The Turtle Beach Multisound Pinnacle and Fiji soundcards were designed during 
1995 to 1996 to be the ultimate PC audio devices of their time. They are based
on a Motorola 56002 Digital Signal Processing chip that does its internal 
processing at an internal resolution of 56 bits, with 24-bit input and output
capabilities at up to 48kHz sampling rate. 

That is impressive, even by today's standards.  It is interesting to note 
that the Multisound Pinnacle and Fiji soundcards were capable of saving 
and playing back audio data in 24-bit resolution years before there was 
a Windows audio program capable of doing this! 

Now that there are several Windows audio editing programs that can record 
and play 24-bit audio, it seemed like a good idea to test whether or not the
Pinnacle/Fiji Digital I/O was capable of sending/receiving 24-bit audio data.
The answer is YES it can (sort of).  

There is one caveat:
The original Sony/Philips specification for the S/PDIF audio data transfer 
format called for a maximum transfer depth of 20-bit data with the additional
4 bits reserved for ASCII control data (meant to be used for SCMS copy 
protection). 

It is possible to make a 24-bit S/PDIF interface, but there is no
industry-wide standard for accomplishing this.  So technically speaking, 
you can't record  true 24-bit audio with a Pinnacle or Fiji, but you 
absolutely can play back a 24-bit audio file produced on a 24-bit capable 
workstation.

The Pinnacle and Fiji can record a 24-bit file, but it will actually be a
20-bit file 'padded' with 0 bits (meaningless 'off' bits).  The reason 
this is still a good thing, is that you can edit and monitor in your favorite
24-bit audio editor using a Pinnacle or Fiji, and reap the benefits of only 
dithering down the final master to 16-bits ONCE, at the very end of your 
editing sessions. You can always save in 24-bit and keep the noise floor 
nice and low (much quieter than 'CD Quality') 'til the very end.  

For more advanced information on digital audio concepts, visit Bob Katz's 
excellent website at http://www.digido.com.  Mr. Katz is a renowned 
mastering engineer who runs Digital Domain and has engineered many sessions
for Chesky Records, an audiophile jazz and classical label.  
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Here's how we tested the Pinnacle/Fiji S/PDIF: 

We set up two Pentium 133 PCs running Windows 98, one equipped with a Fiji 
Rev C with Digital I/O installed, the other equipped with a Pinnacle Rev F 
with Digital I/O installed. 

1. We connected the S/PDIF Out of the Pinnacle in PC#1 to the 
   S/PDIF In of the Fiji in PC#2. 

2. We set the audio settings in a 24-bit capable audio editor to 
   default to 24-bit 44.1 kHz on both PCs. 

3. On PC#1 with the Pinnacle installed, we recorded a stereo, 
   24-bit 44.1 kHz Wave file in the audio editor. We made sure to record 
   4 seconds of silence at the beginning of the Wave file to give the two 
   machines enough 'pre-roll' time to synchronize their digital clocks. 

4. On PC#2 with the Fiji, we set the audio editor to record-ready
   (Monitor Input). 

5. We selected the S/PDIF Input as the recording input on PC#2 (Fiji), 
   in the PC Mixer.  On PC#1 (Pinnacle) we played a section of the recorded
   24-bit Wave file and checked the level meters to make sure that the audio
   data was being received on PC#2 (Fiji). 

6. We rewound to the beginning of the file, started recording in the audio 
   editor on PC#2 (Fiji) and started playback of the 24-bit Wave file 
   on PC#1 (Pinnacle).  

7. We saved the new copy of the 24-bit Wave file on PC#2.  To make sure that 
   it was indeed a 24-bit Wave file, we opened the file in Turtle Beach Wave 
   SE II, which could not open the file (Wave SE can't read 24-bit files) but
   did report that the file format was indeed 24-bit 44.1 kHz sampling rate.
   To make doubly sure, we opened the file in yet another 24-bit capable audio
   program, and yes, it was indeed a 24-bit audio file! 

So there you have it: you lucky Multisound Pinnacle and Fiji owners
have a true 24-bit internal soundcard with 20-bit S/PDIF I/O, without
any required upgrades.  Enjoy! 


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