Pre built chip amp kit

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
A

AndrewT

R.I.P.
Joined 2004
the 120+120W is into 4ohms+4ohms.
The internal heatsink looks a bit small to cool 4 chipamps. I would guess that it operates on ±30 to ±32Vdc to get to that power output.
I fear it will run hot.
±10mF shared between two 4ohms channels will compromise LF power delivery.

This may make a good 8+8ohms amplifier.

I ran a test on two channels of 3886 delivering simultaneously 1W into 8ohms and 2W into 8ohms on an external heatsink of about the same size. Within about 5minutes the chip was too hot to touch for longer than a second or two. Look at the graphs in the datasheet when delivering low power.
 
Last edited:
A

AndrewT

R.I.P.
Joined 2004
You could reduce the operating voltage. That gives less quiescent heat and gives less maximum output power as well as increasing the heatsink in conjunction with only using 6ohms, or higher, load impedance.

But you are buying a complete product.

Look at the datasheet.
 
Nico Ras

Nico Ras

Member
Joined 2005
The amp looks fine, if the heat sink gets too hot to touch there is definitely something wrong, The quiescent current should not cause the amps to dissipate several watts and playing music even at fairly high levels in an apartment should not break a sweat.

If it makes you more comfortable then add a small fan in the box which would make a big difference, also as AndrewT mentions, 8 ohm should be a suitably safe load.

I would agree with him that the 10 000uF per rail is a bare minimum at a peak output of 7 amps into 8 ohm. One would expect that the power rails will sag notably at high power and heavy bass.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom