Hi there,

Not too sure which marshal you are trying to rebuild or if you're looking for the pre 80s "Plexi" sound


follow my dropbox link there are a few tutorials and a spreadsheet that will help you better understand design and tweaking
https://www.dropbox.com/sh/e5sloiplrbmf07z/AAB9g4Qj8CV6TtM7ph3rjONja?dl=0


Most design hookups will look something like this... here you will see how the bassman and plexi compares



Go to the el34 forum for schematics etc .... http://el34world.com/Forum/index.php

I'm rebuilding that hybrid I got from Arno West. It's a Marshall S80. 2 x fat 12" 4 ohm drivers.
I loved the sound. Unfurtunatly after sizable effort to repair it was declared dead. A few of the chips fried, and the PSU is faulty. So I really want to get something almost the same in sound..
I've got the solid state power stage ready. 2 x 40 watt outputs. So now I simply need to build an overdrivable preamp section that the guitar will plug into.
At a later stage I will get that 5 watt tweed kit from Mars, but for now a simple design only for the pre-amp section is what I need.

Hey man!
consider joining http://www.ssguitar.com/
These guys are all about SS and hybrid amps, some very knowledgeable guys on there, there is many many diagrams for amps, pre amps and power amps.

Im sure you will get something there, or just make a post and ask, someone will def help you out and get you sorted!

Awesome Marshall btw! I want one of those so bad, but it seems they are becoming extremely rare, ive got 1x12 8080 at home but would love the 2x12 version.

All the best!

faid you will battle to modify that amp purely because the circuitry is PCB based and is therefor not so modifiable.

If you like it so much replace the faulty crisps ?

I looked at the schematic briefly and there is precious little you can use from then entrails. my advice is turn it into an Marshal 18 watter,

The biggest cost of building amps and pedals goes to the hardware, chassis, enclosures, Speakers, transformers, fixtures and fittings. the lighter things are a few buck here and there. Most of this you already have

So lets see what you will need.

1 x Power Transformer - Karel can wind as can your local transformer winder
1 x Output transformer - Karel can wind as can your local transformer winder - Output tube specific

2 x 9 pin sockets and fittings - preamp and phase inverter
2 x power tube sockets 9 pin for el84 8pin for El34/6l6/

A turret board or termination boards

Tubes

a bundle of passive electronics ... and a handful of sockets .......this pic should give you an idea

http://www.trinityamps.com/ForumGallery/trinity/TrinityAmps18_Watt_Kit_sm.jpg

So with the help from the guys at ssguitar, i'm going to go with an alembic jobbie as was used by Gilmore. Should be getting some schweet tones from that. Seems rather solid. Transformer from karl should be in the mail already ?
Any crunch though will have to come from external pedal. Not too bothered about that though. Still getting my fingers to loosen up.
Thanks for all the input guys. Much appreciated.
Towards october, i will build a full valve amp.