Design

[mirmite]

This might be the Wrong place to ask for this but anyway
I have been searching Thure the site för a while now for a good singelsided
Design for a lm3886 amp board and power supply
But havent really found one that has been verifiera and that people seam to use
, so is There Any design out There ? And hopfoly a eagle file aswell

 

[AndrewT]

The 3886 datasheet shows a single supply implementation.

It has been said, more than a few times, that the single supply implementation is a better schematic than the dual polarity version shown before it.

 

[djoffe]

For "single sided design", these two web sites have lots of information, and designs worked out for the modules, and for a complete amplifier kit. You may find the information useful:

Update My Dynaco

Akitika GT-101

 

[Jsixis]

been looking myself as I have some really huge 12 and 18 volt transformers out of battery back up units that I would like to use for something.

 

[JMFahey]

@ jsixis:
If you have 12V transformers that means around 16V single supply.
Best bang for the buck will be some bridged TDA2005 or a more modern implementation of "car type BTL", up to and including some Class D chip, for around 20W into 4 ohms.
LM3886 will perform very poorly with such low voltage.
The 18V transformer will give you around 25V DC, you might try bridged TDA2030/50 .
There the limiting factor will be peak current into the load.

 

[Jsixis]

Thanks JMFahey, the only reason I keep those huge 12v trannys is they can push a lot of current judging by their size and the 14 gauge wire on the secondaries.
I wasn't planning on using them for a 3886 just looking for some power supplies schematics that use a non center tap transformer

 

[wwenze]

There, +/- voltages without a center tap.

 

[AndrewT]

post7 shows a voltage doubler.
It has effectively two half wave rectifier connected in series.
The output ripple is very bad.
The voltage droop as output current is increased is about 4times worse than a full wave rectifier.
This Voltage doubler should only be used for low current duty and really benefits from having a voltage regulator before the next stage.

 

[sofaspud]

been looking myself as I have some really huge 12 and 18 volt transformers out of battery back up units that I would like to use for something.

For your consideration, I propose a combination of bridged and/or single-ended chip amp circuits used to bi-amp/tri-amp speakers in a 2.0 or 2.1 configuration. Let that transformer muscle power it all.
Or use it to power a car audio -type amp with it's own voltage multiplier. But I like the first idea better.