Matamp/Electric amp schematics

[rocket88]

Got me a couple of sweet chassis made :-p

That chassis looks fantastic. I have to get moving on ordering parts. If they all come at once the old lady is going to catch on, and she's already not happy with the number of pedals I build. It's at the point where she says either you start selling or stop building.

Where did you get the chassis made? How did you determine the dimensions and placement of everything?

Also, does the transformer matter that much when ig comes to the sound? IE: the ones you got are listed for a Marshall, if I got ones for an old orange or even bought the one directly from green will the sound of the amp be different?

[Beefcake]

Where did you get the chassis made? How did you determine the dimensions and placement of everything?

A buddy of mine works at a rather big metal fabrication company and he made two of these for me out of 2mm thick stainless steel. I determined the dimensions by looking at the pictures and measuring the Orange a friend of mine has. All of these Orange/Matamp/ElectrAmps have a front panel that's supposed to be 19" wide. I just extrapolated the rest of the dimensions from that, added those 8 holes you see under the the powertubes to put external bias measuring points, drew it up in AutoCAD and sent it to my friend to have fabricated. Here are some more pictures, including a screenshot of the AutoCAD drawing.

Also, does the transformer matter that much when ig comes to the sound? IE: the ones you got are listed for a Marshall, if I got ones for an old orange or even bought the one directly from green will the sound of the amp be different?

I'd say probably yes, but I don't think they'll have a very large impact on the overall sound. I was thinking of ordering the OR120 PT and OT from Mercury Magnetics and building two of these amps. One with the Hammonds and one with the MMs to allow me to do some double blind testing. Would make it pretty expensive though.

[served]

Hi.

I have built the amp also.
And its here and ready.
I had some discussion with nutjob over the schematic and I also concluded the same differences.
But there are still some things that really doesnt sound good.
For example Presence control. Does yours sound good?
I can only turn it to a 10o clock and after that there is no change in sound.

Some notes for thouse who are building it.
Skip the Shiled for anode V1A and connect 2x100ohm resistors from preamp tube V1A heaters to the same ground post as the first 50uF - 2.2k.
This will remove some of the loudest noises. If I then compared different shieldings, there were no difference for me.
There are some things still strange in my amp. But I will get them solved.

Just can you share your experience with the presence knob?
I will post some updates on the schematic that I have done.

[silverfox]

The shielded wire from the input to V1's grid, the shielding is connected to V1's anode and NOT to ground. Oscillation eliminated!

So how does this work? inverted phase cancels the oscillations?

I would be interested in seeing the schematics of this amp also. My first encounters with an Orange, and I know this isn't one, my first encounters were in about 1974 Escape Country in Irvine Park, Irvine CA. Some outdoor Jam with hundreds of people blocking the only road in after the concert ended. The Jam Band played Walk this Way and I almost got into a tussle over some chippy that wanted to talk to me and not her boyfriend. Great times, great music... Never forgot Orange after that.

edit: Regarding the feedback from the company reps. Ignore it. They put the information into the public domain as the stated. Many unstable minds in our present state of being... It may also be a bad schematic they have offered to the public like many other designers.

Silverfox.

[served]

Hi.

The presence control issue is solved. There was a Anti log pot in my build. And this was the reason for a strange behaiviour.
This amp really has some interesting charracter. And I would say it performs really well on clean tones also.

Here is the schematics and updates by me on the Nutjob schematic.

[served]

So how does this work? inverted phase cancels the oscillations?

Silverfox.

It should work like this. But there is no big effect there because the signal is already different from the inputsignal. And the effect is very small, for me it has no effect. It might lead to some really bad oscillation if the shileld is feeding the input. You can have an oscillator made like this where the output is driving the input.

[Beefcake]

It should work like this. But there is no big effect there because the signal is already different from the inputsignal. And the effect is very small, for me it has no effect. It might lead to some really bad oscillation if the shileld is feeding the input. You can have an oscillator made like this where the output is driving the input.

What transformers did you end up using? Mine really can't do clean and I think it might be because the PT is 178-0-178 while the old Orange OR120 PT is 190-0-190.

[potatofarmer]

Home / Hilbish Design

^^ This guy is selling clone chassis, faceplates, full kits, etc. of an old Matamp/Orange design. I've never ordered from him, just thought I'd pass the info along.

[jussi]

Thanks for the schematics. I build and amp with the same preamp but whole tone control replaced with big muff tone control and poweramp is plexi 6v6.. JJ 6v6 sounded crappy but TAD 6v6GT sounds like sleep-dopesmoker when I crank it with depth control at lowest bass.