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I recently purchased a pair of ultrasonic transducers from gavial (4 ohm) for hydroacoustic work. The website offers very little information--I bought the ITC-1042 transducers (https://www.gavial.com/itc-products). Can anyone recommend appropriate amplifiers for these devices? What specifications should we be looking for, and what are the likely tradeoffs?

The intent is to use these units to transmit sounds in the realm of 50-100 kHz.

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    Can you be more specific about exactly what you've bought (perhaps with a web link) and what you want to use it for. Also, what do you mean by ultrasonic? Does that mean 20kHz, or 200kHz to you ? Jul 27 at 16:56
  • Thanks for pointing this out--I've edited for clarity. The units ship with decent calibration documentation, but no user manual or guidance of any kind. The mfgs assume I already know what I'm doing (wrong!)
    – TCS
    Aug 1 at 13:32

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As you can see from the spec, the transmission out of a hydrophone is frequency dependent – about 135dBre1uPa/V at 50kHz and 20dB higher at 100kHz (or it would be if it wasn’t rolling off above 79kHz).

Your choice of amp now depends on how loud a sound you want to generate: e.g. If you want a sound at a level of 180dBre1uPa-m at 50kHz, you’d need a voltage input of 180-135=45dBre1V. In volts that’s 10^(45/20)=178V. Developing high outputs requires specialist equipment!

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Here you can find a circuit specifically designed for piezo hydrophone amplification: https://www.analog.com/en/products/lt1792.html Changing the value of some components you can adjust the DC correction and conseguently the high pass filter. Moreover if you need an anti aliasing filter you add it after the preamplification

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    The OP is asking for amplifier for transmission and not for a pre-amplifier for reception.
    – WMXZ
    Aug 2 at 6:47

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