DI-Box recommendation for firmware 3.0

    Quote from paults

    In one of the NAMM videos, CK indicates Resistor-based Direct Boxes will not provide authentic results.

    You need to reduce the high level, high output voltage of an amp output transformer to a DI level. The passive DI boxes I'm aware of use a resistor or two to do this, plus an optional pot, same as analogue valve amps with built in DI! The ROCKSTAH LINE OUT diagram that Vkaxeman posted is typical. That implies that sound out from those amps with DI outputs don't put out "authentic" results? I'm not buying that.

    The cynic in me thinks sales pitch for an expensive digital Kemper DI box.

    Maybe some testing required - profile from amp with built in DI, profile from same amp with external passive DI box, play back DI profiles through same cab and compare with live amp?

    Steve

    Analog amps with a DI Output are sending a preamp signal. A DI profile can be made of a "preamp out", but that is not a Direct Profile, because it does not contain any characteristics of the poweramp section of the amplifier.

    I watched the video again - I used the wrong term. CK indicated a "dummy load" box could not be used to create an accurate Direct Profile. The poweramp signal must pass through the chosen DI box to a speaker load to enable the KPA to create a Direct Profile.

    Normally these similar terms are interchangeable, but not with All these terms are very similar - DI versus Direct, Resistor versus Dummy Load.

    Quote from paults

    Analog amps with a DI Output are sending a preamp signal. A DI profile can be made of a "preamp out", but that is not a Direct Profile, because it does not contain any characteristics of the poweramp section of the amplifier.

    I watched the video again - I used the wrong term. CK indicated a "dummy load" box could not be used to create an accurate Direct Profile. The poweramp signal must pass through the chosen DI box to a speaker load to enable the KPA to create a Direct Profile.

    Normally these similar terms are interchangeable, but not with All these terms are very similar - DI versus Direct, Resistor versus Dummy Load.

    Not all use purely the pre amp signal. Some take direct off the output transformer, some are hybrid where they take the pre amp signal and mix in some from the output transformer. Those that just use the pre amp signal should have the DI labelled "parallel send" :)

    In the cab clone the dummy load only comes into play if there is no speaker plugged in, otherwise it's bypassed. You'd have to use the line out anyway as the DI out has the cab sims permanently enabled.

    I agree the terms are a bit confusing. I think the only way we are going to get a straight answer on what works without colouring the sound is recommendations from users. Like others I'd like to see what was inside the box Kemper used at NAMM.

    Steve

    It looks to me like the Palmer PDI-03 filters or shapes everything that runs through it. i don't think you will get a clean DI profile using one. it also has an 8ohm load resistance internally. I'm not sure how you would use this if the amp required either 4 or 16 ohms.

    Now that I think about it. a speaker simulator with a allot of choices that could be switched of would be cool. You could do DI profiles or regular profiles with no mic.

    I wonder if it would be possible to make a list of "proven" DI Boxes now. In 2 or 3 price ranges. Any new post brings another option up and makes any decision for non professionals impossible.
    Burkhard: why does Kemper do not give any recommendations ?

    Geht nicht, gibt´s nicht. "Doesn't work" is no option. :!:

    Edited once, last by McRalfix (February 2, 2015 at 9:53 AM).

    I'm still going to wait and see if Kemper gives us some guidance or at least see what real world results tell us. The H&K old Redbox pro has a speaker simulator bypass to allow its use for keyboards and bass, it should work. The ProCo DB1 looks good and those folks made the famous Rat pedal. I would think some of the others designed for bass, keyboards and electric drums should work also. I'm still going to wait to see if we get any further technical details.

    I do not understand why you are searching fo rspecialized di-box - bellow is an example of Bugera 333XL line out (placed after output transformer.)
    It's pure resistor+pot divided signal between out and cab in parallel to the fully pass through amp to cab connection).

    Of course if you want a symmetrical connection it could be enhanced by transformer or opamps - but from my opinion this 22k resistor+ 10kpot will do the trick.
    The 30k impedance of this simple di is negligible to the 4(8,16) Ohm output impedance

    Quote from nightlight

    The Kemper DI box scales down the tube power amp voltage to a line level signal, while sending the high power signal to the speaker cabinet on a different output jack. Not sure if there are other DI boxes that work this way at present, but it would be great to have some recommendations from the company.


    There are plenty. Some are name-checked in the rest of this thread. Behringer ULTRA-G GI100, Art Z-Direct, Countryman Type 85, Palmer PAN 01 to name four...

    Cheers,
    Sam

    Quote from sambrox


    There are plenty. Some are name-checked in the rest of this thread. Behringer ULTRA-G GI100, Art Z-Direct, Countryman Type 85, Palmer PAN 01 to name four...

    Cheers,
    Sam

    Gotcha, but why did Kemper Amps create their own is what I wanted to know? Is there some different science involved in that *massive* DI box they were using at NAMM? Would love to hear their recommendations for a DI box in particular, from the horse's mouth so to speak.

    Well, from a couple of the videos from NAMM, it sounds like CK & co. thought it would just be fun to make their own and put it in a toaster case. I get the impression that it was to be 100% Kemper branded (see the 4x12 cabs they were using, too). I'd be surprised if there was any special tech inside.

    Cheers,
    Sam

    Quote from sambrox

    Well, from a couple of the videos from NAMM, it sounds like CK & co. thought it would just be fun to make their own and put it in a toaster case. I get the impression that it was to be 100% Kemper branded (see the 4x12 cabs they were using, too). I'd be surprised if there was any special tech inside.

    Cheers,
    Sam

    I'm thinking the same.

    Quote from sambrox

    Well, from a couple of the videos from NAMM, it sounds like CK & co. thought it would just be fun to make their own and put it in a toaster case. I get the impression that it was to be 100% Kemper branded (see the 4x12 cabs they were using, too). I'd be surprised if there was any special tech inside.

    Cheers,
    Sam

    Maybe we need to start a thread, and/or poll for who would like CK and gang to make a DI, I think he said on one of the videos, if we want them to make one to let them know.

    Like reported before, the Behringer GI-100 is totally sufficient to create great DI profiles. Since it has two individual stages of -20db gain reduction, it can deal with any level of input signal. I have been using these for over 10 years now and they are simply great value for the money.

    Always keep in mind to have your real guitar cab connected. I exerimented with load resistors before and they change the sound of the resulting DI profile significantly. The reactive load of a real guitar cab has a big influence on the tube amp´s output transformer. Best practice is to connect the guitar cab that you plan to use the DI profiles with later.