The dsl joey mod thread

[jensbrix]

Ok I'll be ordering parts tomorrow, looking forward to work with it

[surface54]

ive just put the stock 470pf c12 value back in i already feel it makes my ears feel better about it. 100pf really does make it have a more lo-fi vintage sound to the lead channels and more classic rock (i have no classic rock in me), lead2 was almost completely unusable after time, lead2 @3.5 gain was the only sweet spot and nothing else. lead1 was fine and a little smoother, but i already thought it was smooth before. my days modding are over, too stressful and unless something breaks i have no reason to alter the stock dsl tone. its actually quite great stock. i got sucked into the c12 movement, not for me.

[StootMonster]

Mine just has some JJ's in it. I love the sound. Not quite giving me "that sound" yet, but I'm getting closer every day.

[cylon185]

Awesome thread... just put my hand on a second hand DSL.

[Major Sparky]

This has probably already been answered. It might have even said it in the OP, but do any of these mods work for the DSL 401?

[chadjwil]

Yup.
Just be sure of the board revisions before you start. Some revisions have components numbered differently. Check page 1 of this thread for the issue number of the boards that the OP is referring to, get that schematic and locate all the parts you plan to tinker with, then get the schematic for your board and make sure that the components in question are numbered the same. If not then you'll just need to make sure that you are tweaking the component that is in the same circuit location of the original drawing (again from page 1) regradless of naming convention.

Good luck

[Salsg]

I remember on that "other" Marshall forum that is no longer around, there was a mod to lower the bass on the green channel. I think it was one resistor.

Does anyone remember or know what that was? I would like to lower the bass on the green by a little, it is unbalanced with the red channel.

[jcmjmp]

Originally Posted by Salsg

I remember on that "other" Marshall forum that is no longer around, there was a mod to lower the bass on the green channel. I think it was one resistor.

Does anyone remember or know what that was? I would like to lower the bass on the green by a little, it is unbalanced with the red channel.

One thing you can do to balance everything out is to change the cathode cap on V1a to a 1uf to 0.68uf cap. That will even things out a little. This is on the tube board.

On the front board, for the
Clean Channel: Try a different value for R3. It will take a large value to make a difference here. Try 47kΩ
Crunch Channel: Try a different value for C8. Try something like 0.001uf (1nf).

[Jchop76]

hello

New here been reading over this post on modding the dsl 100. i have an older dsl 97 model that i eventually changed the main power board for a newer one. As i was hit with a bad bias drift. Tried changing everything that was suggested but nothing helped. The new board I do notice seems to be made of a different material. It looks different and the circuit is a little different. It does appear they have corrected the Grid blockers from 220K to 5K6. The bias is stable now.

I've also installed a Marstran 100w OT and a 3H choke. the only other mod I've done was to lower the value of C12 (treble bleed) on the input board. This did lower the top high end and thickened the tone some. I've also removed the reverb board and unit as I never used reverb.

I've always like the sound of the dsl but as member TwinACStacks mentioned not the fizz.

What Mods should I start with to get rid of the upper fizz In OD 1 and 2 . I want to lower the gain some as well. From reading this post I'm kinda wanting the same thing TwinACStacks was wanting. I never run my gain above 12 on OD 1 and 2 in the stock form it was just to much.

I play Gisbon Les Pauls with Rio Grande BBq set, and a Epi elitist with stock pickups.

On the green crunch I like the crunch but it seemed to beefy or farty in the low end.

I like the Green clean don't really want to mess with it unless it could get cleaner, but it seems to be fine in stock form.

I'm wanting a more open and harmonic crunch. More AC/DC, Thin Lizzy sound. Less Fizzy. what should I start with?

thanks any input would be great.

[Buggs.Crosby]

Try dropping R13 on the tube board down to around 100k

[Jchop76]

I assume you referring to my post Buggs.Crosby?

if so. I notice mention of C12 on the Main valve board as well. will this help?

what would be best mods to start with to achieve what I'm wanting? in what order?


start with?

C12 4.7uf change to a 1uf
R13 220K change to a 100K

[Jchop76]

I'm having a hard time sourcing the parts for this Joey mod. I've only been able to find one part in stock at Mouser.

C12 1uf 63v WIMA that was suggested.
Is it important to go with the WIMA caps in C12 on main valve board and C9?



Anyone know a source? what type of capacitor and resistors? Polyester film? metal film? what brands are best to go with? any help would be great. It would be helpful to include this in the mod description of suggested caps and resistors material tolerance ect.

[jcmjmp]

Originally Posted by Jchop76

I'm having a hard time sourcing the parts for this Joey mod. I've only been able to find one part in stock at Mouser.

Anyone know a source? what type of capacitor and resistors? Polyester film? metal film? what brands are best to go with? any help would be great. It would be helpful to include this in the mod description of suggested caps and resistors material tolerance ect.

for the caps, I use the Wima caps as Joey suggested but also like the Vishay MKT 368 series.

For resistors, metal film types are my favorites. Don't overthink it though.

[Jchop76]

Originally Posted by jcmjmp

for the caps, I use the Wima caps as Joey suggested but also like the Vishay MKT 368 series.

