Marshall Origin 20 - Headfirst Mod, Instructions and BoM
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- čas přidán 8. 09. 2024
- Following on from the first Headfirst Origin mod, this clip contains a short Strat tone demo then head into a detailed walkthrough of the Bill of Materials and Instructions for completing this mod yourself....or for your local tech.
Mod documentation available here:
headfirstampli...
No Charge.... All Good. Bloody Legend.
Tnx Rick...happy to share this one around! Warm up your soldering iron man.
I've checked detailed pictures sent to me of the Origin50 against my stock pre-modded Origin 20 pictures and the good news is that the preamp looks identical, right down to resistor and capacitor numbers. The only difference is in the power-amp where the O20 is cathode biased EL34 and the 50w is fixed bias EL34. The mods will work on your 50w as is! Go for it.
Very impressed. I have an Origin 50H. Any advantage to 6CA7 or KT77's with your mods???
how about on a 5C?
Did this mod yesterday... Holy crap what a difference... This is how it should have been built to begin with
Congratulations man! That's great to hear.
I'd love to see someone do this mod from start to finish, and put it up on CZcams. Headfirst had gained an insane amount of respect and fan-fair from this mod alone. I hope some day I get up the nerve to give it a go. 👍
I have just finished the mod.
What incredible amp it has become. I will use it as my main one for sure.
The bonus, I have learned so much modding this boy that I actually oppened my DSL20Hr and tweaked it a little bit.
Thank you so much Jason! You have helpped and taught a guy from the other side of the globe, this is crazy hahaha.
Haha, awesome and congrats on creating your own tones!
Thanks so much for sharing this mod, this amp finally makes sense. I found the fx loop to be useless for such an amp that gets most of the drive from the power amp section. And the preamp was definetly missing something, it didn't have enough gain to rely on the preamp distortion but also lacked clarity because of the flobby low end. This mod fixes it all, gonna try soon. Thanks!
You are right. Any 'plexi' type circuit that drives the PI and power tubes into distortion has no requirement for a fx loop. If you run the amp clean(ish) then you can run your time based fx out front.
Man, thank you very much. Happy 2021 you just made it a bit better for me.
Mate, I pleased to hear that!
I can't thank you enough for your generosity in sharing this mod. I performed it yesterday on my Origin 20h and it is incredible! I liked the amp very much to begin with, but found that I always favored boosting it with an overdrive to function as an added gainstage. Pulling V2 into the mix makes this amp roar. As you mentioned in your videos, I found the PCB to be a bear to work with despite quite a bit of experience building, fixing, and modding pedals; definitely took longer than I expected, but it sounds absolutely killer. Many thanks again!
Great to hear you completed it!
Hello,
Once modded can you still have the crunch sound from the stock amp or does it change the character of the amp once and for all ?
🙏
@@Vince1974 Hi, there. It definitely changes the gain character of the amp permanently as it's reassigning the tube that the stock Origin used as an FX loop buffer as an added gain stage. I really like the sound with the added gain stage, but be aware that the FX loop will be disabled unless you install a solid state loop such as the metro style loop that Jason makes, which I also highly recommend.
Well I know what im gonna do when I purchase my next amp ....
Thank you for sharing your mod.
It is appreciated....
Thank you so much !!!
Will share with everyone....
Just say thank you because I mounted the mod as well as the effects loop, and now it is fantastic, a plexitone input boost, an AX8 in the loop for modulations and an equalo ....... just to say this will be my main amp
WOW!! Above and beyond generous.
My pleasure!
Hey got it working first try! Love it. Going to do a choke and the rest of the mods as well
Thanks for putting this together!
No worries, very happy to share.
Thanks for the great mod!! This gave my amp just the lil' boost it needs :)
Enjoy!
Thank you so much for putting these videos together and detailed instructions!! I’d been tossing around the idea of doing this mod for the past year, and I’m so glad I did it. I’ve never done this much work on an amp before but I’ve built 7-8 effects pedals from kits and all the skills translated to the amp mod well. The amp has so much more gain on tap, much better bottom end, and chords have so much more clarity. Absolutely love the pick attack now as well.
