There seems to be an endless supply of first-class string quartets. I was introduced to the Cuarteto Casals by a recommendation of Arriaga's lovely third quartet by Marco of Primephonic Support.
Arriaga: String Quartets by Cuarteto Casals on Apple Music
In the last few days I've been listening to more by them. First Beethoven's Op 18 no 1 and no 4 and Op 59 no 1 from these albums. Marvellous music beautifully played. (I especially love the first Razumovsky; the scherzo unfailingly brings a broad smile to my face.)
Beethoven: Inventions 1 by Cuarteto Casals on Apple Music
Beethoven: Inventions 2 by Cuarteto Casals on Apple Music
And then Schubert: his great G Major quartet accompanied by a delightful early quartet D87.
Schubert: String Quartets, D. 87 & D. 887 by Cuarteto Casals on Apple Music
An abundance of riches! I’m listening to, and hugely enjoying, the Casals recording now, and will listen to the Jerusalem Quartet this evening. It’s hard for me to imagine either of these could surpass Chiaroscuro’s performance of Op 18 No.1, but I’m keeping open ears 😊
I’m much enjoying the two volumes of the Birth of the String Quartet:
https://app.idagio.com/albums/birth-of-the-string-quartet-vol-1
https://app.idagio.com/albums/birth-of-the-string-quartet-vol-2-5E04B13B-1FC7-40D6-B41E-671ADB082C54
These are such compelling performances by the Casals Quartet!
by the Casals Quartet
These albums are by yet another quartet: http://casalquartett.ch/
Thanks for the recommendation. 
These albums are by yet another quartet:
You’re right!
(How confusing - but it’s always good when a mistake turns to serendipity 😊)
I’m so glad you are on the ball with this Hugh (and apologies for accidentally hijacking the thread 😊)!
So, for clarity, there are indeed two quartets:
Cuarteto Casals (Casals Quartet) is a Spanish quartet based in Barcelona and formed in 1997. It is this group who performed Beethoven Op 18 No.1 to such accolade.
Casal Quartett (Casal Quartet) is a Swiss quartet formed in 1996. They play on a matching set of Staiger instruments, which perhaps explains their wonderfully coherent sound. And this is the group who recorded the two volumes of the Birth of the String Quartet. I’m finding these to be a fascinating survey, beautifully played, and some lovely gems previously unknown to me. It’s perhaps not an academic survey, though? (Maybe I should read the booklets before saying anything else that is incorrect 😂)
booklets
Have you found the booklets? I don't see them in Idagio.
Not yet. I was hoping to find them elsewhere on the internet, but no luck so far…
