Anyone interested in learning the fundamentals of sampling and drum machine programming for making beats will find the pocket operator po-33 k.o. a very appealing offering! It comes with a lot of features, including sound effects, data transfer functionality and an integrated microphone, all in a tiny, cheap package.
The learning curve is short compared to a full size sampling drum machine, which can be overwhelming to use for a beginner. The pocket operator po-33 k.o. is small enough to take field recording so, you can sketch ideas on the fly, which you can then later use on a digital audio workstation (DAW).
The pocket operator po-33 k.o. measures 12.5cm tall, 6cm wide, 2.5cm deep and weighs 75 grams (54 grams without batteries). The pocket operator po-33 k.o. has the look and feel of a bare-bone calculator circuit board and it's certainly modeled after one because of the SMD type momentary micro switches, which only engage while they are being depressed.
The pocket operator po-33 k.o. features a positive liquid crystal display (LCD) similar to the positive displays of old G-Shock watches where the background is light and the digits are dark. The po-33 k.o. LCD screen has functional parameter feedback so, it provides information about the changeable features such as LPF/HPF, volume, pitch, input level, playback level, pattern, sound, trim, etc. The animation of the two fighting boxers doesn't serve any functional purpose other than adding a fun touch to the machine.
The pocket operator po-33 k.o. is powered by two AAA batteries, which you can remove at any time since settings and samples are saved in real time. You can back up and restore all your settings and samples on and off of the po-33 k.o. via a linear PCM recorder (not included). To make removing the batteries easier, it's best using a plastic pry tool.
The memory onboard the po-33 k.o. gives you 40 seconds of total sample time. There a total of 23 momentary switches and two multifunctional knobs. The numbered switches (1 to 16) are designed to sample and record sounds into them. The numbered switches are divided into a drum sampler section (switches 9 to 16) and a melodic sampler section (switches 1 to 8), which transposes beats in a harmonic progression.
Samples can be copied and pasted between the sample engines (melodic and drum) by holding down the WRITE button, SOUND button and any numbered button (1 to 16). The sampler records from the line input or built-in microphone. Samples can be trimmed, filtered and their resonance volume adjusted to increase or decrease the volume of the audio output signal.
The pocket operator po-33 k.o. is also a basic 16 step sequencer that lets you write a beat pattern in sixteenth notes with one bar per pattern (up to 16 patterns) or write a beat in eighth notes with two bars per pattern.
If you want more bars, you cannot change the 16 step resolution of the po-33 k.o. but you can link 16 patterns together into a song (pattern chaining), as well as copy and paste them by holding down the WRITE button, PATTERN button and any numbered button (1 to 16). To link patterns into a song, you hold down the PATTERN button and the pattern sequence. Steps can be played live or programmed manually.
With 16 patterns, the pocket operator po-33 k.o. is able to produce a detailed song but because it is limited to only 16 patterns, you cannot make multiple songs unless you copy the data of the previous song off the pocket operator to start a new song. Aside from sequences and patterns, the pocket operator has 16 built-in effects that can be used during playback or recorded into a pattern. Effects include scratch, reverse, stutter, octave up/down, and loop. The number 16 sound effect switch is designed for disabling any sound effects that you apply.
By holding down the SOUND switch, you can select an instrument and play it. By holding down the PATTERN switch, you can select up to 16 patterns from the 16 numeric switches on the po-33 k.o. You can press switches in any sequence to create the pattern you want and then play it by pressing the Play switch, which also doubles as the Stop switch.
The pocket operator po-33 k.o. comes already pre-installed with sounds but, if you want to record a new sound into it, you simply hold down the record button and any button (1 to 16) and record a sound into it via the built-in microphone or line in.
If you record a sound in the melodic sampler section. The recorded sound is automatically matched to different notes on all 16 switches, giving the recorded sound 16 different tones to it. If you record a sound in the drum sampler section (buttons 9 to 16), the auto slicing feature on the pocket operator's drum sampler section automatically slices the sample into 16 slices based on the transient no matter how long your sample is.
If you don't want automatic slicing, you will need to set up a drum sample kit via a software music sequencer (i.e. Ableton) and then, sample it into the pocket operator or, you can sample a sound on the melodic section then, press a numbered button within the now selected drum group and the sound should be copied over into the drum section without being chopped into 16 parts. You can copy any individual slices this way as well.
You can raise and lower the pitch of the recorded sound (pitch shift) via the left knob, which doubles a pitch shifter, and you can volume up and down via the right knob. Both knobs are multifunctional, meaning they have several functions other than pitch shifter and volume control.
The left knob functions as a pitch shifter, as well as low pass (LPF) and high pass (HPF) filters and Trim tool so, you can edit the sample by setting the start and end times of the sample sound. To make the left knob function as low pass and high filter and Trim tool, you press the FX button each time to select.
The left button also controls the swing in real time when the BPM button is held down, while the right knob adjusts the BPM speed (tempo) when the BPM button is also held down. The BPM are the number of beats happening in a minute so, if you set the tempo to 60 BPM, the po-33 k.o. the beat pattern will beat once per second. If you raise it to 120 BPM, the beat pattern will beat twice per second; hence the beat pattern will be sped up.
The Swing function lets you space out the beat so, you can adjust the rhythm of a beat. The more swing you add, the greater the space before the beat and the less space after the beat. The po-33 k.o. adjusts the Swing consistently so, the song won't be be off-beat.

When creating a song, you can layer several drum instruments but you are limited to a maximum of four melodic voices being played at the same time. Aside from melodic sounds, drum instruments and beat patterns, there are also sound effects that you can add on to a song. You can create eight drum instruments by sampling via the microphone or via the line in.
By holding down the FX (sound effects) button and a numbered button, you can apply up to 16 sound effects on the po-33 k.o. You can also record sound effects as part of the beat pattern by pressing the Play button first and then holding down the FX button and pressing the numbered buttons. The recorded sound effect can be deactivated (or disabled) by pressing button 16.
Another limitation of the pocket operator po-33 k.o. is that you cannot use sound effects on incoming audio before it is sampled, meaning the sound effects are only usable on samples. There is a power-save mode feature that kicks in automatically after 5 minutes of inactivity (a sleeping zzz animation appears on screen).
If there is a cable connected in the line in, the po-33 k.o. will auto power off after 60 minutes of inactivity. During sleep mode, all patterns and settings are automatically saved, leaving only the LCD lit.
While a professional music maker will find the pocket operator po-33 k.o. useful, the pocket operator is something everyone will enjoy because not only you can sketch ideas, you can also sample sound effects from real instruments, thanks to a decent built-in microphone, which records surprisingly good.
It's worth keeping in mind though, that the pocket operator po-33 k.o. is a low-fidelity (lo-fi) sampler with lower bitrate than normal since the pocket operator po-33 k.o. can only transfer eight bits of data at the same time; hence 8-bit.
The Teenage Engineering pocket operator po-33 k.o. can be paired with multiple pocket operators, but you can adequately produce complete tracks with a single po-33 k.o., which could also be used as a standalone drum unit with a loop machine and guitar.
One of the best features of the pocket operator po-33 k.o is its portability as you can plug in a pair of headphones and rock along while sitting on a train or bus on the way to work. Check out the review of the PO 128 Mega Man Edition.