And we are back hard at work on our FT-6, 6 Channel Audio Mixer.
Today we take a look at audio distribution.
Back in the day, I made LARGE D.A. Amplifiers.
It was the first time I did my own metal work. I thought they came out nice.
They gave me 8 Channels of Audio for Program, Audition and MONO.
For this 'scaled down' version I don't need that many outputs so we are using a design that will fit into the Mixer. (Thus, saving us more space.) The design comes right out of the Radio Systems Manual.
Here is a closer look at just one channel (The rest are the same.)
The design is probably the easiest we will tackle building this project. Simple IC's and if you plan correctly, it will work extremely well.
We need an output to run to the computer's audio editing software. And another output to drive some digital VU Meters I have planned. (We will also use standard VU Meters as well.)
Why do I need two versions of VU Metering? I don't, but I have a ton of Analog VU Meters I can use.
Back in the day I built some digital units and really liked them.
But you can get the idea. Cool, aren't they?
So why not?
But back to the DA Amp.
We thought about bypassing the prototype here and going direct to a manufactured board. But I do not trust myself, and a protype helps ferret out mistakes BEFORE I spend money on an expensive board from JLCPCB.
Here is your PARTS LIST
C-01 CAPACITOR DISC 100 PF 500V
C-02 CAPACITOR DISC 100 PF 500V
C-03 CAPACITOR DISC 100 PF 500V
C-04 CAPACITOR DISC 100 PF 500V
C-05 CAPACITOR DISC 47 PF 500V
C-06 CAPACITOR DISC 47 PF 500V
C-07 CAPACITOR N.P. 100 UF 16V RADIAL
C-08 CAPACITOR N.P. 100 UF 16V RADIAL
C-09 CAPACITOR N.P. 100 UF 16V RADIAL
C-10 CAPACITOR N.P. 100 UF 16V RADIAL
C-11 CAPACITOR ELECT. 15 UF 35V RADIAL
C-12 CAPACITOR ELECT. 15 UF 35V RADIAL
C-13 CAPACITOR FILM .1 UF 50V
C-14 CAPACITOR FILM .1 UF 50V
C-15 CAPACITOR DISC 47 PF 500V
C-16 CAPACITOR DISC 47 PF 500V
C-17 CAPACITOR DISC 47 PF 500V
C-18 CAPACITOR DISC 47 PF 500V
C-19 CAPACITOR FILM .1 UF 50V
C-20 CAPACITOR FILM .1 UF 50V
C-21 CAPACITOR FILM .0022 UF 50V
C-22 CAPACITOR FILM .0022 UF 50V
C-23 CAPACITOR FILM .0022 UF 50V
C-24 CAPACITOR FILM .0022 UF 50V
C-25 CAPACITOR FILM .0022 UF 50V
C-26 CAPACITOR FILM .0022 UF 50V
C-27 CAPACITOR FILM .0022 UF 50V
C-28 CAPACITOR FILM .0022 UF 50V
C-29 CAPACITOR FILM .1 UF 50V
C-30 CAPACITOR FILM .1 UF 50V
C-31 CAPACITOR FILM .1 UF 50V
C-32 CAPACITOR FILM .1 UF 50V
C-33 CAPACITOR FILM .1 UF 50V
C-34 CAPACITOR FILM .1 UF 50V
C-35 CAPACITOR FILM .1 UF 50V
C-36 CAPACITOR FILM .1 UF 50V
C-37 CAPACITOR FILM .1 UF 50V
