Jack Casady has a bass balalaika that he bought in the 60s. His is not the contrabass model but still huge. He brought it out to Jorma's Fur Peace Ranch early last year and played it during one of Jorma's Quarantine Concert Series streams. It is a gorgeous sounding instrument, rich acoustic sound. Here is a youtube link, he talks about getting the instrument and the modifications Rick made to it. Then they play "Third Week in the Chelsea", Jack played his balalaika on the studio recording.
Here is an excerpt from an interview with Jack where he talks about his balalaika.
FlyGuitars Are there basses that you have liked over the years, and hung on to?
Jack Casady I would say that my most favourite instrument to pick up and hit one open A note off is a bass balalaika that I have. Rick Turner transformed it in to a four string bass from a three string bass. There's a contrabass and a bass, I have the bass balalaika and I got it in Paulo Alto in 1967, from a gentleman named Dante Perfumo. He was an Italian musician who just collected all kinds of instruments. I went down and visited him and I remember he had almost like a chicken coup garage out the back and he had all these woodwind instruments from the 1800's that were tuned before they went standard 444.
The bass is a big triangle and at the bottom is probably 40 some inches. It looks like you're playing a giant flat iron.
FlyGuitars Did you ever use it in the studio?
Jack Casady I recorded a number of songs with it with The Jefferson Airplane. I recorded 3rd week at the Chelsea on it and I even did a whole album with Canadian guys called The Good Brothers and it just has one of the most beautiful acoustic sounds. It was EAD and then I had Rick Turner narrow the nut a little bit and add on a different metal bridge so that I could convert it. It's still gorgeous to this day. I could walk over and hit that instrument, and the neck is like a tree trunk (laughs). The thickest part of the neck I think is about two inches deep.