Re: Chip amp
The 3875/3886 has a max of 84V and the 1875 is less so the usual suspects are out unless you used the two secondaries in parallel (or separate windings for a stereo amp) and created a virtual ground or used a single ended supply (the 3875 ap note illustrates the SE supply). You'd only end up with about a 20 W amp thou -- not too bad thou, these are optimum at about 25 W max.
dave
Petervg said:
The 3875/3886 has a max of 84V and the 1875 is less so the usual suspects are out unless you used the two secondaries in parallel (or separate windings for a stereo amp) and created a virtual ground or used a single ended supply (the 3875 ap note illustrates the SE supply). You'd only end up with about a 20 W amp thou -- not too bad thou, these are optimum at about 25 W max.
dave
)Hi,
one important thing with those overture series amplifier chips is the protection circuitry which will depend on the load impedance you will connect to your amplifier.
If you use 4Ohm speakers for example I wouldn´t use your transformer cause the output power will be limited.
You get full 68W at 4Ohm load with +-28V which is the voltage I use for my LM3886 amp.
Connecting an 8Ohm load to +-28V you won´t get full power then
(for full power +-35V) so you should think about what you´ll use and carefully read the datasheet.
Another concern is power dissipation which will be of course higher with higher voltage and is one of the few big limits to those chips.
Owning this transformer already I would choose to use the TDA7294,7293 (Can´t remember which was the improved version).
one important thing with those overture series amplifier chips is the protection circuitry which will depend on the load impedance you will connect to your amplifier.
If you use 4Ohm speakers for example I wouldn´t use your transformer cause the output power will be limited.
You get full 68W at 4Ohm load with +-28V which is the voltage I use for my LM3886 amp.
Connecting an 8Ohm load to +-28V you won´t get full power then
(for full power +-35V) so you should think about what you´ll use and carefully read the datasheet.
Another concern is power dissipation which will be of course higher with higher voltage and is one of the few big limits to those chips.
Owning this transformer already I would choose to use the TDA7294,7293 (Can´t remember which was the improved version).
Hmm, the TDA7293 looks like a solution to me, but is it possible to put two or more of them in parallel to be able to drive a 4 ohm load when the supply is +/-40Vdc? I've seen people doing this with the overtures using either very accurate resistors in the gain circuit or by using a servo... If It's really that simple, I'll put 2 or 3 of them in parallel to be sure they can handle the dissipation well.
Anybody have any experience with this?
P.
Anybody have any experience with this?
P.
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