Turn your Origin 20 into a PROPER PLEXI!!

My original O20 that I modded to JCM800 spec is back on the bench, lets see if it can become a hot 20w plexi! This one gets it's voltages tuned in to be similar to a Plexi running with a Variac, and we also implement a PPIMV which makes the amp super useable.
Parts list:
headfirstamplification.com/mo...
[e-mail]
headfirstamplification.com
/ headfirst.amplification
/ 225949122469679
/ headfirst_amplification
0:00 Intro
0:47 Plexi modded tones
2:24 Modded amp features
4:51 Dimed
7:03 At The Bench
16:12 Voltages
19:37 PPIMV
21:35 Play Out

[@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.

[@ignacioibanez6138]

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

[@christopherguzzi1316]

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

[@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!

[@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.

[@weschilton]

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

[@davidwicksmusic]

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

[@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!

[@tonefreak3403]

Awesome stuff! Always look forward to another video!🤘

[@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!

[@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!

[@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!

[@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!

[@rdavid3848]

Nicely done. I like woolly bass on 10 and can roll off the potentiometer as desired. I would leave the bright channel bypass cap off altogether. You are getting a Van Halen tone. Bravo.

[@vondragonnoggin]

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

[@MAP448]

Great show bro!

[@davidboyer4466]

Awesome video man! thanks for making it .

[@HeadfirstAmps]

Glad you liked it!

[@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.

[@rocknroll1973]

Origin is based on the jtm45. Not the 1959slp. Which many get wrong. That's why you didn't get that "marshall" sound

[@willdenham]

Did you try turning the master up?

[@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)?

[@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.

[@boatingforbeginners7949]

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

[@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!

[@zlutz814]

Wow, does that sound good!

[@speedunknown]

Pure genius my man!!!

[@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?

[@rareform6747]

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

[@rangerdoc1029]

That sounds insane!

[@andrewdenine1685]

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

[@HeadfirstAmps]

Welcome!

[@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 .

[@BradsGuitarGarage]

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

[@CianRourke]

The second you started playing Black Shuck I subscribed.

[@HeadfirstAmps]

Awesome, and welcome!!

[@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.

[@anthonydevito1298]

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

[@HeadfirstAmps]

Thanks!

[@BenjaminDodkin]

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

[@P3t3rPizzarelli]

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

[@HeadfirstAmps]

Agree!

[@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. 👍

[@carsandguitars6264]

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

[@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.

[@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

[@ericzeng318]

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

[@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!!!

[@me.roderick]

What a killer channel🌟🌟🌟🌟🌟

[@HeadfirstAmps]

Thanks!

[@johnmarshall3903]

Totally agree!

[@mikefromusa6902]

Miiight have to try these in my combo

[@HeadfirstAmps]

The combo is the same as the head circuit wise

[@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.

[@RiffMusic1970]

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

[@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!!! :))))

[@dylanjastle]

So sick

[@CedricSatterfield]

I love this video- you sound like Taika Waititi.

[@HeadfirstAmps]

Thanks. We are both from New Zealand! 🇳🇿

[@peevee605]

One word…….DAYMN!

[@francisgarde]

ooooft now I want me an Origin 20 :O

[@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!

[@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!

[@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. 🤷‍♀️

[@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.

[@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?

[@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

[@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

[@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

[@Gtrtech]

Flick of the switch!

[@HeadfirstAmps]

100%!!

[@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. 👍

[@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!

[@jens-steffenklimasch5187]

Great mod and tone! Could you please share your recording chain? Especially which cab/speaker/mics or sim did you use? Thanks!

[@goldenboy8167]

Wow! Sounds amazing. I might have missed it, but does the output power switching still work after these mods? Will you be posting instructions to go from the stock amp to this mod, as you have with the previous mod?

[@HeadfirstAmps]

The power scaling works great in this configuration. The video steps through all the changes, if anything is not clear let me know and I’ll look at a follow up video.

[@goldenboy8167]

@@HeadfirstAmps Thank you.

[@cliffords2315]

Sounds allot like my Marshall Vintage Modern 50Watt

[@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

[@alexloda7660]

Great job 👍 quick question ⁉️ what would you suggest between the Origin/ Suhr Badger and Friedman pink taco 20 ?

[@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!

[@brookchivell]

Man that is KILLER!!! So tempted to have a go at that Would these mods all work on the combo as well? Is it the same?

[@HeadfirstAmps]

Yes. The combo is identical. I’ll be doing a parts list and will post it to the website.

[@brookchivell]

Awesome. I’ll look forward to it (there are a few combos floating around here in brizzy so when I see one pop up Cheap I’ll get on it. Thanks heaps for all this info

[@seane1081]

That thing sounds awesome! I was wondering, when you do the plexi mod, how pedal friendly is it, like if I wanted to use something as a boost for leads?

[@HeadfirstAmps]

If I used say a 100pF rather than the massive 4700pF, then it would be more pedal friendly.

[@vic.joe.lee06]

I highly recommend that you make a discord server. I'd bet tons of people would communicate about these mods on there

[@HeadfirstAmps]

I’ve thought about it before, even created one but never did anything with it. I have the DIY Group on Facebook but I realise there are quite a few people that won’t post there because of the whole FB thing. Maybe it’s time to get it going..

