Turn your Origin 20 into a PROPER PLEXI!!

[@matthewf1979]

I am FLOORED at how good that sounds with a few relatively simple mods. You killed it! Marshall couldn’t build these like this. The Studio Vintage line would sit and rot on the music store shelves.

[@HeadfirstAmps]

Thanks. Playing it again today, it really rips at about 8/10 on the treble channel!

[@jackbyrd4921]

@@HeadfirstAmps Are these mods that novice could do relatively easy. I have one brand new in the Box. I've had it a while so I'm not worried about the warranty.

[@nates4936]

@@jackbyrd4921 I wouldn’t necessarily say a novice, but intermediate with soldering? My experience in the past has been with effects pedal kits and made about 8 or so of those. The two scariest parts for me with the original headfirst mod were: the screws that hold in the main pcb are cheap and strip easily, one of mine totally stripped and I had a really challenging time getting it out, and second - getting the perfect soldering iron temperature to melt the cheap and/or lead-free solder used on the board without burning traces. Other than that everything went pretty smoothly!

[@willdenham]

​@@nates4936I believe he was asking Headfirst.

[@frequencyOneTV]

I heard that Darkness riff! Nicely done...and the sound of the amp...I picked up an Origin 20 combo recently for my studio so I'll be following suit!

[@jayteesgear]

Bought an Origin 50 and sent it back within 5 Days! I put every pedal through it and NEVER got an actual “Marshall” sound out of it. I cannot believe you made this 20 sound good. I literally had to pay 1/7 the price in shipping to return it. Never shoulda sold my 80’s Jcm 800.

[@HeadfirstAmps]

The stock Origin circuit is really a mess. Marshall could have made it more true to it 'origins' as the name implies!

[@jayteesgear]

@@HeadfirstAmps agreed. But I LOVE what youve done with it!

[@1973strat]

Did you try an EQ in the loop? Sounds much better. A low gain Tumnus into a Revv G3 up front, and a 10 band in the loop.

[@willdenham]

Did you try turning the master up?

[@killer268]

Agreed the stock origin sounds pretty good, but the gain needs to be dimed, and the master has to be between 6-10 @@willdenham

[@christopherguzzi1316]

The hot rodded Plexi tone you had with the Les Paul was killer. Thanks for doing the work to achieve these results.☺

[@massapower]

I swear my phone almost dropped out of my hands... What a FKN SOUND and that's plugged straight IN. No ridiculous Distortion pedals . Great stuff MATE.. The way a MARSHALL should sound !!😜🤟👍🏻

[@HeadfirstAmps]

Straight in!

[@batpigguitar]

Magic, your going to boost origin sales.

[@HeadfirstAmps]

They could have made the Origin sound so much better - and used less components to do it!

[@IgnisIban]

Coolest mods on the world! Thanks to share all this with humanity! Sound so good and make this amps truly “origins”

[@ronylemos4797]

Awesome, I bought my Origin 20 in 2018 few months before returning to Brazil, it has been my baby, thrully workhorse ...love this amp. You created a monster my friend 😂😂😂😂 I'm going to research this. Thanks for sharing. Cheers from Brazil

[@HeadfirstAmps]

Cheers!

[@wenzelli]

The mod sounds great and the large box cab on the 1987t looks cool too. Ive been wanting to build a plexi for a while. Always fun to rip an amp on 10.

[@PsionicAudio]

Good job man. And to think they could sound like this from the factory at the same price - IF they had designers like you.

[@HeadfirstAmps]

Lyle! Thanks brother. I still haven’t figured out why they came up with the Origins alongside the Studio series…they should have stuck with the classic circuits and then perhaps had the Vietnamese assembled ones and the UK assembled at different price points. Also, both the Origin and Studio series are built with identical components right down to transformers.

[@waynecribb4922]

Exactly.

[@TheIrishLoaf]

@@HeadfirstAmps The Origin is an original Fender-based circuit from which many other Marshall amps are modded with. That is why it's a pedal taker. You put a Friedman BE-OD in front, and you have a JCM800. You put a Small Box in front and you have a Plexi.

