The Official Marshall DSL40c Information Thread

[Jethro Rocker]

You could run in series off the 16 ohm oitput but it's painful! If 1 speaker is hooked up in the internal, the other has to stay attached to it. Or, if you unclip one connection, MAKE SURE YOU RECONNECT before turning amp on. Painful. Really not a good way yo do it at all. You are waaayyy better off with 1x16, 2x16, or 1x8.

 

[Greatwhitenorth]

Greatwhite, I recently changed to 50's wiring too. I notice a big difference, for the better. The clarity I gained is very noticeable. I can now clean up, especially on the bridge pickup, quite nicely. I didn't think it would be as noticeable on the neck pickup but it certainly is. I find myself using volume and tone controls more. Best 5 minute mod I've ever done. As you stated, it's just as easy to reverse if you don't like it.

Cheer bro. I can't believe I waited as long as I did to do this mod. I'm almost as impressed with it as my C19 change.

 

[Knopfler]

Cheer bro. I can't believe I waited as long as I did to do this mod. I'm almost as impressed with it as my C19 change.

I have read; If you do the MOD speaker G12M 65 is not necessasry do C19 Mod. IT IS CORRECT?
C19 MOD is only for speaker 70/80???

C19 Mod, is basically just touched a lo-powered soldering pencil to one leg and pried up the cap. It is correct?.

Thanks!

 

[Micky]

I have read; If you do the MOD speaker G12M 65 is not necessasry do C19 Mod. IT IS CORRECT?
C19 MOD is only for speaker 70/80???

C19 Mod, is basically just touched a lo-powered soldering pencil to one leg and pried up the cap. It is correct?.

Thanks!

No, not necessarily correct. There are many speakers that are 'bright' and could benefit from an adjusted C19 value. I think what many are saying here is that you may not need to adjust C19 with a different speaker than the stock one.

And sometimes the legs of the cap are 'bent' underneath the board and difficult to pull one leg just from unsoldering it.

 

[jlinde1973]

No I think the c19 mod needs to be done regardless of the speaker. The value of the cap installed after the clip will be determined by the speaker chosen. I run dark speaker and tubes and 220pf works perfect for me. Brighter speaker and tubes, 120 pf might work better. But either way, the stock 470pf is just too bright unless you play the amp with volume half way up or more.

 

[Greatwhitenorth]

I have read; If you do the MOD speaker G12M 65 is not necessasry do C19 Mod. IT IS CORRECT?
C19 MOD is only for speaker 70/80???

C19 Mod, is basically just touched a lo-powered soldering pencil to one leg and pried up the cap. It is correct?.

Thanks!

First off, yes. All you do is either use a soldering iron or a set of wire cutters(as I did) and clip one leg of the C19 cap.

Second, as Micky states, you should try the speaker/tube swap first before doing the C19 mod. I had already swapped out the 70/80 stock speaker with a WGS Retro 30 which is supposed to be a brighter version of a Celestion Vintage 30. The thing I found, and read here, is that the mod changes the gain, taking away the brightness of the amp compared to having it in the circuit(thus being called the bright cap). Removing the cap entirely(or lifting the leg) reminded me of a "fuzz" sound similar to what I would get with my Big Muff turned all the way down, but better. The sound with C19 removed was instantly better to my ears, but I knew right away that it needed some of the bite back in the circuit. With the advise of some of the folks around here I decided to buy an assortment of capacitors ranging from 20pF to 120pf. This way I could use some alligator clips and try different capacitors to find one, or a combination that I liked. I ended up going with the 120pF cap by itself, but I left some extensions off of the cap so that I can add others if I feel the need. I have a jam coming up on Super Bowl weekend so that I can see if this is where I'm going to leave it.
As with all things you read on here, it's all up to your personal preference. Some guys love the amp as is, some swap speakers or tubes and they find that works. Find what works for you and rock on.

 

[Knopfler]

No, not necessarily correct. There are many speakers that are 'bright' and could benefit from an adjusted C19 value. I think what many are saying here is that you may not need to adjust C19 with a different speaker than the stock one.

And sometimes the legs of the cap are 'bent' underneath the board and difficult to pull one leg just from unsoldering it.

In that case the solution would be to cut it, without the possibility of re-welding except buying a new component

 

[Knopfler]

First off, yes. All you do is either use a soldering iron or a set of wire cutters(as I did) and clip one leg of the C19 cap.

