A Little History
The TR-707’s predecessor, the TR-909, was developed as an analog-digital hybrid rather than a fully digital device. As memory chips and digital-to-analog converters were very expensive at the time, there was concern that an all-digital design would make the product unaffordable for too many musicians. Also, while PCM sound generation could produce more realistic drum sounds, it offered little in the way of tone editing.
After the TR-909’s release however, digital PCM became the trend for synthesizers and drum machines. We embraced this trend with the TR-707 and TR-727, but expensive memory and lack of high-precision D/A converters resulted in a 25kHz, 8-bit (or 6-bit for some tones) sample playback engine that was primitive by today’s standards. Though the TR-707 and TR-727 were developed primarily for rhythm programming and did not give users the ability to edit their sounds, they were ultimately appreciated for their characteristic lo-fi punch and continue to be sought after to this day.
Capturing the Originals
Even though the TR-707 and TR-727 were primarily digital devices, it would not have been possible to perfectly replicate their sound using samples. Due to the low bit-rates of the original units, quantization noise became a problem, particularly during the sound’s decay. To reduce quantization noise, a clever design was employed where PCM sound was produced using non-decaying waveforms and decay was then introduced in the analog circuitry after being converted. Also, at the time these units were developed, deviations in the clock that triggered the PCM caused differences in pitch, and deviations in the analog circuitry downstream of the D/A converter caused variances in decay characteristics.
To replicate these sounds for the TR-8, we started with the original PCM wave data found on the classic machines. We then used our ACB process to completely model the PCM output stage, carefully including all of its quirks and instabilities. Modeling the analog envelope and amplifier stages that came after the D/A converter allowed us to implement the “Tune” and “Decay” parameters that are available on the TR-8, but not present on the original units.
A Seven in Your Eight…And Then Some
Adding the 7X7 Drum Machine Expansion takes the experience of playing a TR-8 to a whole new level. All 30 original TR-707 and TR-727 sounds—each with Tune and Decay controls—open up a whole world of sonic possibilities. Aside from the original TR-707 and TR-727 sounds, the 7X7 expansion includes four new, never-before-heard sounds inspired by the original TR engineers. Modified TR-909 kick and snare take the classic combo into new territory with enhanced attack characteristics. A highly percussive Finger Snap offers an alternative to snares or claps and sounds great when layered. And, in addition to the classic TR hand claps, Big Hand Clap is a new tone inspired by the sound of hundreds of people clapping at once.
Once expanded with the 7X7, your TR-8 can have all the sounds of a TR-707, 727, 808, 909 and more—newly color-coded by kit for easy selection. And the eight stage flam of the TR-909 and versatile accent behavior of the TR-707 dramatically enhance how you can manipulate the feel of a groove. Any step can have a weak or strong hit, a weak or strong accent, an adjustable flam, step based effects and side chain. All the sounds and behaviors of four iconic TR drum machines, plus the TR-8’s own dynamic swing, rolls, playable faders, and across-the-board tune and decay controls make the TR-8 the most advanced Roland drum machine we’ve ever built.