9.9 Sound über Mic-Eingang

Mit dieser Kabelverbindung ist es möglich sich Audio per Mikrofoneingang von einer Stereoanlage zu holen. Vergessen Sie nicht die Schutzwiderstände in die Stecker einzulöten! Die 220KOhm-Widerstände können in einzelnen Fällen zu klein sein, hier muß der Wert leider durch probieren ermittelt werden. Das geht u.A auch mit einem Poti.

Poti benutzen um den entsprechenden Widerstandswert zu ermitteln. Danach das (die) Poti wieder ablöten und durch den so ermittelten Festwiderstand ersetzen.

Vergessen Sie nicht per Kontrollfeld die Empfindlichkeit des Mikrofoneinganges entsprechen einzuregeln! Meistens genügt es schon wenn der Mikrofoneingang unempfindlicher eingstellt wird.

Falcon Sound Input

Pages 21, 31 and 33 of Falcon030 Hardware Documentation

   Stereo Microphone Jack

   The effective impedance of the microphone port is:
   2.15 K Ohm,    0 Hz -     30 Hz
   1.77 K Ohm,   30 Hz - 900 KHz
   0.00   Ohm,   >900 KHz

   IMPORTANT: A 200K Ohm resistor should be used in series on each mi-
   crophone input when connected to a 1V RMS "Line" level signal (such
   as the Line Out signals from a CD Player)

Your best bet is to have the Falcon modified for line input as described below, or if you can't do that use the 200 KOhm series resistor in each live feed as an attenuator as suggested originally.

Also the 8V DC on the input for phantom powering mikes, possibly this was only on early Falcons avaiable, can be a source of trouble. They suggest the following to (mostly) overcome this and also reduce the 8V DC level from line to mic:

   Stereo amp OUT >----\/\/\/--+--------> Falcon sound in
                       ca.80K  |
                               \
                               / 1K
                               \
                               /
                               |
                              ---

You also found more details of the mods to the Falcon on Audio Area of this Archive.
Line Level' input to the mike socket on the Falcon030

The following alterations have to be made as described from atari on an seperate document:

Remove components: R56, R47, R90, R92 as well as C21 and C81
Alter existing components:

Change R66 from 100 KOhm to 15 KOhm
R87 from 100 KOhm to 15 KOhm
C129 from 0.01 uF to 330 pf +/-5%
C124 from 0.01 uF to 330 pf +/-5%

The following additional components have to be added:

Capacitor 470 pf NPO, parallel to R67
Capacitor 470 pf NPO, parallel to R88
Capacitor 330 pf NPO, parallel to R66
Capacitor 330 pf NPO, parallel to R87

Resistor 100 Ohm in series with output Pin 4 of the LM387 (Chip U9)
Resistor 100 Ohm in series with output Pin 5 of the LM387 (Chip U9)
Attention: Both pins have to be lifted off the board!

No other modification needet.