Hello my mates,
Since I have this bugger, Im wondering about both "Decay" functions of the Filter section: Positioning the sliders in the middle "5" and anywhere above there is no function any more, and very close up to "5" "Decay is not to perceive for a longer time and then drops suddenly. Very weird to me. Is this normal ? My tech and I were wondering about this and guess if there must be a logarithmic slider instead of linear placed there ???
The “Decay” function of “Loudness Contour” can be set for very long Decays and all works as it looks like properly.
Does anybody know about this or has any idea ?
Maybe R70 simply needs recalibrating ? (max attack & delay times trimpot in the filter contour section)
Tank you for the hint, I`m going to take a look at.
Well, to take a look first on the R70 was a good idea, but obviously its not the culprit. First after marking, I turned the pot to and fro, and as my tech confirmed later this pot has only a very slight influence and doesnt alter pretty much. We also measured the impedance and its o.k., also all three printed circuits that are connected with. My tech approved finally the Contour Generator as a whole does work properly and its not allowed that the upper third of the Filter “Attack” and “Decay” is dead, as after simulating the whole section on the computer it has been shown up clearly a function in that area.
We`re still weird about that thing, and after simulating the voltages my tech will do the same with the “time” to find out probably some more after.
We checked also the “Amount” and found out when Cutoff has been placed on “zero” there`s a very slight Filter opening and closing to perceive when moving the “Amount” up and down, but this has nothing to do with the upper problem and can be set and fixed by a different trim pot in the Filter section.
In the simulation and of course confirmed by myself physically my tech discovered a dead zone in the beginnig of the first third at the bottom of the “Attack” and “Decay” slider and function. This is obviously a normal construction behaviour but can be fixed ,as he said, and improved significantly by swapping two silizium diodes into germanium ones on the PCB below the right panel board. This will make that dead zone “appearingly” and probably make the Filter Countour more snappy. But this is an assumption and has to be experienced.
But that thing with the upper dead zone makes us still wondering and getting stuck…