Waldorf M Filter

Hello! it is about the engineered analog filter in the M of the SSI 2144. a store in cologne claims that this filter is also known as the curtis filter, which tends to have a bad reputation. did they make a typo here and that’s complete nonsense? I think the SSI 2144 is more likely to be compared to the filters from PPG Wave, Kawai K3, Octave Cat, Korg Monopoly and Polysix, Simmons SDS V, CMI Fairlight II, Crumar Bit One or Siel Opera 6.

The Microwave had Curtis filters I believe, the shared DNA between that and the M might account for the confusion?

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I’ll quote the store here: “The carefully constructed and (on request) modulated sound spectrum leads to an analogue 24dB lowpass filter with an SSI 2144 chip, which is also known to many as the Curtis filter and was already used in the first microwave.” so I was a bit confused because the SSI 2144 has nothing in common with the Curtis filter!?

Yeah, I think they’re just a bit muddled up.

Also, I know when people talk about Prophet 5s they’ll talk about ‘the Curtis filter’ as opposed to the earlier one but haven’t there been several variations of Curtis filter over the years? The Microwave filter isn’t the same model as the one in the Prophet 5… I dunno, just seems a little weird the way they’ve written that.

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I don’t know if there were several Varitons of the Curtis filter. But then I also think that they simply made a mistake.

I think they are confused. This chip is a descendant of an SSM design, not Curtis. Same one used in Prophet X:



very good, then I was right. thank you