Marshall 2203 S.I.R. #36 - TONES AND FULL DIY MOD GUIDE!!

[@artysanmobile]

‘Rock’ never left, though it did a lot of growing up since GnR and George Lynch. I write and produce guitar heavy power trio music regularly, perhaps a bit more compositionally complex but still very much rock. It never stopped, it just got better.

[@qua7771]

It's not as mainstream as it once was, but that's okay. Artist, and engineers aren't mainstream people. I'm more 70's style, but I play my share of 80's music. I'm not sure what modern music is exactly. I haven't heard anything new worth mentioning. People need to keep the old stuff alive.

[@MrWilly2204]

Good lord. The mids on that are awesome. Not to mention the definition in the string separation with that amount of gain is phenomenal. You can hear all the notes in those triads you’re using in the chorus section. Unreal.

[@jamescarpenter4777]

Awesome video Jason. You're the man! Thanks for actually showing and telling us how, and what do do. I have a TSL 100 Modded to SIR 39. It sounds pretty much the same. Apparently Levi copied the 39 to make 36. Slash used 39 on pre production. If you ever have time, please give me your opinion on SIR 39. Thanks again Jason, you have the best modding videos on KZbin!

[@SteveVLee]

He really does I totally agree. Let's just hope and pray he doesn't take it all away once he becomes (more) rich and famous.

[@HeadfirstAmps]

Ha, at 1,500 subscribers that feels like a long long way away! I'll keep putting them out if you guys keep watching!

[@jamescarpenter4777]

@@HeadfirstAmps sure will Jason!

[@Mark70609]

The 39 has a clean channel but it will be quite bright sounding Jason has a copy of that schematic. How do you find your clean channel James?

[@jamescarpenter4777]

@@Mark70609 the clean channel sounds great. My amp is a TSL 100. It has 3 channels. Clean, Crunch, which is like jcm 800,and then the lead channel. The guy that modded it said he modded the crunch channel. But i can also hear the mod on the lead channel, it just has more gain.. So im guessing modding the crunch channel also modded the lead and clean channels?

[@ioncewas]

Mom! MOM! They're doing it again! They're making that noise that makes my ding-dong shiver! Great job and great vid mate! Keep doing what you do and I'll keep coming back.

[@rowenthomson2351]

Nice! I've put an extra stage & fixed depth switch in my late 70s 2203 & 2204 between the 2nd and 3rd stages, both push pull pots to avoid more holes. Keeping the squeel down with all the gain is a challenge, especially in the small chassis!

[@johnmarshall3903]

Thanks Jason, really appreciate these Marshall mods.

[@auntjenifer7774]

That amp sounds great on it own without mods ! But that keeps you in work !

[@meadow1854]

That sounds absolutely incredible, Jason! Subbed!

[@HeadfirstAmps]

Thank you, and great to have you join the channel!

[@TheGriff7628]

Oops, noticed I'm on my daughter account. Subbed on my account now, cheers!

[@KrstovicNikola]

When u said "it sounds like this" and hit that first chord... :O Aswesome sounding amp....

[@samunden]

Mother of God...that tone at 1:27. I guess I'll be spending my night trying to tweak my amp and pedals to get something even close to that!

[@marvelharris9540]

This is excellent information.. thank you for posting this. Now I need to do this to my 2203!

[@geezberry8889]

looks like the lead channel of the CAE 3+. Just built that pre it's got two cold clippers in a row

[@HeadfirstAmps]

Yep!

[@johnmiller9219]

i'm going to incorporate this mod to my 2204 build. i have drilled an addtional preamp tube socket and will put V1 at the end and V0 second . This will be a clean look and it wont be switchable , if there's too much gain i can swap the cathode caps/resistors

[@HeadfirstAmps]

Awesome. Let us know how it goes.

[@RDamps]

Glad he came around to the idea of using that preamp tube.

[@HeadfirstAmps]

Well Chris, I nearly broke his arm clean off. lol

[@RDamps]

@@HeadfirstAmps glad he conceded, he’d struggle to play with only one arm.

[@HeadfirstAmps]

Ha ha. Exactly.

[@riniones]

jeez sounds totally sick!

[@KelsterVonShredster]

Sounds fantastic!

[@user-np8hi6yd3j]

A SIR #34 mini based on a Marshall DSL1 would be fine. 🤘

[@batpigguitar]

I prefer the sound of this one over the #34. Sounds awesome.

