I found this synthetic guitar-like sound on my Roland Juno-106, tweaked it a little bit, and then ran it through some delay and reverb. The envelope gives it a similar sound to an electric guitar played clean. If I wanted it to sound more realistic I would stagger the attacks and perhaps distort the signal, but I like the synthetic nature of it. If I wanted a realistic guitar, then I’d record some guitar. Imitating acoustic or even most electro-mechanical instruments with synthesizers is something that was a necessary step in the evolution of synthesis and modeling. These days we appreciate how synthesis sounds apart from the modeling and reproduction of traditional instrumentation.
Juno-106 Synthetic Guitar