Sounds great, and love that the other input is the stock plexi sound. I was torn between the sv20 and sc20 but this does both basically. EDIT: I have since realised you have a modded SC20 video as well. Would be great to do a head to head comparison and show what ranges they cover, overlap or where each makes sense etc.
Wow sounds fantastic. Question: is one input disabled when the other one is used? Or would be able to use an a/b switcher to in effect have two channels?
Sounding great, Jason! Nice mods to an already great sounding amp. Good to see people finally waking up to quality Japanese guitars, they easily hold their own against Gibsons and Fenders. Used to be a weird kind of stigma attached to them back in the 80's/90's, but that's just ignorance.
@@HeadfirstAmps For sure. My first Les Paul was a Burny, it was amazing. Couldn't afford a Gibson. When I finally got to play a Gibson Les Paul I was actually disappointed by comparison!
lol…on a wider scale we’ve been woken up to Japanese guitars for over 25 years. Unfortunately this means the prices have got too high for them (domestically in the U.S.) to be a real deal anymore. Have to try and find them through Japanese sites.
These videos are astonishing. How even one capacitor can dramatically change, or improve tone. *Your amps/mod's are an extraordinary, and a text-book example of what happens when you combine a passion for what you do with the commitment, and ambition to stick with it.* That said, it's important to keep in mind that pro's don't comb UA-cam for amp mod, or amp building videos There's a very large percentage of people who have absolutely NO idea what you're talking about. All they know is that, they love amps, and tone-chasing, and mod's are a huge part of that, and you're brilliant at what you do, and they want to be like you. And, no amount of knowledge, regardless of how fundamental, should ever be assumed (that in-and-of itself, can and usually does, lead to catastrophic consequences). At best you'll get the periodic electrician who while they may understand a diagram, or the different capacitor, fuse, or diode values/functions.....they still don't necessarily know how an amp works, and what component effects what aspect of the tone. *For that reason, sometimes "paint-by-numbers" is by FAR the best way to do these videos.* I agree, it's almost always (as far as UA-cam goes) completely impractical to explain an entire amp build/functionality for the sake of explaining the functionality of a given mod. And, that approach is almost always WAY too much info for a newbie to absorb, when for the sake of getting the mod done, they just want to know what to solder/de-solder, and where. When an otherwise, very-inspired viewer get's overwhelmed, these videos turn into nothing more than a brilliant display of your abilities. *Which is more-than-enough reason to watch these videos, as far as I'm concerned. Watching talented pro's work, never get's old* But, if the purpose of these kinds of videos is to help get people comfortable with doing their own mod's, then a paint-by-numbers approach, or better yet, a more intensive online class-room style approach, doing the more simple mod's, would work best. I believe that's been brought up before, if memory serves. And, you can, and should, charge for that. You'd make some good money making a very well-thought-out, clear, articulate, easy to understand video on an A-Z mod, that people could refer to as many times as they need to. Most of these mod's could be done in what....a couple of hours? How long does it take to understand the complete layout functionality of a Marshall head??? . Yes, it's an enormous amount of work to do something THAT tedious. But, what's the alternative? Buying some PCB's, and a bunch of components, then referring to Facebook groups isn't enough.....at least not initially. It's just a suggestion if a your goal is to truly get people who don't know any better, to get comfortable with doing these mods. Possibly building an amp from scratch where you have a blank slate to work with is a better way to approach this stuff. Rather than jumping into an intimidating PCB with thousands of capacitors on an $1800 head. Not trying to be over-critical...as stated, I'm a huge fan. Just trying to help the people learning the basics of this stuff, get the most out of these videos. You don't want to find out someone ruined an $1800 amp, because they had $10, and a false, sense of confidence, due to a very inspiring video, watching someone who's been doing this for a VERY long time. Just sayin'.
