Sounds great. You could sell these!! perfect size, wattage, gain range, and full size EL-34s.

Great job Jason, appreciate the schematics and your explanations.

Sounds awesome...3 good tones, you know the tones man, great work!

Jason's guitar selection is always on point.

I really appreciate this kind of detail review and mod - fantastic content and great to share the knowledge. Much respect. Cheers.

Sounds phenomenal.

That has become a really versatile and great sounding amp Jason !

Thanks for sharing this and the details about it Jason.

Holy crap, Dude! That sounds incredible!

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 .

Mate, this sounds so good! 😮 Playing is on point too 👌

Awesome Jason! Beautiful Explorer! Cheers from Maine Dave from Iron Age

You have created my perfect amp here.

And I thought those things were incredible right out of the box! Damn!!!!

Really good tones, thanks for share Jason…👏👏👏👏 For me the best configurations are low imput with diodes and high imput without diodes

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.

marshall circuit. destroyer type guitar. old dimarzio super distortion. always gives me old school van halen vibes! kudos!

That Greko mate!!! 😍😍. Amp sounds killer too

Excellent video.

Sounds good, Jason!

Awesome, Super Video🎸

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 🙀🙀🙀

The Master does it again.

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, 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!

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:)

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.

Sounds killer! Would give you my sv20 to mod if I could!

This sounds amazing! What's the signal path? Any load boxes, IRs, mics?

Using AC/DC tunes to demo the mod doesn't hurt either. 🤘🤘🤘

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.

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 KZfaq 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 KZfaq 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'.

Sounds fantatstic, what is the signal path if I may ask. ? Especially which cabinet speakers or which IR you are using ? Thanks

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?

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

Sounds so FAT! And the depth in the sound. Once again you have removed the cardboard box tone👍

Winery dogs nice

👍👍

Almost sounds like a bogner !! So clear and defined Do you do this mod ? Thanks

Amazing. Is it better to puchase this one or the Origin and mod it?

Is there a schematic to follow this mod? This sounds incredible..

Awesome detail, thank you. So when switching out the zeners, you're also lifting the 150k from ground along with the zeners?

Would using the #2 inputs for the Jose Mod be viable, leaving the #1 inputs for the original plexi?

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

Would it be possibl to the Randy Rhoads type mod on these? Sorry if its a silly question not an amp tech

And mod for hdrx20 yet boss?

Lol, did you just create a silver Jubilee 😊

can you post a schematic please? just the paint by numbers is good for inexperienced people but i need to see schematics to understand

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?

How would you feel about moving to Sweden?

What kind of clipping diodes are you using

Oh yeah just in time haha

So you made a Jcm 800 /900 hybrid?

How much does the mod cost to have done?

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