I just want to mod this channel to give me roughly an 80 to 150hz response, peaking around 100hz.
I'm not that adept at doing calculations concerning op amps when it comes to filters like these.
I was for decades a service tech, so much of that was not doing this type of thing.
I thought that some simple parts changes would be in order, but so far the comments I've gotten makes me more confused.
I'll wait until someone wants to spend a few moments to give me some definite info, since as I originally mentioned in Post #1 that I don't want guessing. (or arguing)
To service/mod this board is a pain in itself, so I don't want to have to dig it out more than once from the equipment.
I'm not that adept at doing calculations concerning op amps when it comes to filters like these.
I was for decades a service tech, so much of that was not doing this type of thing.
I thought that some simple parts changes would be in order, but so far the comments I've gotten makes me more confused.
I'll wait until someone wants to spend a few moments to give me some definite info, since as I originally mentioned in Post #1 that I don't want guessing. (or arguing)
To service/mod this board is a pain in itself, so I don't want to have to dig it out more than once from the equipment.
C1 , C2 could be
100n for 150 Hz
180n for 80 Hz
470n output coupling cap and 100k
form 3.38 Hz Highpass so is non issue
100n for 150 Hz
180n for 80 Hz
470n output coupling cap and 100k
form 3.38 Hz Highpass so is non issue
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The 100K is behind the doubler, meaning its apparent value is ~halved, but more importantly, the doubler is also loaded by the triac or SCR gate, which is low-impedance and heavily non-linear
Now that was easy, right?
So my initial, previous mod that didn't seem to work was actually close to what I wanted.
I guess that that bass leg of the organ's filters will require a bit more drive then.