Hello GM,
Thanks a lot for your very useful and interesting information.It is the first time that i hear that the first generation 604 (i guess you are refering to 604 and 604B)sounds actually better that the later one.I have indeed always struggled with the high crossover point (1500 to1600)which gives a hard job to the woofer and may be the cause of the shoutiness i have heard with some 604E i have listened to.Thanks also for advising me to read the recommendation of Jeff Marwart regarding cross over and loading caps.I contacted him and he was kind enough to answer my questions.He also recommended the GPAIII with the help of a sub.
Today,i am back to square regarding the option vintage vs GPA since i missed the 604 E opportunity.
Incidentally,my local reconer,who is supposed to be a competent one is telling me that he has low frequency cones produced by Nuway in the US which are the original Altec woofer since Nuway was producing those cones for Altec.I am not sure how to check wether this info is reliable . Any body who can comment on that with a documented information is welcome.I 'll keep you posted with the development of my project.