Spin Semiconductor

hi
we design an amp that uses fv1 chip. we bought and use old series of fv1 and i can say those chips works perfectly. but now we use a new series of that with serial no 836 and 948. we have a problem with that. in delay effect after a 3 delay a tik sound appear on sound like you switch the mic and the tik sound delayed with original sound...???

in our design we use external oscillator instead crystal made by 74hc14..

this problem just appears in new series but old series works perfectly..
what should i do?

0836 and 0948 are very old chips, they are 6 to 7 years old. They may not have been stored properly or they may have been failures that someone is selling so you should contact the person you got them from.