Oberheim OB-Xa
| Manufactured by | Oberheim |
|---|---|
| Dates | 1980 - 1982 |
| Price | US$4595 - US$5595 |
| Technical specifications | |
| Polyphony | 4, 6 or 8 |
| Timbrality | 2 |
| Oscillator | 2 |
| LFO | 2 |
| Synthesis type | Analog Subtractive |
| Filter | 12 and 24dB/Oct LP |
| Attenuator | yes |
| Memory | 32 - 120 patches |
| Effects | none |
| Input/output | |
| Keyboard | 61-key |
| Left-hand control | Pitch Modulation |
| External control | Oberheim system |
The Oberheim OB-Xa was Oberheim's overhaul of their first compact synthesizer, the OB-X. The OB-Xa was released in December 1980, a year after the OB-X was released. Instead of discrete circuits for oscillators and filters, the OB-Xa (and the Oberheim synths to follow) switched to Curtis integrated circuits. This made the inside of the synth less cluttered, reducing the labor required to replace bad parts; and reduced the cost of manufacture. However, today it's much easier to fix an OB-X than OB-Xa, as Curtis parts are getting scarcer, whereas discrete parts used in OB-X are almost always readily available.
Aside from hardware changes, the OB-Xa had better interface features compared to OB-X. These included being able to split the keyboard into two halves with different voices; the ability to layer voices to create thicker sound (essentially making two notes sound for every key pressed). polyphony stayed the same - again 4,6 and 8-voice models were offered.
One function that did disappear from OB-X voice architecture, was cross modulation, or frequency modulation of vco with the second vco. When done with analogue circuits, it's a unique sound made famous by Prophet 5 and its poly-mod section. Lack of this somewhat reduced the range of sounds possible on OB-Xa.
[edit] Albums that feature OB-Xa
- Paul Davis - Cool Night (Album) (1981)
- Stevie Nicks - The Wild Heart (album) (1983)
- Jean Michel Jarre - Concerts in China (1981)
- Jean Michel Jarre - Zoolook (1984)
- Laurie Anderson - Big Science (1982)
- Gary Numan - Warriors (1983)
- Prince - 1999 (1982)
- Queen - Hot Space (1982)
- Queen - The Works (1984)
- Simple Minds - New Gold Dream (1982)
- Simple Minds - Sparkle In The Rain (1984)
- The Stranglers - Feline (1983)
- The Thompson Twins - Quick Step and Side Kick (1983)
- The Thompson Twins - Into The Gap (1984)
- Van Halen - 1984 - (1984)
- Mike Oldfield - Crises (1983)
- Silent Running (Belfast band) - Shades of Liberty (1984)
- Mike Oldfield - Killing Fields - Soundtrack (1984)
- Rush - Signals (1982)
- Rush - Grace Under Pressure (1984)
- Rush - Moving Pictures (1981)
- The Police - Ghost In The Machine (1981)
- Electric Light Orchestra - Time (1981) & Secret Messages (1983)
