Lollipop - DJ Mixer

DJ
Mixer

toy groovebox with sampler, touch sensors, many effect samples & rhythms

What's that? - is this an extraterrestrial lawnmower with built-in kitchen sink? No, it is a toy groovebox keyboard made in 2004 (printed PCB date) by Lollipop Industrial Limited, with plenty of sound effect samples and lo-fi background preset music pattern loops. Instead of drumpad buttons it employs optical touch sensors and can even store a 5 seconds short lo-fi sample.

The concept of the instrument strongly resembles Kid's Com - Mix Me DJ. Unfortunately the light barrier matrix in the "kitchen sink" bowl work poorly; it has difficulties to recognize multiple fingers over sensors, and unlike Beat Square - AIR-Dance Mixer, their range is only few cm narrow, thus normal buttons would have been more useful here. The sensors have each a red pilot LED underneath, those like with Mix Me DJ flash in simple patterns. Nice is that the keyboard part, accompaniment, line in and microphone have independent volume controls, however there is no master volume knob. Unfortunately the keyboard ignores key press duration and refuses very fast played notes. Many sounds are already major chords, which makes them badly suited for melody play. The whacky, spring- loaded lever ("scratch disc rod") triggers in one direction a preset sample and in the other the user sample; buttons would have been much more useful. Unfortunately this sample can neither be played on the keyboard nor modified in any way, which limits its use very much, and its battery backup feature makes the batteries empty themselves until leak when not in use for some months. The best you can do with the sampler is recording sounds from the internal speaker to play them back in a loop and mix them with other sounds of the instrument. This way you can e.g. create polyrhythms by mixing a preset rhythm with the same or a different one from sample memory. When you change the tempo ( = playback sample rate) of the preset rhythm or record it with a different loop length, the result can be nicely complex tekkno trance structures.

main features:

20 long mini- keys (Slow keyboard matrix prevents very fast play. Keyboard ignores key press duration.)
9 touch sensor matrix (3 x 3 IR light barriers)
built- in speaker (with little bass)
keyboard polyphony up to 3 notes
9 keyboard preset sounds (selected by 3 buttons those each cycle through 3 sounds)

1-3 {synth gamelan chord, synth saxophone, sitar}
4-6 {ah! voice, orchestra hit 1, orchestra hit 2}
7-9 {synth piano chord, e-organ chord, heavy metal guitar}

8 sets of preset background pattern loops (mislabelled "rhythms", each 3 patterns)

8 sets of preset insert pattern loops (each 2 inserts)

tempo +/- & reset buttons (8 steps, control "rhythm" sound loop sample playback speed)
separate volume sliders for sound effect, rhythm, line in and knob for microphone volume
no master volume control
primitive sampler (stores only one low-res user sample of 5s length, battery backed-up)
scratch disc rod (anti-clockwise triggers actual "disc effect" sample, clockwise triggers the user sample)
12 preset "disc effect" samples

1-4 {scratch rhythm 1..2, scratch voice rhythm, synth bass alarm 1}
5-8 {scratch voice down, scratch organ howl, scratch fast, synth bass bubble}
9-12 {bass zap, scratch creaky, vocoder bass buzz, synth bass alarm 2}

8 sets of drumpad sounds (selected by 2 buttons those each cycle through 4 sounds, 32 sounds in total)

1-4 {ratchet, synth snare, tekkno base, snare | crash cymbal, high snare, metallic cymbal, conga | film projector spin up, robot voice purr, low zap, high zap | jet plane noise, siren up, reverse drum, gun shot}
5-8 {"one!", "two!", "three!", "four!" | "yeah!", "bo!", "rock it!", "come on let's go!" | synth clap, shaker, zap up down, bright ring | car overtake noise, crash, touch tone synth pattern, synth phone ring}

all sounds based on medium low resolution 8(?) bit samples (with audible aliasing noise by low bit resolution). The sound generator seems to be 8 note polyphonic (3 for keyboard/ button click, 1 for rhythm/ insert, 1 for sound effect, 1 for disc effect, 1 for sampler, 1 for startup sound).
multi-chip hardware:

CPU1= "ROHS EM60600S" (48 pin COB, crystal clocked?)
CPU2= "ROHS" (28 pin COB, crystal clocked?)
IC= "ST, LM324N, GK60819F, [logo] V6 GK CHN" (14 pin DIL)

auto power-off (only in demo mode? (after 22s))
jacks for AC-adapter, line in, line out, phones & microphone

light barrier sensor holes

pcb back with leds

light barriers

notes:

After power on, the instrument starts up with a scratch sound and a reverbing male voice speaks: "I'm your DJ!". Instead of a real power switch their is only a standby button. Although this permits to hold the user recorded sample in memory with power off, the down side is that it empties the batteries also with power off, which makes them leak after few months when not in use. On the case bottom is a demo/play switch, that powers the instrument off after 22s in demo mode. Odd is that the startup jingle seems to have an own polyphony channel which is not used by anything else, since no other function truncates it. The keyboard polyphony is shared with the button click. Like with Mix Me DJ the sensors (there drumpads) of this instrument flash red in semi- random walking light patterns (stepping here with about 3Hz, each 2 LEDs light at a time); when a sensor is touched, only its own LED lights up and the others stay dark for about 7s. A bit annoying is that the LEDs mix a buzzing and ticking key matrix interference noise into the sound, which can not be turned lower. At least the volume sliders work reasonably, despite their is no master volume control. Only when set very low, the sound suddenly mutes completely despite they are analogue. The "sound effect vol." slider controls keyboard, disc effect (scatch rod), sound effect (drumpads) and sampler volume. The "rhythm vol." slider controls the volume of "rhythm" and "insert" patterns. All buttons play a clave click or (in the "disc effect" section) their selected sound, which disturbs life performance. Because the preset sounds and rhythms etc. have no visible names on control panel or manual , their names in this text were chosen by me.