For resistors, metal film types are my favorites. Don't overthink it though.

having a hard time finding C9 1000pf (.001uf) 630v for the valve board. can't find a WIMA, and I don't need a minimum order of 3000. lol!

any idea where to find one possible other brand?

[Jchop76]

having a hard time finding C9 1000pf (.001uf) 630v for the valve board. can't find a WIMA, and I don't need a minimum order of 3000 from germany. lol!

any idea where to find one? possible other brands that would work for this application?

[jcmjmp]

Originally Posted by Jchop76

having a hard time finding C9 1000pf (.001uf) 630v for the valve board. can't find a WIMA, and I don't need a minimum order of 3000 from germany. lol!

any idea where to find one? possible other brands that would work for this application?

Like I said, don't worry about the brand too much. Get what you can find, especially for the 630v cap.

[Jchop76]

ya just having a hard time in general finding a 630v cap.

so a silver mica would be okay?

what wattage on the metal film resistors? for R13, R30 on main valve board?

and R12 on the front board?

[chuckharmonjr]

For that matter, if you can't find a 630v rated one, get a 1000v one. like I did.

[Jchop76]

chuck you have a source for the 1000v?

[chuckharmonjr]

found it at a local supply store here in mobile

[Buggs.Crosby]

Originally Posted by Jchop76

having a hard time finding C9 1000pf (.001uf) 630v for the valve board. can't find a WIMA, and I don't need a minimum order of 3000 from germany. lol!

any idea where to find one? possible other brands that would work for this application?

MKP2J011001B00JSSD WIMA Polypropylene Film Capacitors

[Jchop76]

ya that one is back ordered until Sept if you look. not in stock.

I've found a couple others.

Either A Mallory .001uf 630v or a Xicon polypropylene .001uf 630v

would either of these caps work for C9?

[Joey Voltage]

Originally Posted by Jchop76

ya that one is back ordered until Sept if you look. not in stock.

I've found a couple others.

Either A Mallory .001uf 630v or a Xicon polypropylene .001uf 630v

would either of these caps work for C9?

Yikes! doesn't really matter all that much, I spec'd the wimas because I lika da reda collah!, and more importantly they have the correct lead spacing, which is the most important part. any poly cap, or what ever you want to use with a 5mm pcm is what you want. they have several film caps that fit the bill, and may other types that do too.

[Jchop76]

thanks Joey

I'm excited to try your mods. I've been visiting this site for a long time. this caught my interest and I finally signed up.

looking forward to hearing how this mods will affect the dsl 100

[cylon185]

Hey

Is it C12 on the tube board?
Thought it was C12 on the front board...

[Buggs.Crosby]

Originally Posted by cylon185

Hey

Is it C12 on the tube board?
Thought it was C12 on the front board...

There are more than 1 C12's in these amps.....each board starts fresh
C12 on the pot board is the treble bleed cap
C12 on the tube board is the cathode cap on V1

[Jchop76]

+1 what Buggs said.

[RickyLee]

OK!!

I finally got on the Bandwagon that is owning a Modded DSL!

I did not go that crazy, but the few things I did to this amp made a huge difference. I put the Mercury 3H choke in it. I am sure that had a huge impact when I had this thing cranked up a few hours ago. Now I did these mods all at the same time, so I have no idea what impact each one had overall.

I basically just did a few of the mods at the beginning of this thread. Lowering the first gain stage cathode bypass cap is a big improvement for sure. And lowered the first gain stage plate resistor to 150K. I snipped out the Ultra channel bright cap C12 as well.

The only bitch I have left is the Clean channel. It still is not too clean, and is quite bassy/boomy. I had already lowered the value of C2 on the front control board down to .018uF but I am not sure if I am hearing any change there. And that leads me to a question of what exactly is the purpose of this cap in this part of the circuit? And what does higher/lower values achieve? This part of the circuit I am having a hard time understanding. SW1b is going to Ground/negative and the schematic is shown in the Clean mode state, correct? So then will a higher value cap in C2 bleed off/pass more high frequencies to Ground, making the clean channel bassier?

Originally Posted by jcmjmp

One thing you can do to balance everything out is to change the cathode cap on V1a to a 1uf to 0.68uf cap. That will even things out a little. This is on the tube board.

On the front board, for the
Clean Channel: Try a different value for R3. It will take a large value to make a difference here. Try 47kΩ
Crunch Channel: Try a different value for C8. Try something like 0.001uf (1nf).

Lowering the value of the huge 1MEG R3 will let more signal to Ground making the Clean channel cleaner? How will this effect the Highs and Lows?

[RickyLee]

I should add I am also wondering how I might have altered my Crunch channel when I lowered C2 from .047uF to .018uF?

If lowering the value of R3 cleans up the clean channel, then those frequencies will also slightly bleed off when on the Crunch channel I am figuring . . .

[Jchop76]

I believe I read you can mess with the value of R30 on the tube board(main board) which will affect both channels but you can reduce to clean up the fizzy and it will also clean the clean channel more.

Also C8 if I believe will only affect the clean channel. seems like I read a post from Twin talking about this. read back through this thread to be certain.

I'm wanting to do the same thing. I don't want to lose the clean channel, but want to clean up and reduce the fizz and the gain in od1 and 2 and decrease the boomy bass in the clean green crunch.