[@HeadfirstAmps]

More body through the mids right. The #34, with clipping, has that real toothy top end, which is pretty popular with a few of the modern chug guys, but I also prefer the more vintage hot rodded tones. Did you think it sounds in any way similar to the SE100?

[@batpigguitar]

@@HeadfirstAmps I heard that you mentioned that in the video, yeah kind of, but yours has more of that lovely marshall kerrrrang to my ears, you'd need to wind the mids way back on the SE to get that.

[@MrWilly2204]

If I’m not mistaken, wasn’t #39 used by Lynch on Back for the Attack?

[@lbvbnhbqdjh]

Hello, great tone. Reminds me a little more of Satriani. And where does the sound come from - you just can't see the guitar cabinet? Is this some kind of reactive load or other device you have? Or a speakersimulator? Still by ear, but I can be mistaken - are there any reverb effects?

[@mikegillham2905]

Sick 🔥 Pls capture it for the quad

[@HeadfirstAmps]

Captures are up! 2203 SIR26 DI & GBIR.

[@mikegillham2905]

Just loaded them, incredible. You are the hot rod Marshall master, tone is 🔥🤘🏻 Def want to say thx for loading all your captures, nobody does hot rodded Marshall s, your are so sick…

[@HeadfirstAmps]

Thanks Mike. Spread the good word!

[@jaylinton3003]

The mystery of what the #36 amp was…is no longer a mystery. The ‘ACTUAL’ #36 mod specifications are NOW known. And they are NOT …what everyone thinks they are/were. The ACTUAL #36 amp was a ‘STAGE-1’ mod. No extra preamp tube. Based on sound clip comps to the AFD raw isolated guitar tracks, and identically matched spectrum analyzed plotting points. There’s no question any longer as to what the #36 actually was. Case closed.

[@theishing1]

You are too good Jason, I wish I can play like you. Love from India

[@HeadfirstAmps]

Thank you!

[@kalleankaa7536]

Nice version of 36. But it only sounds like a typical 4 gainstager. It lacks the sting and curl sound when you hit the high strings 2 notes..... There is nothing wrong with a hot sheild. If you wire a belden shield that has a tolerance of up to 1000 volts sustain, it is more than enough for 250v on the preamp...

[@HeadfirstAmps]

I don’t want 300v on any cable that connects to my guitar.

[@kalleankaa7536]

@@HeadfirstAmps I respect your decision. I have the hot shield for more than 15 years and i hope it stays like that 😂. There is one other way to do the safe sheild we call it. I believe you already know it. But i dont think this particualr version from you needs any hot shield as it doesnt sound as bright as what we usually have with the 36 mod.

[@Parkerx2]

Hi Jason! I've seen other SIR 36 schems that had the 2nd gain stage cathode be 10/.1 like yours, but had the 3rd gain stage cathode be 2.7k//.68, where-as yours is only a 10k. Have you tried a 2.7k//.68 combo there? You are sure the SIR 36 had the 3rd gain stage be an unbyassed 10k?

[@marvelharris9540]

that's a good question.. I wonder how that affects the tone? Do you have a link to the schem?

[@alancraig1854]

@@marvelharris9540 I've seen a few versions with the 3rd gain stage at just a 10k, a 10k+.1(like Marshall slash head), and also a version that's 2.7k+.68. the +. 1 version would have added gain mostly in the highs, 2.7k+.68 will be thicker and have a bunch more gain

[@voxpathfinder15r]

Now all one has to do is go back in time a couple years before Guns ‘n Roses and solder an amp like this together and rock it out before Slash ever got his hands on it or George Lynch for that matter, and become a guitar god! Because we all know rock ain’t ever coming back.

[@zAvAvAz]

metal is part of 'the' rock. rock is part of metal. Where metal is of rock. Rock is metal and metal is rock. Rock is , was, and always shall be. Because it pleaseth i am.

[@HearGear]

Is this mod similar or the same thing as the Hot Mod V2 that you just put in the V2 preamp tube scoket ? or is this better ?

[@HeadfirstAmps]

It’s similar in that both add an extra triode gain stage, voicing and inter stage setups will be different. Better will depend on what tones and feel you dig.