C-38 CAPACITOR FILM .1 UF 50V
C-39 CAPACITOR FILM .1 UF 50V
C-40 CAPACITOR FILM .1 UF 50V
C-41 CAPACITOR FILM .1 UF 50V
C-42 CAPACITOR FILM .1 UF 50V
C-43 CAPACITOR FILM .1 UF 50V
C-44 CAPACITOR FILM .1 UF 50V
C-45 CAPACITOR FILM .1 UF 50V
C-46 CAPACITOR FILM .1 UF 50V
C-51 CAPACITOR DISC 100 PF 500V
C-52 CAPACITOR DISC 100 PF 500V
C-53 CAPACITOR DISC 100 PF 500V
C-54 CAPACITOR DISC 100 PF 500V
C-54 CAPACITOR DISC 47 PF 500V
C-55 CAPACITOR DISC 47 PF 500V
C-56 CAPACITOR DISC 47 PF 500V
C-57 CAPACITOR N.P. 100 UF 16V RADIAL
C-58 CAPACITOR N.P. 100 UF 16V RADIAL
C-59 CAPACITOR N.P. 100 UF 16V RADIAL
C-60 CAPACITOR N.P. 100 UF 16V RADIAL
C-61 CAPACITOR DISC 47 PF 500V
C-62 CAPACITOR DISC 47 PF 500V
C-63 CAPACITOR DISC 47 PF 500V
C-65 CAPACITOR FILM .0022 UF 50V
C-66 CAPACITOR FILM .0022 UF 50V
C-67 CAPACITOR FILM .0022 UF 50V
C-68 CAPACITOR FILM .0022 UF 50V
C-69 CAPACITOR FILM .0022 UF 50V
C-70 CAPACITOR FILM .0022 UF 50V
C-71 CAPACITOR FILM .0022 UF 50V
C-72 CAPACITOR FILM .0022 UF 50V
D-01 LED 3 MM
D-02 LED 3 MM
J-1 HEADER MOLEX 3 PIN - .1
J-2 HEADER MOLEX 3 PIN - .1
R-001 RESISTOR FILM 5.11 K ¼ W 1%
R-002 RESISTOR FILM 5.11 K ¼ W 1%
R-003 RESISTOR FILM 5.11 K ¼ W 1%
R-004 RESISTOR FILM 5.11 K ¼ W 1%
R-005 RESISTOR FILM 10 K ¼ W 1%
R-006 RESISTOR FILM 10 K ¼ W 1%
R-007 RESISTOR FILM 10.2 K ¼ W 1%
R-008 RESISTOR FILM 10.2 K ¼ W 1%
R-009 RESISTOR FILM 10.2 K ¼ W 1%
R-010 RESISTOR FILM 10.2 K ¼ W 1%
R-011 RESISTOR FILM 10.2 K ¼ W 1%
R-012 RESISTOR FILM 10.2 K ¼ W 1%
R-013 RESISTOR FILM 10.2 K ¼ W 1%
R-014 RESISTOR FILM 10.2 K ¼ W 1%
R-015 RESISTOR FILM 1.50 K 1/4W 1%
R-016 RESISTOR FILM 1.50 K 1/4W 1%
R-017 RESISTOR FILM 1.50 K 1/4W 1%
R-018 RESISTOR FILM 1.50 K 1/4W 1%
R-019 RESISTOR FILM 10.2 K ¼ W 1%
R-020 RESISTOR FILM 10.2 K ¼ W 1%
R-021 RESISTOR FILM 10.2 K ¼ W 1%
R-022 RESISTOR FILM 10.2 K ¼ W 1%
R-023 RESISTOR FILM 10.2 K ¼ W 1%
R-024 RESISTOR FILM 10.2 K ¼ W 1%
R-025 RESISTOR FILM 10.2 K ¼ W 1%
R-026 RESISTOR FILM 10.2 K ¼ W 1%
R-027 RESISTOR FILM 46.4 ¼ W 1%
R-028 RESISTOR FILM 46.4 ¼ W 1%
R-029 RESISTOR FILM 10.2 K ¼ W 1%
R-030 RESISTOR FILM 10.2 K ¼ W 1%
R-031 RESISTOR FILM 10.2 K ¼ W 1%
R-032 RESISTOR FILM 10.2 K ¼ W 1%
R-033 RESISTOR FILM 46.4 ¼ W 1%
R-034 RESISTOR FILM 46.4 ¼ W 1%
R-035 RESISTOR FILM 46.4 ¼ W 1%
R-036 RESISTOR FILM 46.4 ¼ W 1%
R-037 RESISTOR FILM 750 ½ W
R-038 RESISTOR FILM 46.4 ¼ W 1%
R-039 RESISTOR FILM 46.4 ¼ W 1%
R-040 RESISTOR FILM 750 ½ W
R-079 RESISTOR FILM 5.11 K ¼ W 1%
R-080 RESISTOR FILM 5.11 K ¼ W 1%
R-081 RESISTOR FILM 5.11 K ¼ W 1%
R-082 RESISTOR FILM 5.11 K ¼ W 1%
