The OSCar’s filter was unique, consisting of two 12dB filters, which could be combined in series to create 24dB filtering. The filtering modes were LPF, BPF and HPF with a ‘no track’ option. We have removed the ‘no track’ option as it’s possible to achieve the same using the KEYB TRACK Knob. However, impOSCar3 has expanded on these original modes by adding several more that were only possible to realise on the original instrument with the careful use of a soldering iron.

Filter

Filter Type Selection Windows

Select from the following filter options:

• Low-Pass 24dB: The two 12dB filters are combined in series to allow the low frequencies to pass through while filtering the high frequencies out.
• Band-Pass 24dB: The two 12dB filters are combined in series allowing the selected band of frequencies to pass through while filtering out anything outside that range. NB: In this mode the two filters are arranged as one lowpass and one highpass, not 2 bandpass.
• High-Pass 24dB: Again the two 12dB filters are combined in series allowing the high frequencies to pass through while filtering out the low frequencies.
• Low-Pass 2-Pole: The two filters are arranged in parallel allowing the low frequencies to pass through while filtering out the high frequencies. In this mode, when the Separation is set to zero, it’s the same as a normal 12dB filter. However when it’s set to anything other than zero you get two resonant peaks and cut-off points.
• Band-Pass 2-Pole: The two 12dB filters are combined in parallel allowing the selected band of frequencies to pass through while filtering out anything outside that range. Again, when the Separation is set to zero it’s the same as a single 12dB filter. However when it’s set to anything other than zero you get two resonant peaks and cut-off points
• High-Pass 2-Pole: The two 12dB filters are combined in parallel allowing the high frequencies to pass through while filtering out the low frequencies. Again, when the Separation is set to zero it’s the same as a single 12dB filter. However when it’s set to anything other than zero you get two resonant peaks and cut-off points
• Low-Pass//Band-Pass: The Lowpass and Bandpass filters are arranged in parallel. In this mode with zero or higher Separation you get a notch or band-reject effect.
• Low-Pass//High-Pass: Similar to the above but the Lowpass and Highpass filters are arranged in parallel.
• Band Pass//High-Pass: Again, similar to the previous two filter modes only this time the Bandpass and Highpass filters are arranged in parallel.

Q Knob

More commonly referred to as Resonance. A narrow band of frequencies, boosted at the cut-off point.

Separation Knob

This takes the two 12dB filters and allows independent control of their cut-off frequencies. When used with either the 4 or 2-pole filter modes, it’s possible to separate the filters by up to 24 semi-tones.

<aside> ⚠️ In the first six filter modes, no Separation takes place when the knob is turned fully to the left. In the first three multi-modes, no Separation takes place when the knob is at ‘12 o’clock’.

</aside>

Frequency Knob