a ridiculous amount of work in that thing! was like having a second job lol...

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Unread 04-08-2012, 01:42 PM   #227 (permalink)
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Re: my '79 JMP 2203 project

first part of the video is the low input jack, didn't get a good recording the volume is too low... It sounds better in person... Just the marshall, no pedals... (I need a new 9volt for the tube screamer....)

Marshall JMP 2203 4 x 12 custom cab with Jensen C12R speakers - YouTube
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Unread 04-09-2012, 06:43 AM   #228 (permalink)
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Re: my '79 JMP 2203 project

Looks really nice man! Aesthetically, I would leave the front un-badged and tolex the back.

Regarding the sound now, I have the impression that with some expensive speakers it would sound awesome. The Jensens you put in it sound extremely trebly without sign of bass response, exactly as described from people in forums from what I see. I don't think it's the cabinet that makes it sound that way.

The cabinet should sound fine since you built it similar to a Marshall cab. Did you use the same type of wood? Same dimensions?
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Unread 04-09-2012, 07:54 AM   #229 (permalink)
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Re: my '79 JMP 2203 project

thanks, I'll try to get some better recordings but yeah better speakers would help it I'm sure. It sounds better in person and I found it sounds better with my Gibson les paul pickups... the recording is the epiphone.
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Unread 04-09-2012, 12:12 PM   #230 (permalink)
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Re: my '79 JMP 2203 project

Here is a video of the entire project...

Custom Angled 4 x 12 Guitar Cab Build - YouTube
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Unread 04-09-2012, 12:45 PM   #231 (permalink)
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Re: my '79 JMP 2203 project

Cool sum-up. What microphone are you using for recording, by the way?
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Unread 04-09-2012, 02:02 PM   #232 (permalink)
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Re: my '79 JMP 2203 project

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Cool sum-up. What microphone are you using for recording, by the way?
It was recorded with a Electro-Voice PL84 Handheld Condenser Mic using Audacity. JMP MV was around 2 on the distorted parts, I think 3 or 4 on the low input in the beginning. When i first recorded it it was way too loud so I set the mic level to 1/2 way in Audacity, but I think that was too low... Going to play with it some and will try a few more recordings...
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Unread 04-09-2012, 02:59 PM   #233 (permalink)
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Re: my '79 JMP 2203 project

Nice build...You might want to just paint the back black and tolex later when you're feeling frggy.

Also, I really like Jensen speakers but those are not very beefy.
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Unread 04-09-2012, 03:34 PM   #234 (permalink)
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Re: my '79 JMP 2203 project

thanks, I'm planning on Tolexing the back later... was just too beat to do it this weekend and wanted to get it in one piece....

Update: I played the following through the amp and cab so far: Gibson LP Special, Epi LP standard, Jackson RR3, Epi SG and an Epi Strat knockoff. I think maybe the 100watt amp and high-output humbuckers are a bit too much for the speakers. I had hoped that the 25watt speakers would break up earlier so I could play at low volumes, but it seems to me they breakup earlier but just don't sound good when they do lol... I'll try them cranked some this weekend and see if it makes a difference...

The Epi strat with the single coils actually sounds best through it I think. Can get some really nice 60s type tones with it.

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Unread 04-16-2012, 09:51 AM   #235 (permalink)
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Re: my '79 JMP 2203 project

JMP 2203, 4 x 12 Jensen C12R, Tube Screamer, Epi LP 496R 500T pickups


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Unread 04-18-2012, 11:58 AM   #236 (permalink)
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Re: my '79 JMP 2203 project

Really nice job on the 4x12 Smashed!

I took apart a beaten up '72 checkerboard cab a few months ago and spent about 10-12 hours just taking it apart, removing all the old tolex and glue and fixing some odds and ends. I can really appreciate the time and effort you spent to build one from the ground up. Looks like solid craftsmanship entirely and looks identical construction to a Marshall cab.

Cheers!
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Unread 04-18-2012, 07:16 PM   #237 (permalink)
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Re: my '79 JMP 2203 project

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The 2 x 12 as braced in the pic (with the back put on), no effects just marshall MV around 2 and gain 7 or so.... (sorry for the playing i went where the guitar took me...)

cab sounds better huh?

Marshall JMP 2203 after repairs and after bracing 2x12 cab - YouTube
Much better!
Dude, I've been silently following this and I've gotta say, you are doing an extremely commendable job! Some guys jump all over the place making wild guesses at what's not right with their rig. I salute you for taking the time to listen to experienced members and their advice, as well as trying one thing at a time until you get the right results.
That cab is gonna rock...I can see the tone just oozing from it already!
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Unread 05-14-2012, 09:15 AM   #238 (permalink)
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Re: my '79 JMP 2203 project

thanks guys! it was a labor of love lol... well i got 2 carvin 100watt 8ohm british series in it now and I have 2 carvin vintage series vl-12 100s on the way. going to mix them in and see what it sounds like! I really like the 2 british series so far and am looking forward to getting the other 2 in there... will post clips as soon as I have it together....
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Unread 05-22-2012, 08:21 PM   #239 (permalink)
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Re: my '79 JMP 2203 project

much better! Got the other 2 carvins in... will post some clips soon.
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Unread 05-26-2012, 07:09 PM   #240 (permalink)
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Re: my '79 JMP 2203 project

recorded with the handheld and the playing sucks, but hopefully you can tell how much better it is....

Gibson les paul special w/500T bridge, JMP 2203, 4 x 12 cab w/2 carvin british and 2 carvin vintage - YouTube
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