When I first plugged in there was a lot more noise, but magically today that has gone away…I’m wondering if I should switch the under-PCB hot connection from regular wire to insulated co-ax like you do in the videos?
Time to start planning for the effects loop addition :D Such a great feeling I was able to improve this amp so much with a $15 mouser order!!
Wow, I didn't realize the parts would be that reasonable. Good info Nate.
Another cracking video mate 👍
Thanks Dan! Appreciate the support mate.
Amazing, I will share your channel. ✌️
Yes need more subscribers Jason is a master builder and mean picker to boot!
Thanks guys, I appreciate the feedback and support!
Jason, very kind of you to put forth so much effort to make this mod accessible to all. Well, anyone comfortable with a soldering iron anyway. After watching, the scariest thing about the whole thing is doing battle with the no lead solder already on the board. I realize it's a legal requirement in many nations, but I do hate it. 1 general question. Why are coax leads in amps only grounded on 1 side? Ground loops? Thanks very much.
Yes, it’s just to shield RF and you want that grind only at one end for it to be effective
This instruction and BOM video is pure gold! Subscribed. Is there any chance of the same coming for your recent 'Turn Your Origin Into Proper Plexi' mod?
So I just finished this mod on my origin 50, just plugged it in for the first time! and Wow, my mind is blown. Absolutely stunned! This amp kicks so much ass now. Do you have a PayPal or something that I can donate a couple bucks to? I owe you man, you are a genius!
hey man, I'm so pleased to hear this! Awesome. headfirst.amplification@gmail.com for PayPal coffee donations :)
I'm in the middle of doing the modification on my Origin 50 and I've realized the PCB is slightly different and it's V2 rather than V1. Did you come across this during your modification? If so did you continue to do the mod as per the instructions or did anything have to change?
The only thing I came across was there was an extra transistor in the filter network thing off the gain boost relay. (I'm not sure if was a transistor) It was labeled c64 I believe. I ripped that out, and I ran the wire lead that is supposed to go from r65 to r67, from bottom of c64 to r67. Because I noticed that with that removed r65 is not touching the input signal anymore. But everything else I did 100% as the instructions said and it worked out great! Everything else matched up exactly.
If you want I cant take picture of this mod done to my 50 watt pcb board so you can see what I mean. I might not be describing it exactly right.
@@icepick859 Thanks for replying! I don't think pictures are necessary. I think I understand what you did. Run a wire from the bottom of C64 to the bottom of R67 and the wire from R67 to R65 as per the instructions?
C64 is a 2.2nf box capacitor. I mistakenly removed it as well but I desoldered it without clipping the leads in case I need to put it back into the circuit. I'll carry on with the mod and follow the instructions and do what you ended up doing since you seemed to have good luck with it.
I also noticed there's a 220nf capacitor next to R62 that isn't there in the video. That's what made me realize this is a slightly different PCB. So far I haven't noticed much else different.
On the instructions concerning the 470K/470pF & 470Kvoltage divider, I found that the ground reference pad was different than the written MOD instructions specify. The actual ground reference is found at the bottom of R57 (not R56).
The bottom of R57 and R56 (I just double-checked with my multi-meter just to make sure) are connected so I guess either would work.
5 years from now a used un-modded Marshall Origin will be a unicorn
Sounds like a million bucks... Kudos. Any chance you can explain how the loop works in this configuration and how to install a ss loop in case the original one becomes unusable from the mod. That tone though... That tone...
After this mod the loop is completely disabled, the send/return jacks aren't connected to any circuitry. Good idea, I should show the SS loop install too!
@@HeadfirstAmps That'd be awesome. :)
So I'm doing this to the 50 watt. I'm almost finished. there's an extra capacitor in the filter network thing off the gain boost relay, it's labeled c64. I accidently took it out and I noticed that on the 50 watt with that cap cut out i had to run my wire lead from the bottom of c64 to top of r65. Does this sound right? It essentially looks like the same exact circuit
I couldn't run the wire from r67 to r65 because of that cap I cut out.
How'd it go?
