i´m new to this forum, if it is useful, i share a schematic from the ken smith middle moduledavidmochen wrote: ↑30 Jul 2021, 20:47 Hi guys,
Been checking the posts in this thread in search of a reply for a question I have. Please see schem below:
It strikes me that this configuration has been used in many types of EQ (particularly mid bands), from 3-band HAZ to Gallien Krueger RBs. Please see the similar-looking mids section schematic of the 3-band HAZ below:
However, I can see that for R9 and R10 in the top circuit (270K), for instance, the HAZ has 1M. Same for R3 and R4 (2.0K) vs. 20 K for the HAZ.
Finally, the relationship between caps (2n2 for both caps in HAZ, 33n and 3n3 for the other circuit) is completely different.
My question is, is there any calculator readily available for checking the differences in this topology? Does a specific value of matched resistor influences in, say, the total Q? Does the relationship between caps influence on Q as well? Do R3 and R4 in the top circuit limit the boost/cut for the EQ?
I take it all these parameters interact, so that is why I am curious about a calculator or, at least, some explanation behind the different approaches taken in the examples above.
Thanks very much in advance!
David
i copied from a 90´s haz/smith board, it works!!