1. ECHO IN connector (XLR type) is balanced, transformer-isolated. The nominal level and
impedance are +4dB and 600 ohms, respectively.
2. GROUND (GND) LIFT Switch is for pin 1, which is used to avoid ground loops that are
often caused in connection with other equipment and that may induce hum. Sliding the
ground lift switch from the NORMAL position to the LIFT position cuts ground loops and
may reduce hum. For most applications it should be set to the NORMAL position.
3. ACCESSORY SEND/RECEIVE jacks are unbalanced and their nominal level and
impedance are +4dB and 10k ohms, respectively. They provide the capability to insert
signal processing devices into the signal pat h for special applications. The regular signal
path between the group mixing bus and group out is interrupted at the RCV jack by
inserting a plug into it.
4. SUB INPUT connector (female, XLR type) is balanced, transformer-isolated. Its nominal
level and impedance are +4dB and 600 ohms, respectively. This connector is useful for
cascade connection with another mixer to expand the input capacity.
5. GROUND (GND) LIFT switch is for pin 1 of the Sub Input connector.
6. ECHO SEND PEAK level indicator tur ns on when the echo send output signal level
reaches l0dB above nominal.
7. ECHO SEND master control adjusts the output signal level of ECHO SEND output on the
rear of the frame.
8. EQUALIZER for ECHO IN consists of the following three equalizers
HIGH 10kHz ±15dB boost/cut shelving type
MID 200—5kHz variable ±15dB boost/cut peaking type
LOW l00Hz ±15dB boost/cut shelving t ype
Flat frequency response is provided at "0" position of each equalizer.
9. EQUALIZER IN/OUT switch permits the equalizer to be either in circuit or out of circuit.
10. GROUP ASSIGN pushbuttons apply the ECHO input to any of the four mixing busses.
11. ECHO IN master control adjusts the level of the signal to be fed to the group mixing
busses.
12. CUE pushbutton assigns t he signal (pre ECHO IN master control) to the cue bus for
monitoring with headphones, monitor speakers, and/or the cue VU meter. A separate cue
VU meter is provided on the RX-7-328, bu t the cue and talkback VU meter is combined
and is switchable on the RX-7-164 and RX-7-248.
13. GROUP ON/OFF pushb utton connects or disconnects the signal to the GROUP out and
group out bus. The adjacent green LED illuminates when th e group out is "on".
14. PEAK level indicator turns on when the group output signal level reaches l0dB above
nominal.
15. GROUP FADER TRAVEL is calibrated in dB and insures very smooth operation. The
fader controls the level of the signal to be fe d to the group out and group out bus.
16. CUE pushbutton assigns the pr e group-fader signal to the cue bus for monitoring with
headphones, monitor speakers, and/or the cue VU meter. A separate cue VU meter is
provided on the RX-7-328, bu t the cue and talkback VU meter is combined and is
switchable on the RX-7-164 and RX-7-248 .
Group/Echo Module (GEM-7 )