Marshall DSL 50/100 Clean/Crunch Footswitch - at last!

[RickyLee]

Switch is completely installed and fully functional on the first attempt! I ended up mounting the third volume pot centered below the crunch gain and volume pots. Absolutely awesome addition to this amp!!!

Yeah, unlike you I did my footswitch kit as well as the FX loop kit in two sessions as I was wanting to tweak some other areas while I was in there. Just finished putting it back together and playing it before going to dinner. BUT, my independent Crunch volume control is loose iside the amp - sealed up with some plastic of course. LOL I could not make up my mind about drilling the hole in the front of the chassis. My brain was thinking it was a blend control between the Clean and Crunch volume difference. It IS actually an independent Crunch volume control.



So I need to make up my mind if it is going on the front as you did or in place of the A reverb control.

But excellent mod I have to say. I have not tried the FX loop as of writing this . . .

 

[Buggs.Crosby]

the reverb knobs on these amp are useless anyway

 

[RickyLee]

the reverb knobs on these amp are useless anyway

I got a call this afternoon for a gig tomorrow at 1PM. So I got in a hurry to finish this DSL so I could try it out at the gig. That is why I just left the new volume pot loose thinking I could set the volume difference between Clean/Crunch and use it that way for tomorrow.



I need to read my instructions a bit better. I have always been bad that way - just reading enough of the instructions to get the task done. Too much "being in a hurry". And then I still have not tried any of the Joey DSL Mods. I am trying to get my motivation up right now to reduce the value of the first gain stage cathode bypass cap at least for this gig tomorrow.

 

[jimmy3711]

And then I still have not tried any of the Joey DSL Mods. I am trying to get my motivation up right now to reduce the value of the first gain stage cathode bypass cap at least for this gig tomorrow.

Only mods I have done so far are the C12 removal, JC's OT and Choke and now the clean/crunch mod. I will replace the PT in short time, but I am not sure what else to do. I am real happy so far with the results. I am not sure that I have to mod more, but I am curious to know more what the amp can do!

 

[RickyLee]

Only mods I have done so far are the C12 removal, JC's OT and Choke and now the clean/crunch mod. I will replace the PT in short time, but I am not sure what else to do. I am real happy so far with the results. I am not sure that I have to mod more, but I am curious to know more what the amp can do!

In the end, I put the new Crunch volume control in place of the Reverb A pot. As I have a much better FX loop now, I will probably run some rack stuff into this beast.

As for mods? I had already removed the Ultra channel C12 bright cap. And I forgot that I increased the value of the global negative feedback resistor to 100K. I did that when I first got the amp. It adds a bit more bottom end punch and darkness to it for sure. I have a bar gig this afternoon, so I will put her through her paces today. Only thing is I never tinkered with the first gain stage cathode bypass cap yet. AND I did not install my choke either. But this beast is coming alive already regardless.

I have to give most of the credit to Graham and his Mode Footswitch mod and the FX Loop mod as well, as that has made this a good working, gigging amp.

 

[RickyLee]

Played the reworked DSL100 via Drunkfest yesterday. The new footswitch mod is awesome for turning the DSL into an awesome cover tunes gigging tool.

 

[jimmy3711]

Played the reworked DSL100 via Drunkfest yesterday. The new footswitch mod is awesome for turning the DSL into an awesome cover tunes gigging tool.

What are you using for a foot switch for the new mod? I am bidding on another standard DSL foot switch to use. I am going to change the LED in it to another color.

 

[RickyLee]

Here is a clip towards the end of our DrunkFest Jam yesterday taken with my Gal's cell phone. Sound quality is terrible as well. I am still feeling the aftermath of the Tequila and draft beer + a few different Dark beers as well. We had a fella jump onstage with a harmonica - kinda threw us off a bit. Kept me from doing my usual long ass shred thingy. LOL

[ame=http://www.youtube.com/watch?v=p-SnB7m4iRk]YouTube - Red House Klones 4 30 2011[/ame]


But the DSL is on it's way for sure. This amp sounds freakin' bada$$ when I roll back the guitar volume as well. And I have not even tapped into much modding yet.

What are you using for a foot switch for the new mod? I am bidding on another standard DSL foot switch to use. I am going to change the LED in it to another color.

Yesterday I used two separate Marshall single button footswitches PED801's. But I had issues with the second one and the first one was already acting up previously. So I am going to use one of my older two button footswitches and modify it for the DSL, or just add a insert cable tip ring sleeve type to allow it to plug into each jack on the back of the DSL.

 

[RickyLee]

I noticed Saturday at my jam with the DSL100, that I had a bigger disparity in overall volume between the Green and Red channels - more of a difference than before I did the footswitch mode mod. The Red channel always had to have it's volume a touch higher than the Green channel to get them equal. But now that I have this independent volume for the Green channel Crunch mode, the volume difference was even more noticable.

Anyoneone else having this same effect? I have not performed any preamp mods yet I should add.

 

[unclenazz]

I noticed Saturday at my jam with the DSL100, that I had a bigger disparity in overall volume between the Green and Red channels - more of a difference than before I did the footswitch mode mod. The Red channel always had to have it's volume a touch higher than the Green channel to get them equal. But now that I have this independent volume for the Green channel Crunch mode, the volume difference was even more noticable.

