User guide

MS-DMT Guide v1.04

Released 05-30-2014

NOTE: Some professional and even some lesser sound devices provide for an external clock source,

however most devices do not. Many devices can be modified without much effort for referencing the

sound device to an external frequency standard. The common 24.576Mhz (or other frequency)

reference crystal used in sound devices can be swapped out for a more accurate crystal or better yet a

TXCO reference can be soldered in place of the crystal. These practices have been used by many MARS

members and others to achieve accurate and stable sample rates, however such practices are beyond

the scope of this document.

For a more complete battery of tests of your sound device see:

http://audio.rightmark.org/index_new.shtml

This tool immediately displays sound device latency when you first click to start testing, see the

effect that moving you mouse about has on latency and why you should not do so during serial

tone modem signal reception. Then too the battery of tests will allow you to gauge your sound

devices as to Frequency Response, Noise, Distortion, THD, IMD, and more when you configure

for loop back testing.

As with all tools reading the documentation will allow you to get the most from the tool, see:

http://audio.rightmark.org/download.shtml