diy amp

[aleks990]

for this one TDA7294 BTL & Speakers Protected KIT Audio Amp 150W*2 - eBay (item 260701348286 end time Jan-30-11 01:12:40 PST) i know i only need a transformer, but for this one it is not writted do i need only transformer 2PC TDA8920 BTL 2.0 Audio Amplifier AMP Kit 200W+200W - eBay (item 260708920904 end time Feb-14-11 00:10:07 PST)
and at what ohm do they ouyput 150 watt and 200watt.
does somebody have expirience with this amps, are they good , is the sound good?

[tangmonster]

tda7294 will deliver 70W into 4ohm with voltage rails of +-27V (19 0 19 AC transformer)
tda7294 will deliver 70W into 8ohm with voltage rails of +-35V (25 0 25 AC transformer)

Since the board using tda7294 has two chips in bridge mode per channel for 8 ohm loads you will have to use 19 0 19 AC transformer. and you will get (According to datasheet) 140W rms.

Would not advise using 4 ohm speaker. Would not advise using 26 0 26V transformer. use big enough heatsink.

[pacificblue]

The TDA7294 in BTL configuration will deliver 150 W into 8 Ohm from a beefy transformer and with a big heatsink. It will likely overheat with a 4 Ohm load, except if you listen at levels far, far below 150 W.

For the TDA8920 you will only need a transformer, because the rectifier is already on the board. It will deliver 174 W into 6 Ohm and 138 W into 8 Ohm at 0,5 % THD. You will get 210 W into 6 Ohm out of it at 10 % THD. For 4 Ohm it is the same as the TDA7294, not recommended.

[aleks990]

thanks guys but can i connect only one loudspeaker so they would play. and are this a car or home amplifiers, i think its home... and why there are 4 outputs on TDA8920 .

[pacificblue]

You can use a single channel only. They are designed for home. The TDA8920 has two outputs. Maybe the photo does not show the same product, but a similar one with four channels.