5v333
Well-known member
thought i give some update on my eq plannings. i have been checking alot of different datasheets on cores, wiring diagrams, various threads about winding inductors. and i hope i make some ordering on all meterial soon.
reading some posts on the forum it seems that to high AL can cause early satuaration and that sounds a bit scary in my head. however, the db fall in the eq might keep the inductors far away from saturation with higher AL.
anyway, looking at cores, large enough to have enough turns with not to thin wire at moderate Al values, is not so easy it seems.
the largest inductors in the eq are the hard once to achieve under such demands.
cores with less AL have tighter tolerance and sounds like a good thing for a stereo unit.
also cores with a tightening screw, or at least a hole for a screw and a nut, sounds like a neet thing for trimming the eq in he last stage. i was looking at the rm cores, the rm12/rm14 was bigger and would be good to house 1140 turns @ 630AL for the 820mH inductor but they dont have any hole so thoose plans went down the drain...
the rm10 has got threaded holes and screw but they are juuuuuust about to small for making the 67DCR requirement...
this NYD EQ is a demanding one
so right know the only core big enough with atleast a hole and not to high AL is a PM50 core. its a whooping 50mm in diameter, N27 material core. it will cost, with bobbin, about 18euro each. thoose are made for making power transformers. doesnt that have a nice ring to it?
i think the mid and high inductors ill use rm10 and perhaps rm7 cores. thoose are much much cheaper.
reading some posts on the forum it seems that to high AL can cause early satuaration and that sounds a bit scary in my head. however, the db fall in the eq might keep the inductors far away from saturation with higher AL.
anyway, looking at cores, large enough to have enough turns with not to thin wire at moderate Al values, is not so easy it seems.
the largest inductors in the eq are the hard once to achieve under such demands.
cores with less AL have tighter tolerance and sounds like a good thing for a stereo unit.
also cores with a tightening screw, or at least a hole for a screw and a nut, sounds like a neet thing for trimming the eq in he last stage. i was looking at the rm cores, the rm12/rm14 was bigger and would be good to house 1140 turns @ 630AL for the 820mH inductor but they dont have any hole so thoose plans went down the drain...
the rm10 has got threaded holes and screw but they are juuuuuust about to small for making the 67DCR requirement...
this NYD EQ is a demanding one
so right know the only core big enough with atleast a hole and not to high AL is a PM50 core. its a whooping 50mm in diameter, N27 material core. it will cost, with bobbin, about 18euro each. thoose are made for making power transformers. doesnt that have a nice ring to it?
i think the mid and high inductors ill use rm10 and perhaps rm7 cores. thoose are much much cheaper.
