Usher s520s with lm3875

[redrum.42]

Hi,

I recently bought some Usher s520 bookshelf speakers: http://usheraudiousa.com/products/lo...s-520-shielded

I also have an lm3875 kit which I bought but have not constructed yet. I wanted to know if this chip amp would be suitable for these speakers (first time project) as they have fairly low sensitivity (86 dB). If so would I require a larger transformer to compensate for the lower sensitivity? any recommendations on which transformer to go for would be greatly appreciated!

Thanks

Andrew

[panson_hk]

Originally Posted by redrum.42

Hi,

I recently bought some Usher s520 bookshelf speakers: http://usheraudiousa.com/products/lo...s-520-shielded

I also have an lm3875 kit which I bought but have not constructed yet. I wanted to know if this chip amp would be suitable for these speakers (first time project) as they have fairly low sensitivity (86 dB). If so would I require a larger transformer to compensate for the lower sensitivity? any recommendations on which transformer to go for would be greatly appreciated!

Thanks

Andrew

Andrew,

I have two pairs of S-520 (rose wood and glossy black finishing). It is a nice speaker. LM3875 should be sufficient to drive the speaker. We don't use it for BIG bass. I have been using a similar output level chip amp TDA7294 for 520.

You don't need to do any special thing for 86 dB sensitivity. An over size transformer does not help. The data sheet has shown you a design example. For that 40 W example, a 2x 22-0 VAC, 8 A transformer is sufficient for two channels.

Panson