The MOTU Audio 24I/O is considered by some to be the ultimate in audio interfaces for VTPO work and it is compatible with Gigastudio, and Hauptwerk amongst others. The PCI interface card sits neatly inside the computer and has firewire style (connectors which carry "Audiowire") for connection to up to four main rack mountable units, so no other interface is required to run the 24I/O. Each unit provides 24 high quality, 24-bit/96kHz(max) analog inputs and outputs which allows control and routing to 24 simultaneous analog channels, and is ideal for use with software such as Hauptwerk, where routing to many multiple channels is built in to the sound engine. Sample rate can be controlled from software or from the front panel as can most of the other features.
With a price tag usually in excess of $1500(US) the 24I/O has far more facilities than just 24 channel throughput and is in fact a complete recording studio which stands proud with the best of the best. For VTPO it can be 'stacked' up to four units, giving a total of 96 discrete channels of audio, which should be sufficient for the needs of most VTPO builders, even at 2 channels per rank! Hauptwerk users can take great advantage of the its capabilities of routing ranks/parts of ranks, traps etc. along with ambient noises ("clunks") to individual channels to great effect, presenting a realism that has until now been unatainable, and it has been found that the Hauptwerk software and the 24I/O integrate well and cause no problems to the user, once correctly set up.
At the time of writing there are no drivers for Linux, but there is a comprehensive set of drivers for Windows XP and Vista, which are updated regularly and can be downloaded from the MOTU website. As with other MOTU products, the User Manual is written both with PC and Mac users in mind.
Warning: Always ensure that you have the correct drivers installed for the MOTU 24I/O. Stupidity of this author could account for past problems, but there has been some confusion when choosing the correct driver for Vista, especially the 64 bit version. Although the driver may appear to install correctly and audio will indeed emanate from the interface, there will likely be unpredictable results and unaccountable 'spits and farts', if the incorrect driver is installed.
The MOTU UltraLite bus-powered FireWire audio interface has 10 inputs and 14 outputs and is a viable alternative to the 24I/O where a smaller number of channels is required. However, it does require a PC with a fully functional IEE1394 (Firewire) interface, but has the advantage that it also povides a MIDI port and can be powered from the Firewire bus or from an external power supply (supplied).
Installation is straightforward. Just connect to the PC via Firewire cable, load the appropriate drivers and for those concerned about overloading their PC's power supply, connect the Ultralite to a wall outlet via the separate power module (supplied).
Warning: Ensure that you install the correct drivers for your operating system, otherwise you may get unpredictable results. At the time of writing drivers are not available for Linux. Updated drivers are available as a free download from the MOTU website.
The Ultralite comes with adequate software to adjust settings and a comprehensive manual written with both Mac and PC users in mind. It is possible to setup and test the module from the software 'console' (supplied) but despite setting a parameter allowing external software to change the sample rate, it has occasionally been found that Hauptwerk has been unable to change from 44KHz to 48KHz, but should this occur, it's quite easy to change the setting manually via the front panel controls.
A further warning: If you're using the MOTU Ultralite with Hauptwerk, don't use the MOTU's internal MIDI facility. There is a delay issue when accessing Hauptwerk menus and a possible loss of settings. This is caused by a slow handshake from the Ultralite and at the time of writing, there's no known fix for it, other than to use a separate MIDI interface, such as the excellent E-MU Xmidi 2x2 USB 2.0 which is quite happy to work alongside the Ultralite, and should cost no more than 30GBP.