No. 5709-7/8

LA70001, 70001M

Record Amplifier Gain Control

The LA70001 achieves an adjustment-free record current by adding an AGC circuit in the record amplifier block. The

record current can be modified using the following method.

• Record current adjustment 2: When left open.

Ro1.

Design value: When Ro1 is 1.5 k

Ω, the record current will be 12.7 mA per channel.

• Record current adjustment 2: When used.

The gain can be varied by –6.0 dB to +3.5 dB relative to the value set by Ro1 by applying a control DC voltage of

between 1 and 4 V to pin 12.

Note: The technique shown in the figure below can be used to apply a DC level to pin 12. This allows a control voltage of between 1 and 4 V to be applied.

Record current (mAp-p) design value