Second, as Micky states, you should try the speaker/tube swap first before doing the C19 mod. I had already swapped out the 70/80 stock speaker with a WGS Retro 30 which is supposed to be a brighter version of a Celestion Vintage 30. The thing I found, and read here, is that the mod changes the gain, taking away the brightness of the amp compared to having it in the circuit(thus being called the bright cap). Removing the cap entirely(or lifting the leg) reminded me of a "fuzz" sound similar to what I would get with my Big Muff turned all the way down, but better. The sound with C19 removed was instantly better to my ears, but I knew right away that it needed some of the bite back in the circuit. With the advise of some of the folks around here I decided to buy an assortment of capacitors ranging from 20pF to 120pf. This way I could use some alligator clips and try different capacitors to find one, or a combination that I liked. I ended up going with the 120pF cap by itself, but I left some extensions off of the cap so that I can add others if I feel the need. I have a jam coming up on Super Bowl weekend so that I can see if this is where I'm going to leave it.
As with all things you read on here, it's all up to your personal preference. Some guys love the amp as is, some swap speakers or tubes and they find that works. Find what works for you and rock on.

Very interesting.

Thank you so much

 

[Bownse]

What everyone is saying is that what you "need" (want) is entirely based on your preferences. Speaker and tube swaps are easier to reverse if you don't like the results. Try them first and address C19 only if you think you still need to after playing with the other changes.

 

[Micky]

What everyone is saying is that what you "need" (want) is entirely based on your preferences. Speaker and tube swaps are easier to reverse if you don't like the results. Try them first and address C19 only if you think you still need to after playing with the other changes.

This.

 

[jep1210]

I'm conceding defeat. after numerous tube swaps/combinations and bias settings, I just can't get this DSL to sound like I want. The only thing I haven't tried is a speaker swap. After all the other changes I've tried, I don't have much confidence it'll be worth it for me to go that route. I hope I'm not overlooking the one mod that'll get me there. I guess I just don't have the skills to get what I want from it. I have one more tube combination that is going to get tested at Friday's gig...provided the snow doesn't cancel it. We'll see if that changes my mind. Either way, I have learned a lot in this process and from this great thread.

Notice I was very careful to NOT say this amp sucks, FWIW. I don't feel it is, it's just not what I'm looking for.

 

[Micky]

it's just not what I'm looking for.

So what ARE you looking for?
What is it you are trying to dial in?
What sound are you after?

There is a possibility that this is not the amp for you.
I recently had a friend try mine, and after a while, he said flat out, that it has too much distortion. Then he tried my '77 Fender Princeton Reverb. Only after we cranked it way up did it get distorted, and that is what he was looking for. He wanted clean, and needed that in order to use his collection of pedals.

I tried to explain that Marshalls do clean as well, it is just you need to get a higher-powered one to get the clean 'headroom' he wanted. He wanted my Fender, but I will never let it go...

 

[BanditPanda]

Speaking with my tech last night. I had requested that he bias at 39 mA as most of you do . He told me that the amp came out of the factory at 34mA and that in his opinion we should trust the factory to know what they are doing. If there is something wrong sound/tone wise then we can re bias.
34mA would seem to be somewhat on the cold side would it not.?
Anyway I'll trust his advice and learn how it sounds with the new tubes and at 34mA
B.P.

 

[Micky]

So where did he get his info?
From Marshall directly?
From a Technical Service Bulletin?

My opinion is that 39 is too hot.
30-35 is good for me with EL34's...

 

[Greatwhitenorth]

What everyone is saying is that what you "need" (want) is entirely based on your preferences. Speaker and tube swaps are easier to reverse if you don't like the results. Try them first and address C19 only if you think you still need to after playing with the other changes.

Like

 

[BanditPanda]

So where did he get his info?
From Marshall directly?
From a Technical Service Bulletin?
My opinion is that 39 is too hot.
30-35 is good for me with EL34's...

Micky the only info he used was what the factory setting was.He advised to leave it at that.
My info from here where it seems most players are biasing from 38 to 42 mA.
B.P.

 

[ken361]

I use 38 just gets into the hot territory

 

[MarshallDog]

I use 38 just gets into the hot territory

I've been using the 48 pF lately

 

[MarshallDog]

Micky the only info he used was what the factory setting was.He advised to leave it at that.
My info from here where it seems most players are biasing from 38 to 42 mA.
B.P.

I always cringe when I see info about setting the bias between two mA ranges, Why, you dont want to exceed 70% dissipation on an EL34 and the only way to safely and accurately do this is by knowing the plate voltage. P = I * V so as the plate voltage goes down, the bias current goes up and vise versa. Plate voltage varies with wall voltage then there are variances in tubes...I just do get statements like this. You can also use a scope but still voltage is a variable. Am I missing something here

 

[jlinde1973]

Speaking with my tech last night. I had requested that he bias at 39 mA as most of you do . He told me that the amp came out of the factory at 34mA and that in his opinion we should trust the factory to know what they are doing. If there is something wrong sound/tone wise then we can re bias.
34mA would seem to be somewhat on the cold side would it not.?
Anyway I'll trust his advice and learn how it sounds with the new tubes and at 34mA
B.P.

Hmm. Mine came from the factory at 46ma. Yes, mine sounded lame at 34ma. I personally like mine at 42ma. Nice and hot around 78%