1. Home /
  2. Repository-circuits /
  3. The Ultimate Audio Filter

The Ultimate Audio Filter

Posted on Feb 7, 2014

This project is an extension of two projects - first is the work on adding an APF-type high-Q bandpass feature to the 2nd RX of the FT-2000. More on that project may be found by CLICKING HERE. And the second driver is the memory of the fun I had as a kid with active filters. An active audio filter is in many ways comparable to the digital variety


The Ultimate Audio Filter
Click here to download the full size of the above Circuit.

without the complexity. It has the performance and flexibility advantages without the need for specialized DSP hardware or coding implementations. There are two areas that the DSP is superior - in current rig implementations, the DSP filter is typically part of the AGC loop where a back-end AF only filter is not. In addition, the ringing performance of the DSP can be better than the analog variety at the expense of higher demands on DSP hardware. If any active filter project can be called a Beast, it`s possibly this one. Based on the Maxim MAX262 universal 4-pole switched capacitor filter (SCF) to provide the BPF function. That is followed by a pair of MAX7400 8-pole elliptical response LPF modules. These filters are adjustable for performance like cutoff frequency and (in the BPF filter case) Q. Total pole count here is 24. In addition, fixed LPFs on the input, output and amplification modules add an additional 6 poles of noise rejection roll off. 15 IC total. The design objectives were to allow for maximum flexibility of settings. The disadvantage of traditional fixed active filters are that their performance is not adjustable. Yet often times, band conditions would allow for a different Q or center frequency setting and with a fixed filter, that is not possible. The low end filtering was not considered because the 1K-mod combined with the IF shift on the 2nd RX allows for the similar steep roll-off on an adjustable...




Leave Comment

characters left:

Related Circuits

  • muRata Manufacturing Measurement-Based SMT Capacitors
    Murata Manufacturing Measurement-Based GRH Capacitors Equivalent Circuit Model Schematic Design shows the equivalent circuit model schematic design of the muRata Manufacturing Measurement-based GRH...
  • Rev Limiter Circuit
    It`s based on an LM2917 and an SCR, which has the very nice side effect of being impossible to generate any mis-timed sparks, a highly desirable attribute for high output rotary engines. When the...
  • Ladder Tutorial
    In this tutorial, I will show you how to write a very simple program. I am assuming that you have written ladder logic before, and that you have some basic familiarity with microcontrollers, but...
  • 555 Timer with a Speaker
    555 Timers are very fun to encounter and experiment with. They can be used as a timer and can be set to a certain frequency. In Part II of Electronic Project I, we created a circuit that would get...
  • SMPS circuit
    Its a simple fly back tester, I believe you can built it, i use this circuit to test all of high freq transformer like SMPS transformer or fly back, this circuit is an astable multivibrator with...
  • Purpose of SCRs in Power Factor Circuit
    I have a Power Factor Correction board that was taken from an old Sun Microsystem Spark450 power supply p/n 300-1359-xx. It has everything I need for a 650 watt inverter. The entire PFC circuit is...
  • 555 Timer To Control Motors
    I am a mechanical engineering student, and for a part of my design project I wish to use a timer as so the motor switches off about 40-50 seconds after activation. The 555 timer chip is a rectangle...
  • Circuit Diagram for a 12V LED Lamp
    What color LED it makes a difference. One LED or how many 3mm 5mm What is you power source These are vital things to answer. More info required. It does not compute! There`s them that knows and...

    • New Circuits

    .

     
    Create NOW your QR MENU for your Restaurant / Hotel / Bar / Caffe,

    Comprehensive ordering/paying features. fully personalized to suit your Business.

    Update Anytime! Easy and Simple!


    Popular Circuits

    Three-chip-ekg-simulator
    Three-chip-ekg-simulator

    Two 555s and a quad NAND-gate IC can simulate an electrocardiograph signal and a -y-wave...

    Low-power-inverter
    Low-power-inverter

    This low-power inverter uses only 9 parts and turns 10 to 16 Vdc into 60-Hz, 115-V square-wave...

    Uninterruptable-supply
    Uninterruptable-supply

    This circuit provides a continuous supply of regulated + 5 V, with automatic switch-over between...

    Sawtooth Converter
    Sawtooth Converter

    Simple function generators normally provide sinusoidal, rectangular, and triangular waveforms,...

    2N3055 and LM723 3-30 V/2.5 A Stabilized power supply
    2N3055 and LM723 3-30 V/2.5 A Stabilized power supply

    This is a very useful project for anyone working in electronics. It is a versatile power supply...

    20W Low cost Emergency Light PCB
    20W Low cost Emergency Light PCB

    Here is simple circuit of a simple emergency light that can be constructed without much pain. The...

    Commodore 64 Reset Logic
    Commodore 64 Reset Logic

    U20 is a 556 timer configured as a one shot multivibrator. The output pulse width is determined...

    Adding an Inrush Current Reducer to an Astron Linear Power Supply
    Adding an Inrush Current Reducer to an Astron Linear Power Supply

    Those of you who own large 500 watt and higher Astron linear power supplies, and even large HF...

    electronic chime
    electronic chime

    This page provided to the domain owner free by Sedo`s Domain Parking. Disclaimer: Domain owner...




    Top