Midrange passive eq
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Sleeper
Well-known member
I recently researched this, because the pultec's in my mastering chain do not have a mid...
I suspect you have similar problems.
Check out Ian's EQ system - ruffrecords–
I like the helios which has a switched mid section_lot's of frequencies_ +-12db
He also has done the MEQ
But the system is cool, it's just the EQ, makeup gain is on a separate board, or you could go totally passive and just use one of your mic pre's for makeup.
I suspect you have similar problems.
Check out Ian's EQ system - ruffrecords–
I like the helios which has a switched mid section_lot's of frequencies_ +-12db
He also has done the MEQ
But the system is cool, it's just the EQ, makeup gain is on a separate board, or you could go totally passive and just use one of your mic pre's for makeup.
ruffrecords
Well-known member
Many of the passive EQs I have designed have a mid boost/cut section and it would not be too hard to build one with only this section if you wanted. All passive EQs with boost do require a gain make up amplifier of some sort.
Cheers
Ian
Cheers
Ian
Many thanks guys!
... I know the passive and peak doesn't go together, I forgot to specifie one tubed make-up added. I'm thinking to a filter LC switchable from 0.3 to 3/4 KHz...
Thank Ian, did you design this?
https://www.dropbox.com/s/1g8rt01aavot861/unipassiveEq.jpeg
@Sleeper, yes you're right....!
Thanks!
Marco
... I know the passive and peak doesn't go together, I forgot to specifie one tubed make-up added. I'm thinking to a filter LC switchable from 0.3 to 3/4 KHz... ruffrecords said:
Thank Ian, did you design this?
https://www.dropbox.com/s/1g8rt01aavot861/unipassiveEq.jpeg
@Sleeper, yes you're right....!
Thanks!
Marco
ruffrecords
Well-known member
Yes, that's one of mine. You can make just about any EQ using that PCB. Just add the gain make up of your choice.
Cheers
Ian
Cheers
Ian
ruffrecords
Well-known member
wizard60 said:Thanks again Ian!
... just to start to experiment... do you have a simple LC calculator to suggest to me? I need to check differents impedance scenario
Cheers
Marco
This should give you a basic starting point:
http://www.ianbell.ukfsn.org/EzTubeMixer/docs/EzTubeMixer/UniversalEQ/PCB/InductorCalcs.pdf
Cheers
Ian
ruffrecords
Well-known member
wizard60 said:
This document gives a broader overview of the Universal EQ:
http://www.ianbell.ukfsn.org/EzTubeMixer/docs/EzTubeMixer/UniversalEQ/PCB/UNIEQConfiguration.pdf
Cheers
Ian
Thank you again Ian... now all it's more clear to me. One more question please:
When the RCL mids are setted in boost, the variable partition is made by the pot and by VR2 (Hi-cut shelf). When we're in cut position, supposed that we dial the mids for max attenuation, the partion is made by Rfix and Rcut, but is VR2 in parallel to Rcut?
Sorry for may bad English...
Cheers
Marco
When the RCL mids are setted in boost, the variable partition is made by the pot and by VR2 (Hi-cut shelf). When we're in cut position, supposed that we dial the mids for max attenuation, the partion is made by Rfix and Rcut, but is VR2 in parallel to Rcut?
Sorry for may bad English...
Cheers
Marco
ruffrecords
Well-known member
wizard60 said:
In the cut position the basic potential divider is Rfix and VR2. However, VR6 and Rcut are connected across VR2. As VR6 is rotated clockwise, more and more of VR2 is shorted out by the RLC so we get cut. When VR6 is fully clockwise we could in theory get infinite cut. The purpose of Rcut is to limit the maximum cut to the desired value.
Cheers
Ian