[@HeadfirstAmps]

It’s none of those things, but if you like the amp stock then good for you.

[@TheIrishLoaf]

​@@HeadfirstAmps The Origin is based on a Fender bassman. That is why comparison videos use a Fender bassman. You said you don't know why it is made the way it is, and there is your answer. If it is not that, then what is it?

[@myuncle2]

You know, I heard all your demos, and every time I have to say, this is the best sound so far. This time, I am afraid I have to say the same thing again, this is the best sound from your demos so far, I remember the Alta and the first Origin mod sounded great, but this new mod sounds even better. Speechless. I would record an album with this tone.

[@HeadfirstAmps]

Hey Michael, thanks man. New Alta demos yet to come, hopefully you’ll say the same again!

[@myuncle2]

@@HeadfirstAmps I find it hard to believe I'll hear something better than this Origin mod, it's the perfect guitar sound. But I'll be happy to be surprised by the Alta!

[@boatingforbeginners7949]

Genius! You couldv started a whole new career now doing these mods for players.. Your'e gonna be a busy guy.. Sounds awesome

[@jaydendrennan9567]

I just had this mod done to my Origin 50 and could not be happier! Super thick and crunchy like a Marshall should be. Thanks for the demo and the parts list!

[@HeadfirstAmps]

Great to hear!

[@obsessedwithguitars3157]

Is there any difference doing this mod to the Origin 50? I just bought one and was going to do the JCM800 mod, but now I want to do this instead!

[@HeadfirstAmps]

With the Origin50 there will be a slight difference with how the PPIMV is wired - as it’s a fixed bias amp rather than cathode bias like the O20

[@obsessedwithguitars3157]

@@HeadfirstAmps I see the list on your site for the 20 plexi parts, is there a note about the ppimv difference? Want to do it right!

[@frednoce3043]

If you don't mind me asking, how much did it cost to have this mod done by a tech (parts and labor)?

[@jhut5150]

Wow! That is incredible. I have an Origin 20 head and while I like it, I’d LOVE to have these mods done. Being in the states, I’m sure it would cost a fortune to send mine your way and have the work done. Well done!! Thanks for sharing the video.

[@HeadfirstAmps]

Take it to a local tech to follow the vid!

[@vondragonnoggin]

I like this mod better than the JCM800 type. Partial to that Plexi sound. Great work!

[@phillamoore157]

OMG….this sounds as good, if not better than the SV20! I can NOT believe you got this sounding THAT good. And, these amps are dirty cheap in the states. The problem though is that, for us newbies, the explanation in the video wouldn’t be enough to buy one and try this on your own. I think I brought it up before in one of your videos. But, this type of mod would be a GREAT live stream for guys that have one who want to get their hands wet with this stuff. It’s incredibly exciting knowing this amp can sound like this, with comparatively little money. But, a bit disappointing, knowing it’s still above a lot of people’s heads. But, you’ve out done yourself, yet AGAIN….. 👍

[@cliffords2315]

I would buy two if i could get them setup like this

[@robertlevasseur8896]

I gonna agree with this. I recently picked one up used for $300, and I'd love a more step my step tutorial to do this on my own.

[@phillamoore157]

@@robertlevasseur8896 Hang in there. I told Jason I’d get him some info on how to get online classes going, quite some time ago, and “life” got in the way. It may seem simple, but there’s quite a lot involved in an online class like this (soldering knowledge, making sure everyone has the same kits, scheduling, what would be charged, time-zones…..and whether or not Jason has the patience and interest to teach newbies, etc, etc). So, hand in there. Hopefully, before the end of the year he’ll have some sort of a prototype class setup to test the waters with this idea (so to speak).

[@johnmarshall3903]

Very cool, better sounding and more versatile than a Studio Vintage 20 and less than 1/2 the cost!

[@HeadfirstAmps]

Hard to beat at the price

[@anthonysilva5312]

Disagree

[@davidwicksmusic]

Sounds amazing, as soon as I can get a second hand one I'll be sending it your way to mod!

