Symetrix 628 - Appendix C Output Level Conversion; Convert Analog XLR to Mic Level; Change Max Analog Output Level

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Converting an Analog XLR Output to Microphone Level:
We shipped your 628 with its analog line outputs configured for line level output (+4 dBu). We
recommend that you use the 628 configured this way and use a line level input on your mixing
console. The microphone preamp in the 628 exhibits better performance characteristics than those
found in most consoles. Dont throw away all this gain by padding down the output unless you
absolutely must.
If you must use a microphone level input one, or both, of the 628s XLR outputs convert to
microphone level output (-40 dBu) with internal jumpers. This feature allows one XLR output
configured to microphone output level while one XLR remains at line level.
Note: The 1/4 inch TS outputs may not be switched to microphone level. These remain unbal-
anced, line level outputs only.
Here’s the procedure:
1.) Unplug all connectors from the 628 and remove it from the rack.
2.) Remove the top cover. Dont forget those pesky 3/32 inch allen screws in the front
panel.
3.) Locate the ANALOG OUTPUT XLR connectors on the rear panel.
4.) Immediately behind the chassis XLR connectors find black pin jumpers J6 and J7, or
J10 and J11, depending on which XLR output you want to convert to microphone level.
5.) Move both jumpers next to the output connector which you want to convert to
microphone level rearward to the jumper pins closest to the XLR connector.
6.) Replace the top cover and all retaining screws.
7.) Reinstall the 628 in your rack.
8.) Connect the power and audio cables.
Changing the Maximum Analog Output Operating Level
When the 628 is shipped from the factory its maximum output level before clipping is +22dBu (as
referenced to 0dB full scale digital on the digital outputs). Provisions to pad the maximum level of
the balanced outputs to +16dBu or -20dBu are provided via the internal jumpers J4, J5, J7, J9, J10
and J12.
Output Level ConversionAppendix C
G
1
3
2
G
1
3
2
J11
J13
U24
D3
C66
C61
L14
R82
R81
C65
R83
C64
R79
BP28
R85
C63
R78
R70
J8
R77
R71
U19
R68
C58
L10
C39
L9
J6
C50
R59
R60
R51
C47
C53
U16
R57 R61
R44
C43
R45
R48
C42
R47
R52
BP23
R64
U21
C62
BP30
U22
BP31
BP26
C59
R72
L13
R69
R65
R66
BP24
C51
C52R58R54
R46
U14
R49
U12
BP20
C45
C40
BP22
R53
C54
C48
C56
BP29
BP33
L15
R87
R88
J3
C36
R30
R31
C34
C28
BP17
U11
C31
C25
D1
C32
R41
BP14
C35
BP18
R43
J10
J9
J7
J5
J4
J12
Jumper positions
for +22dBu
maximum output.