Note this one is not new. I found it on this electro-music.com thread which states it's about half a year old. Normally I wouldn't call this out, but it is NAMM season and I know people are looking through them NAMM goggles... Remember, old can be new here. You can find more info on Bergfotron."Delay isn't one of the ”classic” modular synth modules. Maybe this is because analog delay chips became available when the synth industry had moved on to non-modular and polyphonic synths.
This module is based on the MN3207 BBD chip or it's modern equivalent, the BL3207. The latter is still produced and can be had for a very modest sum of money (you can buy it here). This is a 1024 stage chip and the board should also work with the 2040 stage BL3208, if you want a longer delay. The board also uses the companion clock chip MN3102/BL3102.
The delay time is voltage controlled, by using the VCO part from a standard 4046 PLL chip. An exponental converter controls the frequency of the PLL VCO. The delay circuit and anti-aliasing filters is based on the MN3207 application circuit from the datasheet. I increased the cutoff of the anti-aliasing filter by dividing all capacitor values with 1.5. Note that the BBD chip runs on +10 V single supply, which is the maximum supply voltage. So for this module, the +10 volt pin on the AMORE connector is used and therefore you need the 10 volt supply that is specified in the standard, in addition to +15 and -15 volts.
The board also contains a 3080-based VCA, which is used to give voltage control over the delay feedback. There is a high pass filter that rolls off the bass in the feedback loop. Otherwise the self-oscillation will occur at a very low frequency (1/delay time), which isn't very musical. If you don't want this bass roll-off, you can substiture the 15 nF capacitor with a 1 µF one.
The feedback loop has external connections so you could patch in other modules in the feedback loop if you want. Note that there is a jumper on the board for completing an internal feedback path (below/to the left of the 4046). This jumper must be removed if you want to use an external feedback path. The jumper can also be removed for troubleshooting. The CA3080 OTA can be difficult to find nowadays but you can get it from Banzai Effects, where you can get the BBD chips too."
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