Improve the Marshall Studio SC20H with $10 parts - DIY DEEP DIVE!!

[@LeonTodd]

It doesn't get said enough here, your playing is KILLER!

[@HeadfirstAmps]

Thanks brother, this makes my day :). Especially coming from you

[@belligerentamateur]

Wow, this nakes me REALLY want to grab another SC20. Already thought it was an awesome amp in stock form but this just sounds ridiculous, excellent work Jason!

[@HeadfirstAmps]

Thanks! They are cool amps for sure.

[@benburnett8109]

Jason, Would you consider a video describing your soldering tools? A video where you give detailed instructions on selecting a soldering iron, solder, and the steps to solder properly? I build and modify guitars. Tim From TNTones pickups custom builds pickups for me, and I would like to be able to solder to volume and tonepots correctly.

[@BlakeC27]

Thanks as always Jason for sharing your knowledge and expertise.

[@HeadfirstAmps]

No worries!

[@adamswanson8216]

Don’t play it very often but I still have my Zach Wilde signature JCM 800 head from some years ago and truly it’s amazing. It has the 6550 tubes in it and I can tell you the tones are amazing. I had to put a $700 attenuator on it to make it right lol but when I use it, it is fantastic, but I have truly found that with Friedman I get everything I want of these tones from my Jake E. Lee head and also I use the dirty Shirley so between those two amplifiers it pretty much covers all of my major tones and the JC 800 side of the Jake Lee signature 21 ahead is amazing and compared to this don’t get me wrong. I love Marshall and I broke my heart to switch. I still have my silver jubilee. I just won’t let go of that and I have my signature Bernie Marsden 74X and my Zack Wilde those things are important to me and I’ve had them some of them for years. I’ve been playing guitar for 37 years and there’s nothing I love more than that JC 800 but truly Friedman has changed the world as far as I am concerned, and I am happy about that change the hand wiring. The tones are incredible, thanks for a great demo though. It is a nice one sell 5:52 5:55 5:57 5:59 6:01

[@batpigguitar]

That sounds KILLER.

[@brucetaylor1753]

Wow. I just purchased one of these yesterday. I will definitely be doing these mods. Thank you!

[@crflores76]

Awesome tones, congrats Jason… you doit again!!!

[@HeadfirstAmps]

Thanks!

[@ryanlucivero9598]

You knocked it out of the park, mate! So much more versatile than stock with plenty of gain on tap. Absolutely love my mini jcm 😀

[@omarheavy2009]

Thanks for sharing this man!!

[@lechstryzewski9350]

Awesome stuff Jason ...... as they all are man !!! - Thanks for sharing with us - Cheers

[@HeadfirstAmps]

Thanks for watching!

[@lechstryzewski9350]

@@HeadfirstAmps I just so happen to have a second SC20H (other hhan my main SC20H) .... still in the box ..... that I bought about a month ago. Absolutely crazy deal that I couldn't pass up. I got it for $800 and it's like brand new !! - As soon as I get my '75 1959SLP off the bench - I may just have to apply this mod to the 800.

[@terrydemol5354]

Jason, nice mods, the SC20H is a great little amp that is well made, reasonably priced and a good platform to work with. A few tips -> the 68k R at IP just adds noise, more than 2 x that of V1 itself. You can make it a lot smaller. The 470pF LPF cap on follower will have a corner freq of well above 100k(Hz), remember it's a follower = low impedance ( 1/gm).

[@HeadfirstAmps]

That 470pF works and is way less than 100kHz, theory aside. I use my ears.

[@nestorcano4354]

Thanks for doing these videos!

[@HeadfirstAmps]

Glad you like them!

[@Nightjar726]

You make the best mod videos hands down. Great explanation, visuals etc. hats off to you man. Seriously good work. On another note, I can’t believe Marshall for so many decades was kinda just bamboozling people with these such cheaply made amps which weren’t even thought out well. I have nothing against PCB boards in the least. But the quality of these , the cheap potentiometers , components, etc. if their amps of the last 25 years didn’t have the Marshall logo on them, they would never sell any of them. I really wonder what the new company that bought them will do now. Anyways. Great work man. Super work

[@HeadfirstAmps]

Thanks brother! Will be interesting to see what happens with Marshall with the new owners now in place.

[@shredgd5]

Sounds great!

[@alexeloi1563]

Thinking about all the costs reduction they made in the amp, I would first undo these reduction costs by changing all the cheap parts in to real quality ones... mods... maybe include a clean channel and a spring reverb... maybe.

[@donnyboy911]

great vid...gotta try some of these mods

[@jaykafcas4342]

THAT is where the money’s at. The NFB🎯. Spend as much time as it takes to crack the code. That’s where I’ll be posting up.

