The SMR-4mkII is a revision of the classic 4-pole VCF / VCA board shipped with the Shruthi-1 kits. It keeps the “solid” sound of the original version — actually the core filter circuit is unchanged — but its part count has been reduced thanks to a few optimizations in the circuit. Another of its distinctive features, compared to its predecessor, is the reduced number of trimmer adjustments (from 4 to 1) that need to be done.

While this product is in fact a Shruthi-1 originally designed, sold and supported by Mutable Instruments,  it is no longer manufactured by them and therefore is not supported by Mutable Instruments.  Any requests for help troubleshooting issues as they arise during a build that are sent to Mutable Instruments will be ignored.  Please, send any support requests to us, Laurentide Synthworks, or to the SDIY community forums - not to Mutable Instruments.

Although this is not an official Mutable Instruments product, we have been in contact with them during the whole process of continuing the legacy of the Shruthi-1 synthesizer.  All Mutable Instrument's Logos have been removed from all of the products and replaced with our logo.  A disclaimer on every PCB reads "Originally designed by Olivier Gillet for Mutable Instruments, cc-by-sa".  Basically, what this means is this is no longer a supported product of Mutable Instruments, but rather Laurentide SynthWorks.  It carries a Creative Common's license which allows anyone with the PCB files and code to manufacture them, as long as any changes to the design are also shared under the same license.  Although the license does not require the original designers name/logo be removed from the product, we felt it best to adhere to Mutable Instruments wishes regarding this matter.  They want to distance themselves as far as possible from this product and we ask you, the purchaser, to respect their wishes when it comes time to ask for some troubleshooting guidance.