Please suggest a transformer

[Jdot]

Hi,

I'm onto my second amp build, this time a LM3886 stereo chip amp kit from LM3886 Amplifier Kit | Chipamp.com

Could someone do me a big favor and suggest the best transformer from my local supplier here Altronics - Transformers - Toroidal for this kit? It's the stereo kit with one amp board and two power supply boards.

Thanks for your help!

 

[AndrewT]

those transformer are either 30VA or 50VA.
Completely unsuitable for powering a stereo Power Chipamp.

 

[vinodt1347]

Read the instruction manual. If you are using 4 Ohm speaker then you can use the 18 V supply and if you are using the 8 Ohm Speaker you could use the 25V supply. I would be happy if there was a 22V transformer but there is not.
I recommend you then go for 18V / 160 VA transformer.
Altronics - M5318 18 + 18 160VA Toroidal Transformer

 

[Jdot]

Thanks for the replys.

The bag of components came from chipamp.com as just that.. a bag of components. No manual, no nothing. The manual section on their site is blank.

I'm struggling a little to figure what trafo to order??

 

[vinodt1347]

Hi,

There is lot of material on the site.
http://chipamp.com/docs/lm3886-manual.pdf

As discussed, you can get either a 18-0 x 2 or 25-0 x 2 V , 160VA, 300VA for 4/8 Ohm speaker. Will be best if you can get 22 V x 2 at around 200-300VA.

 

[Jdot]

Thanks for the advice vinodt1347 😉

 

[vinodt1347]

Cool. if you cant get a (0-22V) x 2 transformer at about 200-300VA go for the (18-0) x 2 at 160VA. Look at the altronics site. The transformer has on the secondary, white and red in the same phase.
On the chipamp site this is shown as AC1 / AC2 with same phase. The same with the other pair. Wire this up carefully. Check polarity of output with a voltmeter. All the best
http://chipamp.com/images/ps-rev3-sch.gif