Doepfer

I'm interested in filters creating formants. It's not about human
voice vowels or the sounds usually produced by by vocoders, but rather
the formants associated with certain acoustic instruments, like cello,
trumpet, trombone, French horn, etc.
Probably nothing can beat the Yamaha FS1R when it comes to parameters
 shaping formants, but like many other digitals it can't process
external sounds. I've read the specs for Doepfer A-104 Trautonium
Formant Filter, A-127 VC Resonance Filter, and A-128 Fixed Filter
Bank, as well as Analogue Systems RS-110 Multimode filter, and RS-360
Vocal /Phase Filter Bank. Certain details caught my interest like the
input sensitivity with A-104 that easily creates distortion and the
RS-110 external resonance feedback chain where reverbed signals can be
fed back. Some have extensive CV features like A-127, but unless
programmability is desired, this is not a prerequisite since formats
have fixed center frequences, bandwidth, etc, AFAIK. 
Unfortunately there are no audio samples for any of the above
mentioned, so I like to ask if any of the list members have looked
into/ experimented with instrument formats. Is there any reading to be
recommended?
I'm new to this list, but it looks quite promising/Lars