Hello to everyone at Doepfer’s,

I have a two-voice system in which I use two A-141-1 modules as amplitude envelope generators to drive the final VCAs (second generation A-131s).

Some time ago I discovered that the envelope curves seem to be a little different from one A-141-1 to the other. When connected to the same A-131, it appears that one of the two A-141-1 is definitely a little “sluggish” compared to the other one.

I was curious to see if there could be differences in their circuits and/or if I could find trimmers to adjust the curves, so I took the A-141-1 modules out of the rack and had a look at the boards.

There I noticed that the IC at the upper right of each main board was not the same for the two modules. The first module has an ST HCF4052BE while the second one has a TI CD4052BE.

Also there are two added resistors on the soldering side of the second module’s main board.

Could these differences be the reason why the two modules have a slightly different behaviour And if so, do you think that I could get the same curves from the two modules by changing the second module’s IC with an ST HCF4052BE and removing the two added resistors