[@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

[@jackrussellbruce7565]

This sounds killer. I know you posted a schematic for the stock circuit on your website, do you have a schematic for the changes? I want to do most of your mods, but keep the master volume. It'd be easier for me to pick and choose if I could see a diagram.

[@HeadfirstAmps]

Scheme wise, it’s a standard 1987/1959 preamp.

[@davidrosenberg9016]

This is a very unusual question, especially since it's coming from me but how does it sound clean? Love those distorted tones but am curious at how the cleans hold up?

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?

[@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!

[@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?

[@nathanstein589]

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

[@user-tb9rw7dh2t]

👍👍

[@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

[@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..

[@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?🤔

[@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?

[@pakujewpiwnicy6701]

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

[@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..

[@Vince1974]

It sounds awesome ! But ! 😬 Could you make an A/B comparison between this mod and a stock amp with an overdrive in front of it (Clone of Klon, TS...). Best regards !

[@HeadfirstAmps]

I don’t have a stock amp to compare it to, but I can tell you from experience that an OD pedal, no matter how good, will not have a the feel of a browned out plexi.

[@pablocacaster]

sounds amazing! a question, if i have a 50 can i skip the part of the gain pots and keep using it the same?

[@HeadfirstAmps]

Yep

[@nathanshapiro6076]

Aw man, I just completed the 800 mod last month and now I feel like as a huge EVH fan I might need to convert it to this plexi version! I am really enjoying the way the standard mod sounds, my next thing on my to-do list is to swap my speaker for a greenback. Thank you so much for all these videos. Do you have a preference so far between your two mods to this amp (plexi vs 800?)

[@johnmarshall3903]

I really liked that 880 mod too. Since the're not terribly expensive used, would be great to have one of each

[@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?

[@Glensully]

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

[@DJ33]

Wow

[@RByrne]

I just got the Origin20 today, and it's pretty underwhelming. I'm sure when I take some time to set it right it'll sound better, and with pedals too. I'd love to do this though. I have one of the 50th anniversary white JCM mini stacks that sounds so much better, but it's 1watt so only really good for the house, even though it gets pretty loud. Any idea what it would take to have a tech do this mod? Thanks

[@michelewade5415]

I got mine a few days ago and I’m very happy with it. Just dialed it in with a 2/12 cab, Les Paul with 57 pickups, a strat, and semi-hollow and got some awesome tones. And definitely loud enough to play with my band. Just give it a few days, get a decent cab, lower the treble and add the presence to taste. And you’ll be fine unless you somehow got a dud. Good luck

[@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?

[@bradleywood1499]

Quick question on the value of the blue cap going from the input lug to the wiper lug of the push/pull pot. The print you flashed shows a 500pf, is this recommended or should I use the 470pf as you called out in the video? Same for the other one coming off the wiper of the push/pull pot and going to the input of V2B (schem calls out a 560pf for this one) Does it really matter? Thanks

[@HeadfirstAmps]

Hi Brad, go with either a 470pF or 500pF. I will have the parts doc ready soon too.

[@bradleywood1499]

@@HeadfirstAmps Thanks Jason. Already have some 470s on-hand so I'll just roll will those. One less thing to buy..

[@joeltc1]

Very nice indeed! Is the send/return loop still switchable? I need it for what I do.

[@HeadfirstAmps]

this mod disables the loop, which in a driven plexi is pretty much useless anyway. You can re-add the loop function with my fx loop pcb

[@zigzignuts]

@@HeadfirstAmps awesome work...I am floored. Question: would your fx loop pcb still sound like a mess and unusable? I really do not like using my delays and verb in front of an amp. Would LOVE to be able to get this sound with agood sounding useable loop. Not possible? I guess there is always the option to incorporate a Fryette Power $tation just for the ability to use its loop as an expensive $olution.

[@zAvAvAz]

hey awesome amp and guitar playing excellent headfirst amplification :o) i am. i am was thinking of an origin 50 to mod like this and use for metaL, i am play 8 string metaL bard classicaL kind of ways kind of thrashy, kind of shreddy like and kind of industrial in the way of fear factory and divine heresy. kind of like all styles of metaL really oh well, i run an akai deluxe and clear boost, delay, etc. it sounds like my kind of amp, amps i like are the peavey solid state , crate stealth hybrid, EVH 5150 and EVH 5150 III, and the sig X pittbull vht, i like the bugera i like marshalls although i usually use an eq through them in FX loop, can i mod an origin 50 to sound great and keep or install a nice FX LOOP?

[@Glensully]

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

[@michaelwiebers5866]

Think I'm going to see if my tech guy can handle this mod! I only paid $400 us dollars for mine new. Sounds so nice! Stupid marshall didn't make it like this in the first place 😒

[@filipedoria9561]

Hi!I am a great fan of your work! I live in Brazil, do you think that it's easy find someone here to do this mod? Besides, my amp is a Origin 50h, the process is the same in this case?

[@HeadfirstAmps]

It’s the same mod for the Origin50, but the O50 is fixed bias so if doing a PPIMV that will need to be configured a little differently. If you show the video to a local tech, maybe they can help.

[@sailacristina]

Caso esteja no estado de SP, você pode mandar pro Rodrigo Martins de Marília/SP

[@Swanlord05]

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

[@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!!