SL+, JCM 800 Mod or No?

[kbause]

So I started with an XTC, traded it for an ultra, then traded that for a SL+.
I had originial avoided the SL+ because the band I was in up until recently the other guitarist played a TSL.

I've always really really liked Marshall crunch for rhythm tones. And the SL+ totally delivers it with that modern voicing.
I've been reading about the JCM 800 mod and think I might do it, however I do find that the midrange is enough with my TS-808.
Is a midrange shift the only difference in doing the JCM 800 mod?
Because if so I won't even bother most likely.


http://grailtone.com/guitar-tone-articles/randall-jcm800-modification.html

 

[SacredGroove]

I did a quick clip with both, stock, and JCM800 modes. If you can control the balance on your speakers, you can hear each mode individually.

The link is in Rigs and Tones called "SL+ Sample clip"

Maybe that'll help.

 

[maximus1]

i hear more midrange in the left( jcm 800 side) thats about it though the right(stock) seems to have an ample amount of midrange as well but not as much as the left maybe a hair more girth too. if ts-9 doesn't have have the low end mod i'd say probably leave it alone you could always just turn the mids up on the stock? the ts-9 should give it a little bit of mids even if it has the low end mod. i don't know hard to say i guess, i never played a jcm modded one but i have heard the stock one quite a few times and to me it sounds like it has plenty of mids and they can be sooped out easily enough. you should get the rectifier mod :wink:

 

[crankyrayhanky]

consider an 800 mod with a switch, that way you can flip back and forth
The 800 is a mid boost, but it is much smoother and lead friendly
Both tones are cool, try to get the best of both worlds

 

[Rellik]

I did the mod to my SL+ without a switch. I changed my stock silverface SL+ to a .0022 C3 cap to tighten it up, and I did the JCM800 mod. I was cranking the mids all the way on my stock SL+ to cut in my band mix with another guitarist. After I got my Ultra XL, I decided to mod it to get a different flavor. The modded SL+ is the epitome of the Marshall classic rock tone to me.. my friend that helped me mod agreed. I am happy with the mod, but I also have the Ultra XL for anything that needs modern gain.

 

[Tajmoben]

My SL+ was already modded when I got it. I love the tone, but I wouldn't mind trying the stock configuration out. What would it take to put the mod on a switch? Are there instructions online anywhere???

 

[brandon9271]

I have a question.. according to the article it says.. "change R31 to a 33K resistor and C14 to a 470pf" but if you look at the pdf of the SL+ PCB layout the values are already 33k and 470pf! So is the article incorrect or is the layout? I was really hoping the layouts were correct so I could do some mods based on them.. what a shame..

 

[SacredGroove]

I have a question.. according to the article it says.. "change R31 to a 33K resistor and C14 to a 470pf" but if you look at the pdf of the SL+ PCB layout the values are already 33k and 470pf! So is the article incorrect or is the layout? I was really hoping the layouts were correct so I could do some mods based on them.. what a shame..

Check your module to see what components you have. Mine came with the JCM800 components, like the pcb says. I had to ask the forum for the original stock components to compare the two modes.

 

[brandon9271]

I have a question.. according to the article it says.. "change R31 to a 33K resistor and C14 to a 470pf" but if you look at the pdf of the SL+ PCB layout the values are already 33k and 470pf! So is the article incorrect or is the layout? I was really hoping the layouts were correct so I could do some mods based on them.. what a shame..

Check your module to see what components you have. Mine came with the JCM800 components, like the pcb says. I had to ask the forum for the original stock components to compare the two modes.

I actually don't have an SL+.. I was going to try and convert a Clean module into one :lol:

 

[okstrat]

I have a question.. according to the article it says.. "change R31 to a 33K resistor and C14 to a 470pf" but if you look at the pdf of the SL+ PCB layout the values are already 33k and 470pf! So is the article incorrect or is the layout? I was really hoping the layouts were correct so I could do some mods based on them.. what a shame..

Check your module to see what components you have. Mine came with the JCM800 components, like the pcb says. I had to ask the forum for the original stock components to compare the two modes.

I actually don't have an SL+.. I was going to try and convert a Clean module into one :lol:

Good luck with that. the SL+ uses an entirely different PCB. Changing a few parts isn't going to make it into an SL+, unfortunately. You'd be better off selling/trading it and buying an SL+.

Pete

 

[brandon9271]

I have a question.. according to the article it says.. "change R31 to a 33K resistor and C14 to a 470pf" but if you look at the pdf of the SL+ PCB layout the values are already 33k and 470pf! So is the article incorrect or is the layout? I was really hoping the layouts were correct so I could do some mods based on them.. what a shame..

Check your module to see what components you have. Mine came with the JCM800 components, like the pcb says. I had to ask the forum for the original stock components to compare the two modes.