[@SuperSeanXXX]

I'd like to hear that with just a little backed off with the bright cap engaged more

[@maopedals4415]

Hey Jason, when bypassing the #36 gain stage is it preferred to leave the switched end of the 33k grid resistor floating as you show in the drawing, or would it be better to ground that end?

[@HeadfirstAmps]

Better to ground it - can be done

[@dannyd.8860]

Curious, did you leave the filament unwired on the unused triode? Kinda hard to see if pin 4+5 were bridged. Great video though! Sounds killer.

[@HeadfirstAmps]

Hi, yes I bridged so that both filaments are active. Thanks man!

[@slashGnRoses1]

Great vid and awesome tone, any chance to could play some GnR stuff as this mod is what Slash used on AFD. Cheers

[@HeadfirstAmps]

If I get the amp back in, then sure! I did record some Sweet Child riffing but when uploading to YT I got a copyright warning! So I ended up editing it out.

[@0megalul309]

Nice work Jason. If I add a hotmod to give an extra preamp tube to an amp modded with the modern mods breakdown video spec, could I get close to this?

[@HeadfirstAmps]

I think so, I’m not totally familiar with the hot mod setup but you’d want it in the lower gain mode for the #36 I’d say.

[@0megalul309]

@@HeadfirstAmps thanks for the reply. Im debating between the 36 and the JEL spec with the hotmod, maybe ill try do both lol

[@andrewspade7969]

Why didn't use both sides of the pre-amp tube for more gain and use a knob to dial it in. Legendary tones does this on there Lynch mod and its very handy.

[@HeadfirstAmps]

5 gain stage + c/f = too much.

[@cap217cap217]

Can you do this to a non cascaded super lead? The super lead will have a master but I dont understand how you would get to the grid of V0b when the signal would come from a volume pot.

[@Mark70609]

The Marshall version of this amp is the same set up as Jason’s amp in that it is a 34/36, but circuit wise it is different from Jason’s version. The power supply has more stages and the cold clipper stages are slightly different. Which one is better, I don’t know?

[@HeadfirstAmps]

Looking at the AFD scheme, it appears that the first gain stage is paralleled V1, ie. V1a and V1b, with a shared cathode iirc. Similar to a superbass or JTM45 with the channels jumped.

[@Mark70609]

@@HeadfirstAmps the paralleled input stage is strange and certainly not what I have heard about the SIR amps. Your circuit departs from the Marshall circuit in that the 0.1uF cap can be switched out of the first cold clipper and when it is switched in there is a 150K resistor switched from the gain control wiper to ground. The second cold clipper has a 0.1uF cap in series with a 10K resistor. This is quite different from other circuits I have seen with 0.22uF and 0.47uF caps being used. I have heard AFD amps made with 0.22uF in the first cold clipper and 0.47uF in the second cold clipper, I did not like this set up much.

[@dolerulz]

Too much low end I think. Maybe a smaller coupler for stage 1? Also, two cold clippers in opposite polarity? With one of them bypassed? Not sure if this is right mate. I think that rumble might be something similar to blocking distortion due to that had symmetric clipping.

[@HeadfirstAmps]

Mate, dual 10k cold stages are common. Research John Suhr’s work and you will see.

[@dolerulz]

@@HeadfirstAmps Will do Or just see for myself once my testbed is finished. Cheers

[@divebomb99]

I have read that the 50w horizontal input amps did not undergo the same capacitor changes as the 100w horizontal input amps, effectively leaving it at the same specs (and tone) as the vertical input units. Does anyone know if this is true or is it just internet false information?

[@HeadfirstAmps]

Yes, correct that the same number of caps but they wired them differently leading to the more brittle tone.

[@2cool4u24]

Sounds amazing. I got the extra gain stage running and switchable between the SIR 34 and SIR 36. However i might have missed something. When switching to 34 there is an unused preamp tube with the heaters still running. This induces a hum. Only way to cut it out is to pull the extra gain preamp tube. Any thoughts on this?

[@HeadfirstAmps]

See if you can ground the grid of the unused tube when it’s switched out

[@pedroberetta4934]

jason you can share the schematic in link please ?i cant found in internet forums thanks a lot great channel and work

[@HeadfirstAmps]

Sure, I'll upload it to my website tomorrow. Under Amp Mods.

[@batpigguitar]

Killer

[@garyeckel1656]

How do you unwire the EVH extra tube Mod? on a JCM800 50W Head?

