CEM 3320 / Roland Filter
2001-07-23 by thomas white
Sorry for the second post JH, I meant something along the lines of 24dB Lowpass with VC Resonance and 3 mixed inputs with similar FM inputs also. I would probably keep walking past this if I thought I would end up with more 440's. The design you and Paul made is untouchable. I recon the CEM3320 will sound thinner in comparison but it will also have different resonance characteristics and an 85dB at best signal to dB ratio. Maybe not MOTM by all standards, but hey without MOTM I wouldn't have the inspiration to even think about this in the first place. I only hope to learn from trying this to get a better grip on circuit design and function and maybe even a new gritty filter or 3. Any thoughts on a Roland IR3109 or similar simulation filter in the future? Paul? Anyone? Juno/SH/MC maniacs speak up! Thomas White >From: jhaible@... >To: "thomas white" <djthomaswhite@...> >CC: <motm@yahoogroups.com> >Subject: Re: [motm] Custom PCB's !!! >Date: Sun, 22 Jul 2001 19:49:43 +0200 > > > I want to do a board layout for Barry Kleins CEM3320 Lowpass VCF circuit > > (fig.5-20 in the book) from Electronic Music Circuits. It will end up a > > lowpass similar in sound and features to the 440 > >You won't. >Or more precisely, you might - if you always run it at signal levels where >nonlinearities are not important. Which is a small subset of interesting >applications. >You will come be able to emulate a Pro-1 filter, of course. But you won't >come close to a MOTM-440 - not closer than a revision 3 Prophet comes >to a rev. 2. > > > This is the classic filter from the sequential > > Pro-1/Oberheim misc and has the bass compensation when resonance is > > increased like the 440 (but on chip) > >"Bass compensation" is just what's going on "on the outside". The similar >bass compensation has very different sonic qualities on a SSM "chip", >a CEM chip. (Or on a Roland chip for that matter. The Juno-6 has a similar >thing as well, but a filter circuit different to both SSM and CEM.) > >JH. > > > > _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp