Cloud Z8II Instrukcja instalacji i obsługi - Strona 16

Przeglądaj online lub pobierz pdf Instrukcja instalacji i obsługi dla Mikser muzyczny Cloud Z8II. Cloud Z8II 18 stron. Venue mixer

& Z8

: Installation and User Guide

Solving problems

26.1

Despite your best efforts, if the completed sound system 'hums' you probably have a 'ground

loop'; the offending signal source can be found by setting the volume control to minimum

then disconnecting the input leads (both left & right channels) on each line input until the

'hum' disappears. This problem is often caused by terminating a screened input cable into a

signal source positioned a significant distance from the mixer. A good way of avoiding this

potential problem is to use signal sources (CD players and the like) that are double insulated

with no connection to the mains supply earth. If a signal feed were derived from a second

mixer (a club or microphone mixer for example) it would be perfectly normal to expect this to

be earthed; we suggest that a transformer be used to isolate the signal and prevent a noisy

loop (see section 25.2).

26.2

We recommend the use of a transformer to convert a balanced signal to an unbalanced

signal suitable for direct connection to the mixer line inputs. The transformer should be

mounted close to the Zone Mixer and the unbalanced output lead should be kept as short as

possible. Where both the source unit and destination mixer are earthed, it is important to

isolate the primary and secondary windings to avoid a potential ground loop; if there is any

doubt about this, we suggest that the balanced cable screen is not connected at the

transformer end. Suitable transformers for this application are the RS Components 210-6447

(primary & secondary series connected) and we recommend the fitting of the screening can

(part number 210-6469); Canford Audio supply a similar transformer OEP Z1604 but we

suggest that these should be fitted in a screened housing. All transformers should be wired

to give a ratio of 1:1.

30/05/03 V8