Anyoneone else having this same effect? I have not performed any preamp mods yet I should add.

I got a custom switch made with a red and a green LED - works a treat.
I get a great sound and volume with the Crunch channel but the Ultra is lacking in volume compared to it! Mines a DSL50 - thinking I need a 100W....

UN

 

[een7gdr]

I noticed Saturday at my jam with the DSL100, that I had a bigger disparity in overall volume between the Green and Red channels - more of a difference than before I did the footswitch mode mod. The Red channel always had to have it's volume a touch higher than the Green channel to get them equal. But now that I have this independent volume for the Green channel Crunch mode, the volume difference was even more noticable.

Anyoneone else having this same effect? I have not performed any preamp mods yet I should add.

I posted (post 83, page 3) mentioning that the extra volume pot does seem to reduce the overall max selectable volume on the amp as the volume pots form a potential divider with a limiting resistor. As there are now 3 pots in parallel rather than 2, the limiting resistor needs to reduce by the same amount in order to get back the max volume level - this can be done by soldering a 1M resistor across the 470K present resistor. This might be the cause of the apparent disparity between volume levels. It is a bit odd as the change affects all channels in regards to the voltage drop.

I will be adding this to the install guide when ive got a second! Feeling a bit sorry for myself at the min. as Ive been doing some pretty long days at work recently!

 

[RickyLee]

Last night I lowered the capacitance value of the three caps in my DSL100's channel switching ducking circuit. I have the amp all apart still and do not know if it will be put back together today, but I will post my results when I do. Hopefully I can find some improvement for this channel switching latency issue as well as the reverb decay and swell when switching channels.

On the main valve board, I lowered the value of C26 from 22uF to 6.8uF, lowered R58 LOL from 100uF to 68uF and lowered C45 from 47uF to 10uF.

Something of interest. My amp does not have D1 on the main board. There is a jumper in it's place.

 

[cylon185]

ooohhhh yeah

 

[fweijers]

I installed the mod too, option 3 and added the volume knob on the front of the amp. Neat!
It all works great (tested only at low volumes), but there seems to be one strange thing:

I get a 'pop' sound (in the speaker) when switching from green to red channel back an forth.
It seems to be there only when I have my pedal board connected in the effects loop.
Anyone else with this popping sound issue?

 

[cylon185]

I have the issue, and I dont even have the kit installed yet.

Will change the front board caps, and do this.

For the LDR (optocouplers) troubleshooting:

1) Connect an ohmmeter onto the two leads coming out of the top of optocoupler LDR 3 on the main tube board.

2) Turn the amp on but leave it in standby and set it to the clean channel. The ohmmeter should read approx 2k or less.

3) Now set the amp to the lead channel. The reading should change to about 100k ohms.

If your readings don't match the above, you have a bad optocoupler and Marshall usually has these in stock. You can also search for NSL-32H-004

Definitely redo the speaker ground jack switch mod.

 

[fweijers]

I have the issue, and I dont even have the kit installed yet.

Will change the front board caps, and do this.

Thanks man for your help! Will try this too.

 

[cylon185]

Good luck

 

[fweijers]

I order to solve the switching channels noise (pops) problem I did the optocoupler check as indicated in this thread.

green channel: 1411 ohm
red channel: 1.5 MOhm, and this value increased to 2.4 MOhm during 1 minute or so.
What does this say?

I am not sure it I measured the right component ... which is LDR3?
I attached a picture of the component I measured.
Can anyone indicate if this is the black thingy is optocoupler LDR3?
There should be LDR's 1 and 2 near it, but those seem to be regular resistors..

See picture at:
https://picasaweb.google.com/lh/photo/4XShv6voZAaKX7LMC3bF4w?feat=directlink

 

[jcmjmp]

I order to solve the switching channels noise (pops) problem I did the optocoupler check as indicated in this thread.

green channel: 1411 ohm
red channel: 1.5 MOhm, and this value increased to 2.4 MOhm during 1 minute or so.
What does this say?

I am not sure it I measured the right component ... which is LDR3?
I attached a picture of the component I measured.
Can anyone indicate if this is the black thingy is optocoupler LDR3?
There should be LDR's 1 and 2 near it, but those seem to be regular resistors..

See picture at:
https://picasaweb.google.com/lh/photo/4XShv6voZAaKX7LMC3bF4w?feat=directlink

For the LDR (optocouplers) troubleshooting:

1) Connect an ohmmeter onto the two leads coming out of the top of optocoupler LDR 3 on the main tube board.

2) Turn the amp on but leave it in standby and set it to the clean channel. The ohmmeter should read approx 2k or less.

3) Now set the amp to the lead channel. The reading should change to about 100k ohms.

If your readings don't match the above, you have a bad optocoupler and Marshall usually has these in stock. You can also search for NSL-32H-004

Sounds like your LDR is fine.

The early amps had three LDRs but the later ones got cost reduced and only have one.

 

[fweijers]

So the LDR seems to be fine?

Then something else is wrong. What would be the next step?
I read about "replacing front caps" ... what does that mean?