[@BradsGuitarGarage]

Bro, the face says it all! Sounded like The Bronx - 'White Tar' at the start there.

[@P3t3rPizzarelli]

Flick of the Switch! That album doesn't get enough love

[@HeadfirstAmps]

Agree!

[@weschilton]

You really know your stuff, Jason! That little amp sounds huge!

[@BenjaminDodkin]

Played a bit of ‘black shuck’. love that!

[@richardpierce7819]

I have an origin 50 but I had kt 66 power tubes installed. Now its killer. That said I still find myself using my fenders either my twin reverb 2 or my deluxe reverb 2 ( these are Paul Revera modded amps ) and they rock.

[@davidboyer4466]

Awesome video man! thanks for making it .

[@HeadfirstAmps]

Glad you liked it!

[@YMESYDT]

This is a really cool series idea if you ever wanna do more of these. Make your studio vintage a Jose, make your etc etc. Awesome vid!

[@CianRourke]

The second you started playing Black Shuck I subscribed.

[@HeadfirstAmps]

Awesome, and welcome!!

[@andrewdenine1685]

I should have been subscribed to this channel before . Thanks for this much appreciated 👍👍👍

[@HeadfirstAmps]

Welcome!

[@ericzeng318]

What a nice job! It sounds so good! I wonder if you can still get the same nice clean tone after the mod?

[@MAP448]

Great show bro!

[@denisvanwassenhoven3822]

Great video! Wonderful!! I agree with the other commentators. Marshall should make such a version. I have the combo version, which I truly like. However, I must use a pedal with it which isn't needed with your mod.

[@tonefreak3403]

Awesome stuff! Always look forward to another video!🤘

[@me.roderick]

What a killer channel🌟🌟🌟🌟🌟

[@HeadfirstAmps]

Thanks!

[@johnmarshall3903]

Totally agree!

[@anthonydevito1298]

Tasty licks on that Kramer bro, well done!!!

[@HeadfirstAmps]

Thanks!

[@jessejorgensen3931]

Just got a 50 and i love it. I may have to get another and have it modded. Gotta say it's my first real amp. I hung around s.s. because one of my favorite home audio amps is the gfa 555. But nothing touches a nice sounding tube amp. I wanted the opposite to be true. Definitely not in the 500 dollar range anyway.

[@HandWiredAmps]

Sweet! Next Mod!, ....pull those factory modded boards out and drop in one of "your boards" using the stock transformers and chassis. It's the next logical mod. The stock PT is offset on the center tap (blue/brown wires) on both the O20 and O50. And when you do it for the O50 move the poor humming OT. Finishing up another handwired O50 here now. Thanks for the videos!!!!

[@HeadfirstAmps]

Like I did with the JCM900 right. 👍

[@Swanlord05]

My 1959 plexi.....now sounds like it pops and boils water when i turn it on .....any ideas HELP!

[@rareform6747]

Have two 50Origins in stereo and love there smooth harmonics 💫 I do roll back bass on both !

[@hungry4des]

Can I make it so the plate bias change to the power section that happens with the flick of the wattage switch also changes the plate bias of the pre-amp tubes?

[@speedunknown]

You’re in Australia, are there any Americans you might recommend for doing your mods? They’re excellent. I wish you lived here, because I’d certainly get buy this amp and get you to do my mods. Pure genius my friend, WOW!!!

[@HeadfirstAmps]

Yes - per the website

[@wokemadeit2826]

Amazing video. Sounds ABSOLUTELY fantastic gonna give this mod a try. Do you have a written instructions list like the headfirst mod ? It would really help.

[@HeadfirstAmps]

Cool. If there is anything unclear in the clip re how to do the mod let me know. I’d consider a follow up clip if needed..

