“Radio pushbutton” controls G, H, I, and J determine the record source. Only one button on at a time is allowed. It may seem strange that button J will set the record source to Line Out. This is done to allow the use of attenuators C, D, or E to control the record level. Using Line Out as the record source will also allow you to record a mix of all 3 input sources if desired. Note that if buttons G, H, or I are used to select the record source, Sliders C, D, or E will NOT control the record level. In order to use these sliders, the record source must be set to Line Out, (button J On). When doing this, be sure Slider K is all the way down. Otherwise, there will be a feedback path which will cause undesirable re- sults. The disadvantage of using Line Out as the record source is that you will no longer be able to directly monitor the recording. You will still hear the source material you are recording on the Line Out, however this is before the actual recording has been done. What you are hearing has not gone through the A/D and D/A. So, if you have set the recording level too high, and the A/D is distorting, what you hear on the Line Out may sound fine. To monitor the actual recording, it is necessary to select the record source using buttons G, H, or I and set the record level with an external device before the signal gets to the Antex Card. The actual recorded signal will then be available using the Play 1 Slider, K. (Note that direct monitoring does not operate for MPEG format with sample rates greater than 32 KHz.)
Play 1 and Play 2 Sliders, K, and L control the level of the files being played back. Note that these sliders operate in the digital domain. They amount to multiplication routines in the DSP which take the signal level and multiply it by a scaling factor between 0 and 1. This is important to note because using these sliders as a master volume control will degrade the signal to noise ratio. This is because using these controls lowers the signal levels while leaving the noise floor unchanged. These controls are intended to mix 2 playback files together, or to fade a file up or down at the beginning or end, not as a master volume control. Best signal to noise ratio will be achieved by setting Sliders K or L to maximum and controlling the volume using the master volume control on the external amplifier or mixing board the Antex Card is connected to. Set the Trim Control (B) to +8 rather than setting Sliders K or L
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