13)TAPE PLAYBACK INPUTS. Used for returning a 2 track tape machine or DAT back to the mixer for monitoring, checking or just listening. Once one records a mix, it is always a good idea to check playback. The 5 position monitor select switch on the front hast to be in the "TAPE" position to hear the playback. These are balanced inputs, TIP hot.
14)EXT INPUTS. Used for chaining mixers for 32 channels if you have 2 mixers and the 1/4" MIX outputs are fed from the other mixer into these jacks. On MIC VERSION mixers there is a gain control on the front panel (EXT) and on LINE VERSION it is a unity gain input direct into the mix. These inputs can be used as an effects return if not required for chaining mixers. These are balanced jacks, TIP hot, RING neg.
15)AUX OUTPUT. Only on the LINE and 8+8 VERSIONS. This is the effect send or a mono headphone send. Channels can feed this jack if their AUX control is turned up and the AUX knob in the master section is also up. This is an unbalanced output on a balanced TRS jack and can be used to feed balanced or unbalanced inputs.
16)SOLO LINK. If one has 2 mixers, they can simply connect a wire between these terminals to link the SOLO system. This allows you to solo one channel and the other 31 channels mute. If the 16x2 is used as a "sidecar" for a large console, it might also be used to link to the solo system of the larger desk. 12 volts = no solo, 0 volts = solo. This is a mini banana post and not the larger size used on test gear.
17)GROUND POSTS. Generally, there should be a wire connecting these two posts. One is CHASSIS GROUND which is also the third pin of the AC plug. The other post is AUDIO GROUND which is the zero volt common of all the audio signals. Having these grounds accessible is useful for solving hum problems and for installations with custom ground schemes. For reference, all 1/4" TRS sleeves or shield points are taken to chassis ground, and all rings are taken to audio ground via a 30 ohm resistor. The internal star ground reference is on the left tube board at the summing transformers / power connector.
18)LINE INPUTS. These are COMBI jacks that allow either XLR or TRS plugs to be used. Unlike the MIC INPUTS the input impedance is always 82K ohms which is an easy load for almost all gear including guitars and basses. With semi pro
PIN 1 = SLEEVE = GROUND = SHIELD PIN 2 = TIP = HOT = Positive
PIN 3 = RING = LOW = Negative
These inputs allow inputs as hot as +30 dBu balanced or +24 dBu unbalanced before clipping which is about 6 dB better than most pro gear can send.
19)CHANNEL OUTPUTS. Balanced outputs used to feed individual tracks on a multitrack recorder or A to D converter. These outputs are after the MIX GAIN controls but are not muted by the MUTE button. So by muting, you can eliminate these channels from the mix buss but still send to a recorder with these jacks. This way, you can use the Mic Pre, Phase Switch, Insert and Mix Gain (for fine level control) on its way to a
T= TIP = HOT = +, R = RING = Low =
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