High Voltages After Headfirst Origin 50 Mod

Amp Mad Scientist said:
Our poor brother Robert is suffering from Chug Deprivation. (CD)
Ask your doctor to see if Chugging is right for you.
Chug: it lets you be you again !
Side effects may include hearing loss and staying up all night drinking tequila....
Click to expand...

Not really "chug" I think, bit a certain tonal character...a combination of sonic frequencies that compliment each other...
 
smitty_p said:
What I mean is, does the footswitch switch between cleans and dirty? It isn’t a two channel amp, correct?
Click to expand...
From the Marshall website:
ORIGIN
Expression begins with the all valve Origin series. It delivers two inbuilt voices, a new tilt control, PowerstemTM our new power reduction technology and forms the perfect marriage with FX pedals. The classically styled single channel amps generate rich and harmonic tones that are ideal for players to explore new possibilities and craft their sound. There is a 2-way footswitch available with all models so you can control the gain boost and turn the FX loop on and off.

Sounds to me like the answer is no.
EDIT: It is not a 2 channel amp. No switching from a clean channel to a dirty channel... theoretically!
 
Last edited:
syscokid said:
From the Marshall website:
ORIGIN
Expression begins with the all valve Origin series. It delivers two inbuilt voices, a new tilt control, PowerstemTM our new power reduction technology and forms the perfect marriage with FX pedals. The classically styled single channel amps generate rich and harmonic tones that are ideal for players to explore new possibilities and craft their sound. There is a 2-way footswitch available with all models so you can control the gain boost and turn the FX loop on and off.

Sounds to me like the answer is no.
Click to expand...

At least they don't call it a "guitar work station." :pound-hand: it's still a guitar amp thankfully.

Isn't that "power reduction technology" a phase inverter with mosfets in place of the plate resistors?
Like a mosfet master volume regulator?

1624809348371.jpg Seems like that's what Mesa has been doing, always trying to make a hybrid circuit with tubes and transistors.
but it never really sounds right or works right when they do it.
 
@syscokid
I also believe it to be a single Chanel amp, the only footswitch ability is in your post, boost, FX loop, and for whatever reason I posses is it is also not a master volume amp, it does have a gain knob, and a volume knob, but it doesn’t work like any other I have played .
Thanks
 
syscokid said:
Whatever you want to call it, it is a standard circuit design. I'll rephrase what I posted earlier: Jason Tong probably and most likely forgot to draw in those two caps when he posted his hand-drawned schematic of the Origin 50. Those two caps are there in your Orgy 50!
Click to expand...

I am super-grateful to you, @ivan H and @Amp Mad Scientist for your time and expertise.
 
syscokid said:
I'll bet if you contact JT and question him on his schematic drawing, he'll immediately slap his forehead and say: "Oops!"
Click to expand...

Ok,

No reply from 'JT' yet (on PM) but one of the builders on his forum responded to my message board post, which included the diagram from a few posts above:

"The 100nf is already there, it’s on the front small pcb next the presence.

Here's how I modded my 50 watt Origin.
I think a lot of this area around the PI is due to how marshall implemented the power scaling, I change a lot of this section back to more traditional values, the presence is a 22k with a 4.7k resistor in parallel, changing this to the classic 5k setup is a major tone improvement tone Imo..."

The poster included this diagram:

FB_IMG_1624816147479.jpg
 
Robert Herndon said:
Ok,

No reply from 'JT' yet (on PM) but one of the builders on his forum responded to my message board post, which included the diagram from a few posts above:

"The 100nf is already there, it’s on the front small pcb next the presence.

Here's how I modded my 50 watt Origin.
I think a lot of this area around the PI is due to how marshall implemented the power scaling, I change a lot of this section back to more traditional values, the presence is a 22k with a 4.7k resistor in parallel, changing this to the classic 5k setup is a major tone improvement tone Imo..."

The poster included this diagram:

View attachment 69878
Click to expand...
The pic only shows the preamp section. The power section contains the PI and the Presence, besides other power components.
 
Some people like the modern Marshall Presence circuit, some like the older style. The older style would require replacing the Origin's 22k presence pot with a 5k pot. Discarding the 4.7k resistor and redirecting the connection between the .1uF (100n) cap.

Your Orgy 50 is probably like this:
20210627_111557.jpg

Very old Marshall style:
20210627_111523.jpg
 
Last edited:
Robert Herndon said:
I sent him a message this morning!!! I will report back!!!

@syscokid , @ivan H , @Amp Mad Scientist - feel free to make modifications to these mods if you feel they are warranted.
Click to expand...
modifications to these mods? you want to modify a modification? :pound-hand:
let me introduce you to the bulk metal foil resistor....
did you know that 70% of the hiss in your amp is coming from 1 resistor? it is.
 
Robert Herndon said:
Ok,

No reply from 'JT' yet (on PM) but one of the builders on his forum responded to my message board post, which included the diagram from a few posts above:

"The 100nf is already there, it’s on the front small pcb next the presence.

Here's how I modded my 50 watt Origin.
I think a lot of this area around the PI is due to how marshall implemented the power scaling, I change a lot of this section back to more traditional values, the presence is a 22k with a 4.7k resistor in parallel, changing this to the classic 5k setup is a major tone improvement tone Imo..."

The poster included this diagram:

View attachment 69878
Click to expand...
At last a real schematic almost.
So it's a JCM 800 2203 (same basic circuit) with diode clipping added.
You are pretty much going to see that circuit in every guitar amp from Mesa to Bogner...
 
You must log in or register to reply here.
Back
Top