[@anondusery1271]

The switching implementation in this mod leaves the grid of stage 3 floating.

[@HeadfirstAmps]

Correct. That stage is completely isolated in that mode tho.

[@slashGnRoses1]

Looks a lot like the schematic I send you a while back....🤔

[@HeadfirstAmps]

You'll need to be more specific, I have no idea who you are / what you are talking about. Sorry!

[@slashGnRoses1]

@@HeadfirstAmps I sent you the schematic like the one you used with the idea I’ve sending you a amp to mod some time ago now no big deal. I actually got a Tom Caswell #39 mod amp ATM, is your mod much different than his I think I sent that schematic too.

[@HeadfirstAmps]

I can't recall that, sorry man. Guys send me stuff quite frequently. That #34 schematic is available on the Net without having to look very hard. The #39 and $34 are quite similar, just a different voicing.

[@joosboer1030]

Hi Jason. I would love to put this on a Foot switch. I guess this would require a relay switch. Can you show us how?

[@HeadfirstAmps]

It certainly would require a relay. My 2204 and 1987x mod clips show how to setup the DC for relays, and using my little relay aux board for the switching. You'd use a DPDT relay in place of my DPDT switch used in this clip.

[@johnmiller9219]

12:30 is this layout/schematic available? i can kinda see it here but a hard copy would be great.

[@HeadfirstAmps]

Hey John, sure - I'll add the #36 to the website for download. Remind me to do it again if you don't see it in within a few days!

[@johnmiller9219]

@@HeadfirstAmps very helpful i'm going to do this mod on my 2204 build. I've joined the FB group as well. The #34 mod if you have it would be great too not sure which one i will incorporate

[@marvelharris9540]

would this mod sound the same with a vertical input 2203 since the preamp voltages are different?

[@HeadfirstAmps]

I had previously adjusted the preamp voltages in this amp to be same as a vertical input. So it should should the same, or better!

[@cap217cap217]

Why do you use a 680 and a 330k voltage divider? Can you use a pot instead?

[@HeadfirstAmps]

You can use a pot. The 680/330 is just attenuating as part of the overall voicing of the amp

[@cap217cap217]

@@HeadfirstAmps If you used a pot, where would it be? 680k to pot to ground? Or 680k to 330k to pot to ground? And is that tag strip center lug ground and every lug is grounded except the first? I can only fit a 3 lug so I’d be craning in a bunch of grounds. I am thinking of putting the 100k plate resistor direct to the pin to save a space.

[@nickmcmillan5704]

Could this be achieved using the hot mod or lynch mod from legendary tones instead of drilling another tube?

[@HeadfirstAmps]

Maybe. It depends on whether those can be set as a 10k cold clipper stage.

[@nickmcmillan5704]

@@HeadfirstAmps I’m very curious. Been looking at getting one for my ‘76 2203 to give it a little extra oomph but I’d love to have that #36 mod sound too lol maybe on my reissue 1959

[@HeadfirstAmps]

The hot mods are legit, good option if you don’t want to mod!

[@barneybreau7515]

Are these amps using 6550s

[@paulhyde6212]

so this amp has jel mods and the 36 mods?

[@HeadfirstAmps]

Hi Paul, no just the #36. The owner has another JMP that is setup with the JEL mod.

[@SuperSeanXXX]

@@HeadfirstAmps so you took out the .68u/2.7k on the 2nd stage and put it to 10k cold clipper with .1 bypass right?

[@nickylittle2817]

That is fucn sick that would work fine on a studio classic ?

[@HeadfirstAmps]

Tricky mod on a SC20 as it needs another preamp tube. Not impossible, but a bit of work.

[@robertbozic4692]

Sounds very '80's, however it doesn't remind me of AFD. Very compressed and fizzy.

[@zAvAvAz]

Yesh. Hey headfirst amplification salutations. i am desire to make an amplifier that please i am. it shall be a number 2203 with multiple gain stages and more tunable eq. thank you very much , i really love your amplifiers. i play really marshall metal sound with marshall metal guitars like monster metal and thrash with rythums and leads big yet defined thrashy hairy razor grind powder crashing roaring crushing winding dibbling sawing chunking thrashing tornado storm riffs. you know?

[@HeadfirstAmps]

Sure, I know!

[@erichemard7066]

It sounds like this….hits the first chord and melts your face off

[@roccogreco21]

Potrei avere lo schema gentilmente