Profiling question

  • I've not done a profile with my KPA yet. But I'm thinking of doing this. I like the JCM 800 profile that And44 done, and I used to own a JCM 900 which had a little more gain.


    I'm building a rig from scratch turned everything off other than the JCM 800 and Marshall 4x12 vintage cab. My plans are to borrow my friends 900 connect it for profiling direct no cab etc and then use the sound from this profile with the 4x12 which is already in my rigs. Is this a good idea or will it not give me the best sounding result. I'm thinking if the cab is already in the rigs, profiling an amp direct would be an easy way.


    If anyone could share their thoughts it would be much appreciated :)

  • Use the send or the direct line out of the JCM900 to profile the Preamp only then use the cabinet from the JCM800 profile and save your new JCM800-900 rig. It should work just fine. Now what is the best way? A lot of users switch cabs on their rigs so it's not really different. I would say if you like what you hear, it's good! ;)

  • question: Does the DI of JCM900 take the sound just from the pre amp? not the whole sound? (included Power tubes)


    I have a 2555SL and I've alway thought that DI thakes the whole sound oh the head.
    Is it different in JCM900?

  • I don't know about this specific model but yes most of the DI send a direct signal of the whole amp and when you want just the preamp you use the send of the FX loop, but what I remembered is that the JCM900 had two kinds of direct out and one of them was just a preamp out, maybe I'm wrong thought... Anyways the 2555sl use something like a JCM900 preamp style to a JCM800 poweramp so either ways (preamp out or line out) would work fine for the OP project.

  • Thanks for Your reply!
    but I must say that (if i'm not confusing ) the Loop Fx of the 2555SL it's in a strange position and what cames out from Send it not the whole preamp (no eq pots working..just the gain knob) signal.
    I suppose that Loop FX in 2555 Sl (also the jubille I have works in this way) it's before the preamp eq section.
    (that's why in My opinion it is not a great fx loop)
    so the only good output for a project like above is the DI output.
    I don't know anything about JCM900

  • Thanks Tylerhb! really intresting!
    does it work good with any impendace setting (4, 8, 16 ohm) and with any power amp (from 5 to 200 watt?) or there are some limitations
    can I use a static load insted of a real cab? (You know..it's so Loud..)

  • Thanks Tylerhb! really intresting!
    does it work good with any impendace setting (4, 8, 16 ohm) and with any power amp (from 5 to 200 watt?) or there are some limitations
    can I use a static load insted of a real cab? (You know..it's so Loud..)

    It works with any impedance and it can handle power amps up to 4000 Watts, so you should be ok ;)
    Of course you can also use a static load instead of a cabinet, but since you do not want to produce power amp distortion, you can also set your output volume rather low so you wont get beatings from your neighbors. From my own experience and my personal taste, power amp distortion is an overrated myth that far too many people are looking for. In most cases a fully cranked amp sounds like shit. Also, far too many people think that tube amps need to be pushed to a good amount in order to sound good. But it´s not the amp, it´s the speakers that need a minimum load to sound good.