Power amp options for nonpowered kemper unit

  • I have:
    1x 100w Marshall JCM 2000 DSL amplifier
    1x Marshall 4x12 cabinet
    1x unpowered Kemper Toaster unit

    I want to use my kemper through the Marshall 4x12 cabinet - using the jcm 2000's power amp(?)

    Is this achievable?
    How would i do this if so?


    Bonus question: What are some good options for an external power amp if the JCM 2000 isnt an option?

  • Hi.
    If your amp has an effects loop it is achievable.

    You would connect the monitor out of the kemper into the effects return on your amp.
    If you’re going through a guitar cab you would also turn off the cab section in the kemper monitor output.

  • If you gig and can afford it, eventually you may want to get a clean, dependable solid state amp. The less coloring after the kemper, the better it reproduces the profile. . Lugging that tube amp around may become a burden and tubes are a liability not to mention doesn't help anything. Kemper profiles don't need to be "warmed up" by tubes and if they do you're using the wrong ones or it's set wrong. Normally profiles are made from tube amps and virtually no one can tell the difference between the real tube amp and Kemper in a blind A/B when profiled properly. That's good enough for me and I want that to appear as uncolored as possible through the mixing desk.

  • In the output section set the Monitor Output to Master Mono, connect with an instrument cable from the Kemper Monitor Out to the amplifiers effects loop return.

    For starters in the Output section you might try setting the Monitor Out Volume to -12db to -18db and the Power Amp Boost to 0, also try setting Pure Cabinet off to start and turn up to your taste if needed. I ran into the effects loop of a combo amp for several years but as Dynochrome mentioned above using a solid state amp (class D) takes away the coloration a guitar amp introduces into the signal chain.


    From the manual, pg41

    "MONITOR OUTPUT (#2 in diagram) Use this mono output to connect the PROFILER to a stage monitor with its own level controls. This output also has its own ground lift. You can also connect this output to a power amp and a regular guitar cabinet. In this case, you need to switch the cabinet simulation off, using the soft button “Monitor Cab Off” in the Output Section, to prevent the unwanted coloration that would result from running a speaker emulation through a guitar cabinet. Bypassing the cabinet module can also be done by simply pressing the CABINET button. However, there are two differences compared to enabling “Monitor Cab Off”: Bypassing cabinet is an individual setting to each Rig, unless you lock the cabinet module in its “off” state. Monitor Cab. Off is a global setting. It will bypass the cabinet module for all outputs, whereas "Monitor Cab Off” will only affect the signal routed to the MONITOR OUTPUT (and the built-in power amp of PowerHead and PowerRack). ✓ If you select the option “Monitor Stereo”, MONITOR OUTPUT and DIRECT OUTPUT become one logical pair of stereo outputs. Functions like Monitor Output Source, Monitor Output Volume, Monitor Volume Pedal, Monitor Output Link, Monitor Cab. Off, Monitor Output EQ, and Aux In > Monitor are applied to both outputs automatically.

  • For starters in the Output section you might try setting the Monitor Out Volume to -12db to -18db

    One thing often overlooked to retain signal to noise ratio if you need to set the Main Output Volume to less than -12 dB, (In this case -18db),then activate the Main Output Pad to reduce the signal level of the Main Output by 12 dB. This increases the range of the Main Output Volume control and preserves the signal-to-noise ratio of the Main Output

    and the Power Amp Boost to 0

    Is there a power amp boost setting on a non powered model?

  • I have the 50w DSL 2000 head and use its power for the Kemper into a real 2x12 with V30s and it sounds great. The Marshall power section works well with any modeler, I also run a Helix this way too. Recently I picked up a Moorer Tube Engine which is only 20w, but I had no volume issues when jamming with a full band, again a real 2x12 cabinet. I am not a fan of CABs or IRs. The Seymore Duncan 170 which is solid state power also sounds pretty good too, but my advice is to go tube power.

  • yes , it was added after the powered Kabinet was launched as people were finding the Kabinet wasn’t loud enough.