@@themusketeer9458 it kicked ass! I ended up selling that all but I really regret it now
Another note, with the bright cap the Tilt knob gets weird and kinda needs to always be down under halfway. Something tinny I don't like much with that.
Agree. I ended up removing my bright cap out.
1/2 watt or 1w? For metal film resistor… it says two different things on the first page
Thank you so much for posting these videos and instructions/pictures on your website, the mod sounds amazing. I’m debating tackling it myself. I remember when I applied the “BillM” mods to my blues junior there were some personal safety checks with the large caps to check with a multimeter before being safe to work on the amp. Are there certain capacitors on the Origin 20 that should be checked before touching anything?
Same with all tube amps. If you leave it unplugged from the mains, with all tubes still in, for say 30mins you'll be fine.
@@HeadfirstAmps thank you!! I am finally getting around to doing this, ordered all the parts, is there a certain gauge for the wire you recommend? I have 22 gauge
Hello there! Your mod sounds fantastic. How is the original Origin circuit? Mostly classic all tube? What does it resemble as far as previous Marshall circuits?
Is it possible to get a clean tone with this mod?
I would like to mod this amp to get a modern clean tone (like a clean tone from jcm800) for my Pedalboard.
My second question is I owm a BlackHeart BH5H and i would like to know if you have a video about mod for this little cool amp to make it killer like the Marshall Origin on this video? Or you have schematics of mods that can be done to the Blackheart little Giant BH5H that can make it killler and more vintage like you did with the Marshall Oeigin?
Sounds good. Thanks. I haven’t had much time to look yet but I’ll be back. . This mod does disable the effects loop correct ?
It does. However you can add a solid state loop to re-enable. I will have a video on how to do this coming out shortly.
Hi i just order all the components for this mod, very excited. Do you have any specific recommendations for the type/thickness of wire used ( coaxial or otherwise) Thanks very much!
AWG22 and for coax you'll only need some that is the same as the amp already has
With the mod, does the foot switch for boost still work. ?
Great sound have you covered your recording setup at all? Is this using a mic’d cabinet or something else?
No I haven't - I'd be happy to do a quick run down of my setup if it's of interest?
@@HeadfirstAmps even just a run down in description would be great but a video would be awesome.
I did this Mod yesterday, pretty straight forward and it’s definitely sounds better, thank you so much for doing this. However after looking back at the instructions and pics I noticed no mention of the top of R70 and left hand side of R64? The amp still works without it because played it yesterday just wondering about that step.
Those 100k plate resistors joined together? That was just a work around because one of the PCB tracks got damaged during the mod.
@@HeadfirstAmps ok got it! Thanks for the reply and the mod instructions. I’m going to by you several coffees!
Thanks man!
Its a bit of a sod after purchasing an amp to discover that it needs to be modded because it wasnt manufactured properly in the first place.
id like to give this a try. can you recommend a good soldering iron/station for jobs like this?
Hakko
@@HeadfirstAmps ty! which one?
Hwllo there i like a lot your video about mod to make amos sounds better i have a question and a request do the Mods for Marshall Origin 20 would work with the same results with a Marshall Origin 50 Head?
Yes. Many have applied my mod to Origin 50's. Join the FB DIY Group if you wan to connect with others that have done it.
Awesome mod man!, I have the Origin 50 combo version, you think the mod will work with my amp?
Yes, works on the O50 except for one minor difference. Join my FB DIY group and you'll find the details there.
@@HeadfirstAmps Thanks man, I will take a look
Any caps need to be drained before doing this?
Filter caps always need to be, but if you leave the amp unplugged for 10 minutes (with the tubes still in) you'll be ok
What about capacitors? Can I use the same 470pF capacitor but with higher voltage like 1kV? I just couldn’t find 470pF 630V in my country.
Yes, that’s fine
@@HeadfirstAmps Thanks!
There is any problem to use 1/4W resistors instead the 1W?
Use 1w to replace 1w
Has anyone else who has done this had issues with getting out the 9 screws holding in the PCB? I found they strip very easily, and on my last one to remove it completely stripped. I picked up one of those “SpeedOut” screw remover kits to no avail. I have all the parts ready to go…wish I wasn’t stuck on a measly screw!!