You went to a lot of effort to write this, thanks for that. Uncle Doug has over 100k subs, which tells me there is an audience there for amp tech content. If it’s not obvious, I do these videos for me. For my profile. If it helps someone who has skills then great, that’s a bonus. Mostly these videos are used by guys that take their amps to their local tech to implement the mod. Look at the Origin series. Sometimes they tackle the mod themselves with a very high success rate. Just look at my DIY builders group on Facebook. Maybe one day, when I can do headfirst full time (I have a regular day job) I can do online classes and the like. Until then it’s the odd video in my ‘spare time’
@@HeadfirstAmps I probably could've made my same point in a lot fewer words....sorry about that. That's the downfall of being able to type 70wpm. But, I digress. You're 100% correct. What you're doing is working (I didn't mean to insinuate that in any way) Just wasn't sure what your overall goal was from a teaching perspective. I don't always follow what you're doing, but watching you is always fun...and I've been watching for quite a long time now with the intention of getting a cheaper amp (like the Origin you mentioned), and giving this a go. When the time comes for doing one of those virtual classes, I'd love to be one of your guinea pigs. I think it would be an amazing learning experience, if you have the stomach to spoon-feed a bunch of newbies... That can be challenging, given the patience required. But, I think you'd do very well with it, should you be inspired one day to give it a try. Btw...that Marshall sounded great! Didn't mean to leave that part out. Not sure what the big deal is with modding a Marshall, given people have been doing it for decades. Especially, when you can improve it to that degree. Seems like a no-brainer to me.👍
Sounds great Phil….if you have any views on what folks might be prepared to pay for online tuition I’m all ears. Maybe that’s what Patreon is all about these days.?
@@HeadfirstAmps Would be more than happy to, Jason. Patroon is always one way to go, but honestly I think your existing business model would be fine, as far as charging tuition. For instance, you would just sell a limited number of reservations for a class, paid in advance, for a set date, with the technical requirements, equipment needed, etc… listed in the description of the class. Keep that part of it simple. Let me look into what others are doing (or the closest thing to it), and I’ll let you know what I find. If you see do decide that you’d like to test those waters, you can always use me, and maybe one or two other students, as a small test class. That way, if it goes to hell, for some reasons on, you’re not left with a mess on your hands, and we can see what problems could potentially arise that we didn’t foresee. And, if it turns out that there’s just too much involved, then at least you can say you tried, and no harm done. Like you said, if this is a side-gig, so to speak, you definitely don’t want to take on something that’s taking up all your free time. I was just recently in a situation like that, and it made me miserable. But, it definitely seems like the demand is there, should you have the interest. In the meantime I’ll see what I can find out in terms of “virtual classroom” software needed, and what others are charging, to give you a little info to go off of. Stay tuned!
@Jason, you have 20 watters wetting their pants with your amazing upgrades. I have an SV20H and will be having this mod done. I'm in the UK otherwise I'd be bringing the amp to you!
Great vid as always Jason, always something to learn, and love the shirt!!. Winery Dogs is one of my favourite bands. As for Japanese guitars, man!. There's a reason the market for them is on the rise in price. I'll take my Edwards over a Les Paul any day, and I've owned Gibson's in the past.
Jason, you gotta try some clipping diodes after the treble wiper, nbefore the master vollume!! it sounds very power amp style distortion and lets you "shape" the sound with EQ! I like green leds ;)
You must be loving that Friedman JEL-100 in the background:) I'd love to hear that fired up and compared to the JCM800. Edit: That SV20H is no slouch:)
Damn! That sounds insane! More gain than the SC20H, and way better tone than the DSL20 (which I guess would be the closest stock Marshall you could get). Btw, have you heard of Neural Amp Modeller (NAM)? It would be really awesome to have a capture of this modded amp! You don't really need to have anything special, other than a reamp/DI box, to capture amps.
Jason, I spoke with you several months ago about turning an sv20h into a jcm800 or 2203. My question is this, is the high input with the diodes switched off the same as the jcm800/2203 circuit? If so how could I accomplish this without adding the switch pot and diodes?
