ISI-HMAPRE-1

Headphones with Built-in Preamp and Microphones

This portable headphone assembly has a built-in preamp, which utilizes itsif you care to plug a different set of mics in, to utilize the preamp. This defeats the built-in mics

This assembly uses lightweight Sony Walkman-style headphones to house the built-in mics and preamp. The cabling is 4 feet in length, and terminated with a high quality, gold-plated, stereo mini connector. This device uses high quality built-in mics available with either omni-directional or uni-directional (cardioid) microphone elements. One microphone element is mounted within each earpiece on the headphones using the earpads as windscreens, thereby covering the microphone elements, as well as the build-in power switch. Note: These headphones are equipped with a preamp and mic elements – NOT the actual speakers for listening as with standard headphones.

Level control
This allows you to conveniently control the output level with a knob discreetly mounted to the earpiece. This is extremely useful when using MiniDisc or other recorders that do not allow level adjustment while recording (most SONY MD recorders), or when using MiniDisc recorders that do not have microphone sensitivity settings (some SONY MD recorders). This feature adjusts the output of the microphone signal passing through the module, before going to the recorder, which will be reflected in your recorder’s level meters. Note: the level control is designed to be used with the line input for on the fly adjustment.

Features:

Preamplifier Specifications:

- Low noise stereo preamp

- Signal to noise ratio: 115 dBu EIN unweighted

- Harmonic distortion: 0.06%

- 106dB dynamic range

- 3 amplifier gain ranges for maximum flexibility:

- 0dB gain for recording loud sounds (loud rock concerts, etc)

- 29dB gain for recording medium sounds (acoustic music, lectures, meetings, rehearsals, etc)

- 50dB gain for recording quiet sounds (nature sounds, distant talking, soft spoken people, etc)

- Frequency response: 20 to 20khz +/- 1dB - EMI input protection

- High output drive-capable of providing 1.5V RMS into a 10K load

- Compatible with all MiniDisc, DAT, MP3, VHS, Camcorder and Cassette recorders with line inputs

- Battery reverse-polarity protection

- Runs approximately 15-20 hours on three coin cell batteries

Microphones to choose from and Specifications:

Standard Low Sensitivity Omni-Directional:

- Signal To Noise Ratio: >58 dB, 1 kHz at 1 Pa - Dynamic Range: 76dB without battery module, 91dB with battery module - Frequency Response: 20 - 20,000 Hz - Open Circuit Sensitivity: -42 dB (5.6 mV) re 1V at 1 Pa - Maximum Input Sound Level: 105 dB SPL, 1 kHz at 1% T.H.D. (120dB with battery module)

Standard High Sensitivity Omni-Directional (+7 dB):

- Signal To Noise Ratio: >62 dB, 1 kHz at 1 Pa - Dynamic Range: 80dB without battery module, 95dB with battery module - Frequency Response: 20 - 20,000 Hz - Open Circuit Sensitivity: -35 dB (5.6 mV) re 1V at 1 Pa - Maximum Input Sound Level: 105 dB SPL, 1 kHz at 1% T.H.D. (120dB with battery module)

Standard Cardioid (Uni-Directional):

- Signal To Noise Ratio: >58 dB, 1 kHz at 1 Pa - Dynamic Range: 76dB without battery module, 91dB with battery module - Frequency Response: 80- 18,000 Hz - Open Circuit Sensitivity: -51 dB (5.6 mV) re 1V at 1 Pa - Maximum Input Sound Level: 105 dB SPL, 1 kHz at 1% T.H.D. (120dB with battery module)

Deluxe Cardioid (Uni-Directional):

- Signal To Noise Ratio: >58 dB, 1 kHz at 1 Pa - Dynamic Range: 76dB without battery module, 91dB with battery module - Frequency Response: 50 - 20,000 Hz - Open Circuit Sensitivity: -45 dB (5.6 mV) re 1V at 1 Pa - Maximum Input Sound Level: 105 dB SPL, 1 kHz at 1% T.H.D. (120dB when powered by our battery module)