R-083 RESISTOR FILM 10 K ¼ W 1%
R-084 RESISTOR FILM 10 K ¼ W 1%
R-085 RESISTOR FILM 10.2 K ¼ W 1%
R-086 RESISTOR FILM 10.2 K ¼ W 1%
R-087 RESISTOR FILM 10.2 K ¼ W 1%
R-088 RESISTOR FILM 10.2 K ¼ W 1%
R-089 RESISTOR FILM 10.2 K ¼ W 1%
R-090 RESISTOR FILM 10.2 K ¼ W 1%
R-091 RESISTOR FILM 10.2 K ¼ W 1%
R-092 RESISTOR FILM 10.2 K ¼ W 1%
R-093 RESISTOR FILM 1.50 K 1/4W 1%
R-094 RESISTOR FILM 1.50 K 1/4W 1%
R-095 RESISTOR FILM 1.50 K 1/4W 1%
R-096 RESISTOR FILM 1.50 K 1/4W 1%
R-097 RESISTOR FILM 10.2 K ¼ W 1%
R-098 RESISTOR FILM 10.2 K ¼ W 1%
R-098 RESISTOR FILM 10.2 K ¼ W 1%
R-099 RESISTOR FILM 10.2 K ¼ W 1%
R-100 RESISTOR FILM 10.2 K ¼ W 1%
R-101 RESISTOR FILM 10.2 K ¼ W 1%
R-102 RESISTOR FILM 10.2 K ¼ W 1%
R-103 RESISTOR FILM 10.2 K ¼ W 1%
R-104 RESISTOR FILM 10.2 K ¼ W 1%
R-105 RESISTOR FILM 46.4 ¼ W 1%
R-106 RESISTOR FILM 46.4 ¼ W 1%
R-107 RESISTOR FILM 10.2 K ¼ W 1%
R-108 RESISTOR FILM 10.2 K ¼ W 1%
R-109 RESISTOR FILM 10.2 K ¼ W 1%
R-110 RESISTOR FILM 10.2 K ¼ W 1%
R-111 RESISTOR FILM 46.4 ¼ W 1%
R-112 RESISTOR FILM 46.4 ¼ W 1%
R-113 RESISTOR FILM 46.4 ¼ W 1%
R-114 RESISTOR FILM 46.4 ¼ W 1%
R-115 RESISTOR FILM 46.4 ¼ W 1%
R-116 RESISTOR FILM 46.4 ¼ W 1%
RV-01 TRIM POT TOP ADJ. 10 K
RV-02 TRIM POT TOP ADJ. 10 K
RV-03 TRIM POT TOP ADJ. 10 K
RV-04 TRIM POT TOP ADJ. 10 K
RV-09 TRIM POT TOP ADJ. 10 K
RV-10 TRIM POT TOP ADJ. 10 K
RV-11 TRIM POT TOP ADJ. 10 K
RV-12 TRIM POT TOP ADJ. 10 K
U-01 OPAMP 8 PIN DIP NE5521
U-02 OPAMP 8 PIN DIP NE5521
U-03 OPAMP 8 PIN DIP NE5521
U-04 OPAMP 8 PIN DIP NE5521
U-05 OPAMP 8 PIN DIP NE5521
U-06 OPAMP 8 PIN DIP NE5521
U-07 OPAMP 8 PIN DIP NE5521
U-08 OPAMP 8 PIN DIP NE5521
U-09 OPAMP 8 PIN DIP NE5521
U-10 OPAMP 8 PIN DIP NE5521
TS-1 TERMINAL 5 PIN 0.2
TS-2 TERMINAL 5 PIN 0.2
TS-3 TERMINAL 5 PIN 0.2
TS-4 TERMINAL 5 PIN 0.2
TS-5 TERMINAL 5 PIN 0.2
TS-6 TERMINAL 5 PIN 0.2
I.C. SOCLET D.I.P. 8 PIN
I.C. SOCLET D.I.P. 8 PIN
I.C. SOCLET D.I.P. 8 PIN
I.C. SOCLET D.I.P. 8 PIN
I.C. SOCLET D.I.P. 8 PIN
I.C. SOCLET D.I.P. 8 PIN
I.C. SOCLET D.I.P. 8 PIN
I.C. SOCLET D.I.P. 8 PIN
I.C. SOCLET D.I.P. 8 PIN
I.C. SOCLET D.I.P. 8 PIN
OK, schematic in hand, parts ready to go, and the solder machine is a hummin'. Let's prototype!
And right off the bat, I found an error! If you look at the schematic above, C52 is connected to R-81. It is supposed to connect to R-80!
So, I just saved myself from having boards made that would be unusable.
Here is the corrected schematic, with the corrections 'circled.' (Note: The resistor numbers are different, but it is the SAME schematic)
Let's see if there are MORE mistrakes.