@@HeadfirstAmps oh ok, I thought that a jcm800/2203 was just a 1959 circuit with a cascaded gain and master volume. Would I be able to get 800/2203 tone and gain structure using any of this layout you provided?
Hey mate love your videos and tone. Would be good to know signal chain right at start of video. Eg what cab / IR are you using as this has a massive effect on the tone etc
I already have been dreamy eyed and weak in the knees for an sv20 but these mods are pushing me to sort of a ...climbing the rope in gym class.....situation
I priced these components and they came out to $10.13. So.......not exactly $10.00 worth of parts. Seems that you are "missing' $.13 worth of parts. Just kidding......but you are missing $.13 worth of componentry here. Every cent counts...................... Great tone. That being said.......digital rules. Tubes are getting better but digital products rule the world.................amps are trailing far behind. Fussy and expensive. Big fan of the channel, Ben
Man why even bother commenting rambling crap like this? When you bought the amp let's say new, you can perform this simple mod by 10 bucks worth of parts, do these thirteen cents that you're rambling about really matter??? How much would you be paying Jason to perform this mods, or any other amp tech for that matter? Are you going to buy these marshall amps in bulk to sell the modded versions, so you have to count pennies because it eats away from your profit? Next time think hard before commenting crap like this... thirteen cents is too much for a bunch of parts, but then uses a 7 liter V8 to go to the grocery store 😂😂😂 Let's not comment about what comes next about analog amps and digital crap 😂😂😂
![[UA] NAVI vs MOUZ | BO5 | IEM Rio 2024](http://i.ytimg.com/vi/CMBYk0cbGoA/mqdefault.jpg)
Fun. DIY is more satisfying than just putting a pedal in front of the amp.
Holy crap, Dude! That sounds incredible!
Sounds great, and love that the other input is the stock plexi sound. I was torn between the sv20 and sc20 but this does both basically.
EDIT: I have since realised you have a modded SC20 video as well. Would be great to do a head to head comparison and show what ranges they cover, overlap or where each makes sense etc.
That has become a really versatile and great sounding amp Jason !
Dude. That guitar…SMOKIN’. Kudos.
That Greco is gorgeous and such a cool mod for the lil plexi too , putting on the push pull pot is classy AF .
Sounds phenomenal.
Mate, this sounds so good! 😮 Playing is on point too 👌
Hey Dan, thanks man!! Hope you’re well brother.
marshall circuit. destroyer type guitar. old dimarzio super distortion. always gives me old school van halen vibes! kudos!
And I thought those things were incredible right out of the box! Damn!!!!
Wow sounds fantastic. Question: is one input disabled when the other one is used? Or would be able to use an a/b switcher to in effect have two channels?
Sounding great, Jason! Nice mods to an already great sounding amp. Good to see people finally waking up to quality Japanese guitars, they easily hold their own against Gibsons and Fenders. Used to be a weird kind of stigma attached to them back in the 80's/90's, but that's just ignorance.
Agree! This Grecko could be put up alongside anything I’ve ever played and compete.
@@HeadfirstAmps For sure. My first Les Paul was a Burny, it was amazing. Couldn't afford a Gibson. When I finally got to play a Gibson Les Paul I was actually disappointed by comparison!
@@HeadfirstAmpswould love to see a video on "Dookie" mod on this amp.
(Bradshaw Gain Mod; I believe)
lol…on a wider scale we’ve been woken up to Japanese guitars for over 25 years. Unfortunately this means the prices have got too high for them (domestically in the U.S.) to be a real deal anymore. Have to try and find them through Japanese sites.
Would using the #2 inputs for the Jose Mod be viable, leaving the #1 inputs for the original plexi?
