SL-X vs. Mk III (both JCM900)

Discussion in 'Marshall Amps' started by Dioesque, Jun 28, 2020.

  1. Kinkless Tetrode

    Kinkless Tetrode Well-Known Member

    Aug 17, 2017
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    The JCM900 1x12 combos, and 80's 1x12 combos like the 2554 and the Studio 15, weighed slightly less than 50 lbs with an H magnet speaker. So about 45 lbs with an M magnet speaker.

    The mini Jubilee combo weighs about 40 lbs, and it has a M magnet speaker.

    A small (not OS) ply 1x12 cab weighs about 30 lbs with a H magnet speaker.

    A 900 head weighs about 40 lbs.

    A studio head weighs about 22 lbs.

    A 1936 2x12 weighs 55 lbs.

    A smaller ply 2x12 (THD , 1922...) weighs about 45 lbs with H magnet speakers.

    MDF and particle board cabs weigh noticeably more than equivalent ply and most solid wood cabs.

    The DSL40CR weighs 50 lbs with an M magnet speaker.
  2. jeffb

    jeffb Well-Known Member

    Oct 11, 2011
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    This is a reducing the argument to the absurd (reductio ad absurdum)

    Running a pedal in front of your amp is completely different than a dioode clipper.

    1) You have no control over when you want or don't want the diode clipping. You can turn a pedal off.

    2) You have no control over the type of clipping. With pedals you can choose whatever you like and multiples of such. Asymmetrical. Symmetrical. Diodes, MOSFET, Germanium, etc etc etc. Diodes have a fizzy sound many don't like (myself included) . FAR more fizzy than a Tube Screamer run into the front of the amp.

    3) There is a reason Marshall no longer makes any amps except reissues with diode clipping. Diode was a necessity born out of needing to produce a higher gain amp during the Cold War and the serious issue of sourcing quality tubes-or whether tubes would go the way of the dinosaurs. It was a cost cutting measure plain and simple. As the 1990s rolled on, the last of the Diode Clippers (JTM/600s, 900s) went the way of the dinosaurs thankfully, instead of tubes. EDIT- And pedals have never been more popular.

    4) Most importantly- Tone is completely different than diode clippers because pedals are used to push the amp further into breakup by overdriving the amp circuit- Sure newbies just stomp on thier new TS9RI pedal with the volume at unity and the drive all the way up, but most of us figured out many moons ago that it sounds like shit, and so do the newbies. Instead we jack the level up, and keep the gain levels back low (which minimizes the pedal clipping). I'd wager far more classic recorded and live tones have been made in this way than with a diode clipping Marshall.

    As for the OP- MKIII are IMO the best diode clipper Marshall made but- the combos are still heavy. You might want to look elsewhere outside of Marshall.
    Last edited: Jun 30, 2020
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  3. KraftyBob

    KraftyBob Well-Known Member Gold Supporting Member

    Sep 5, 2017
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    Chicago Suburbs - USA
    All good points but I think saying going to the absurd is a little extreme. Yes, I'm aware of the different types of diode clipping in pedals, and yes you can turn the pedal off, but then you don't have OD. And since we're talking about OD that's not an apples to apples comparison. My point was there are a lot of guys out there that are tube cork sniffers that condemn the use of diodes, but will then put one in front of their amp in the form of a pedal. In the end is the OD coming from a tube or diode?

    The bottom line for me is if it sounds good then I'm not too concerned how it's created. Afterall, in addition to my DSL I also use several of the preamps in my Helix and I think they sound pretty good.
    jeffb likes this.
  4. Seventh Son

    Seventh Son Well-Known Member

    Jul 24, 2014
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    Naples, Florida
    If I’m not mistaken, the Classic Gain and Ultra Gain channels are voiced slightly different, but they share the EQ, so they’re probable more similar than not. Or, you could have two of those amps and set them up the same in the Ultra Gain channel, but with different volume levels. I realize that two amps may sound like overkill, but they are small, super lightweight, and affordable, plus with two Classic Gain channels, you’d have two extra tones, just in case you need the versatility.

    I’d, however, go with the one-amp solution, if possible, so as to keep it as simple as possible.

    The DSL40CR also has two master volumes, but it’s a big and heavy amp. Probably not a significant improvement from what you currently have.
    Last edited: Jun 30, 2020
  5. headcrash

    headcrash Well-Known Member

    Jun 19, 2015
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    If I'm not mistaken, the DSL20's classic gain channel is aimed towards clean and crunch sounds, whereas the ultra channel is a (rather modern) lead sound. The latter will go through more triode stages than the former. Although they share the same EQ, they should sound and feel different, albeit the two channels may be set to sound very similar (which would be rather moderate gain levels because of the classic gain channel being a clean/crunch kind of thing).

    The JCM 900 Master Volume amps are single channel designs with just a second switchable master volume for different volume levels. I thought this is what he wants.

    However my suggestion for a second swictheable volume level using a passive minus booster in the FX loop will not alter the tone of the amp. It will work with any amplifier with a serial FX loop. A clean boost or an EQ will work too, but you might overdrive the input stage of an FX loop if the level of the boosting device is set too high. Whcih of course can be good!
    Kinkless Tetrode likes this.

    JCMDOUG Well-Known Member Gold Supporting Member

    Mar 1, 2015
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    where its cold
    JMD 1 combo with side handles and wheels, not sure if the side handles are normal I got mine used with the handles and wheels installed. Easy to move cheap to buy lots of options for tones.
  7. Dioesque

    Dioesque Active Member

    Jul 11, 2010
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    So, for example, a Boss EQ pedal in the FX loop could be set with its output level slider at *below* unity (the slider normally sits in the middle of its range at "0" for unity, with the ability to raise or lower the slider +15 or -15)?

    So when stomped on to activate it, the EQ pedal would then actually *lower* (rather than boost) output volume -- sort of like an "anti-boost"?

    So in this backwards-from-normal approach, the in-loop EQ pedal is left *on* most of the time (for rhythm playing, in effect cutting the amp's volume), and then stomped to momentarily turn it *off* (for lead playing, allowing the amp to blast away at full volume) -- briefly like removing a blanket or pillow from its speakers, but in a volume rather than a tonal way?

    Do I understand correctly? Interesting approach....
  8. marshallmellowed

    marshallmellowed Well-Known Member

    Jun 26, 2009
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    Yes, you're understanding correctly. This approach is typically used with non-master volume amps. The downside, it limits the signal to the PI and power section 90% of the time, which prevents you from driving the power section of those amps into clipping (where they sound best). Master volume amps typically have enough head room left (unless the master is on 10), that a simple clean boost in the loop is all that's needed for solos.

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