HiFi Passive Audio Stereo Loudness Contour Controller Equal Volume Control Box FV1

This FV1 Equal Loudness Volume Controller box boosts the high and low frequencies at low volume levels, so that the loudness ratios of the low, mid, and high sections remain the same as at low, mid, and high volume levels. It doesn't need power supply. Cautions: (1) Signal attenuation and gain balance FV1 passive equal loudness circuit usually realizes frequency compensation through the RC network (resistor-capacitor combination), which may cause slight attenuation to the original signal. Solution: Increase the amplifier output volume appropriately, but please avoid amplifier overload or distortion. (2) Impedance matching Please ensure impedance matching between the controller, amplifier, and speakers. And adjust compensation strength based on volume level manually. This FV1 box needs to be matched to the impedance of your front-end and rear-end equipment (amplifiers, speakers), otherwise, it may result in: Reduced signal transmission efficiency: high-frequency loss, dynamic compression Overheating or damage to the device (especially with extreme impedance mismatches (3) Audio source quality requirements The FV1 Loudness Volume Controller box will amplify the source defects (for example recording background noise or compression distortion). Suggestion: high-bitrate lossless audio sources (such as FLAC, WAV), and avoid low-quality MP3 files. Avoid signal chain interference by using shielded cables.

• 1. This is a passive equal loudness volume controller, the circuit design uses an RC network (resistor-capacitor combination) to realize the frequency compensation, and improves the listening experience at low volume through the compensation of low frequency and high frequency.
• 2. Applications: When the volume is at a lower level (such as listening to music or watching TV at night), turning on the equal loudness function can improve the hearing. Commonly used in analog systems such as home theaters, HiFi audio, car audio or headphone amplifiers, old amplifiers, vinyl phonographs, and passive crossover speakers. (Use with caution: Digital audio sources (such as DAC and digital amplifiers) may have abnormal compensation effects due to signal level differences)
• 3.FV1 uses high-quality resistors and capacitors, and also the ALPS RK27 100K Potentiometer. (Note: Ensure impedance matching between the controller, amplifier, and speakers and manually adjust compensation strength based on volume level)
• 4.Correct connection way: Audio source→ FV1 loudness controller → amplifier → speaker (Note: Passive equal loudness can amplify the defects of audio sources (like recording background noise or compression distortion). So the audio source requires high quality. It is recommended to prioritize the use of high bit rate lossless audio sources (such as FLAC and WAV). Avoid low quality MP3 files. And use shielded cables to avoid the signal chain interference.)
• 5.This FV1 is designed with A/B two audio inputs, and 1 output, which can be easily switched through the left AB switch on the front panel, so it can also be used as an audio switcher.