High Voltages After Headfirst Origin 50 Mod

[Amp Mad Scientist]

My thoughts would be to just hire one of our So-Cal based amp gurus - Like @Amp Mad Scientist or @syscokid to do the mods.

I have a problem with this idea.
We have no schematics, unless we draw them ourselves.
We have nothing to follow if something goes wrong.

This is what throws up the red flag as far as I'm concerned.

We don't know if a problem is caused by the modification, or if it's a malfunction somewhere else in the amp.

Well, I would design my own mods. Not copy what everybody else does.
But I would start with a schematic before doing anything.

And any mod I make is going to be very low noise. Probably less noise than the original I start with.
Lots of people modify amps...
But getting the hiss and hum and buzzing or oscillations under control is a different ball of wax; requires a skilled person.

So you see?
The first thing you want to modify an amp is the schematics even if you make your own you still need it.

 

[67plexi]

Why put a bandage on a sucking chest wound what I got out of the first video was got the amp and flight case for $400.00 AUD that's what a flight case cost free amp.
modded amps are one trick pones and a PCB it's a can of worms sounded like the hiss master to me.

 

[Inspector #20]

I have a problem with this idea.
We have no schematics, unless we draw them ourselves.
We have nothing to follow if something goes wrong.

This is what throws up the red flag as far as I'm concerned.

We don't know if a problem is caused by the modification, or if it's a malfunction somewhere else in the amp.

Well, I would design my own mods. Not copy what everybody else does.
But I would start with a schematic before doing anything.

And any mod I make is going to be very low noise. Probably less noise than the original I start with.
Lots of people modify amps...
But getting the hiss and hum and buzzing or oscillations under control is a different ball of wax; requires a skilled person.

So you see?
The first thing you want to modify an amp is the schematics even if you make your own you still need it.

I have access to a hand drawn schematic from the author of this modification. I will post it later today.

 

[gball]

Yeah, my feeling is that if you need to mod an amp to get it to sound the way you want you have the wrong amp and need to start searching for an alternative. Whether more gain, different EQ profile, better loop, whatever, if you have to open it up and dick around with the insides you've bought the wrong amp.

 

[Inspector #20]

Confusing terminology, Robert. Fixed bias means that the circuit has components to adjust the bias. Cathode biased: No adjusting paraphernalia.

Great clarification!

 

[Inspector #20]

Yeah, my feeling is that if you need to mod an amp to get it to sound the way you want you have the wrong amp and need to start searching for an alternative. Whether more gain, different EQ profile, better loop, whatever, if you have to open it up and dick around with the insides you've bought the wrong amp.

I've never played any stock amp that really sounded good to me. However, I did like the timbre and saturation of this Headfirst mod. I also like the Caswell #39 sound.

 

[gball]

I've never played any stock amp that really sounded good to me. However, I did like the timbre and saturation of this Headfirst mod. I also like the Caswell #39 sound.

Don't take this the wrong way but based on that statement I think you need to get out and play more amps. We've never had such a broad variety to choose from, and high gain has never been cheaper.

 

[Inspector #20]

Yeah, my feeling is that if you need to mod an amp to get it to sound the way you want you have the wrong amp and need to start searching for an alternative. Whether more gain, different EQ profile, better loop, whatever, if you have to open it up and dick around with the insides you've bought the wrong amp.

I think this is just something I would really like to try, even if it's senseless...kinda like how guys amass guitars just to increase their count.

Foolishness...that's just my game.

 

[syscokid]

How difficult is this to do???

Headfirst Amps is providing a lot of info and guidance with their mods. I would think that the modding process would be easy as long as you pay attention to detail.

However... How about one of these Marshmallows for $900/Used or $1900/New with warranty?

Marshall JVM205H 2-Channel 50-Watt Guitar Amp Head | Reverb

The Marshall JVM205H 50W two-channel tube guitar head that's wildly versatile, with multiple modes (six in total), and a fully programmable footswitch.

reverb.com

 

[Inspector #20]

Don't take this the wrong way but based on that statement I think you need to get out and play more amps. We've never had such a broad variety to choose from, and high gain has never been cheaper.

You might be surprised at how many amps I am allowed to play in my daily work. Between working in the studio, playing in three bands and working as a part time stage hand/guitar tech, I've been fortunate to play through a lot of amps.

