Файл: Eventide_H8000FW_UM.pdf

Clear Setup

At the factory, all of the adjustable parameters in the H8000FW are set to nominal values called "factory defaults." To return these parameters to their "factory defaults," go to the

service menu page in the SETUP area. The parameters affected include:

everything in the BYPASS area.

everything in the LEVELS area.

everything in the SETUP area.

Highlight clear setup and press the SELECT key. Pressing the <yes> SOFT KEY will replace current parameter values with the "factory defaults." Unless you saved your setup before

pressing <yes>, it will disintegrate into digital dust (see Storing and Loading Setups on page 137). Press the <no> SOFT KEY to abort. If the H8000FW ever gets "buggy," try using clear setup before you do anything more "drastic."

Alternatively, you can clear the internal setup by holding down the SETUP key during startup.

-> See Start-Up Options on page 152.

If the system detects that a new version of software has been installed, it will ask you if you wish to perform a clear setup - you should almost always answer yes, as the old setup may not be compatible with the new software.

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Software Version and Accessories

The H8000FW has expansion and upgrade capabilities. "Information" menu pages allow you to keep track of what options are inside an H8000FW without having to open the box. To

access the "information" menu pages, go to the service menu page in the SETUP area.

Highlight information and press the SELECT key to get a screen that looks something like the screen to the right.

The <more> SOFT KEY reveals additional information pertaining to the current page. The

returns from the additional

The <next> SOFT KEY advances to the next menu page, <last> returns to the previous menu page, and <exit> returns to the service menu page in the SETUP area.

One important piece of information to be found in this area is your H8000FW's Electronic Serial Number, which is the first 8 digits of the Hardware ID number on the screen to the

right. You may be asked for this by a dealer or an Eventide representative. The Time/Date figures are not currently used, so their values are unimportant. The Hours total/power refer to the total number of hours that have elapsed since the unit was built (1248 in this case), and the total number of hours the unit has been powered (206 in this case). A brand-new unit may show as many as 300 powered-up hours to cover burn-in and factory testing.

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A p p e n d i x B - U s i n g t h e H 8 0 0 0 F W w i t h a c o m p u t e r

This section of this manual covers use of the H8000FW with a PC or a Macintosh.

If you don’t plan to use your H8000FW with a computer you don’t need to read it unless interested. We apologize to those readers already familiar with the following subject matter.

Before the H8000FW can be used to connect to a PC or Mac, suitable device driver software must be installed as described in the following chapters. The necessary software will be found on the included “H8000FW Drivers” CD. The purpose of these drivers is to tell the computer about the H8000FW and how to talk to it.

From time to time the drivers will be upgraded and new ones available at www.eventide.com. These are currently available to registered owners only, so be sure to send in the enclosed registration card.

You should also be aware that in many cases new drivers must be installed in tandem with associated new H8000FW software so be sure to read all relevant release notes before installing updates.

The H8000FW can be set as a sound device on any PC running Windows XP (service pack 2 or later is recommended) or any Mac running OSX 10.4 or later. For serious multichannel use a fast computer will be necessary, such as a 2.4GHz or faster PC or a G5 Mac or better.

The H8000FW can be used with any application that supports Core Audio, ASIO or WDM devices. This will usually be a DAW application such as Logic, ProTools, Cubase or Nuendo. An example of the use of the H8000FW with Logic is provided later in this document but otherwise, questions about the operation and configuration of these applications should be referred to their manufacturer’s support personnel. Eventide is not able to provide such support for non-Eventide applications.

There a few general issues that will apply to the use of the H8000FW with any workstation application or computer. Among these are:

Making connections between the H8000FW and the computer.

Setting the sample rate and buffer size for the system.

Synchronizing connected audio devices.

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Making connections between the H8000FW and the computer.

All recent Macs and many PCs support FireWire. Those PCs that do not support FireWire can usually be upgraded with an inexpensive plug-in card.

The H8000FW is connected to the computer using an IEEE1394A FireWire cable which is widely available from computer stores and typically ranges in length between 3 and 15 feet. Cables longer than 15 feet (4.5m) are not supported by FireWire without the use of special adaptors. This cable can be connected to either FireWire connector on the H8000FW, allowing the other one to connect to a following FireWire device if desired.

While FireWire is designed to be hot-pluggable (meaning that it can be connected to powered-on systems), Eventide recommends that where possible it be connected between units when their power is switched off. The reason for this is to avoid certain rare conditions which can damage the unit being connected.

Setting the sample rate and buffer size for the system

A number of settings can be made that affect the performance of your system. The first of these is sample rate, which is the rate at which the audio is converted from the analog world to discrete digital values (or the other way around). This is usually expressed in kHz or samples per second.

The sample rate is normally defined by the computer operating system or by the workstation application and can be set from a menu or dialog box. See the manual for your application to find out how to change the sample rate. You should not change the sample rate directly from the H8000FW when it is connected to the computer as this can cause problems for some applications – change it on the computer and the computer will automatically change the H8000FW setting where necessary. Higher sample rates give better audio performance but use more disk space for recording and place heavier demands upon the computer.

The buffer size setting determines the latency of the system. Latency in this context is a measure of the delay introduced by sending audio to and from a computer and an external device such as the H8000FW.

To help explain this, an analogy may be helpful. Picture a large pile of coal representing the digital information stored in the computer. Each piece is one digital value. The job here is to fill buckets (the buffers) with coal from the pile, and pass them to a colleague who then empties them into a chute leading to the outside world. The chute must be kept

partially full but not allowed to overflow. The chute may be thought of as the feed to an 156

external digital to analog converter feeding a speaker, while the passing of the buckets represents the FireWire connection.

So, if the chute becomes empty the speaker will pop or click, while if it overflows things may get in the wrong order. It also takes time for any given piece of coal to get from the pile to the chute, as the buckets have to be filled and emptied before this can happen. This time is the latency mentioned above.

It will be apparent that the size of the buckets directly affects the latency, as smaller buckets can be filled and emptied more quickly. But, to avoid the chute becoming empty (bad!), they will have to be passed more quickly, which may be tiring. So, there is probably an optimum size for these buckets, to provide a good compromise between the latency on one side, and the energy requirement (computer power) needed to pass them.

Enough of coal for now. The latency is usually almost directly proportional to the buffer size, but the use of small buffers requires more computer power. The default setting is usually a good compromise, but if low latency is important and you have a fast computer it may pay to reduce it.

Some simple math for those so inclined: if you are running at 48kHz, a 1024 sample buffer will introduce a latency in the order of 1024/48000 seconds, or 21mS (milliseconds). So, to send and return to a FireWire device will take 42mS, which is noticeable. Those systems that offer delay compensation can resolve the problem painlessly, but otherwise the use of smaller buffers is worth considering.

Synchronizing connected audio devices

For audio purposes, a computer can be thought of as a device that shuffles processed data between its disk drives, memory and peripherals. As such, it neither has nor needs the concept of a sample rate (except for calculating delays or filters and such-like). This concept only becomes necessary when it is necessary to output audio to or from the outside world, in which case it is set by the hardware conversion devices.

Things become more complex when you have more than one device that cares about the sample rate because if a device gets data at the wrong sample rate it will have to drop samples or insert extra samples to keep up. This will cause clicks or distortion, depending on its severity. To avoid this, we allow one device, known henceforth as the clock master, to define the sample rate and any other devices have to follow its lead.

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