background image

Operation manual

Controls:

each knob sets the level for the corresponding 
input/output (

see diagram

),

fully left (

anticlockwise

) is equal to silence, fully right 

(

clockwise

) to maximum volume level possible.

First run:

turn mixer OFF,

turn all IN knobs to around 50% (

12 o'clock

),

turn OUT knob full anticlockwise (

min. level

),

provide signal to INs of choice,

connect OUT to your favourite piece of equipment,

turn mixer ON,

turn OUT knob slowly clockwise to increase output level.

Notes:

inputs are monophonic and take signal from the tip of the
jack plug (

usually left channel

),

output is stereophonic (

or rather double mono

) and 

works

only with stereo cable

,

max. amplification of mixer is x2 (+6 dB),

both inputs and output are AC coupled,

for fresh battery 

maximum

 mixers 

output is 5,6 Vp-p

 

and it will drop with supply voltage,

6 Vp-p

 can be considered as 

safe input

 voltage level 

(

don't worry if you fry TL072, they are relatively cheap

).

Summary of Contents for 4sum

Page 1: ...4sum portable audio mixer assembly instructions v0 95 by SyntherJack net I ve tried to keep it short and informative Nobody reads manuals...

Page 2: ...n off indicator Mechanical data size without knobs 93 x 60 x 29 mm with knobs 93 x 60 x 35 mm weight without battery 90 g with battery 120 g Electrical data max input signal level 6 Vp p max amplifica...

Page 3: ...R 12 1 V RED V 13 Male spacer 4 8 mm M3 14 4 15 8 6 mm M3 16 Top cover 1 17 1 18 PCB 1 Part value Description Resistors 47 k 4 7 k Potentiometers Alpha Taiwan RV09AF 40 20K A100K Capacitors 10 F tanta...

Page 4: ...older nine 47 k resistors R1 R9 Step II solder one 4 7 k resistor R10 Step III solder one Schottky diode D1 Mind the polarity Black strip should be pointing top Step IV solder one 100 nF ceramic capac...

Page 5: ...ep VI bend legs of four 10 F capacitors C1 C4 and solder them see photo Mind the polarity On tantalum capacitor positive longer lead is marked and it should be pointing to the left Step VII solder fiv...

Page 6: ...should be pointing to the top Step X solder five potentiometers LVL1 LVL4 LVLO Step XI cut the battery connector to around 85 mm strip both ends of the wires and solder them red to V Step XII inspect...

Page 7: ...s and spacers using fingers Step XIV turn the device on the LED should lit The chance you ve soldered everything correctly just increased Turn it off Step XV Slightly bend the IC leads and put it into...

Page 8: ...Step XVII Congratulations Your brand new and shiny portable mixer is ready I hope it looks as good as mine...

Page 9: ...to your favourite piece of equipment turn mixer ON turn OUT knob slowly clockwise to increase output level Notes inputs are monophonic and take signal from the tip of the jack plug usually left channe...

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