These videos are astonishing. How even one capacitor can dramatically change, or improve tone. *Your amps/mod's are an extraordinary, and a text-book example of what happens when you combine a passion for what you do with the commitment, and ambition to stick with it.* That said, it's important to keep in mind that pro's don't comb UA-cam for amp mod, or amp building videos There's a very large percentage of people who have absolutely NO idea what you're talking about. All they know is that, they love amps, and tone-chasing, and mod's are a huge part of that, and you're brilliant at what you do, and they want to be like you. And, no amount of knowledge, regardless of how fundamental, should ever be assumed (that in-and-of itself, can and usually does, lead to catastrophic consequences). At best you'll get the periodic electrician who while they may understand a diagram, or the different capacitor, fuse, or diode values/functions.....they still don't necessarily know how an amp works, and what component effects what aspect of the tone. *For that reason, sometimes "paint-by-numbers" is by FAR the best way to do these videos.* I agree, it's almost always (as far as UA-cam goes) completely impractical to explain an entire amp build/functionality for the sake of explaining the functionality of a given mod. And, that approach is almost always WAY too much info for a newbie to absorb, when for the sake of getting the mod done, they just want to know what to solder/de-solder, and where. When an otherwise, very-inspired viewer get's overwhelmed, these videos turn into nothing more than a brilliant display of your abilities. *Which is more-than-enough reason to watch these videos, as far as I'm concerned. Watching talented pro's work, never get's old*
But, if the purpose of these kinds of videos is to help get people comfortable with doing their own mod's, then a paint-by-numbers approach, or better yet, a more intensive online class-room style approach, doing the more simple mod's, would work best. I believe that's been brought up before, if memory serves. And, you can, and should, charge for that. You'd make some good money making a very well-thought-out, clear, articulate, easy to understand video on an A-Z mod, that people could refer to as many times as they need to. Most of these mod's could be done in what....a couple of hours? How long does it take to understand the complete layout functionality of a Marshall head??? . Yes, it's an enormous amount of work to do something THAT tedious. But, what's the alternative? Buying some PCB's, and a bunch of components, then referring to Facebook groups isn't enough.....at least not initially. It's just a suggestion if a your goal is to truly get people who don't know any better, to get comfortable with doing these mods. Possibly building an amp from scratch where you have a blank slate to work with is a better way to approach this stuff. Rather than jumping into an intimidating PCB with thousands of capacitors on an $1800 head. Not trying to be over-critical...as stated, I'm a huge fan. Just trying to help the people learning the basics of this stuff, get the most out of these videos. You don't want to find out someone ruined an $1800 amp, because they had $10, and a false, sense of confidence, due to a very inspiring video, watching someone who's been doing this for a VERY long time. Just sayin'.
You went to a lot of effort to write this, thanks for that. Uncle Doug has over 100k subs, which tells me there is an audience there for amp tech content. If it’s not obvious, I do these videos for me. For my profile. If it helps someone who has skills then great, that’s a bonus. Mostly these videos are used by guys that take their amps to their local tech to implement the mod. Look at the Origin series. Sometimes they tackle the mod themselves with a very high success rate. Just look at my DIY builders group on Facebook.
Maybe one day, when I can do headfirst full time (I have a regular day job) I can do online classes and the like. Until then it’s the odd video in my ‘spare time’
@@HeadfirstAmps I probably could've made my same point in a lot fewer words....sorry about that. That's the downfall of being able to type 70wpm. But, I digress. You're 100% correct. What you're doing is working (I didn't mean to insinuate that in any way) Just wasn't sure what your overall goal was from a teaching perspective. I don't always follow what you're doing, but watching you is always fun...and I've been watching for quite a long time now with the intention of getting a cheaper amp (like the Origin you mentioned), and giving this a go. When the time comes for doing one of those virtual classes, I'd love to be one of your guinea pigs. I think it would be an amazing learning experience, if you have the stomach to spoon-feed a bunch of newbies... That can be challenging, given the patience required. But, I think you'd do very well with it, should you be inspired one day to give it a try. Btw...that Marshall sounded great! Didn't mean to leave that part out. Not sure what the big deal is with modding a Marshall, given people have been doing it for decades. Especially, when you can improve it to that degree. Seems like a no-brainer to me.👍
Sounds great Phil….if you have any views on what folks might be prepared to pay for online tuition I’m all ears. Maybe that’s what Patreon is all about these days.?
