TONE CONTROL AND SUBWOOFER OUT

PT2350 is a tone control subwoofer crossover low pass filter chip utilizing CMOS technology. It features a tone control range of +10dB (50Hz, 4 kHz) and a subwoofer low pass filter of the second-order Sallen Key design. The roll-off point can be adjusted by changing the value of the external capacitor. Pin assignments and application circuits are optimized for easy PCB layout and cost-saving advantages. More: 2-channel input, 3-channel output (including 1 stereo output and subwoofer output), low total harmonic distortion (THD<0.01%, subwoofer THD<0.2%), high S/N ratio (S/N ratio <-87dB, A-weighting), least external components, adjustment of frequency response by changing the value of the external component, single power supply: 3 to 8.5 volts, available in 20 pins, DIP or SO package. If you make one stereo input device, you need 5 pcs of RCA female as listed in parts list. If you make 2 x 6 input device, you need a total quantity of 15 pcs RCA female and also 2 x 6 changeover switch. Code of J2 to J18 RCA female to PCB, straight, Hosiden, any color. SW1 2 x 6 changeover high-quality DIP rotary switch to PCB 2 x 6, Alcoswitch DRS 2-6, 3.2mm shaft.

The frequency response of the tone control unit is flat between 20 Hz and 20 kHz when treble and bass pots are in the middle. Overall gain is approximately 6 dB when treble and bass pots are in the middle. Treble and bass tone control range is approximately 10 dB (50Hz / 4 kHz) with given component values. The subwoofer cut-off frequency can be adjusted by the bass potentiometer with component values as listed above; it is as follows: bass pot in minimum (left) -3dB point, 240 Hz / -12dB 450 Hz; bass pot (middle) -3dB point 100 Hz / -12dB 200 Hz; bass pot maximum (right) -3dB point 60 Hz / -12dB 120 Hz. Distortion was <0.1% when input level was <0.3V rms. There is no balance adjustment potentiometer in this application; if balance is needed, it must be added separately in this device.

The PT2350 chip is designed to provide flexibility in audio applications, particularly in home theater systems and audio processing devices. The dual-channel input allows for stereo sound processing, while the three-channel output accommodates a standard stereo output alongside a dedicated subwoofer output, enhancing the low-frequency response for a more immersive audio experience.

The low total harmonic distortion ensures that the audio signal remains clean and true to the original source, making it suitable for high-fidelity audio applications. The high signal-to-noise ratio further contributes to the clarity of the audio output, ensuring minimal background noise during operation.

The design of the circuit allows for easy integration into various audio systems, with the possibility of adjusting the frequency response by selecting appropriate external components. This modularity enables designers to tailor the performance characteristics to meet specific application requirements.

The Sallen Key filter design implemented in the PT2350 is known for its simplicity and effectiveness in creating a low-pass filter, which is crucial for subwoofer applications. The ability to adjust the roll-off frequency by changing external capacitors allows designers to fine-tune the performance based on the specific needs of the audio system.

In terms of physical implementation, the availability of the chip in both DIP and SO packages facilitates easy incorporation into printed circuit boards (PCBs). The layout considerations provided in the documentation aid in optimizing space and ensuring efficient routing of signals, which is critical in high-performance audio applications.

Overall, the PT2350 offers a robust solution for tone control and subwoofer crossover applications, providing designers with the necessary tools to create high-quality audio systems.PT2350 is a tone control subwoofer cross-over low pass filter chip utilizing CMOS Technology. It features a tone control range of + 10dB (50Hz, 4 KHz) and subwoofer low pass filter of the second order Sallen Key Design. The roll-off point can be adjusted by changing the value of the external capacitor. Pin assignments and application circuits are optimized for easy PCB Layout and cost saving advantages.

2-Channel Input 3-Channel Output (Including 1 stereo Output and Subwoofer Output) Low Total Harmonic Distortion (THD<0.01%, Subwoofer THD<0.2%) High S/N Ratio (S/N Ratio <-87dB, A-weighting) Least External Components Adjustment of Frequency response by changing the value of the external component Single Power Supply: 3 to 8.5 Volts Available in 20 pins, DIP or SO Package if you make one stereo input device you need 5 pcs of RCA female as listed in parts list If you make 2 x 6 input device, you need total quantity of 15 pcs RCA female and also 2 x 6 changeover switch. Code of J2 to J18 RCA female to PCB, straight, Hosiden, any colour SW1 2 x 6 changeover High quality DIP rotary switch to PCB 2 x 6, Alcos witch DRS 2-6, 3.2mm saft Frequency response of tone control unit is flat between 20 Hz 20 kHz when treble and bass pots are in middle.

Overall gain is approx. 6 dB when treble and bass pots are in middle. Treble and bass tone control range is approx. 10 dB (50Hz / 4 kHz) with given component values. Subwoofer cut off frequency can be adjusted by bass potentiometer with component values as listed above it is as follows : bass pot in minimum (left) -3dB point, 240 Hz / -12dB 450 Hz, bass pot (middle) -3dB point 100 Hz /-12dB 200 Hz, bass pot maximum (right) -3dB point 60 Hz / -12dB 120 Hz. Distortion was < 0.1 % when input level was < 0.3V rms. There is no balance adjustment potentiometer in this application, if you need balance, you must add it separately in this device.

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