Yamaha CS70m - review and deep dive

This is an in-depth review and demo of the rare and magnificent Yamaha CS70m.
In my view, the CS70m is the closest you can get to the sound and voice architecture of the Yamaha CS80 without paying CS80 money.
This synth is bi-timbral, with two VCOs per voice.
It has the same VCO design, the same filter and the same ring modulator as the CS80.
Polyphony is only 6 voices - 2 less than the CS80 - but the CS70m makes up for it by providing a sequencer, patch memory and cool splits.
I go in depth on what sounds this synth is capable of producing.
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[@OudeisEimi]

50, 60 and 80 came before the 5, 10, 15 and 30

[@ksmusiclounge1648]

You are right, I make it seem like the monos came first and then they evolved into polys, but they all appeared pretty much at the same time. Yamaha was big into organs and they had all the mono and polyphonic technology already developed. Chronologically, the "non-M" (M is for Memory) synths are purely analog without any digital control and they all came out in short succession around 1976-77. The "M" line introduced digital control and memory and those came out at the end of the 70s and the 70M was last in 1981, only to be slayed by the DX7 shortly after its release. Fun fact - Yamaha also produced a motorbike of the same name as a synth, the cs5, which came out in 1972! Im also into bikes so I remembered there was a cs5 in the early 70s, but it wasnt a synth but rather a bike! Appreciate your comment - I will pin it to the top to make sure the time-line is clear.

[@VultureCulture]

I really appreciate you doing such a thorough job explaining the history of this synth. Great job!

[@ksmusiclounge1648]

Thanx man!

[@Robert44444444]

I attended a 'clinic' at West L.A. Music in Santa Monica in the early fall of '82 where Jeff Lorber introduced the then new CS-70M. I remember that well. Getting that Yamaha CS sound in an 8-voice poly synth with patch memory… yeah I wanted one. This was the same year the MemoryMoog was introduced also… and I went to a clinic at Goodman Music in Studio City where Tom Coster showed off the MemoryMoog and finished with playing Moog Liberation lead synth through a Marshall stack to a backing track. I must admit I was more interested in the MemoryMoog than the CS-70M. My budget though was in the neighborhood of the newly introduced Yamaha CS-01 (w/ BC-1 breath-controller)… and that's what I bought… my 1st synth.

[@mwmusic29]

Awesome - thanks for sharing this!

[@ksmusiclounge1648]

Thanks Matt!

[@waynerandom11]

Hi. Great video! Could you link to the video you mention of someone who described the Yamaha VCO chip in detail? It sounded like you said his name was Gold but I didn’t have any luck finding the video. Thanks!

[@ksmusiclounge1648]

Hi Wayne thanks for watching my video. Yeah the name of the channel is Golt! - run a search on KZbin for “goltsynth”. Here is a link to the video where he describes the inner workings of a Yamaha CS-type VCO with a schematic: kzbin.info/www/bejne/nGHHgGqhfdGUo7M It starts around the 15minute mark. Hope that helps! And as per usual a shmeless plug - subscribe & hit the bell! 😀

[@schoovaertssimon7904]

great video thank you, priceless...Do you know of a way to make the sequencer a step sequencer? and is there a way to replace the magnetic card reader with a modern USB device?

[@schoovaertssimon7904]

as it is the sequencer is pretty much useless to me.

[@schoovaertssimon7904]

what is the "sensitivity" button for?

[@ksmusiclounge1648]

Thanks a lot man! No way to mod that - its ancient firmware 😅 replacing the magnetic drive with a USB sounds like an interesting idea but I doubt its possible - its not only about the drive but also about how to output the data in a format that the synth understands…

[@ksmusiclounge1648]

The sensitivity is for the aftertouch

[@daniell.9246]

I started making compatible magnetic strips for the CS70M...inexpensive way of storing your created voices.

[@yarone4451]

Nice review. I think those epic instruments are very known and high rated among musicians. Interesting how they stand comparing the much modern and newer ones (mostly digital ). So is it nostalgic and vintage which very important by itself or is it also in term of sound. I am in love also with the vintage organs from the 60' /70' , maybe since im older then you - the b3, vox continental, yc45d, but they are Ofcourse completely different instruments, and a different story. Thanks!

[@ksmusiclounge1648]

These CS-series synths are very special sounding indeed, they dont compare to anything modern today. Deckard’s Dream is the closest. Thinking that Yamaha made them based on their organ technology is also quite mind boggling.

[@dodgyscampton5668]

What about the cs20m?

[@RayyMusik]

What‘s the difference between the red ‘write‘ and ‘store‘ buttons on the right-hand side? One of those for data export to a cassette?

[@ksmusiclounge1648]

Precisely. Write writes patches to memory slots and store stores patches to magnetic strips.

[@VincentPresley]

Cool synth but I'd say it's one of the most overpriced vintage synths out there. You can do a lot more with that money. Those unique chips inside are also impossible to get these days so if it goes bad, you're pretty screwed. Also, prices on nearly all synths have been dropping like crazy the last 6 months or so. I've been buying more synths than ever just because they keep popping up for lower and lower prices.

[@ksmusiclounge1648]

imo its closer to the cs80 than the cs60, overpriced is really a relative term. A lot depends on the condition of the synth, how it was serviced and maintained. The ring modulator is pure magic.

[@VincentPresley]

@@ksmusiclounge1648 Yeah, the ring mod is cool but you can get it in a CS40M for 2k if you really need crazy ring mod sounds.

[@ksmusiclounge1648]

True, the cs40m is a sleeper. Have a vid coming up on her soon! Stay tuned 😜

[@sub-jec-tiv]

Had a 15 and didn’t love the sound of it for mono synth duties. Could make huge sub-bass, but other than that it didn’t hit the spot often enough so after 10 years or so i sold it. I think the CS oscillator works much better in a synth with polyphony. Somehow the tone works better as a chord and texture machine than for leads and such. Obviously sounds great as the basis of pads. That said the CS40m sounds great as a mono synth. Very fat. Completely different sound from the 15. I would guess they used a different filter design maybe?

[@kevinslaney486]

Your CS history is incorrect.

[@ksmusiclounge1648]

Yeah I addressed that in the pinned comment already