DSL-100 Deep Switch

[maltone]

I hate to bug, this has been discussed before, I've even private messaged someone about this, but they haven't responded.

Someone in the forum here had said this about his JCM 800

As for adding the cap to the NFB resistor, it basically adds clean low end to your signal, making the low end clearer and punchier. It works similarly to how the presence control adds more highs. To me, it has a more natural feel than the deep switch. I like .0047uf but if you want more lows, you could use a .0033uf or even a .0022uf. The NFB resistor is R19 on the rear board. You just need to disconnect the leg that connects to the 4ohm spade connector and solder the cap in between.

And I believe Jensbrix did it as well:

Just did that resonance mod thingy to my DSL, added a 0.0047uF cap in series with the NFB resistor - I will recommend EVERY owner of the DSL to do this, it's one of the best mods I've done to it, and I've done alot by now. Thinking of releasing all the mods soon, I'm extremely satisfied with this beast!

I'd like to know, does a JCM 800 sound the same way as the DSL, IF the DSL's deep switch isn't engaged?

If I wanted to remove the deep switch button, and put a pot in it's place, as a variable resonance control instead, with a series of different values, like 0.0047 to .0033uf to .0022uf, how many values would you need to cover the sweep from off to 1—10 etc? — 1 being the least amount of bass, and 10 being the most.

Basically, what would be the lowest to highest set of cap values you'd need to use to have a very natural sweep on the resonance pot?

Thanks.

 

[ampmadscientist]

I hate to bug, this has been discussed before, I've even private messaged someone about this, but they haven't responded.

Someone in the forum here had said this about his JCM 800


And I believe Jensbrix did it as well:


I'd like to know, does a JCM 800 sound the same way as the DSL, IF the DSL's deep switch isn't engaged?

If I wanted to remove the deep switch button, and put a pot in it's place, as a variable resonance control instead, with a series of different values, like 0.0047 to .0033uf to .0022uf, how many values would you need to cover the sweep from off to 1—10 etc? — 1 being the least amount of bass, and 10 being the most.

Basically, what would be the lowest to highest set of cap values you'd need to use to have a very natural sweep on the resonance pot?

Thanks.

Until there is a schematic for the amp, it's hard to know.

 

[Micky]

Are you speaking of the older JCM2000 DSL?

 

[dreyn77]

I've just got the DSL to sound like the maker intended. and it now sounds like an amp of the 70's to me and I'm just jamming along to the CD version of songs from back then and I'm using the scoop switch and NO deep switch.

but the amp's EQ dials are set the way guys set them back then.
and I'm only using the clean and crunch sounds.
Now I can hear the difference between celestion speakers and what celestion is talkin about when they discribe their speakers sound.

SO no the DEEP switch sound is a 'new' add on sound to the traditional marshall sound.
then it got revised and changed to a resonance dial sound.
you don't really want to change the deep switch cause it's the new feature at the time added to a marshall amp sound.
It's unique and not compareable to any previous marshall sounds.

when guys use the 75 speakers, AND the lead settings on the DSL amp, the sound can get really bright, some might say 'too bright' so there's the deep switch feature.

If that one feature is bothering you just update to the latter model amp. it's already built in, in the best possible way.

You'll get even more features with the marshall amp which you may or may not use, it doesn't matter.

 

[dreyn77]

I was just jamming along to richie blackmore sounds from various eras with the DSL amp.
I used a few different speakers and guitars with just the DSL amp setup.

When I wasn't using the greenbacks (which ritchie used) I think the ENGL has vintage 30's but I could be totally wrong)) the DSL amp's dials had heaps of adjustment range, so I was able to dial in a sound which was extremely convincing, that it was a version of the sound.
But those dial settings didn't make any sense and were all over the place in reguard to numbers on the dials.

When I used the speakers of the artist, the amps dial setting changed to exactly what the original artist used with their earlier marshall amp dial settings.
All I had to do was compensate for the type of pickups in the guitar from the different eras.
when I used the vintage strat, the pres was set to zero. when I used the blackmore sig strat, the presence was set to max, '10'.
All other adjustments were carried out on the guitar's tone pots, as how ritchie does on stage.

When I went back and played the mode4 speakers, it showed up the fact that LEO Fender's vintage pole piece height stagger was set with the greenback TYPE of speaker. Each string sounded like it was at the right volume with the greenback speakers I used.
but the mode4 speakers sounded how the polepiece were at different heights. If the magnets were lower in height, so too was the sound from that string. and viseversa.

THe mode 4 speakers took out all of that strange character of the greenback speaker sound. SO each string sounded the same just bigger as the string played got bigger.
the bass string on the mode 4 speakers, sounds kinda weird. like it's got more 'flubb' in the sound.
I used different guitars and still the sound was present on the low 'e' string sound.
that's the sound celestion talks about.

 

[maltone]

I guess I just wanted to know what to expect, why both of those guys chose 0.0047uF - it seems to be a popular mod for the JCM 2000 series DSL-100 - which is what I have — the older one.

Love the amp pretty much, but that deep switch can be over the top, I basically just want a way to stiffen the low end more.