    So the setting is on the KPA that boosts the powered cab? I would figure the "power amp boost" would have to be done on the unit with the power. Otherwise it would be an "output boost"

  • So the setting is on the KPA that boosts the powered cab? I would figure the "power amp boost" would have to be done on the unit with the power. Otherwise it would be an "output boost"

    Basically it is an output boost. Because the Monitor Out and Speaker Out physically share the same signal the power amp boost also boosts the monitor output

  • One thing often overlooked to retain signal to noise ratio if you need to set the Main Output Volume to less than -12 dB, (In this case -18db),then activate the Main Output Pad to reduce the signal level of the Main Output by 12 dB. This increases the range of the Main Output Volume control and preserves the signal-to-noise ratio of the Main Output

    I was suggesting that volume setting for the monitor out only, I have my Main and Monitor out's independent of one another but didn't specify that. I find that convenient when using a power amp or an amp as jaseaus is considering with it's own volume control then you can utilize the volume on the kemper for adjusting the main output if needed.

  • I have the 50w DSL 2000 head and use its power for the Kemper into a real 2x12 with V30s and it sounds great. The Marshall power section works well with any modeler, I also run a Helix this way too. Recently I picked up a Moorer Tube Engine which is only 20w, but I had no volume issues when jamming with a full band, again a real 2x12 cabinet. I am not a fan of CABs or IRs. The Seymore Duncan 170 which is solid state power also sounds pretty good too, but my advice is to go tube power.

    I have no doubt it sounds good.

    The only comment is, is it necessary? Without opening up the debate,that is an entirely personal view of course :).


    Just as an aside, our other guitarist who uses a Helix, started switching to using a Marshall Amp and cab on stage. He recently did a rehersal without it, reverting back to the SS amp he had - it was noticably better. Why? I suspect its because he had spent quite some time tuning his sounds to SS.


    So my point is, we have these very powerful valve amp emulators. If you use them to their full potential, personally I think the valve power amps become redundant and therefore unnecessary. HOWEVER, of course many people prefer the added colour of valves and it adds a dimension, and that is perfectly valid as well.


    The great thing is, we have the choice!!!

  • I agree with you on solid state power, the Helix does sound very good with the Seymour Duncan 170 solid state power amp, it takes just a bit of tweaking (not much) but overall its a great matchup, same with a non powered Kemper. I have the Kemper power head and the built in power amp is very good too. But as I mentioned before I am not a fan of CABs/IRs so I always use a real cabinet. I just find the best tone for me is when I use tube power. Now...do I want to lug around a Marshall 50w head along with the Kemper head or Helix, ummm no lol. As I mentioned above, I now use the 20w Moorer Tube Station which sounds really great to my ears on both Helix and Kemper.


    "The great thing is, we have the choice!!!"....indeed we do!

  • I believe the original post said he was using a real cabinet. In my past experience, tube power sounds best that way. SS is still dam good, but tube power has that feel and tone of a real amp imo.

    I have the oposite experiance. My former Marshall Tube Poweramp coloured my signal into my 12x4 Marshall cab extremely and IMO it was the most negative impact on my sound with profiles. When I switched to a linear solid state amp really the lights went on!

  • I have the oposite experiance. My former Marshall Tube Poweramp coloured my signal into my 12x4 Marshall cab extremely and IMO it was the most negative impact on my sound with profiles. When I switched to a linear solid state amp really the lights went on!

    Same here, every time I think I want to try it through some tube power or into a clean Marshall or tube power section, it colors it too much and makes it blurrier and less defined. No sense burning those tubes and lugging the thing around if a light power amp sounds clearer.

  • Fryette LXII is a nice power amp to use.

    The music business is a cruel and shallow money trench, a long plastic hallway where thieves and pimps run free, and good men die like dogs. There's also a negative side.

  • Hey guys, i got it set up and its running off of the power amp great! quick question, should i put my jcm 2000's EQ to 0 or noon when im using the kemper as the amp?