Specifications

Troubleshooting - Appendix B
80 ADAT LX20 Reference Manual
ADAT HEAD MAINTENANCE
The heads of each ADAT are pre-aligned at Alesis. No user adjustment is
necessary. Eventually, depending on the quality of the tapes used and the
environmental conditions where the ADAT and its tapes are stored, head cleaning
may become necessary. Unlike analog or even video tape recorders, the actual sound
quality of an ADAT recording will not be affected until there is quite a bit of dirt on
the drum and heads. When the Interpolation Indicator (the sunburst at the end of
the location display) starts appearing frequently, even on brand new tapes, we
recommend that you bring your ADAT to an authorized Alesis Service Center for
cleaning. If the indicator is not appearing and the unit is performing normally,
there is no reason to clean the heads. Periodic or preventative maintenance should
not be overdone to prevent premature wear on the head stack.
If head cleaning is necessary and you are unable to bring your ADAT to a service
center, try using a DRY VHS head cleaning cassette. We recommend
3M VHSHC Black Watch Head Cleaner Video Cassette or 3M ASD HC Digital
Audio Head Cleaning Cassette.
• Do NOT use any other type of head cleaning cassette. They are abrasive and
will damage or wear out your heads.
• Do NOT use head cleaning cassettes that require any kind of liquid.
• Do not use the Black Watch cassette any more often than necessary. Over-
cleaning the heads wears them down, reducing their life span.
• Do NOT attempt to clean the heads yourself unless you are a skilled technician
experienced in the maintenance of video cassette recorders. Information for such
technicians is available from Alesis Product Support. ADAT head cleaning
requires different materials and procedures from analog head cleaning, similar
to VCR maintenance. Cleaning the heads with a cotton swab, or rubbing in the
wrong direction, will destroy them. Opening your ADAT’s case will void the
warranty.
Base the need for ADAT maintenance on the Interpolation Indicator (or Error Count
Display, see previous page) or if the unit begins to behave erratically. To
determine if these symptoms are caused by dirty heads, (not a defective or worn
tape), keep a “benchmark” tape from the first weeks of operation set aside in a safe
place. If the Interpolation Indicator lights frequently when playing back this tape,
it is likely that head cleaning is needed, particularly if several hundred drum-on
hours have elapsed since the last cleaning (see next section). Call Alesis Product
Support for more information about head cleaning and authorized Alesis Service
Centers.