 

[ampmadscientist]

I guess I just wanted to know what to expect, why both of those guys chose 0.0047uF - it seems to be a popular mod for the JCM 2000 series DSL-100 - which is what I have — the older one.

Love the amp pretty much, but that deep switch can be over the top, I basically just want a way to stiffen the low end more.

Schematic? anybody?

 

[Micky]

The schematic is available plenty of places on the net... Dr. Tube?

 

[ampmadscientist]

The schematic is available plenty of places on the net... Dr. Tube?

What capacitor (by number on the board) are you talking about?

There are at least 5 issues of this amp, and none of them seem to have a complete schematic...
But if you look at the schematic here
http://www.drtube.com/schematics/marshall/JCM2-61-00 (1997) iss1.pdf
Deep switch is S4 in the tone stack? (because it's not labeled as such...)

Many controls and switches on the diagram are not labeled.

So "which" cap are you changing? What's the number (of the cap) on the PC board?

Then I can understand what you are changing...

 

[maltone]

From what I understand, the deep switch circuit is:

"The NFB resistor is R19 on the rear board"

And if I get my friend to refer to the schematic, and it coincides with that location, then that's what they're talking about.

According to John Wilder, reference url here: http://www.marshallforum.com/workbench/48581-dsl100-rear-board-resistor-failure-r19.html

He qualifies the NFB as being R19 on the rear board, near W4's spade connector.

 

[dreyn77]

It's your pickup which you don't like the sound of. the amps deep switch isn't the problem.

you need to think about other items and stop blameing the amp.
play the single coil pickup, there's NO silly bass notes from those pickups.

 

[maltone]

Hey maybe you're right. I do have another guitar with a completely different bridge pickup that's much clearer - a TV Jones bridge pickup. It is definitely more crisp, brighter.

But then again, it doesn't have the mids of the BB3 I have in the bridge of my other guitar — which I really like. Considering cost, it's not easy to just "try" different pickups unless you have access to a few.

I'm wondering, what pickup has the best expression of mids, lows, that don't sound artificially bloated with the deep switch on, because without using the deep switch, the amp does sound thin. And I wouldn't really call it "blaming" the amp. The amp is great for what I do with it, but a lot of people who own it are also on the fence with the deep swtich.

But I appreciate your comments.

 

[ampmadscientist]

Hey maybe you're right. I do have another guitar with a completely different bridge pickup that's much clearer - a TV Jones bridge pickup. It is definitely more crisp, brighter.

But then again, it doesn't have the mids of the BB3 I have in the bridge of my other guitar — which I really like. Considering cost, it's not easy to just "try" different pickups unless you have access to a few.

I'm wondering, what pickup has the best expression of mids, lows, that don't sound artificially bloated with the deep switch on, because without using the deep switch, the amp does sound thin. And I wouldn't really call it "blaming" the amp. The amp is great for what I do with it, but a lot of people who own it are also on the fence with the deep swtich.

But I appreciate your comments.

I see R19 which connects to W4. The feedback resistor.
But what does that have to do with taking the deep switch out?

You said you wanted to replace the deep switch with a variable resonance control.

Everybody is using .0047.... a popular mod...for what?
And you still didn't say where this cap goes.
It goes across the feedback resistor?

It seems like this is wandering far and wide...
You want to change the bass response of the amp.

That's over here at the tone stack...

What you really wanted to do is change the value of R35 and R36 in the tone stack.
And to possibly change the value of C21 C22 C23 in the tone stack.

TSC
The tone stack calculator may be helpful to you.

Resonance control?
I have no idea what you plan on doing.
How would you bypass the deep switch so you can use the hole for another control?

 

[chuckharmonjr]

In series with the feedback resistor, not across it which would be parallel...and yes..N19 which is by the W4 connector on the rear (output) board

 

[TwinACStacks]

Just bypass the whole ordeal.... You start messing with the NFB resistor values and you either end up with NO bass or MUDDY bass or worse yet you get a VOX AC30.

Some will get the joke, others....FFFFfffffftttttttpppppppfffffff Right over their heads.

(Hint: get an AC30 schematic and find out the values for a negative feedback resistor.)

I just Love f*cking with modders.

TWIN

 

[maltone]

Twin: RE AC30 Joke

I don't get it. I'm not even a modder. I had a friend who's an electronics engineer do the Joey Mods for me, OT, choke, a few tone stack changes, definitely improved the feel and clarity, response of the amp.

I am splitting hairs here, I really do love this amp. It could partly be the cab too - I've had a Mesa Rectifier 2X12 on indefinite loan. It's deeper than most "Marshall" type cabs, and has an extended bass response.

Maybe a more traditional styled 2X12 would decrease some of the WHOOMMF I hear in the bass. I just want it tighter, and stiffer, less bass extension.

 

[TwinACStacks]

Re: Twin: RE AC30 Joke

I don't get it. I'm not even a modder. I had a friend who's an electronics engineer do the Joey Mods for me, OT, choke, a few tone stack changes, definitely improved the feel and clarity, response of the amp.

I am splitting hairs here, I really do love this amp. It could partly be the cab too - I've had a Mesa Rectifier 2X12 on indefinite loan. It's deeper than most "Marshall" type cabs, and has an extended bass response.