@@HeadfirstAmps Would be more than happy to, Jason. Patroon is always one way to go, but honestly I think your existing business model would be fine, as far as charging tuition. For instance, you would just sell a limited number of reservations for a class, paid in advance, for a set date, with the technical requirements, equipment needed, etc… listed in the description of the class. Keep that part of it simple. Let me look into what others are doing (or the closest thing to it), and I’ll let you know what I find. If you see do decide that you’d like to test those waters, you can always use me, and maybe one or two other students, as a small test class. That way, if it goes to hell, for some reasons on, you’re not left with a mess on your hands, and we can see what problems could potentially arise that we didn’t foresee. And, if it turns out that there’s just too much involved, then at least you can say you tried, and no harm done. Like you said, if this is a side-gig, so to speak, you definitely don’t want to take on something that’s taking up all your free time. I was just recently in a situation like that, and it made me miserable. But, it definitely seems like the demand is there, should you have the interest. In the meantime I’ll see what I can find out in terms of “virtual classroom” software needed, and what others are charging, to give you a little info to go off of. Stay tuned!
Thanks Phil!
Sounds great. You could sell these!! perfect size, wattage, gain range, and full size EL-34s.
@Jason, you have 20 watters wetting their pants with your amazing upgrades. I have an SV20H and will be having this mod done. I'm in the UK otherwise I'd be bringing the amp to you!
Post your results in our DIY group on FB….if you’re on Facebook that is!
@@HeadfirstAmps Will do! Might be a whilst though as I need to get the parts in and there is a wait period for stock.
Really good tones, thanks for share Jason…👏👏👏👏
For me the best configurations are low imput with diodes and high imput without diodes
Good to hear this, yeah not all the tones are in the highest gain setting!
You have created my perfect amp here.
The Master does it again.
Hey man, tnx!
Awesome Jason! Beautiful Explorer! Cheers from Maine
Dave from Iron Age
Hey Dave, hope you’re well mate!
I really appreciate this kind of detail review and mod - fantastic content and great to share the knowledge. Much respect. Cheers.
Sounds awesome...3 good tones, you know the tones man, great work!
Jason's guitar selection is always on point.
Is there a schematic to follow this mod? This sounds incredible..
Using AC/DC tunes to demo the mod doesn't hurt either. 🤘🤘🤘
Sounds fantatstic, what is the signal path if I may ask. ? Especially which cabinet speakers or which IR you are using ? Thanks
Great vid as always Jason, always something to learn, and love the shirt!!. Winery Dogs is one of my favourite bands. As for Japanese guitars, man!. There's a reason the market for them is on the rise in price. I'll take my Edwards over a Les Paul any day, and I've owned Gibson's in the past.
Thanks! That Greco is pretty special!
@@HeadfirstAmps I look forward to seeing more of it!. Is there a story behind it?, or it's the fact it's a guitar with serious mojo?!.
Just a rare find. 1978. Greco’s were not exported so are pretty hard to find in this vintage. The build quality is amazing.
Great job Jason, appreciate the schematics and your explanations.
Awesome, Super Video🎸
This sounds amazing! What's the signal path? Any load boxes, IRs, mics?
Awesome detail, thank you.
So when switching out the zeners, you're also lifting the 150k from ground along with the zeners?
You can keep the 150k grounded, less chance of any pop
@@HeadfirstAmps will do, thank you sir.
Excellent video.
Thanks!
Jason, you gotta try some clipping diodes after the treble wiper, nbefore the master vollume!! it sounds very power amp style distortion and lets you "shape" the sound with EQ! I like green leds ;)
Can't wait to get this bad boy! Also, that Greco 🙀🙀🙀
Ed!! You should have the amp by now??
@@HeadfirstAmps haha I haven't been into the office, I'll have to check the tracking.
