Metropoulos Forum

i really want to build a '68 12xxx Plexi.

but im a little confused,

i can buy a bare bones kit without the step by step instructions with all the EVH spec, or i can get the plexi kit with the step by step instructions without the EVH spec.

if i were to buy the bare bones kit with the EVH spec pack and the dual voltage switch, how will i know how to put it together???

im new with all this and i can just about read schematics, but that doesn't tell me were to put things on the board, or how to mouted the valve bases, or wire the switches ect. Does the kit come with idiot proof diagrams on how to get this thing up and running???

ive read the parts list and it does say it comes with the transformer and everything to get the amp working, but does that include the case and valves???

sorry so many questions but i really would like to know what im buying into first.

Cheers, Rob

I built a jtm 45 two years ago ( my first build) came with detailed instructions btw. That gave me a start. Since, I have been learning by reading the forums along with saving money for parts for the 67 spec 100watt which I ordered two days ago. I promise all the info you need is here in the forums just takes a little searching. If you do run into a question or a snag just ask here and post pictures along the way. This place is the #1 resource for anything plexi and filled with very sharp people.

Since you are doing the 12xxx pay attention to "evh" section and "just about everything "rockstah" has posted. (and many others)

Rob theres too many variations through marshalls early history to provide step by step support for every one. So the most common later amps from c69+ are your kits which come with all the instructions. You can build any earlier amp with the various bare bones kit- steel or Al chassis for JTM or 67+ style amps, BUT you have to at least have some knowledge to put them together. There are layouts in the circuit board layout page for many common variations. The 67/68 12 series one is the one youd want to follow even though the specs for the preamp may be different but thats just a changed value here or there. But no step by steps.

You're other option (which is what I did) is to simply get the full-up '69 kit, take advantage of the detailed instructions, and replace a few of the components for '68 spec values. This means exchanging 4 50x50uF filter cans for 3 32x32uF and a 16x16uF, and maybe 2 or 3 coupling caps depending on how you want to tune your amp. If you search this forum, the how/what/where is covered pretty thoroughly. Obviously, the internal cosmetics wouldn't be an exact 12 series, but you would have the same amp so-to-speak. Make sense?

im able to wire the amp fine, i have a bit of experience in doing this i made loads of mods to my guitars and amps over the years.

i just wanted to know if i got the bare bones kit with the '68 spec option, it would come with enough details in order to actually make it eg. pictures of were to route the wires, where to solder the components on the board ect...

its an obvious question, i know. Sorry.

Rob

Hey Fixxxer,
I am new too but getting ready to build a 45/100. Like Monsterwalley said, everything you need is here somewhere. I have found layouts, alternate layouts, schematics, parts lists....you name it, it's here. If you can't find it someone will show you. You're at the right place.

For the 67 I'm starting, I downloaded the instructions for the 69 100watt kit, as far as the filter cap layout I researched all the archives I could find and went way back in the forums. I went so far as to print out all the pics people uploaded for reference of what I am looking for. I am also aware that I will probably get stumped here and there and can count on the people here to help me out. I think by researching it also helps me to understand not only what goes where but also why and how it works. Thats me though. It sounds like your already pretty sharp and just need the phyisical layout. I'm sure if look you will find the variance of the 12xxx you are looking for. I think rockstah has probably done them all as well as a couple other people rgalpin, etc..., check back on there posts