I have owned 3 Coda amps, 2 preamps, and a phono preamp.
Coda is anything BUT neutral, or cool sounding.
Yes, Coda was started in the late 80’s by 3 ex-Threshold engineers, and sonically they sound similar to the Threshold and Pass Labs amps that I’ve also owned. I don’t think anyone will say that Threshold or Pass Labs amps sound cool/neutral, and I would say the same of Coda.
To me, the Coda sound is rich, vibrant, full-bodied, with tight, powerful bass.
Also, yes, Coda does design and build amps for other companies like Innersound, Legacy, and Sanders too.