Maybe a more traditional styled 2X12 would decrease some of the WHOOMMF I hear in the bass. I just want it tighter, and stiffer, less bass extension.

Mal. Voxes don't HAVE a negative feedback circuit.

TWIN

 

[DSL 50]

Re: Twin: RE AC30 Joke

I don't get it. I'm not even a modder. I had a friend who's an electronics engineer do the Joey Mods for me, OT, choke, a few tone stack changes, definitely improved the feel and clarity, response of the amp.

I am splitting hairs here, I really do love this amp. It could partly be the cab too - I've had a Mesa Rectifier 2X12 on indefinite loan. It's deeper than most "Marshall" type cabs, and has an extended bass response.

Maybe a more traditional styled 2X12 would decrease some of the WHOOMMF I hear in the bass. I just want it tighter, and stiffer, less bass extension.

Just get a used Marshall 4x12 and you will see what you have been missing
If you must have a 2x12 the marshall 1936 2x12 sounds great too

 

[Adrian R]

Re: Twin: RE AC30 Joke

I don't get it. I'm not even a modder. I had a friend who's an electronics engineer do the Joey Mods for me, OT, choke, a few tone stack changes, definitely improved the feel and clarity, response of the amp.

I am splitting hairs here, I really do love this amp. It could partly be the cab too - I've had a Mesa Rectifier 2X12 on indefinite loan. It's deeper than most "Marshall" type cabs, and has an extended bass response.

Maybe a more traditional styled 2X12 would decrease some of the WHOOMMF I hear in the bass. I just want it tighter, and stiffer, less bass extension.

I solved this problem very easily. I too replaced the O/T and added a choke...HUGE improvement...but in the end adding the GK85s to my cabinet gave me extreme low end. I don't use the deep switch at all...and have PLENTY of tight bass response (very JMP like)...good power tubes help (love the (EL-34Bs) and vintage preamp tubes...

 

[dreyn77]

You've got to ask yourself, "where is it sounding kinda thin?"

And if you sit there and say on the ultra channels, you'd be right.

that's what they all do with the pedals attached.

the old amps forced guys to have super volume settings so they never noticed the 'thin' effect.
but now you do notice with your amp.
now you have the extra feature not available on previous models.

and if you now say the channels don't blend it's because they DON'T in your perception.
It's a new realm of marshall tone with the deep switch on.

The amp is only designed for, "The best features for an amp, without any care what pickups are in the market place".
That's ideaistic thinking. the rest you have to workout yourself cause you're the professional playing expert who knows what you're buying and can easily workout what the new amp is doing when compared to the older amps in history.

When you check the amp maker's claims against the old recordings you findout they're right and we are wrong/ or we don't have specific knowledge about such products.

I've heard the 'thin sound' view point. You're using the amp in the wrong method/ technique.

The amp has to be made with the old method of how guitar players get sound from the instrument.
Because it's a 'general' amp and not a 'one off/ signature' amp.

You decide your main playing sound with the clean or crunch channels. (you can use the amp as a unique method amp too, but you must know you're doing that. then the amp won't sound 'thin')

then you have 2 SOLO possiblities to choose from. hense the name Dual Lead amp.

Once you use the old technique of amp dialing, you realise the max brightness/tone setting is, all dials on full power. and max dullness is all dials on or near '0', then the effect 'thin' isn't concidered. it doesn't exist.

you're only suppose to think about brightness or clearness.
cause we're only dealing with voltage and it's either on or off. big or small. not fat and thin.
that sound comes from multiple coils and the amp maker isn't concidering that product.

You can slam the whole song with one solo sound but eventually you'll realise you're forced to use the old method of getting sound, which is what the amp is designed for.
main sound and dual solo sound possibilities. with bonus features.
useful features an amp might/ should have.

SO you're trying to compensate for lack of amp history knowledge by using the deep switch with the wrong intention.
you're headed straight for the mod gun and the big dollar spend.

there's people waiting for you to head this way.

Soon you should realise you only bought the amp which has 2 solo possiblities and that's about all it really actually does.
and yet guys are still plugging in solo pedals, or are they amp quiet pedals which turn the big old amp down in volume and give a bit of distortion cause the amp won't make that sound on it's own at low volumes.

THe DSL amp really is only making a really great michael schenker UFO type of sound from way back in the late 70's. Where he has a sound which sits with the band and then the sound for solos has a tiny boost and it cuts through the other sounds to be easily heard by the audience.
you can scoop that sound or add alittle bit of reverb, and maybe you can add something more powerful overall if needed. (that's the deep switch feature)

you're only makeing the sound for YOU to stand infront of. By the year 2000 guys were mikeing the cabs and there was nolonger a need to fill the stadium with the DSL's own sound.

The DSL really has been superseeded with the JVM and really guys should be imbracing that amp and it's extra guitarplayers handy features.

Have that amp set to your personal enjoyment level and use the line out to the PA and join the other players at the perfect balanced volume.

There's NO point in trying to make the guy at the back of the stadium hear the one sound that you on stage are hearing at the same time. It's actually impossible to do that.