Just bought a TDA8950TH 2.1 digital Class D Amplifier Board 2*150W+250W (AM160)

[Chip2786]

Hi Everyone I just joined the forum (Ive been reading it for weeks so thought it was about time) I had a moment of madness on Ebay (as you do) and bought a 2.1 Class D amplifier. Please see my question and specs below

Specification:

• Work: Class D

• Quiescent Current: 65mA

• Work efficiency: 90%

• Left and right output power: 2 * 150W

• Subwoofer output power: 250W 8ohm

• Frequency response: 20Hz to 20KHz

• Operating voltage: Dual AC15V to AC28V

• Recommended supply voltage: AC28V-0-AC28V

• PCB size: 150 * 145MM

Note: The subwoofer output is BTL mode, can only be used to access more than 8 ohms speaker



Here is my question,

I need a small (light weight) power source for it, I had in mind a SMPS but im not sure;
A. Is it possible? it wants AC28-0-AV28 input but SMPS are DC?
B. Ive read a lot about recommended power and believe I need 600w for this amp
C. Please dont make me put a Toroidal in it, im trying to keep the weight/ size down 😀

Chip

 

[nigelwright7557]

If the amp is taking in AC then there must be smoothing capacitors on board.
An SMPS might take exception to that.
I would use a 40-0-40DC SMPS but remove the big smoothing capacitors from the amplifier pcb.

 

[Chip2786]

Is that the black caps in this picture?

An externally hosted image should be here but it was not working when we last tested it.

Why would you go for a 40-0-40DC? (just curious)

 

[tusker]

Why would you go for a 40-0-40DC? (just curious)

See Crest factor - Wikipedia, the free encyclopedia

28 VAC * √2 ≒ 39.6 VDC

BUT: According to the datasheet of the TDA8950, ±40 V is the maximum supply voltage this chip can handle. So I'd rather go with 36/37 VDC (as suggested in the datasheet) to leave a little headroom, just in case. You'd lose some 10 % of the maximum output power though, but you are on the safe side. Edit: The 2x150 W given in your description are at 4 Ω with 10 % THD and VP ±37 V.

Disclaimer: I'm not an expert, so corrections to my assumptions are very welcome. 😉

 

[loudluggage]

can anyone tell me how the audio input system in this amplifier..... ummm... works? i cant think how a jst plug can fit to an audio socket of any kind, or am i acting really stupid and it's plain obvious!!?? thanks