https://www.sinevibes.com/integer/
A real BBD is basically a long chain of analog sample-and-hold circuits. You can't change the number of stages without replacing a chip, but lowering the clock speed lengthens the delay time but also the clean frequency response. Typically there are steep LPFs to reduce aliasing and clock noise, giving a darker sound than digital delays. But some modular BBDs leave the filtering up to you.
This one lets you control delay time directly, setting the clock and filter frequency based on delay time and buffer size. Smaller buffers are dirtier or darker (depending on your filter slope and quality setting). The clock whine is not modeled, and I don't think companding is modeled either.
So it's still not really the ultimate, accurate BBD emulation I was looking for... but playing with it for a while, I found that it is quite cool, and bought it. Yes, I'm sure I could have gotten very similar results with a combination of plugins I already have. But it's $29 and inspiring and easy to work with.
Free Streaming! 