Part way through the prototype, I realized that the board was a bit crowded making wiring a problem.
The power leads I ran was also an issue as they were in the way when I started to mount other components.
So back to the drawing board for a better board design, and this is what I did.
Working on the new prototype.
(I will trim the board to size later.)
Now that the prototype is done, let's test it!
(I ran my computer audio through a matching box in order to get a 'balanced' audio into the D.A.)
Hey, the damn thing makes AUDIO !!!!!
All the outputs adjust according to the design.
And the audio is clean with no hum or buzzes.
I decided to add some more labels.
Not bad for a proto board.
Now we can order the boards. But for now, we will
move onto another part of the project.
VU- METERS
When I get the final boards, I will update this part of our journey.
Ya'll come back now; yaw hear.
And now, a look at our "planning list"
MIXER PLANNING
1) POWER SUPPLIES
+/- 15 VDC XMFR 1
+/- 7.5 V DC XMFR 1
+ 5.0 VDC (CLOCK/TIMERS) XMFR 2 OR COMMERICAL UNIT
SCHEMATICS
CIR BOARDS
CABINET
2) TIMER / CLOCK - SEPERATE UNITS FROM MIXER DUE TO SPACE LIMITS
12 HOUR MOD 60 MOD 60 MOD 12
24 HOUR MOD 60 MOD 60 MOD 23
TIMER UNIT
RE-SET PANEL
DISPLAY BOARD SCHEMATIC CIR BOARD
MAIN BOARD SCHEMATIC CIR BOARD
60 SEC/MIN MOD SCHEMATIC CIR BOARD
23 HOUR MOD SCHEMATIC CIR BOARD
12 HOUR MOD SCHEMATIC CIR BOARD
CABINET
PROTO TYPE
FINAL
3) HEADPHONE AMPLIFIER
DESIGN
SCHEMATIC
PROTO TYPE
CIRCUIT BOARD
4) CUE AMPLIFIER
CAN ALSO USE AS A TEST AMP WHILE BUILDING AUDIO BOARDS
DESIGN
SCHEMATICS
PROTO TYPE
CIRCUIT BOARDS
5) POWER AMPLIFIER (REPLACES TASCAM PA-30)
(USED THE AMP DESIGN FOR CUE AND HEADPHONE AMPS. - I FOUND A GOOD POWER AMP AT THRIFT STORE)
DESIGN
SCHEMATICS
PROTO TYPE
CIRCUIT BOARDS
6) OUTPUT BOARD
DESIGN
SCHEMATICS
PROTO TYPE
CIRCUIT BOARDS
7) MONITOR SELECT
DESIGN
AVOID OLD STYLE SWITCHES, USE DIGITAL
SCHEMATIC
PROTO TYPE
CIR. BOARD
8) PGM / AUD / MONO SELECT
DESIGN
AVOID OLD STYLE SWITCHES, USE DIGITAL
SCHEMATIC
PROTO TYPE
CIR. BOARD
9) INPUT SELECT
DESIGN
AVOID OLD STYLE SWITCHES, USE DIGITAL
SCHEMATIC
PROTO TYPE
CIR. BOARD
10) AUDIO INPUT BOARD
DESIGN
RS-12 VERSION
SCHEMATIC
PROTO TYPE - NOT DOING A PROTO TYPE
CIR. BOARD
11) MONITOR BOARD
DESIGN BASED ON MONITOR SELECT DESIGN
SCHEMATIC
PROTO TYPE
CIR. BOARD
12) EXTERNAL MONITOR BOARD
DESIGN
SCHEMATIC
PROTO TYPE
CIR BOARD
13) VU METER BOARD - SEPERATE UNIT ON SHELF
ONLY USED BECAUSE IT IS ALREADY BUILT
14) LED METERING - ON BOARD
USE RS-12 CIRCUIT REG LED'S OR BAR GRAPHS ????
SCHEMATICS
PROTO TYPE
CIRCUIT BOARD
15) D.A. AMPLIFIER
DESIGN
SCHEMATIC
PROTO TYPE
CIR BOARD
16) 4 PORT EXPANDER BOARD
DESIGN
SCHEMATIC
PROTO TYPE
CIR BOARD
17) POWER SUPPLY DISTRIBUTION BOARD??
MAY BE NEEDED WITH MULTIPLE BOARDS??
So, that it for now, see you next time !!!
God Speed, Mother Nature.
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