Davelizer Mastering EQ

[king-rb]

....

 

[Biasrocks]

maybe someon already build this and can help me with the values?

From Dave

f=1/(2piRC)

Here's the original thread, with some suggested values.

http://recforums.prosoundweb.com/index.php/mv/msg/29585/0/0/4799/

Mark

 

[king-rb]

...

 

[Biasrocks]

thanks for the link. the frequencys swithces are finished but im still missing the values for r2, r3, c3
should i post my frequency choices here?

Those values have nothing to do with your frequency selections. It's for the opamp buffering the input stage and determines the gain of that stage. I'm assuming you'd want unity gain for that stage.

Look here for info on Opamp feedback.

http://www.ecircuitcenter.com/Circuits/opfeedback1/opfeedback1.htm

Mark

 

[SIXTYNINER]

cool project
8)

 

[king-rb]

is there a way to get the input/output symetrical with the same opamps?

 

[Biasrocks]

is there a way to get the input/output symetrical with the same opamps?

I'm assuming that this is a single band implementation, you could add additional bands, as many as you want.

It requires some sort of summing/makeup/balancing stage after it.

Study the Sontec project for how to implement this.

You could also use something like this.

http://www.thatcorp.com/1600-series_Balanced_Line_Driver_ICs.shtml

Really, the Daveilizer EQ is not a connect the dots, stuff the components and you're done kind of project.

He gives you enough to get going but you really need to understand all the parts of a functioning EQ that are required to get something like this going.

Mark

 

[Tekay]

Looks like the original uses 3 band in serie. Barry Porter design?
Low = 30, 50, 75, 125, 180, 250
Mid = 400, 600, 800, 1k25, 2k5, 5k
High = 2k, 4k, 8k, 12k, 16k, 20k
Broadband

 

[king-rb]

...

 

[duende]

Hi,

I'm planning to build this project but i have some doubts...

The first buffer opamp is needed per additional band or it's just an input buffer for the circuit ?

I don't understand the gain resistors values, is there a method to calculate this resistors ?

The junction at R19/R7/R9 is not like R21/R18/R8, is it  due to the gain "curve" ( log , rev log ?) or it's an schematic error ?

Thanks.

 

[Gold]

Looks like the original uses 3 band in serie. Barry Porter design?

It’s a Wein bridge design not an SVF.

 

[duende]

It’s a Wein bridge design not an SVF.

Hi Gold, can you you tell me more on this circuit ?

Hi,

I'm planning to build this project but i have some doubts...

The first buffer opamp is needed per additional band or it's just an input buffer for the circuit ?

I don't understand the gain resistors values, is there a method to calculate this resistors ?

The junction at R19/R7/R9 is not like R21/R18/R8, is it  due to the gain "curve" ( log , rev log ?) or it's an schematic error ?

Thanks.

 

[Gold]

Hi Gold, can you you tell me more on this circuit ?

I haven't studied it. It's a fixed bandwidth Wein Bridge EQ with the bands in series. I know Dave built it with a wide bandwidth as a general tone shaper. Not a surgical EQ.

 

[duende]

I haven't studied it. It's a fixed bandwidth Wein Bridge EQ with the bands in series. I know Dave built it with a wide bandwidth as a general tone shaper. Not a surgical EQ.

Thanks!

 

[Gold]

The only other thing I remember is him saying he used a 5532 “just to piss everyone off”

 

[pucho812]

Does anyone have this schematic?