[@phillamoore157]

@@HeadfirstAmps Yes, PLEASE do a follow up video. I just posted a similar comment, not just on how jaw-dropping you got this to sound, but that for us newbies still learning this stuff, we’d kneed a bit of hand-holding. I know I’d pay good money to have a live-stream with on on a simply mod on a cheap amp like this. You should consider it. I’m sure a LOT of people would take you up on it, and you’d make a tone of money in the process. 👍

[@HeadfirstAmps]

Interesting idea. A live stream to take people through and answer questions etc?

[@phillamoore157]

@@HeadfirstAmps Absolutely! Something in-depth. A live stream where you take a cheaper amp like that Origin, and show a mod step by step. We’d all log in, and send our questions via the chat. I can’t remember what company did it (may have been Stew Mack) but there’s a company out there there makes those simple all-inclusive fender circuit amp kits, and they did a live video showing the online class how to put it all together from start to finish. They record the entire thing so the students (or anyone interested) can watch the build as many times as they need. But, they did it with a nice over-head camera like yours. Obviously, they’d buy the mod kit from you, and pay for the class itself. Short of that, they would obviously need the amp, and would need to have basic soldering skills, and you could even do a small intro session to that if you wanted to. But, there are some really cool things you could do (if you have the time, and interest) with the production equipment you already have. With the reputation you’ve built up, and the interest, I think you’d get a LOT of interest in it. You just have to keep in mind that with something Iike that, you have to assume that short of some soldering skills, you’ll be dealing with people who’ve never built, or modded an amp before, so you have to put on you “Amp modding for idiots” hat :-). Think about it….you’d be helping a lot of people, and could do it from your existing studio, with existing equipment, and make some good money. 👍

[@driversmith2435]

That amp have become a complete marvellous beast. Great work waw! Can it be done to the Origin 50 as well? I want to mod mine and that mod sounds amazing!

[@HandWiredAmps]

Yes, the boards are nearly the same as far as this mod goes.

[@driversmith2435]

@@HandWiredAmps thank you!

[@nathanstein589]

@@HandWiredAmps He mentioned setting up the cathode bias a specific way, I thought the 50 had a fixed bias?

[@HeadfirstAmps]

The 50 is fixed bias

[@JOOODYJOOODY]

why cant it be built correctly the first time

[@speedunknown]

Pure genius my man!!!

[@Valerio_VDF]

You should stop, really... Now I am sourcing another Origin ahha you are the main responsible for the entropy increase in my office room! Really amazing result! I am surprised of how gainy is...maybe is the PPIMV that adds all this additional gain? I think i will get rid completely of that pots board...once the 2 gains are out of it, the MV and the presence too...there is not too much left (the TS but it can also be built directly on the pots) Thank you Jason, nice stuff!!

[@HeadfirstAmps]

Yeah, the thought occurred to me to ditch the pot board altogether!

[@rangerdoc1029]

That sounds insane!

[@aliZoso]

Any reason the V2 is bridged underneath the board, could it be done on top?

[@Glensully]

Since the 20 and 50 both have 2x same power tubes I’d assume the driving of speakers s in loudness is similar?

[@wytewrabbit]

Unbelievable I want this done to my amp so bad!! I own the 20 W and the 50 W I just need to find a tech that can pull this off!!! ..Thank You!!!

[@BenJ2827]

Sounds amazing - Why don't Marshall just do this? They would make a fortune!

[@Valerio_VDF]

well the small plexi it is basically like that (except than for the PPIMV) they differentiate the customer targets ...there is virtually no difference in doing a small plexi, the 20w jcm800 or the origin...to be honest the origin with that weird scaling is the most "complex" of the 3 :D...

[@andmoreagain]

@@Valerio_VDF what does any of that mean

[@RiffMusic1970]

:45 🎶 well there’s a love gone down on mine Suicidal voltage line! 🎶

[@triumphnacked]

Can't find the list of material and the instruction on the website anymore. Could somebody can tell me wgere i can have it? Thank you

[@HeadfirstAmps]

There is a Mods Share button on the DIY page of headfirstamps.com headfirstamps.com/?page_id=1195

[@triumphnacked]

Ok thank you, but in the list, what is the mod should i choose to mod it like in the vidéo? And is this mod keep the fx loop in place?