[@Burgschall]

Whilst I love the MKT1813s for classic builds on Turret PCBs I prefer to replace the grey box with ERO/Vishay MKT1822. These are tonal in the same league as the MKT1813 (and a general replacement I use when I have a leaking/Dead Coupling Cap in more modern Marshalls) and do look not so displaced as the 1813 do in modern PCB Circuits.

[@spiromandylor]

Any upgrade recommendation for the transformer?

[@felinekaiju4517]

I found desolder braid, and if it's beinf stubborn, i found a tub of flux (onviously not dumping the whole thing on) helps too. Although that took a bit of mastery so that it wouldnt mess up the board.

[@HeadfirstAmps]

Great tip, thanks!

[@kylebarton6498]

I’m waiting to receive a 2500 mark iii head (900) and there isn’t a ton of info about it. I think it would be cool if you made a video where if nothing else you looked at the schematic and noted how much it differs from a 2204. Thanks! (Cheers)

[@fatchoppers01]

Oooh Jel in background

[@zandig666]

I've got a sneaky suspicion I'd get this amp home and I'd still suck lol I liked the original tone the gain took the chime outve the amp with I love

[@Burkhimself]

Sounds killer…..does the amp clean very well with the guitar volume while amp is on the “highest gain setting on the switch” ?

[@HeadfirstAmps]

Cleans up ok, similar to a 2204 really

[@lynyrddeville]

Hi Jason, the amp sounds great! Would you say the way gain switch is similar to that which a lot of the Friedman amplifier line feature? I am curious about your depth mod as well. I think it might be a suitable mod for my Friedman Smallbox,

[@shredding51]

Please do a DSL20h :)

[@HeadfirstAmps]

When someone sends me one, it will happen!

[@shredding51]

@@HeadfirstAmps you’re awesome man! I’ve learned a tone from you. Thanks again

[@dBoogieNights]

Dankeschön aus St. Petersburg

[@Guitarista78]

Fan fkn tastic!

[@hybridjohn1]

wow, super sounding head.

[@hayabusa1300100]

Headfirst can you send me the parts list and maybe a few pictures of each point if you will had to see the screen I have one of these SC20H’s and would like to do this mod f I know all the specific’s I will order the parts I need from Mouser thanks man

[@shredding51]

Will there be pics of these mods on your website?

[@Burkhimself]

That 470 to cut a little treble, it goes across the top of which R on the board….is it R10 ? I’m playing with values…..I put a .1 over the top of the 10K and trying to pull a little more treble down…..

[@HeadfirstAmps]

Across the 100k (V2a). If you put it across the 10k you'll get more treble.

[@distortedchannel1022]

Your playing smokes! Maaan

[@HeadfirstAmps]

Thank you man!

[@shredding51]

Could you use a mini toogle for the bright cap instead of a push pull pot? Thanks

[@HeadfirstAmps]

Sure

[@shredding51]

probably a stupid question, but on the depth pot one leg of the 4700pf does on the wiper right?@@HeadfirstAmps

[@cactus-mcjacktus]

how’d you get the Knaggs?

[@HeadfirstAmps]

It's an Eric Steckel sig model, I bought it from a mate here in Australia.

[@jaykafcas4342]

It sounds the best with no mods. While I get what your after, what happens in reality when the polish wears off the mod? Plug & play the raw Marshsll. I say get intuitive, bring something that doesn’t give the overdrive/boost sound & vibe. More Billy Gibbons less pushed for the same old same old same old….

[@bradleywood1499]

Do you ever sleep, Jason?

[@HeadfirstAmps]

Haha, oh I do. 8 hours minimum!

[@Nightjar726]

Pardon. But depth knobs makes amps sound a bit hifi. No offense man. It’s just another opinion. Great work

[@HeadfirstAmps]

No offence taken! Can be handy for a vibe at lower volume, cranked up in a band context then dial it down…even to zero for a more stock sound.

[@Nightjar726]

@@HeadfirstAmps yeah it’s ok for low volume playing , agreed. Thanks for not taking offense. You can’t see inflection in text. Worst way to communicate. Great channel man.

[@Nightjar726]

@@HeadfirstAmps for a slight change from stock I usually like just a slight change to the V1A plate resistor to 120k or 130k from 100k stock for a slight bit more of gain and compression. It’s ever so slight but keeps the whole Marshall kerrang. And maybe a fat cap . Too much gain sometimes takes away from that kerrang Of course I should mention I did that on a low voltage 2204 from ‘78 which don’t lend to adding much gain because of the lower voltage. Mine was around 390v on the plates from what I remember. Just too low for more gain. Would get too mushy. Cheers

[@k.t.5864]

A Super Lead is SOOOO much better sounding.