well, the cs70m is sort of the last development step for yam
well, the cs70m is sort of the last development step for http://www.sequencer.de/syns/yamaha Yamaha ending the CS series, you finally had some more memories (who the fuck needs memories?) , if you like the CS sound you may feel cool with a cs40m anyway.. the 70m is very rare and has some strange magnet card system to save it's sounds..
btw: it's 15 memories for patches for each "channel"..
in fact it is "2 synths in one" like most http://www.sequencer.de/syns/yamaha Yamaha cs series synth
and: you can't access edit mode when recalling the ram sounds later!
I'd only go for it if you LOVE the CS series and the cs80 is too heavy for you
imo it is worth 900 for the "collectors" point of view.. but anyway: no CS ever see any lights agains http://www.sequencer.de/syns/moog Moog

back in the new synthforum!!!
it's 2x 6 voice, so this is the big thing on the cs70 compared to the mono cs40m or the 8voice monster cs80..
the VCOs are limited in tuning to special settings , no free selection..
but it has multi mode filters (As usual no self osc'ing ones)
with ADSR / can be inverted.
VCOs feature pwm each by lfo..
the LFO is fast (100hz max) , there are at least 2 lfos ..
ring mod with extra OSC , not VCO1 ringmodded by VCO2!!
with AD env for LFO mod intensity...
second LFO is 50hz max, one if it will be global, the other one is saved with the patch..
it has aftertouch.
and it has a little <a href="https://www.sequencer.de/specials/sequencer.html">Sequencer</a>
btw: of course there is only ONE filter per voice.. it's not real 2 channel..
but: be sure you like the CS overall sound..
the cs30 can do more but is one voice only. 2 filters! 3 envs, cv lfo, ring, FM, wide range vcos..