Amazing tones! Is it possible to this mod to the Ultra gain channel on DSL20CR, and completely remove the reverb from the amp and use it for something else?

[@leohobbleohobb3781]

Your links under the video for parts list when used yust send me to headfirst startsite. cant find a partslist for the mods on this.

[@HeadfirstAmps]

headfirstamps.com/?page_id=1195

[@leohobbleohobb3781]

Did you solve or found out where the bleed problem from pre with input ain at zero and master at full i can hear sound from guitar. Design layout of pcb fault have i heard?

[@HeadfirstAmps]

yes, layout fault. The mods fix it.

[@zlutz814]

Wow, does that sound good!

[@Nighttripper504]

The Shawn Ryan of guitar

[@eldark2b]

where can i find on you website the schema for that mod please great video! cheers from france

[@HeadfirstAmps]

Sorry, no scheme just the video guide.

[@willdenham]

Can one remove the master as well to get a straight non-master plexi style circuit?

[@HeadfirstAmps]

Yes

[@joefarmer7727]

I thought normal and bright channel were jumpered from the stock version and the tilt control blends normal and treble channel. So was this not the case?? When you had to do a mod to allow this?

[@HeadfirstAmps]

The stock Origin is not a plexi circuit, nothing like one actually.

[@vic.joe.lee06]

Is there an adjustment to make it sound like a standard 69 plexi without the variac sound built in?

[@HeadfirstAmps]

The voltages in the 20w are too low. You could get them high enough in the Origin 50 to be like a regular 50w model 1987

[@murrayatuptown353]

Dr. Headfirst: Are these services you provide, or are the changes also published for DIY'er's who know enough to live to tell the tale after doing the work? A friend is picking up a used O20C & if he's lying awake at night thinking he made a mistake... I'll start out listening to the whole video and taking notes. Thank you

[@-rubbersoul-]

hi guys! quick question: which is suitable marshall under 40 w. to get sweetest and mellow tone just for clean sounds?.. i mean looking for to fender tweed territory instead silver type… i find this little beasts nice only when they are pushed up wildly especially sv20 or origin . otherwise nasty harsh tone come out at medium volume…especially w/s.coils , i wouldn’t pair w/v30 speaker every time to sort out…

[@HeadfirstAmps]

Jtm45 reissue might be a good option if you can find one.

[@FTF96]

Please please please can you make a step-by-step guide for this? I’d pay for it!

[@HeadfirstAmps]

This one builds on the first mod, which is documented

[@HearGear]

Hi.. I am currently working on two Marshalls, one MG15 and one Lead 12, both have a blown transformer, do you have any suggestion for a replacement transformer of these two amps.. ? I live in Europe so it would be great with an option that is available here :D. thanks... cheers..

[@joegood4155]

How much to get the board populated?

[@andrewdenine1685]

Very nice sounds amazing with that Les Paul . Put them in a blind fold test and people would have a Berry hard time telling the difference if they could in the first place. Only amp I've head come close moded to a plexi is an old Traynor bass amp used as a guitar amp .

[@josephdimalante7023]

Hello I just got the Origin 20 combo and want swap out the pickups it was a floor model and one tube was dead I got scared but I opened it up and saw a dead tube I put in a cheap tube I had in my tube box and works okay. I would like to know the tubes you put in yours before I order any. Thank You!

[@HeadfirstAmps]

JJ’s are reliable and sound fine

[@josephdimalante7023]

Thank you! @@HeadfirstAmps

[@foldigeri]

Could I use the JHS little black amp box (goes in the FX loop) to crank the master on a stock Origin or I need an atteunator?🤔

[@carsandguitars6264]

Holy shit this thing sounds killer I think I might get one

[@rokinrandy]

Sounds killer. I like cheap Marshal amps. They’ve been good to me . So have my old peavey Amps. But I never work on them. I just put them up and buy more. 🤷‍♀️

[@justingreen8006]

What is Marshall's model name for "plexi"? I hear "plexi" all the time but haven't seen that model before.

