DSL40C / 100H C19 Bright Cap Mod

[Kenster]

Hey Guys - First post to the forum and hope all are doing and rocking well. I own a DSL40C and like most didn't care for the channel switch treble increase when going from the green to the red channel. Because this amp has so much gain I wanted to keep it low on the red channel. Well because of the cap marked C19 in front of the gain pot on the board it caused the amp to be way too bright when switching to that channel. Well I found out from a thread on TGP new Marshall DSL 40 and 100 cap "mod" - The Gear Page from a generous player TMAC about C19 being the culprit. See pictures of the cap in the link above. So this morning I pulled a leg of that cap out and voila, no harsh treble. Just a smooth transition from green channel to Red on Lead 1.

I don't know what Marshall was thinking putting that cap in but this amp is now that much better for covering Marshall tones in a small versatile pkg and probably so with DSL100H since its the same circuit. I do not miss a separate set of tone controls at all. Just a switch from a clean slightly breaking up amp to a thick juicy lead or rythm tone.


Sorry I don't have clips but it's totally a worthwhile endeavor to try it. If you don't like it solder the cap leg back in. Takes 10 to 15 minutes to do.

Also I would suggest using a low wattage iron like 25 watts or so or you got to be fast with a 40 watter when pulling the cap leg. Also be careful when messing around inside of these amps since they have lethal voltages stored up in the filter caps. If you don't know what you're doing have a tech do it.

Anyway thought I would share since so many players have experienced frustation from these amps being too bright on the Red channel.

Just for reference the only other mod I did is replace the 70/80 speaker with a G12-65 and put Electro Harmonix pre amp tubes in V1 and Mullard reissue in V2. I play mostly a mahogany maple capped strat with Van Zandt single coils and a Wolftone Marshallhead A2 magnet in the bridge.

Cheers
K

 

[Micky]

Thanks. Good info.

 

[Rocktane]

Great news, thanks for posting!

 

[strathaze]

Just did the mod - fan f@$king tastic!!!! Like most I had given up on the red channel as being too untameably bright - without compromising the green channel and turning it to mush, given the global EQ. Now it just transitions across seamlessly to a fat, thick searing high gain lead. Still slightly brighter than the green channel, but that's exactly what I want. I liked this amp a lot before, now I'm lovin it!!

 

[ibmorjamn]

Thank you for posting here !
I just paid $100 for the extended warranty so it is questionable if I did this. I would hate to wait 3 years to find out how it sounds !

 

[Kenster]

Thank you for posting here !
I just paid $100 for the extended warranty so it is questionable if I did this. I would hate to wait 3 years to find out how it sounds !

If you know how to solder good just desolder and pull one leg of the cap. If you need some kind of warranty work solder the leg back in before you send it off.

If you're not good at soldering though then it may not be worth the risk. Another option is take it to a tech.

To me it was well worth the risk.

K

 

[paradox]

Thanks for the info Kenster!!!

However I seem backwards from most, I like the 'cut' I get from the treble response of the red ch, but I play LP's maybe with darker pickups. I've heard the green channel actually has a 'fixed' eq tone stack that then cascades into the main (shared) eq tone stack. My approach may be to brighten up the green channel by modding the 'fixed' eq tone stack it has and then I'll have more range on the shared eq tone circuit, maybe.... lol... If I do a mod to it that works well I'll report back.

 

[atstrother]

Hey,

I would recommend just clipping the cap leg as close to the cap as possible
and just lift the cap body slightly to create an open. No risk to the pcb from
desoldering that way. If you decide it's too dark you can clip the
other side in the same way & have metal legs to alligator
clip some new cap options to, to see how they sound before you
break out the soldering iron for a permanent install of the new cap.
On my last generation DSL 50 head, the red channel was too dark,
so I ended up putting a lower value cap in IIRC.

 

[guitarman3001]

Thanks for the info Kenster!!!

However I seem backwards from most, I like the 'cut' I get from the treble response of the red ch, but I play LP's maybe with darker pickups. I've heard the green channel actually has a 'fixed' eq tone stack that then cascades into the main (shared) eq tone stack. My approach may be to brighten up the green channel by modding the 'fixed' eq tone stack it has and then I'll have more range on the shared eq tone circuit, maybe.... lol... If I do a mod to it that works well I'll report back.

Did you ever figure out a mod to make Ch1 brighter instead of making Ch2 darker? I think we may have heard the same thing with these amps. To me, it wasn't a case of the red channel being too bright, but rather the green channel wasn't bright enough. I'd rather find a mod that will make the green channel brighter instead of making the red channel darker.

