
via JH on AH:
"Hi, just wanted to give you a quick update of my upcoming (fall 2008) "Subtle Chorus" PCB project, which, among other things, will be able to emulate a Dimension D, (using original ICs and all), plus "Dim T" (Same topology but with two 20-stage phasers instead of BBDs), plus generic true-stereo, dual-BBD chorus. Depending on what configuration you want, this will use one, or up to four PCBs. (Dim D emulation needs two PCBs.)
The "Subtle Chorus" is a variable project consisting of 3 different PCBs that can be combined for various functions.
a.. You can build a rather simple, true-stereo, dual-BBD Chorus with voltage controlled Chorus Rate and voltage controlled Chorus Depth, using a single PCB.
b.. You can emulate the famous "Dimension D" (Trademark of Roland / Boss) sound with it's unique filtering and presets, using two PCBs, the "Dim D" (You even have the choice between vintage HA1457W opamps, or more common TL071 / TL072 opamps.)
c.. You can build a similar effect that uses 20-pole all pass filters instead of BBDs, using three PCBs, the "Dim T".
d.. And you can build an overkill effect device that allows to choose between the Dim D and Dim T effect, using 4 PCBs, the "Dim TD" version. So far, the BBD board design is finished; main board will be the next.
Documentation is here:
http://www.jhaible.de/subtle_chorus/jh_subtle_chorus.htmlThe BBD board needs 2 x MN3007 and 2 x MN3101. These are quite easy to get, compared to other vintage BBDs. The Dim T version doesn't need any BBDs, of course...
Forgot to mention:
BBD board also needs 2 x NE570 (or NE571, or SA571) companders."