The keyboard preset sounds are plain low resolution samples and sound quite bright, grainy and a bit thin. Some are up to 3s long, but most are <1s; they are all unlooped samples and ignore key press duration, which is annoying particularly with the longer sounds. Some have a key split zone in the middle. Nice is that when a key is trilled, each new note occupies a new sound channel, which produces a nice phasing sound and volume increase effect although this eats up polyphony. The sounds have only numbers instead of names thus all sound names were chosen by me. The "synth gamelan chord" is a short major chord sound that roughly resembles a gamelan or xylophone. The "synth saxophone" is a dry buzzing saxophone- like tone with somewhat smacking attack. The "sitar" is a long bright tone that goes "wwoiiing" with a brighter turning resonance in the middle; it may be a synth filter sweep with much resonance. The "ah! voice" roughly resembles a children choir singing "ah!"; high notes rather resemble "eh!". "orchestra hit 1" is percussive and may be a major chord, while "orchestra hit 2" is a bright and scratchy yelling violin chorus sound. The "synth piano chord" seems to be a major chord on piano. "e-organ chord" resembles an about 2s long major chord on a dull and slightly rough Hammond timbre (as used in ambient music) that decays at the end. The "heavy metal guitar" buzzes bright and about 2s long.

The "rhythms" are genuinely loop samples and include a lot of wicked complex tekkno synth stuff. Each rhythm number selects a set of 3 different patterns those can be switched, started and re-triggered in realtime with the 3 "rhythm" sensor pads. Rhythms can be stopped at any time with the "rhythm stop" button. Any rhythm can be breaked with the 2 "insert" pads, those start each an "insert" pattern. The difference between "rhythm" and "insert" patterns is that the latter stops immediately when the pad is released, and then continuous the previously running rhythm pattern (like a fill-in) exactly from the point where the insert begun, so far a rhythm was running. But nothing is automatically synchronized, thus the player has to decide when to switch or re-trigger rhythms or stop insert patterns. This is all very basic sample- based stuff and nothing in any way sequencer- like. Also the tempo control only changes the speed and pitch of "rhythm" pattern (like changing the speed of a phono record) but not of the "insert"; it anyway has only 8 steps and doesn't go very far. Selecting a new rhythm set or pressing "tempo reset" resets it to default.

The "rhythm" pattern loops are:

1-4:
tribal breakbeat | rhythm with female scream & male "yeah!" | e-guitar, e-bass & drum kit
tribal scratch rhythm with "jip!" voice | slow ambient with disharmonic bass | woody knocking rock rhythm
fat base & snare | tribal/ reggae with congas | scratch rhythm with metallic clicks
fat base with howling ghost sounds | tribal with bass drum & metallic cymbals | scratch rhythm with harsh reverbing claps

5-8:
jungle rhythm | breakbeat with agogo bells | fast samba rhythm with cymbals
slow irregular fat bass drum with synth gong | scratchy phaser rhythm with synth digeridoo "ou!" | fast tribal with shouting man
fat irregular reverbing cymbal cough phaser rhythm | tribal with shouting man | fat breakbeat rhythm with female "ah!"
fat jungle rhythm | phaser breakbeat | 4-beat scratch rhythm

The "insert" pattern loops are:

1-4:
fat synth drum 2-beat | fat synth drum 2-beat with hihat
heavy metal guitar 1 | heavy metal guitar 2
warm dull synth woing hum | sitar pattern
tribal with congas | distorted crunching tekkno 2-beat

5-8:
phone call message | fat breakbeat
louder fading psychedelic train sound | slow howling scratch noise
ocean waves | fast buzzy squarewave synth loop
thin fading phaser rhythm | dull bubbling synth loop

The "scratch disc rod" is fairly flimsy and simply pushes a button switch contact on each end to start a sample, thus it can not do anything that 2 buttons could not do also. The sample plays as long you hold the rod there, which has nothing to do with simulated record scratching, but is a similar cucumber like the scratch disc of Casio Rapman and most other DJ toy keyboards.

The sampler can only record one sample of max. 5s; hold "voice rec." for the desired duration and e.g. speak or make a noise into the microphone. Purring blips indicate that the memory is full. But the sampler is pretty useless since it can be neither edited nor played on the keyboard. You can only play it by turning the rod clockwise; holding the rod for longer plays it in a loop (with noticeable pop noise at the loop point). As soon anything has been sampled, the green LED above the "voice rec." button will start to flash and keeps flashing from that time on to annoy the user until you take the battery out. And because you can open the battery compartment only by screwdriver, this feature really sucks, because the sampler was never designed to purge the memory contents again; even when you press "voice rec." very short or with microphone disconnected to fill the memory with silence, the LED will keep flashing. Of course the LED goes out when you turn the instrument off, but it flashes again after you switch it on, so this pilot LED is useless when you use batteries. Only during AC-adapter operation it can be seen as a small warning not to unplug it because a sample has been recorded. But the LED does not show whether the memory contains only silence (e.g. after accidentally hitting "voice rec." again), and since there is only space for a single sample, it will be anyway overwritten very often during performance, which makes it fairly pointless.

*removal of these screws voids warranty...*

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