 

[Wootty90]

Hi guys I purchased a new dsl40c recently in stealth let me say I love this amp compared to the dsl401 I had an early model which had a lot of dials and crap uses . It had a v30 in and a cooling mod and it was a let down.
I tried this amp in triode mode at home and I did notice slightly the ultra 1 channel when changing could be bright so I read your forum found the schematics and chopped the leg at centre point on the right side , wolla it sounded to have more girth instantly.
BUT!!
I them took it for a loud spin with my pretty bright telecaster and I found the od channels to be lacking that stabbing sound I live from the tele plenty low end balls but I lost that great shrill sound , so I went home and soldered the cap back , took it back out for a spin and I've gotta be honest I like it better with the cap on , I found just using the ultra 2 channel has more low end just whack the gain down to 9 clock and it sounds fab I'm not sure how it will sound with my humbuckers tho may have to keep the gain low and tame it as let's be honest this amp as so much gain it's not needed reverb is weak but I only use a mild amount usually do it's perfect for me love the size of the cab on this one aswell far better than the old dsl401 clean channel and crunch are stunning Bargain.

 

[Micky]

Holy NecroPost Batman!

There is a whole thread dedicated to this amp...
http://www.marshallforum.com/index....ial-marshall-dsl40c-information-thread.53780/

 

[Screamin Willie]

Holy NecroPost Batman!

There is a whole thread dedicated to this amp...
http://www.marshallforum.com/index....ial-marshall-dsl40c-information-thread.53780/

You a funny guy, Micky.

He's excited.

@Wootty90 Check out the link Micky posted. Let us know when you get caught up. LOL Just a little ribbin'. It's all good, man.

Willie

 

[sloan_amps]

The 1st mod I did to my DSL100H was C19, only I just lowered it to 100pF instead of removing it from the circuit. Helped a lot!

I did some other things to it as well and it's now one of my favorite amps. Here's that thread:
http://www.marshallforum.com/index.php?threads/dsl100h-upgrades.76029/

 

[tman]

I did the c19 mod,a speaker upgrade to a Creamback in the combo,changed the OT to a Classictone and added a Choke. Plug it into a 1960B 4x12 cab(loaded with Celestion 75's),and changed the tubes to NOS Mullard"Blackburn" 12ax7 in v-1/NOS Sovtek LPS 12ax7 v-2/TAD 12ax7WA in v-3/Mullard RI 12ax7 in the PI and changed power tubes to 6AC7 EH "FAT BOTTLES" now I got a great Marshall DSL40C!!Not that the amp isn't great on its own,because it is.I'm just a tone freak and like mods.Now I play that baby all day long cranked getting some awesome tones out of it.

 

[DeadStarRule]

Hi guys, I have the dsl100h matched with the recommended MX412A cab, as many here, the amp was sounding very nasal and extremely bright/harsh when I bought it, I was playing that stock way about 2 months, but I wasn't happy with the sound and couldn't believe this was the sound of a 800bucks all tube amp... but later on I did some research about "dsl100h too bright" and I ended here.

I want to share with you the things I did/ recommend to do to your amps dsl100h or dsl40h as those are basically the same to get the best of them and a good juicy sound without the harsh, first of all I recommend you to check and adjust the bias, my dsl was about 74mV, I do adjust it from 60mV to 90mV and compare the sounds, the less the voltage, the more digitally/nasal/thin sound, but with more voltage the more rounded/warm sound, I read that some people adjust them to 80, 85 and also 90, it is supposed that the recommended voltage from marshall is 90mV but also somewhere I read that could be very hot, so I finally decided to leave both sides at 88mV, this simple adjust gave more tone, warm, body sound. I guess for the DSL40c is the half: 88mV / 2 = 44mV.

Second to get rid of the harsh/fizzy sound I did the c19 470pF mod by cutting it, helped a lot cutting the ear bleeding highs, but also seems that you lose some sparky/addictive highs that are so Marshall , so I tested 47pF, 68pF, 100pF and 150pF, definetely the 100pF capacitor is the perfect replacement of the 470pF stock.

Third the clean channel on the mode1 was also very fizzy/harsh and nasal, specially if you put in front any pedal, distortions or multieffects. c4 100pF is the equivalent cap in classic gain as c19 is for ultragain channel, If I just remove this cap same as above happens, no harsh sound but the addictive sound is lost, so I tested here 22pF, 47pF, 68pF, the perfect replacement cap for c4 is 22pF.

So in summary If you have the DSL40c or DSL100h first adjust your bias, second replace the c19 with 100pF and third, replace c4 with 22pF.

I now have a very pleasant, full body, warm, addictive highs sounding amp