Marshall Origin 50 - Distorted/Low Output After Headfirst Modifications:

Inspector #20

Inspector #20

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BACKGROUND:

This post originated on the Headfirst DIY Facebook Group Page when Ken (@Daytop) posted asking for help with an Origin 50 problem. This thread was totally lost in the recent server crash, so I am re-posting it here:

@daytop wrote:

"Help please!
This is the second Origin 50 (Headfirst Modification) I've done and it's driving me crazy. Very distorted output is the the symptom and I noticed the cap c50 one side goes to the jumper from pin 1 and cn22, other side goes to the bottom of r56 which was removed so c50 effectively goes nowhere. Any help is greatly appreciated..."

Ken is an experienced electronic tech and this is his second headfirst Origin 50 Mod for hire, so not only was this frustrating, the problem had effectively stalled his progress on 15 amplifiers on his bench awaiting service.

Needless to say, this one was a real headscratcher. Through the course of the HF mod on my personal Origin 50, we discovered (@ivan H & @syscokid) not only is the 'C39' jumper different on the Origin 50, but there are at least two versions of the origin 50 PCB. My amp has Version 1 and Ken has Version 2.

Ori 50 Version 2 PCB.jpg

Here is another photo that ken sent of his modifications:

R65.jpg

And another photo sent by Ken:

V1 PCB.jpg

A lot of tech support was offered here by @Amp Mad Scientist , @ivan H and @syscokid, but everything seemed to be in order and the problem was a mystery.

We are all pleased that a solution has been found. Here's the update sent to me a few days ago by Ken:

"Hey Robert, after chasing my tail on the c50 not going anywhere which it does, I dived back in. Was tracing the signal with my scope. Saw signal on both sides of r90 but nothing on pin 7 of v2. What I found was a broken land from the bottom of r90 to pin 7. Done! Works great! Thank you Robert for all your help. I do appreciate it!"

Hope this thread proves helpful...

Many thanks to forum amp gurus @ivan H & @syscokid for their expertise and tireless dedication to helping out...

- Rob
 
Robert Herndon said:
BACKGROUND:

This post originated on the Headfirst DIY Facebook Group Page when Ken (@Daytop) posted asking for help with an Origin 50 problem. This thread was totally lost in the recent server crash, so I am re-posting it here:

@daytop wrote:

"Help please!
This is the second Origin 50 (Headfirst Modification) I've done and it's driving me crazy. Very distorted output is the the symptom and I noticed the cap c50 one side goes to the jumper from pin 1 and cn22, other side goes to the bottom of r56 which was removed so c50 effectively goes nowhere. Any help is greatly appreciated..."

Ken is an experienced electronic tech and this is his second headfirst Origin 50 Mod for hire, so not only was this frustrating, the problem had effectively stalled his progress on 15 amplifiers on his bench awaiting service.

Needless to say, this one was a real headscratcher. Through the course of the HF mod on my personal Origin 50, we discovered (@ivan H & @syscokid) not only is the 'C39' jumper different on the Origin 50, but there are at least two versions of the origin 50 PCB. My amp has Version 1 and Ken has Version 2.

View attachment 73454

Here is another photo that ken sent of his modifications:

View attachment 73455

And another photo sent by Ken:

View attachment 73457

A lot of tech support was offered here by @Amp Mad Scientist , @ivan H and @syscokid, but everything seemed to be in order and the problem was a mystery.

We are all pleased that a solution has been found. Here's the update sent to me a few days ago by Ken:

"Hey Robert, after chasing my tail on the c50 not going anywhere which it does, I dived back in. Was tracing the signal with my scope. Saw signal on both sides of r90 but nothing on pin 7 of v2. What I found was a broken land from the bottom of r90 to pin 7. Done! Works great! Thank you Robert for all your help. I do appreciate it!"

Hope this thread proves helpful...

Many thanks to forum amp gurus @ivan H & @syscokid for their expertise and tireless dedication to helping out...

- Rob
Click to expand...
How long would this have taken, if there was a readable complete schematic?
Like 10 minutes.... :pound-hand:

Rule #1 never modify an amplifier without a schematic.
 
Amp Mad Scientist said:
How long would this have taken, if there was a readable complete schematic?
Like 10 minutes.... :pound-hand:

Rule #1 never modify an amplifier without a schematic.
Click to expand...

I agree. A full schematic would be useful....

The HF Origin mod sounds so good that people just throw caution to the wind and do it....and I cannot blame them.

I play daily through a Tim Caswell style modded JCM 800-2204 and the Origin 50 with HF mod absolutely destroys it in every way you can imagine. there is no comparison.

The JCM 800, with an extra gain stage AND a Tube Screamer does not put out anywhere near the level of saturation that the Greg Modded Origin 50 does without any added FX.

@syscokid and @ivan H really knocked this Origin 50 mod outta the park. They not only reduced the high volatges, but also "colored" the amp's voicing and took steps to reduce floor noise.

Amp 1.jpg

Morin Phone Original Image.jpg

biggest amplifier disappointment ever???