[@HeadfirstAmps]

Plexi = plexiglass front panel, which were featured in the 60’s. However, when people say plexi, they generally mean models 1959 and 1987.

[@anthonydratnal1870]

This is phenomenal, sounds even better than your 2204-esque mod! Do you think it's possible to tune the circuit to get more into mid-60's JTM territory, or would that require different transformers and rectification?

[@HeadfirstAmps]

Thanks! Well, the preamp could definitely be set in that configuration.

[@anthonydratnal1870]

@@HeadfirstAmps if only Marshall would make something like a DSL with a bunch of relays to switch between the four sounds we actually want: this circuit with a JTM or JMP preamp, and the 2204 circuit with a "stock" or hotrodded preamp. Maybe they're just allergic to money?

[@vic.joe.lee06]

If I want to do this mod from a stock Origin 20, should I follow the JCM800 modding guide video and do that mod, then come back here to make the changes for the plexi? I'm not sure if this just adds onto the JCM800 mod, or if I have to remove components from that mod to do this one. thanks

[@HeadfirstAmps]

You can just do the plexi mod, no need to do the 800 mod first

[@mikefromusa6902]

Miiight have to try these in my combo

[@HeadfirstAmps]

The combo is the same as the head circuit wise

[@CedricSatterfield]

I love this video- you sound like Taika Waititi.

[@HeadfirstAmps]

Thanks. We are both from New Zealand! 🇳🇿

[@dano9704]

damnnnnnnnnnnnnnnnnnnnnnnnnnnnn son! I emailed you a few weeks back and im so looking forward to my O20 to get this Plexi mod. It sounds sooooooooo fat!

[@HeadfirstAmps]

Awesome, do I owe you an answer on a question? Sorry, I get behind on emails!

[@dano9704]

@@HeadfirstAmps nah you answered it mate, you are waiting on me to send it to ya so don't worry. Jesus im excited for the work to be done. This video is seriously scary how you've done this.

[@stevecampbell5731]

Sounds awesome! Will you be posting the plexi mod instructions on your website? I see the instructions that I think are for your earlier JCM800 mod, but I only see the parts list for the Plexi mod? Thank you!

[@bradleywood1499]

I've been trying to round up the parts to do this mod since the video has been posted. The three pots and knobs are killing me, I'm beating my head against a rock trying to find these with the correct values, shaft diam, shaft length, small housing diam etc.

[@HeadfirstAmps]

Hey Brad. Ok, happy to help here. I’ll do a parts document for the website today, and I’ll post on my DIY builders group when it’s ready.

[@bradleywood1499]

@@HeadfirstAmps Hey Jason, thanks again for sharing so much of your priceless know-how with us tone chasers. You truly rock!

[@HeadfirstAmps]

No worries, my pleasure. Spread the good word, I need to grow the channel!!

[@Nitrav.]

Why did I not get recommendations of this great channel from the KZbin. Love your awesome videos. I am surprised why you your channel has this low subscribers. You deserve more. Which amp is better value for money Marshall dsl100 or Jetcity. And which is better to mod so that we can get best sound and versatility or should I get something else. Thanks for your awesome videos. And thanks for your suggestion also in advance. Please help

[@HeadfirstAmps]

The DSL100 is better than the jet city imho

[@jamesoconnor5154]

Have you ever worked on the new supro's, specifically the black magick reverb? Its a dark sounding amp i play it with the bass off treble all the way up and its still kinda dark. Is there a mod that can be done that will make it less dark but not really change the sound?

[@vic.joe.lee06]

Does this sound like a standard plexi? I don't know if I want to mod my origin with the old video (JMC800) or this new plexi mod. Im trying to get what sounds most like a standard plexi with those full beefy tones and that bite sound.

[@HeadfirstAmps]

This is the closest to a standard plexi of my Origin mods. This sounds like a SV20 now, but with a PPIMV.