I actually don't have an SL+.. I was going to try and convert a Clean module into one :lol:

Good luck with that. the SL+ uses an entirely different PCB. Changing a few parts isn't going to make it into an SL+, unfortunately. You'd be better off selling/trading it and buying an SL+.

Pete

then why does it have the exact same layout and have Brit Module silkscreened on the front? I'm sure many of the modules use the exactly same PCB but with different component values.. Especially if the Bassman, Blackface and MTS were all based on the same amp to start with.. Maybe I could at least turn my Clean into a Tweed or something..

 

[SacredGroove]

I have a question.. according to the article it says.. "change R31 to a 33K resistor and C14 to a 470pf" but if you look at the pdf of the SL+ PCB layout the values are already 33k and 470pf! So is the article incorrect or is the layout? I was really hoping the layouts were correct so I could do some mods based on them.. what a shame..

Check your module to see what components you have. Mine came with the JCM800 components, like the pcb says. I had to ask the forum for the original stock components to compare the two modes.

I actually don't have an SL+.. I was going to try and convert a Clean module into one :lol:

Good luck with that. the SL+ uses an entirely different PCB. Changing a few parts isn't going to make it into an SL+, unfortunately. You'd be better off selling/trading it and buying an SL+.

Pete

then why does it have the exact same layout and have Brit Module silkscreened on the front? I'm sure many of the modules use the exactly same PCB but with different component values.. Especially if the Bassman, Blackface and MTS were all based on the same amp to start with.. Maybe I could at least turn my Clean into a Tweed or something..

You might be able to convert a Clean to a Blackface. I think those 2 modules use the same pcb. Regardless, if it can be done, it would be close to rebuilding from the ground up.

 

[okstrat]

I have a question.. according to the article it says.. "change R31 to a 33K resistor and C14 to a 470pf" but if you look at the pdf of the SL+ PCB layout the values are already 33k and 470pf! So is the article incorrect or is the layout? I was really hoping the layouts were correct so I could do some mods based on them.. what a shame..

Check your module to see what components you have. Mine came with the JCM800 components, like the pcb says. I had to ask the forum for the original stock components to compare the two modes.

I actually don't have an SL+.. I was going to try and convert a Clean module into one :lol:

Good luck with that. the SL+ uses an entirely different PCB. Changing a few parts isn't going to make it into an SL+, unfortunately. You'd be better off selling/trading it and buying an SL+.

Pete

then why does it have the exact same layout and have Brit Module silkscreened on the front? I'm sure many of the modules use the exactly same PCB but with different component values.. Especially if the Bassman, Blackface and MTS were all based on the same amp to start with.. Maybe I could at least turn my Clean into a Tweed or something..

Probably has brit module silkscreened on the 2nd board where the tube sockets are located. The clean module that I had here didn't even places to put the parts on the PCB for the extra gain stages. I'm not sure what you mean by 'exact same layout' either, as the SL+ has more gain stages and about the only thing it and the clean have in common layout wise is that they both use two tubes.

Pete

 

[brandon9271]

Probably has brit module silkscreened on the 2nd board where the tube sockets are located. The clean module that I had here didn't even places to put the parts on the PCB for the extra gain stages. I'm not sure what you mean by 'exact same layout' either, as the SL+ has more gain stages and about the only thing it and the clean have in common layout wise is that they both use two tubes.

Pete

I dunno.. to me they look kinda similar
:wink:

 

[SacredGroove]

The pcb layout is the same in the file found on grailtone, but the actual boards are different for the Clean. There's a lot less components in the Clean and Blackface modules.

 

[Jaded Faith]

Pete's right on this one...I have the Clean module he is referring to! It is VERY similar to the Blackface when I put them side by side PCB-wise. But it is missing MANY of the component positions of the SL+. Maybe I should peek at my Tweed for you and let you know how they look.... :wink:

 

[okstrat]

I'll plug into the clean module I modded and you plug into that PCB artwork file you posted, we'll see which one is louder.

FYI, NP means 'no part' and again, on the clean modules that I have seen in person, not graphic files, not only were those 'NP' parts not on the board, but in many cases there weren't even places to PUT the missing parts on the board.

Pete

 

[SacredGroove]

I'll plug into the clean module I modded and you plug into that PCB artwork file you posted, we'll see which one is louder.

FYI, NP means 'no part' and again, on the clean modules that I have seen in person, not graphic files, not only were those 'NP' parts not on the board, but in many cases there weren't even places to PUT the missing parts on the board.

Pete

+10

My Blackface

 

[brandon9271]

The pcb layout is the same in the file found on grailtone, but the actual boards are different for the Clean. There's a lot less components in the Clean and Blackface modules.

ahh.. so the layouts are incorrect.. I wondered about that