The studio's Dumble Overdrive Special. 100% B.S. and Hype. Nothing at all even remotely interesting or unique about those amps...just the mystique... :)
 
Last edited:
Robert Herndon said:
The studio's Dumble Overdrive Special. 100% B.S. and Hype. Nothing at all even remotely interesting or unique about those amps...just the mystique... :)
Click to expand...

I've played through two of the things and found them shockingly pedestrian. From everything I had heard before plugging into them I expected a life changing experience but was left a bit bewildered. Like most things, rarity builds hype and hype morphs into legend, earned or otherwise.
 
Robert Herndon said:
BACKGROUND:

This post originated on the Headfirst DIY Facebook Group Page when Ken (@Daytop) posted asking for help with an Origin 50 problem. This thread was totally lost in the recent server crash, so I am re-posting it here:

@daytop wrote:

"Help please!
This is the second Origin 50 (Headfirst Modification) I've done and it's driving me crazy. Very distorted output is the the symptom and I noticed the cap c50 one side goes to the jumper from pin 1 and cn22, other side goes to the bottom of r56 which was removed so c50 effectively goes nowhere. Any help is greatly appreciated..."

Ken is an experienced electronic tech and this is his second headfirst Origin 50 Mod for hire, so not only was this frustrating, the problem had effectively stalled his progress on 15 amplifiers on his bench awaiting service.

Needless to say, this one was a real headscratcher. Through the course of the HF mod on my personal Origin 50, we discovered (@ivan H & @syscokid) not only is the 'C39' jumper different on the Origin 50, but there are at least two versions of the origin 50 PCB. My amp has Version 1 and Ken has Version 2.

View attachment 73454

Here is another photo that ken sent of his modifications:

View attachment 73455

And another photo sent by Ken:

View attachment 73457

A lot of tech support was offered here by @Amp Mad Scientist , @ivan H and @syscokid, but everything seemed to be in order and the problem was a mystery.

We are all pleased that a solution has been found. Here's the update sent to me a few days ago by Ken:

"Hey Robert, after chasing my tail on the c50 not going anywhere which it does, I dived back in. Was tracing the signal with my scope. Saw signal on both sides of r90 but nothing on pin 7 of v2. What I found was a broken land from the bottom of r90 to pin 7. Done! Works great! Thank you Robert for all your help. I do appreciate it!"

Hope this thread proves helpful...

Many thanks to forum amp gurus @ivan H & @syscokid for their expertise and tireless dedication to helping out...

- Rob
Click to expand...
No
I'm not counted as an "amp guru..."
because I don't subscribe to popular opinions blogged on the internet. (which everyone assumes are correct just because of popularity)

No
I'm the guy who fixes Mesa Boogie amps, which the Mesa Factory techs themselves could not fix. Even when they tried to repeatedly.

I'm the guy who wrote the first reliable procedure for testing a DSL circuit board, even when nobody understood how to do it....or even tried to do it.


In other words, I'm a total worthless idiot.
Certainly not an "amp guru."

So, don't count me and my 44 years of hands on experience, I'm not popular !
I'm not on facebook either !
I'm nobody.
 
Amp Mad Scientist said:
No
I'm not counted as an "amp guru..."
because I don't subscribe to popular opinions blogged on the internet. (which everyone assumes are correct just because of popularity)

No
I'm the guy who fixes Mesa Boogie amps, which the Mesa Factory techs themselves could not fix. Even when they tried to repeatedly.

I'm the guy who wrote the first reliable procedure for testing a DSL circuit board, even when nobody understood how to do it....or even tried to do it.


In other words, I'm a total worthless idiot.
Certainly not an "amp guru."

So, don't count me and my 44 years of hands on experience, I'm not popular !
I'm not on facebook either !
I'm nobody.
Click to expand...

I have nothing but respect for you, Sir...
 
67plexi said:
I'm at 47 years at amp repair what do I know still a student.
Short buss stop's at clown world.

Click to expand...
I debated over and over of modding my 900 but it's not a Dual Reverb like his here, its an SLX. But, ive came to the conclusion to leave it the hell alone and keep it stock. I figure if Marshall took the time to basically keep evolving to that amp dating back to the first Master Volumes ( hence its unoffical nickname , the Mk4 following the 900 Mk3 and earlier JMP Mk2), it's worth keeping it as is.

Matter of fact, was gonna call my guy up north tomorrow and see when i can send it off for some repairs lol
 
Clockworkmike said:
I debated over and over of modding my 900 but it's not a Dual Reverb like his here, its an SLX. But, ive came to the conclusion to leave it the hell alone and keep it stock. I figure if Marshall took the time to basically keep evolving to that amp dating back to the first Master Volumes ( hence its unoffical nickname , the Mk4 following the 900 Mk3 and earlier JMP Mk2), it's worth keeping it as is.

Matter of fact, was gonna call my guy up north tomorrow and see when i can send it off for some repairs lol
Click to expand...
There is one mod, or two for a 900.
But most people can't handle the unbridled power and glory.
 
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