Yamaha i88x About connections with external devices when using the i88X with a computer

English

About connections with external devices when using the i88X with a computer

When using audio devices, musical instruments and computers at the same time, there is bound to

be some noise in the system, the amount of which depends on the connections. Knowing how to

minimize noise is extremely important when designing and setting up a studio.

As advanced as the i88X is, it too is susceptible to noise. Various types of noise may be generated

and recorded to your audio sequencer, depending on the power sources/grounding scheme and

how the various devices are connected.

There is no ideal way to completely eliminate such noise. However, one can decrease noise by iso-

lating the cause and applying a suitable remedy. Below are a couple of examples that may apply.

•High-pitched buzzing or whirring operation noise in the computer

This is caused by operation noise of the computer leaking to other devices through the mLAN

cable or audio cable, and may be caused by improper grounding of the power source.

•Low humming noise

Noise of this type is generally due to improper grounding of the power source.

The noise may differ depending on the circumstances (speciﬁcations of each device and loca-

tions of use).

If problems like these happen, try the following measures to minimize the noise.

If the noise disappears when turning down the volume of the i88X and/or if the noise persists

even when disconnecting the mLAN cable or turning off the computer, other reasons for the

noise are likely. Refer to the Troubleshooting section in the Owner’s Manual.

1. Use balanced cable connections when connecting analog audio.

By using proper balanced connections, you can minimize the noise.

This may have no effect depending on the speciﬁcations of the connected device.

■Recommended Cables

i88X Inputs

i88X Outputs

2. Insert a conventional direct box (passive, with transformer and ground lift switch) for con-

necting the audio (analog) cable.

You may want to use several direct boxes when connecting multiple devices.

Example:

OUTPUT 1/2 of i88X – [direct box] – powered speaker

Synthesizer – [direct box] – i88X

3. Changing the power source for each device.

Attempting this remedy is extremely dangerous and may result in electric shock. It should be done only by

qualiﬁed, experienced personnel. Contact your nearest Yamaha representative or an authorized distribu-

tor (see the last page of the Owner’s Manual).

Outputs of connected devices / i88X inputs (balanced) i88X inputs

Balanced

(mixer, mic preamp, etc.)

TRS 1/4" phone / XLR ↔ TRS phone / XLR balanced cable Ch. 1-2

TRS 1/4" phone / XLR ↔ TRS phone balanced cable Ch. 3-8

Unbalanced

(MIDI tone generator, etc.)

Unbalanced 1/4" phone ↔ TRS phone / XLR balanced cable Ch. 1-2

Unbalanced 1/4" phone ↔ TRS phone balanced cable Ch. 3-8

i88X outputs (OUTPUT1-OUTPUT8) / Inputs of connected devices (balanced) —

Balanced Balanced TRS 1/4" phone ↔ TRS phone / XLR balanced cable —

NOTE

WARNING