Only the Engl Fireball truly impressed me, but I'm too frugal to buy one...lol

 

[Inspector #20]

Headfirst Amps is providing a lot of info and guidance with their mods. I would think that the modding process would be easy as long as you pay attention to detail.

However... How about one of these Marshmallows for $900/Used or $1900/New with warranty?
View attachment 65827

Marshall JVM205H 2-Channel 50-Watt Guitar Amp Head | Reverb

The Marshall JVM205H 50W two-channel tube guitar head that's wildly versatile, with multiple modes (six in total), and a fully programmable footswitch.

reverb.com

A few of the local studio's have these as house amps. They are OK but I wasn't own away.

JCM800's are the amps du jour, and I only like them with an extra gain stage.

 

[gball]

You might be surprised at how many amps I am allowed to play in my daily work. Between working in the studio, playing in three bands and working as a part time stage hand/guitar tech, I've been fortunate to play through a lot of amps.

Only the Engl Fireball truly impressed me, but I'm too frugal to buy one...lol

You'd save money and a lot of tone-chasing in the long run if you just got one. You'll probably end up there anyway if that's the tone you are after, because Engls are kind of their own thing and you will never get a Marshall to sound like one through modding. Well, maybe with a JVM, but then you're into Engl price territory so why not get what your heart desires?

 

[gball]

A few of the local studio's have these as house amps. They are OK but I wasn't own away.

JCM800's are the amps du jour, and I only like them with an extra gain stage.

View attachment 65828

View attachment 65829

I love me some JCM-800 tone (I played one live for about a decade) but I would not consider them a high-gain, or for that matter very versatile, amp.

 

[Don O]

A few of the local studio's have these as house amps. They are OK but I wasn't own away.

JCM800's are the amps du jour, and I only like them with an extra gain stage.

View attachment 65828

View attachment 65829

Robert, is that 7th pot on the far right an addition? I don’t see that on a 800 lead series I’be been watching.

 

[Inspector #20]

You'd save money and a lot of tone-chasing in the long run if you just got one. You'll probably end up there anyway if that's the tone you are after, because Engls are kind of their own thing and you will never get a Marshall to sound like one through modding. Well, maybe with a JVM, but then you're into Engl price territory so why not get what your heart desires?

Well, there are a lot of reasons reality and our philanthropic ventures are my biggest self-limitation, but its something that I'm very passionate about.

 

[Inspector #20]

I love me some JCM-800 tone (I played one live for about a decade) but I would not consider them a high-gain, or for that matter very versatile, amp.

I tend to agree. I mean, it's a great amp for what we do, like the Germino Lead 55, but not super versatile.

 

[Inspector #20]

Robert, is that 7th pot on the far right an addition? I don’t see that on a 800 lead series I’be been watching.

Yes, that's something from the Mike Morin modification...not too sure what it does exactly.

It's a very sloppy mod. Mike also paints over resistors and caps with conductive paint to hide his work. It's a total joke.

Search for a thread herein titled "JCM800 Goes Boom" for gut shots...

 

[Inspector #20]

https://www.worthpoint.com/worthopedia/mike-morin-preamp-amp-wizard-marshall-139542442

 

[Clockworkmike]

I love me some JCM-800 tone (I played one live for about a decade) but I would not consider them a high-gain, or for that matter very versatile, amp.

There in lies the great diode clipping debate. It is nearly impossible in any realistic situation for any amp designer to conjure ultra hi gain without them somewhere in the mix. The highest gain Marshall that i know of that doesnt utilize Clipping Diodes is a JCM900 SLX 2500/2100 and it is really nothing more than a factory modded 800 using an extra preamp tube. They are by definition, a Hi Gain amp and border into Ultra Hi Gain areas but not quite there. Without a boost, it cant quite make it. But then again: what is a boost but diodes? Lol

 

[Inspector #20]

There in lies the great diode clipping debate. It is nearly impossible in any realistic situation for any amp designer to conjure ultra hi gain without them somewhere in the mix. The highest gain Marshall that i know of that doesnt utilize Clipping Diodes is a JCM900 SLX 2500/2100 and it is really nothing more than a factory modded 800 using an extra preamp tube. They are by definition, a Hi Gain amp and border into Ultra Hi Gain areas but not quite there. Without a boost, it cant quite make it. But then again: what is a boost but diodes? Lol

I wish that I even had conversational knowledge of these amps. All I really do is change tubes and bias to keep them running...