Noob needs help.

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Aussie Noob

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Joined 2015
#1
Hello All,

I am just starting my 1st audio DIY Project. I have very very limited knowledge so please bare with me.

I purchased a 2 X 2 Watt 4 Ohm Class D Audio Amplifier Board - PAM8803 2W Stereo Power Mini From ebay. Picture attached.

I am hoping to run it on a battery i have at home. 12 V 34.0w/cell HR 1234WF2

i am using some old logitec speakers .

I have wired it all up and I cannot get any sound.... the power led comes on. Green. Now i am using the terminal blocks for power and i have just found out that they are only good for 4v not 12 so i will stop by jaycar today and buy a plug for the 12v socket. ( not sure if this would effect it working or not )

Now i have no idea what im doing so not sure if im missing a key part ?

Also some other questions...

1.should i run a fuse in between the battery and amp ?
2. it says i should earth each mounting point on the amp... how is this achieved ? should it go to the negative on the battery or ? i only have experience with auto where i just earth it to the car body...

sorry for the noob questions... sorry for the long thread i just thought i would provide as much info as i can.


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Amp SPECS
Brief Introduction:

This is a high-quality dual-channel class-D audio amplifier board capable of delivering 2W per channel of output power into a 4Ω load. It employs PAM’s PAM8803 IC which offers 64-step digital volume control and low THD+N, allowing it to produce high-quality sound reproduction. It’s especially suitable for small speakers. This amplifier board can also be used to drive passive 4Ω or 8Ω speakers. Three kinds of unique design make this product a perfect "Class D" architecture: (1) This board can be either powered by wide DC voltage (DC4.5V to12V) via a power port or powered by 2 to 3 AA batteries or DC2.5V to 4.0V via a terminal block. (2) Audio signal can be input via 2510 connector or 3.5mm headphone jack. (3) Volume control is available via on-board buttons or an external rotary encoder daughter board.
Net weigt:85g /3oz
Features:

Size: 74.40 (L) × 54.80 (W) × 18.00 (H) ±0.2mm
A perfect "Class D" architecture
Miniature and high quality
Full-bridged stereo output
64-step gain adjustment
Frequency response: 20Hz to20KHz(±3dB)
Signal/Noise Ratio: 85dB (f=22 to 22KHz, THD=1%)
High Output Power
1.2W @ 8Ω, < 10.0% THD+N

2.0W @ 4Ω, < 10.0% THD+N

High Efficiency
85% @ 1.2W 8Ω

88% @ 2.0W 4Ω

Audiophile Quality Sound
0.19% THD+N @ 0.5W 8Ω

0.17% THD+N @ 1.0W 4Ω

Mounting holes facilitate installation and fixing
Several wiring methods facilitate connection
Excellent heat dissipation eliminates the requirement of an extra heat sink
Over/under voltage turn off
Over current protection
Over temperature protection
Over 90% components are SMT based, which are reliable and environment-friendly
Ideal for DIY and industrial applications
Specifications:


Parameter
Condition

Min.

Typ.

Max.

Supply Voltage

-

4V

-

12V

Quiescent Current

DC12V, NO load

-

100mA

-

MUTE=0

-

10mA

40mA

Input Sensitivity

A=0dB

-

0.720V

-

THD+N

RL=4Ω, Pout=1W

-

0.17 %

-

RL=8Ω, Pout=0.5W

-

0.19 %

-

Output Power

THD+N<1%

RL=4Ω, f=1000Hz

-

1.5W

-

RL=8Ω, f=1000Hz

-

1.0W

-

THD+N<10%

RL=4Ω, f=1000Hz

-

2.0W

-

RL=8Ω, f=1000Hz

-

1.2W

-

Input Impedance

-

-

60K

-

Minimum Load

-

3.2ohm

-

-

SHDN, UP,
DOWM, MUTE

High-level input voltage

-

1.2V

-

-

Low-level input voltage

-

-

-

0.5V

Channel Separation

Po=1W, RL=4ohm

60dB

80dB

-

Power Gain

Volume Adjustable

K1=OFF

-75dB

-

23.8dB

Volume Not Adjustable

K1=ON

-

2.6dB

-

Operating Temperature

-

0℃

20℃

70℃

Storage Temperature

-

-20℃

20℃

105℃

Thermal Shutdown

-

-

150℃

-




Battery Specification
Cells Per Unit 6
Voltage Per Unit 12 V
Capacity 34W @ 15 minute-rate to 1.67V per cell @ 25°C (77°F)
Weight Approx. 2.50kg. (5.51lbs.)
Maximum Discharge current 100/130A (5sec.)
Internal Resistance Approx. Approx. 19mΩ
Operating Temperature Range Discharge：-15℃~50℃(5°F~122°F)
Charge：-15℃~40℃(5°F~104°F)
Storage：-15℃~40℃(5°F~104°F)
Nominal Operating Temperature Range 25°C ± 3°C (77°F ± 5°F)
Float charging voltage 13.5 to 13.8 VDC/unit Average at 25°C (77°F)
Recommended Maximum Charging current limit 3.4A
Equalization and Cycle Service 14.4 to 15.0 VDC/unit Average at 25°C (77°F)
Self Discharge It should be more than 75% of the capacity that before storage after stocked for 6 months at ambient temp. 25℃
Terminal F1/F2-Faston Tab187/250
 
#7
"This board can be either powered by wide DC voltage (DC4.5V to12V) via a power port or powered by 2 to 3 AA batteries or DC2.5V to 4.0V via a terminal block."

"I have wired it all up and I cannot get any sound.... the power led comes on. Green. Now i am using the terminal blocks for power and i have just found out that they are only good for 4v not 12.."

Maybe an OOoops..?

"Volume control is available via on-board buttons or an external rotary encoder daughter board."

Might need a jumper installed or changed somewhere to make the on board controls work..
 
#10
You need to ground this thing, for sure. Since it is floating with the battery, the board wants a ref point, specifically something conductive for the mount points. A piece of sheet aluminum would work, but don't let it touch the underside or any solder points.

Also, those old speakers may not be high enough ohms - remember this thing wants 4 ohms, it cuts the output when you get up to 8 ohms by almost half. Also, get some proper speaker wire to the speaker - you don't want to confuse the impedance load of the chip. Also - some chips do not like it when you try to run it without load, so if it is 2 speakers, connect them both.
 
#11
Great feed back thank you very much ! I will try when i get home from work.

Looks like the speakers are 4 Ohms, Specs are below that i found on-line.

I have 4 speakers. 2 X set of two. can i use all 4 or only 2 ?


Satellite Speaker (each)
Driver Diameter 2x 2" (5.1 cm) per channel
Power Output 6W per channel
Nominal Sensitivity > 96 dB
Nominal Impedance 4 ohms

Loudspeaker - Full Range, 2' Dia., 4 Ohm, Aluminized Mylar/Paper Laminate Cone, Cloth Surround, w/ Bucking Magnet

Subwoofer Enclosure Box - 3/8' Particle Board & MDF, Black Vinyl Laminate Veneer, 6-Sided

Power Transformer - Laminated, Horizontal Mount, w/ End Bells, 120VAC/60Hz Input, 14.4VAC/1.0A Output

Amplifier - Audio Power, Quad, 2x30W, 4x6W

Loudspeaker - Woofer, 5' Dia., 6 Ohm, Treated Paper Cone, Foam Surround
 
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