I've slapped three early 70s Zappa shows on a slap up blog page. All crisp SBDs (recording taken from a feed from the soundboard).
http://theproofisintheplaying.blogspot.com
El Paso 23rd May 1975
KCET Studio, Los Angeles 6th August 1974
Sydney, Australia 24th June 1973
All primo sound, I promise.
EDIT: Just added Dallas 17th October 1980 and more.
EDIT: and Santa Monica 11th December 1981
Coming Soon:
Frank Zappa - 76 - Boston Music Hall, 24th October 1976
Frank Zappa - 77 - Palladium, New York 31st October 1977
Frank Zappa - 78 - Deutschlandhalle, Berlin 15th February 1978
Frank Zappa - 79 - Manchester, United Kingdom 12 February 1979
Here is the ONLY soundboard from Zappa's truncated 88 show 1988 tour, as far as I know.
http://tinyurl.com/y4ldn7q
http://tinyurl.com/y445o2n
http://tinyurl.com/yyehkcu
http://tinyurl.com/y5r387c
Sounds superb.
1st May 1988
Johanneshovs Isstadion
Stockholm
Sweden
01. Tuning
02. Heavy Duty Judy
03. Packard Goose Medley
04. Any Kind Of Pain
05. More Trouble Every Day
06. Penguin In Bondage
07. Hot Plate Heaven At The Green Hotel
08. Cosmik Debris
09. Inca Roads
10. Advance Romance
11. Bobby Brown
12. Keep It Greasey
13. The Torture Never Stops Medley
14. Big Swifty w/ Mats & Morgan
15. Joe's Garage
16. Why Does It Hurt When I Pee?
17. Peaches En Regalia
18. Stairway To Heaven
19. Whippin' Post
20. I Am The Walrus
21. Loops Jam
22. Sofa