| br>Very happy with my discrete ladder filter thanks
Time to get building the next phase... a couple of filter-related questions
1. Maybe you can't be explicit on the web site, but I'd like to know what the other filters are based on or are clones of. The DLF is a Moog 904a clone and a damn fine one too. The transistor ladder is presumably miniMoog-like but not a clone as it has VC resonance, variable slope and different level characteristics with resonance. The state variable filter is Oberheim SEM-like and the COTA is Roland SHx - like. But what are the Croglin, diode ladder and Journeyman?
For info, analogue-wise I already have Moog Voyager, your DLF, Korg Odyssey and am building a minimoog VCF clone. I'm a Prog/ELP type of player.
2. the SVF lacks the original's variable state knob. What's the best way of achieving this? Is it as simple as cross-fading two of the state outputs?
Steve br> br>
| br>Only the DLF and COTA are near clones but even they add a few more bits that I thought would be useful. The other filter modules are all of my own invention but inspired by some of the classic synths I like.
The SVF is a state variable filter. It's not clone of the SEM but more of a classic text book implementation of an SVF. It does sound somewhat different to the SEM having a level dependant feedback path - the amount of resonance is dependant on the level of the input signal.
|trebmonster wrote: |
|the SVF lacks the original's variable state knob. What's the best way of achieving this? Is it as simple as cross-fading two of the state outputs? |
On the SEM it's a cross fade between the LP and HP outputs.
The Journeyman is a traveller. It's core is based partly on the mid period Korg and the early Yamaha filters (700, 770, GX1, SY1, etc) design which is essentially a Sallen-Key filter using diodes as current controlled resistors.
The original Superladder was a four pole version of the 303 filter that could be built either using transistors or diodes. The design of the circuitry surrounding the ladder core changed over the many versions of the SL. Both of the current superladder modules, diode and transistor, are as unique as any ladder filter could be.
The Croglin was inspired by Electro Harmonix's Minisynth but since the original was rather too quirky and limited it was re-worked considerably.
Tony br> br>
| br>Magic, thanks Tony br> br>
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