[@vic.joe.lee06]

@@HeadfirstAmps I when you showed the changes, is that changes to the stock origin or adding onto the JMC800 mod

[@JohnHamnett]

This is awesome and I'm definitely doing these mods! I've built a couple amp kits (RobRob site and StewMac were super helpful) but have never modded an amp outside a 1 component bright cap on my Hot Rod Deville. I'm wondering how to approach this - hoping for some clarity. This will be after buying all appropriate parts (do I need to get shielded cable as well?): 1 - Follow the instructions from the first Headfirst mod but swap in the Plexi components; knowing the potentiometer replacements & wiring are different. OR 2 - Follow this video along with my amp open; list out all components for removal or replacement (along with the schematics from the HF site). Or somewhere in between? I'm admittedly not at the experience level of an amp tech - but I can follow soldering directions very well! This is also screaming for a 100pF/1000pF/4700pF bright cap switch to go between eras!

[@JohnHamnett]

Well, diving headfirst (pun intended) into this. I recommend the following. I'm at Step 3 pending a couple components I didn't order and didn't have spares. 1 - open your amp with the parts list printed out and go through everything. The parts list is a guide and not exhaustive (couple resistor values not called out). 2 - remove the main board and the control board and cut out what's not needed and being replaced. 3 - solder in new components and wires to the main board. Include the wires going to the new pots. 4 - wire up the pots. 5 - install control board and new pots. 6 - hookup wires from main board to pots. 7 - install main board.

[@JohnHamnett]

Finally finished, sounds killer! Gotta figure out why I'm only getting the bright channel to work when jumpered and nothing when pushed in... but otherwise fired up and cranked upon first go!

[@JohnHamnett]

Forgot to clip the leads on the 10K power resistors 🤦🏼‍♂️ Noticed I had the switch wired in reverse and the presence pot lug 3 not going to ground. So that's all fixed. Still nothing from the normal channel volume when jumpered. Checked continuity - grids are connected when jumpered, normal coupling cap connected to plate, normal volume wired correctly... guess I'll check if it's a bad pot but happy to hear other suggestions!

[@JohnHamnett]

Dumb ground killing the normal from the V1b plate. Done! Needed that girth - sounds amazing!! Thank you.

[@JohnHamnett]

Couple changes: bright channel (V1a) cathode resistor to 820ohm & 5.6K bias resistors for V1 and V2. I liked the original mod, but wanted more an early 70s Plexi tone. It's nice that they're easily reversible!

[@adamBnEII]

Hi mate.Is it possible to do this same mod on my Origin 50C please?

[@HeadfirstAmps]

Yes, I just did an O50 Plexi mod last week

[@charlesyoung8600]

Been thinking about one of these but can't make heads or tails of whether or not its worth it.

[@HeadfirstAmps]

Totally worth it if you are up for a project to mod yourself. If you are paying someone to mod it for you, then maybe there are better options?

[@MartinMignogna]

Hello, I have an Origin 20 with a bad Tilt pot... I think it's the pot... when I dial it off of 0 it pops and I get a volume cut compression sound and nothing changes the whole way to 10.... what pot is it ? 250k ? Is it the pot though ?

[@HeadfirstAmps]

The Origin 20 uses a 100k tilt, whereas the Origin 50 uses a 1m tilt pot. Might actually be a bad cap - there is a 0.1uF cap there that acts like a bright cap. You could try a little deoxit contact cleaner sprayed into the pot to see if it sorts it.

[@willdenham]

I think I want to try this with my 50wt. Is it much different if going for an earlier style plexi like the 68' 1987X?

[@albertocorippo7309]

This is incredible!!! WOW! I really would like to see a mod to get JTM45 sounds... :))

[@HeadfirstAmps]

Replacing the 4700pF bright cap with a 100pF will get closer to that vibe

[@albertocorippo7309]

Thank you!!! :))))

[@vin9976]

Question: can you get a “less hot rodded” tone with this mod in place? I LOVE this but I’m interested in how much I can dial it back if I wanted to as well. Or is it a resister that I could make switchable from a cleaner to hot rod sorta thing?