I did on one. I just drilled it out!
@@HeadfirstAmps glad to hear I’m not alone, I finally got it out though! Onwards to the mod now!
You might want to add the note about not reconnecting the effects loop wire to the pcb board to your written instructions... If it was noted I didn't see it...
Also how does this effect the boost function? I notice that when I pull it, I lose a tiny bit of gain. Just curious what's actually happening...
I think I say to tie it off, or unclip it and remove it from the amp. In any event you want to keep if progressing to install my fx loop PCB.
The boost function brings the 0.68uF bypass cap on the 2nd cathode in or out of the circuit.
...you did the mod....how did it turn out, how are your tones?
@@HeadfirstAmps I really like the tones I'm getting out of it. The Volume knob is much more useable now and there's no need to crank it- actually going past 6-7 on the volume adds too much gain and feedback for me. I really like the tones I'm getting with a TS808 as a boost in front too. Very saturated, thick and harmonic. I'm very pleased with this mod- thank you!!!
That's great! I think I'll do a further clip on how to add a SAT switch to this little beast.
@@HeadfirstAmps ok so I need some tech help.... When I boost the front with a TS I'm getting a ton of feedback... I'm just learning to read schematics, but can you point me to which cap I should look at to resolder?
This mod is valid for the Origin 5C? Thanks.
I have 0 experience modding amps. Literally none. I have no idea how to solder. Could I learn how to do this mod? I'm very interested in getting an Origin 20 head that sounds like this.
Join our DIY group on Facebook and post there. Lots of help and tips.
I see that r64 resistor leg is connected to another resistor below ot. Is that part of the mod?
No, not part of the mod. R70 and R64 leave stock at 100k.
I can use film resistors 1w?
Yes, no problem
I’ll wait for the pre made pcb to be made lol
Ha ha ha, nice one.
Hey man I have had this mod done for about 1 month now. Everything has been going well until yesterday. My amp keeps blowing the 100k resistor at r55. It also has a huge volume/power drop now, even after I replaced r55 just to see what would happen. It was super low in volume, and then blows the resistor. I do have leaking filter caps, kind of like yours in the video. Could that be causing that resistor to blow? I have checked my entire mod and it looks like I have done everything spot on as instructions. It sounds amazing, up until yesterday. Could it be a bad pre amp tube causing r55 to blow? I don't have any known good tubes to swap out currently.
Hey Shaun, replace V2 mate. That 100k resistor is the plate resistor for the 3rd gain stage, and would most likely only fry like that if the tube was shorted.
@@HeadfirstAmps Crap I just put all new ecc83s in and it still blew that resistor!
R55 right - the 100k 1w resistor that's above V2? It's getting shorted some how. Pull the tube out and use the DMM to check for shorts on connections to V2, and also on the cathode side.
@@HeadfirstAmps OH shit! I put a 1/4 watt 100k resistor there ! I'm guessing that could definitely be the problem?
Could be. Its a 1w spec resistor for a reason. Your HT fuse should protect the amp, so try a 1w with that new tube.
Can u do this for the dsl 40 😅
Well, I’ve had a crack at a dsl100h!
Hi ! Is it possible to download this documentation ?
On my website. headfirstamplification.com
@@HeadfirstAmps ok ! I've found it ! Thanks. One question... the capacitors listed as 630V rating really need to be buyed 630V ? Is it possible to lower this rating in any place ? Like 450V or so...
Do you sell the board already built?
No. You'd need to send me your amp.
Can this mod be applied to the Origin 50?
Yes
I wonder if I can just buy a modded one from you mate. I surely can play but I surely can't mod.
If you're in Australia you sure can, or if overseas you can send me the PCB out of your amp. Email me to discuss!
@@HeadfirstAmps let see if I can actually remove the PCB by myself ☺️. Surely love your work mate.
Is it same on 50h?
Yes, same preamp in the 50
Someone know if it's possible to bypass the speaker sim but still have the Di out option with no speaker, so I can use my IRs?