Filter tuning (the operation of pressing Record + Filter buttons) is supposed to yield values of 145-160. I started to notice that chip 5 (a CEM 3379) began returning values below threshold. The problem was intermittent, but when it struck, the usual “every 8th note played would drop out completely or partially” occurred. I started to notice that chip 2 (they are all CEM 3379s) started doing the same. I run the ESQ-1 OS 2.0. I ordered two replacement chips as well as a the OS 3.5 chips from syntaur. I replaced chip 5. Threshold value of chip 5 returned to 145. The value was consistent with several hours of use, but chip 2 now consistently returned a value between 100 and 130. I went in to replace it, and decided to upgrade the operating system at the same time.
Now all the filter chips (1-8) seem to have dropped a bit. From 1 to 8: 146, 136, 127, 138, 144, 137, 145, 144. Notice that the two newly replaced chips, 2 and 5, register 136 and 144.
I have seen the problem of low filter values addressed elsewhere on the internet. The solution is always to change the chips. There is no discussion of why this occurs (other than the chips are old and are failing). Obviously, something else is going on here. Does anyone have any insight on how the filter chips work (also in tandem), and what may be the root cause of this problem? Power is clean from a conditioner. I suppose I should test the rails and make sure power is steady. Sound right? Any other ideas? Seems strange that an upgrade from OS 2.0 to 3.5 would alter behavior.