[@jacob_miller]

This is incredible Jason, what an amazing sound from what was a quite underwhelming amp. 😎 🤘 These videos are quite inspirational. P.S you still need to mess with a Vintage Modern while they are still affordable!

[@ryans9029]

Do you have a parts\value list posted somewhere? Id like to get started on this one right away

[@HeadfirstAmps]

I haven’t yet, maybe I should do a follow up clip to outline what I used…?

[@ryans9029]

@@HeadfirstAmps a short clip would be great.. or even just a PDF or link. Anything really. Thanks for the reply 👍

[@bradleywood1499]

@@HeadfirstAmps A PDF of materials req'd would be fantastic! Thanks for sharing this mod with us.

[@Glensully]

Since it has the power reduction features, it’s changing to the ppimv really noticeable difference?

[@vic.joe.lee06]

Is this mod meant to sound like a stock 69 marshall super lead? I might do this mod to get those first album Boston tones, but I dont exactly want it to sound like a variac

[@HeadfirstAmps]

It’s like a variac because the Origin 20 voltages are so very low. If you did the mod to an Origin 50 it will sound and feel more like a 1987 50w plexi.

[@iarlaroche7782]

With these mods will it still make for a good pedal platform when needed?

[@HeadfirstAmps]

Yes, if you implement the mods per the latest plexi mod vid

[@SJ-kk4bm]

Hi Enjoyed your video/s. Have you every work on the Wangs VT15 Head. It is also suppose to be like a Plexi (but based on a JMC 800 layout?)? Reviews say they are a High End Chinese Quality Amp.

[@HeadfirstAmps]

Hi, thanks. I’m not familiar with those amps. I might look it up..

[@nathanstein589]

Do you plan on creating instructions for this like for the headfirst mod? What would be different between a 20 and a 50?

[@willman100]

Thats fantastic. How do the DSL heads compare? Are they easy to mod as well or better off getting a Origin to mod? Thanks

[@pakujewpiwnicy6701]

hello :) the amplifier is well built? have you had any crashes?

[@chordfinger1]

Would be cool if you could make a drop in pcb for these so anyone could gut the amp of original parts and have a high quality build. Offer the board as unpopulated, unpopulated with components, or populated. Would also be cool if you made the boards mod ready and offered easily added mod boards and/or component kits to be added to the amp board later! Having good quality pcb that how would have to worry about fragile traces and pads would be awesome!

[@HeadfirstAmps]

That’s a cool idea, a bit like my ST1 Marshall board. People would lose the power scaling too l, it could become a standby switch I guess. Are people prepared to sacrifice power scaling? Maybe I’ll post this question in my DIY group on FB.

[@chordfinger1]

@@HeadfirstAmps What becomes of the pull boost on other the mods? Also like your efx loop board to replace the tube driven stock, could there be a power scaling board that could be installed and have the original switch wired to it? Also if it were possible maybe get the main board to have the ability to put an adjustable bias.

[@HeadfirstAmps]

On the 800 mod it still works but in reverse. If I did a replacement main board it would be based on ripping out the pot board and just using regular pots. Power scaling is too tricky, I'd not bother. Fx loop I'd have to consider the best way to do this. It's a board with PCB mounted tube sockets, so will take some doing to make a drop in replacement!

[@chordfinger1]

@@HeadfirstAmps Hey I understand that this is not as easy as just "Make it happen" and I felt that as junky as these amp are constructed to be merely throw away items in a few years, I find it sad from an eco point of view. And in the years there's going to be a lot of these floating around on the used market as well as something sitting around broken collecting dust and something like the boards could be preimptive for future proof fixes. Thanks for hearing me out and I appreciate your consideration to my thoughts!

[@francisgarde]

ooooft now I want me an Origin 20 :O

[@dylanhighwood7458]

Can you do this same mod to the origin combo amp?

[@HeadfirstAmps]

Yes, the combo format is still the same amp