Bridging 8 watt power amplifiers?

[sir_modulus]

I have eight LM383 Power Amp's

http://www.generalguitargadgets.com/richardo/practiceamp/lm383.gif

and want to join them together to make a 2 X 32 Watt Amp. Anyone know if this is possible? Anyone have a better schematic than the one above?

thnx

LM250 +

[gez]

Why not use a single amp with a higher power rating?

[sir_modulus]

well I would, cept that i already have eight little ones, and i don't have the money to buy a bigger one (saving up for a G & L ASAT).

LM 250+

[brett]

The easiest thing to do is to parallel two separate halves of what you've got (ie 2 lots of 4), then bridge the two.  The bridging is easily done by inverting the signal to one "half", using the "-" input of any op-amp.  There's some info at the Elliott Sound Products website about this.  The outputs of the two banks of 4 amps are connected to the two speaker terminals.  There is NO earth. Be aware that each bank only sees 1/2 of the speaker impedance.  So if your amps are only good for 4 ohms, use an 8 ohm speaker.

have fun

[Gilles C]

Some info.

http://sound.westhost.com/project14.htm

http://sound.westhost.com/project20.htm

http://www.bcae1.com/bridging.htm

[Mark Hammer]

In an article in Practical Electronics a year or two ago, they provided layouts for power amps based on a couple of different power-amp chips.  One of the layouts was for a bridged amp using a pair of TDA2003's which are replaceable with LM383's.  I think I scanned that.  If you send me an offline note with yor e-mail address I'll see if I can send the scan to you.

[Boofhead]

I'm pretty sure the National Semiconductor data sheet for the LM383 show how to bridge these without any additional active components.  Bridging  gives double the power into double the load impedance.  The idea should work with the TDA2003.

As far as paralleling devices go  - that's probably not a good thing to do.  You have to make sure the two parallel parts share the current properly (otherwise one will fry).  You also have to make sure the scheme you use is stable - ie. doesn't oscillate.  As far as I recall it's not a straight forward thing to do with these devices.

[sir_modulus]

Thanks for your input guys

LM 250+