An extended Amiga 1200 may have multiple audio devices at its disposal. For instance, an Amiga may have:

• a sound card:
  • a Creative SoundBlaster Card via a Mediator board,
  • a clockport Delfina card,
• a "music card", such as the Prisma Megamix,
• the default Paula audio output via the RCA jacks.

Multiple recommendations stand, for example, the Prisma Megamix creators advise routing Paula through the Prisma Megamix line-in and then using the Prisma Megamix backplate to connect to speakers. On the other hand, if the Amiga has a Mediator board with an audio card, then it is probably more desirable to route everything through the audio card.

The main reason for routing everything through the PCI sound card given a Mediator board is that PCI soundcards for the Mediator benefit from AHI whereas the Prisma Megamix does not yet have an AHI driver - tersely, the Prisma Megamix is said to be a "music card" and not really a sound card because it is meant to be used as a decoder/encoder for various formats.

The following hardware is assumed:

• SoundBlaster 128 4.1 PCI mediator card (1),
• Amiga with RCA outputs (2),
• Prisma Megamix (3),
• CDROM (4)

                                                      +---------+
                   +-+---------------------------+    |       +-|--------------------------------
                   | |  (1)                      |    |       | |  CON300 
       \           +-+       SoundBlaster 128    |    |       +-|+
Amiga   +----------|*|            4.1            |    |       |**|       Prisma Megamix
 RCA   /           | |                           |    |       |**---+         (3)
 (2)               |*|           TEL  CD   AUX   |    |       |..|  |
        +----------|*|           **** **** ****  |    |       |  |  |
        |          +-+-----------||||-||||-||||--+    |       .  .  |
        |                              +   |  +-------+             |
        |                              |   +------------------------+
        |                              |
        v To Speakers                  +----< From CDROM (4)

The following cables are needed to connect everything to the sound card:

• The Amiga is connected to the sound card with a stereo to Y RCA cable,
• A 4 pin CD audio cable runs from the CDROM the CD input on the soundcard connector,
• Two wires run from the upper left-most pin from the CON300 connector to the AUX in of the soundcard.

Given this setup it is possible to manage all sound sources via AHI. It is important to note that the pins right below the connected pins on the Prisma Megamix are labelled as ground but it is the developer's recommendation to not connect ground to those pins (ie: the ground from the AUX port).

From Michael Boehmer, the following information is available on the Prisma Megamix connectors:

Some ASCII art first (pin header on right side of PRISMA, CON300):

 EXTIL oo GND
 EXTIR oo GND
   LIL oo GND
   LIR oo GND
   LOL oo GND
   LOR oo GND
  EARL oo EARGND
  EARR oo EARGND

EXTIL/R will only work if the jumper block (3x2) next to the pinheader is set correctly. The SPDIF module sets this pins correctly (it fits on the 3x2 jumper block). In SPDIF operation EXTIL changed to SPDIF_IN, EXTIR to SPDIF_OUT, and the CD sound input connector CON304 will be active.

LIL/R are line in (usually Paula).

/R are line out

EARL/R are ear phone, BUT TAKE CARE: EARGND MUST NEVER BE CONNECTED TO GND! EARGND is a floating virtual GND, and must stay floating (only connect to earphones). The VS1063 protects this GND, but I would not rely on that.

3x2 pinheader (CON301):

   ooo
   ooo

Jumper (++ or ##) set like that

   ++o
   ##o

mean: use CD pin header on top of card

   o++
   o##

mean: use EXTIL/R

Using a mixer, such as GhostMix and quite intuitively, the Prisma Megamix output will be controlled through the AUX channel, CD audio will be controlled through the CD channel and Paula will be controlled through the sound card's Line-In. One consequence is that when playing WHDLoad games, Paula sound output will be passed through Line-In to the soundcard without having to re-cable anything. Similarly, using AmigaAMP to play MP3s or other sound files will be passed through AUX…