DI-boxes suitable to create Direct Amplifier Profiles

  • Kemper DI is best

    Agreed. Most standard DI's or direct boxes have a lot of circuitry that can affect the profiling results and is not really necessary for profiling. The Kemper DI appears to only have what is necessary to do the job and nothing else, so it sounds great.


    If you do have to buy an off the shelf direct box, you want as good a unit as you can afford, especially if you buy a passive one with an internal transformer (for input\output isolation as well as impedance conversion). Good sounding transformers are NOT cheap.

  • Another vote for the Behringer Ultra-G. Very transparent and natural. I used one for 6 months before I "upgraded" to a Two Notes Torpedo Cab Captor reactive loadbox. If you don't mind having the speaker cab engaged, the Behringer is tops.

    Not sure about the Captor but my Torpedo Reload definitely colours the sound compared to having a speaker attached. Some people prefer the sound that way though.

  • Another vote for the Behringer Ultra-G. Very transparent and natural. I used one for 6 months before I "upgraded" to a Two Notes Torpedo Cab Captor reactive loadbox. If you don't mind having the speaker cab engaged, the Behringer is tops.

    My experience with a Behringer Ultra-G was far from satisfactory in the past when profiling a Mesa Mark V.

    In the end I profiled using the slave out instead, which gave me the result I wanted.

  • I have the Kemper DI and the Behringer Ultra DI. Both give great results, but I just trust the Kemper DI more not to fail and blow up the amp!


    As an example, here is a test I did with a Peavey Special 130, which is a solid state amp. There's a studio profile, a merged profile using the Kemper DI, and a merged profile using the Ultra DI. To me they sound pretty close.PV Special 130 DI example.zip

  • You are missing a very important aspect. In normal operation there is huge amount of interaction between the output transformer of the tube amp... This means that the speaker itself has a big impact on the sound of the amp. This is why companies like Suhr or Two Notes produce rather complicated reactive load boxes... A simple load resistor like in your setup may work but in many cases it will sound totally different to the sound with a real cab attached. This is why profiling with the cab conncted will be the preferred method in most cases...

    tylerhb, I understand your concern about the speaker as a reactive load, etc. However as MKB stated a simple resistive voltage divider across the speaker will attenuate the signal from the speaker w/o coloring or changing the tone of the output, IF the resistors are chosen wisely. The larger the value of resistors, then the less interaction the resistors have on the speaker impedance. It's not just about the ratio of the voltage divider resistors used to derive an acceptable DI voltage level but also the total impedance in parallel with the speaker. Imagine 2 10k Ohm resistors wired in series across the speaker. It's still 8 Ohms with a 0.039% variance. Increase the values to 27K and you're close to the Kemper DI box design. It also uses no transformers and is a voltage divider with capacitors.


    Please note that I stated that the amp speaker was connected to the amp during profiling. Also the resistor values in the cable are clearly not for a transformer load, but for signal attenuation only. The cable is sampling the signal at the speaker terminals, and attenuating the signal to the proper level for the Kemper.

  • Hello,

    since a few days I am finally an owner of a kemper.

    I know this forum is a bit older but...

    I saw some posts about the Radial JDI in this forum and have something to add. I have a Radial JDI and it also has a "speaker parallel" knob with -30 dB. Also the manual says that you have to activate the -30dB and the -15dB knob to record the wet signal directly from the speaker output of an amp. Also make sure that a cab is plugged and the JDI is on the other parallel out from the amp or the parallel out of the cab because it can not handle the load on its own.

    In conclusion, I am very positive that the JDI (with speaker knob) is perfectly suitable to create direct profiles.

  • Anyone try a Rupert Neve DI ?

    Just incase anyone was wondering the RNDI needs phantom power which the Kemper XLR in doesn't supply, which is a bummer.


    So I am now looking to buy a Kemper Di box in the US, is it still the best box for direct profiling? I have a Suhr RL IR and a Waza TAE and not really happy with the results I'm getting. Some amps when profiling seem really way off like my Rivera Ktre or Sunn Enforcer.

  • Anyone try a Rupert Neve DI ?


    Just incase anyone was wondering the RNDI needs phantom power which the Kemper XLR in doesn't supply, which is a bummer.


    So I am now looking to buy a Kemper Di box in the US, is it still the best box for direct profiling? I have a Suhr RL IR and a Waza TAE and not really happy with the results I'm getting. Some amps when profiling seem really way off like my Rivera Ktre or Sunn Enforcer.

    My RNDI just got delivered. I'll try to grab a Phantom Power Supply and test it on a PRS J-MOD 100 in the next few weeks.