You must be loving that Friedman JEL-100 in the background:) I'd love to hear that fired up and compared to the JCM800.
Edit: That SV20H is no slouch:)
The JEL is a beast for sure.
Amazing. Is it better to puchase this one or the Origin and mod it?
That Greko mate!!! 😍😍. Amp sounds killer too
It was a lucky find Chris…it’s so nice to play!
Damn! That sounds insane! More gain than the SC20H, and way better tone than the DSL20 (which I guess would be the closest stock Marshall you could get).
Btw, have you heard of Neural Amp Modeller (NAM)? It would be really awesome to have a capture of this modded amp! You don't really need to have anything special, other than a reamp/DI box, to capture amps.
Have heard of the NAM but not checked it out yet
Would it be possibl to the Randy Rhoads type mod on these? Sorry if its a silly question not an amp tech
Sure, that’s possible
Sounds good, Jason!
Tnx Robb!
Sounds killer! Would give you my sv20 to mod if I could!
Jason, I spoke with you several months ago about turning an sv20h into a jcm800 or 2203. My question is this, is the high input with the diodes switched off the same as the jcm800/2203 circuit? If so how could I accomplish this without adding the switch pot and diodes?
Not exactly, this is higher gain than a stock 2204 even with diodes out
@@HeadfirstAmps oh ok, I thought that a jcm800/2203 was just a 1959 circuit with a cascaded gain and master volume. Would I be able to get 800/2203 tone and gain structure using any of this layout you provided?
@@rodneystaats9817a jcm uses a cold clipper 10k cathode resistor in the low gain input stage
Hey mate love your videos and tone. Would be good to know signal chain right at start of video. Eg what cab / IR are you using as this has a massive effect on the tone etc
Good tip. This was into an original Suhr reactive load and a York Audio black back IR
Almost sounds like a bogner !!
So clear and defined
Do you do this mod ?
Thanks
Yes, this was done for a customer. You can contact me if you want the same for your amp.
Sounds so FAT! And the depth in the sound. Once again you have removed the cardboard box tone👍
How would you feel about moving to Sweden?
Well, I can think of worse places!
What kind of clipping diodes are you using
Regular zeners. In this config I go higher values 20v or so.
Winery dogs nice
I already have been dreamy eyed and weak in the knees for an sv20 but these mods are pushing me to sort of a ...climbing the rope in gym class.....situation
👍👍
So you made a Jcm 800 /900 hybrid?
Ah no, a 900 has solid state gain stages
can you post a schematic please? just the paint by numbers is good for inexperienced people but i need to see schematics to understand
Well, I did do a schematic walk through of the front end. There’s enough info here to draw your own one up.
And mod for hdrx20 yet boss?
Lol, did you just create a silver Jubilee 😊
No. Completely different circuit
How much does the mod cost to have done?
You can email me for prices
Oh yeah just in time haha
Hey Paul!
I priced these components and they came out to $10.13. So.......not exactly $10.00 worth of parts. Seems that you are "missing' $.13 worth of parts.
Just kidding......but you are missing $.13 worth of componentry here. Every cent counts......................
Great tone. That being said.......digital rules. Tubes are getting better but digital products rule the world.................amps are trailing far behind. Fussy and expensive.
Big fan of the channel,
Ben
Whaaaaaat ?
Digital sucks mate. Yes Digital is cheaper and more convenient and more versatile, but it still feels and sounds shit.
Man why even bother commenting rambling crap like this?
When you bought the amp let's say new, you can perform this simple mod by 10 bucks worth of parts, do these thirteen cents that you're rambling about really matter???
How much would you be paying Jason to perform this mods, or any other amp tech for that matter?
Are you going to buy these marshall amps in bulk to sell the modded versions, so you have to count pennies because it eats away from your profit?
Next time think hard before commenting crap like this... thirteen cents is too much for a bunch of parts, but then uses a 7 liter V8 to go to the grocery store 😂😂😂
Let's not comment about what comes next about analog amps and digital crap 😂😂😂