The sound velocity dependence on temperature ,and pressure is strongly connected with basic properties of the solids. Ultrasonic measurements of the sound velocity can bring a lot of interesting information about the materials investigated. The measurements can help to build diagrams vs temperature and pressure for known objects and can approve or reject the physical assumptions for the structure of new materials. Really, the ultrasonic instrument is one of the important parts of the experimental department in most physical institutes or research laboratories. Several ultrasonic devices are exploited tens of years. They were designed on the technical basis of past years. To obtain the sound velocity, one should measure the width of the sample and time, required for the acoustic wave to reach one surface from another. Absolute velocity measurement needs precision measure of the sample width. But in many cases the relative change of the velocity under temperature or pressure change is important. It allows one to deal with samples with a more convenient instrument. Anyway, precision measurement of the propagation period is required. Because the samples for a physical experiment are typically small, the propagation time lies in the microsecond range and must be measured with nanosecond accuracy. The task is not simple and in past years designers of ultrasonic systems used several tricks. There is the feature of an acoustic wave, that it reflects from a border between two different materials and circulates in the samples body tens of thousands times until it disappears. Such feature gives excellent possibility to measure the period of several circulations and divide it on the number of circulations. Demand on accuracy significantly goes down. This method is one of the so-called strobing methods ,and is widely used in ultrasonic instruments. The device consists of a radio-frequency generator with external triggering to create the acoustic crests (bursts) periodically, a high-stability sound-frequency range generator and a precision variable delay line to measure the period of the circulation on the strobe basis, ,and a set of amplifiers, filters, oscilloscope. When prep,wing the experiment, a user first turns a frequency disk to provide resonance between generator ,and sound wave circulations in the sample, under which several crests from different reflections appear on the oscilloscope screen. The second stage is measurement itself, when the user adjusts the variable delay line to conjoin the crests. The position of the delay lines node is the Y-coordinate of the dependence, and X is a temperature or pressure, applied to the sample at the current point of the plot. Well known progress in electronics during last years stipulates a criticism to the scheme, described above and allows the design of new devices with better characteristics and lower dimensions.and weight, based on direct measurement of the propagation period instead of strobing. The article describes an acoustic measuring device, designed in the Institute for high pressure physics, for investigation of sound velocity deviation versus pressure and temperature. The system is built up of modern electronic components, analog and digital like Digital signal processor, Programmed logical device. Instead of a lot of separate devices, the system consists of a power pulse amplifier, input RF amplifier and a printed circuit board for IBM computer. All functions for the crest generation, synchronization and precise measurement of the propagation time ,are realized on single PCB. The crest generation is realized on direct digital synthesis. It eliminates the need for synchronization of the RF-generator with stable acoustic range and makes results of the measurement highly repetitive. No need in the periodic process to strobe crests -the stable quartz internal generator provides the differential accuracy of the propagation time measurement at least ten times Ifigher than in the old scheme. No need to adjust the delay line -the signals from receiving sensors are digitized at a rate up to 100 MHz with a picosecond aperture error, which gives the interpolation result of the moment, when the signal crosses zero, with better than 1 ns accuracy. The measurement can be provided in fully automated mode, but for verification and for compatibility with old notions a program displays crests and shows its displacement during a sweep of temperature or pressure.