LM3886 owners needed

kanifee

Member
2008-04-02 11:59 am
Hi all, i recently came across the Lm3886 chip amp kit and this took my attention away from the 41hz amps because of its simplicity and price.
having never dealt with electrical appliances at this level before im very noobish but after weeks of learching around and looking at differant things i think im starting to get a general feel for the diy amp world. Im slowly starting to uncrypt schimatics though im still not 100% and i still find it hard to clearly know what parts are what or called what exactly from them.
im thinking of getting one of these chip amps form chipamp.com but i have a few questions first, are these loud/powerfull, i was also told the LM series of chips could be run in paralel, how hard is this to do, would it involve new pcb's or a new kit completely?

I have hundreds of questions boiling around in my head but these seem like the most prudant at the mnute and ill search the rest fo the forum for the others but any helpp is really appreaciated!
 

ttan98

Member
2006-04-04 11:24 am
Melb
kanifee said:
H
im thinking of getting one of these chip amps form chipamp.com but i have a few questions first, are these loud/powerfull?

i was also told the LM series of chips could be run in paralel, how hard is this to do, would it involve new pcb's or a new kit completely?

I have hundreds of questions boiling around in my head but these seem like the most prudant at the mnute and ill search the rest fo the forum for the others but any helpp is really appreaciated!

to answer your questions above

1. with +/- 35V dc power you can get about 60 watts(LM3886) into 8ohms if you drive the speakers directly using active x-over even with 88db spl drivers, the sound can be very loud. I am doing this now.

2. look up the thread on PA150 it is 3*LM3886 in parallel you can get 150W norminal. Plenty for most applications

I suggest you do search first a read a few threads and then ask SPECIFIC QUESTIONS, then you ill get answers. They are many here who will help.
 
Hi,
for your first power amplifier project, keep it very simple.

Ordinary Power Supply (PSU) using just a dual secondary transformer + rectifier + smoothing capacitors.

Single chipamp, do not even look at parallel or bridged until you are very familiar with understanding the requirements and consequences.

Download and read the National datasheet and application notes. Re-read and memorise. Then come back with questions.

Use DC blocking on both the input and the Negative FeedBack loop (NFB). Decide later if you want to use a DC coupled design.

Use 8ohm speakers, not 4ohm and not 4 to 8ohm (which have become very common).

Buying a kit with good support makes the first project much easier, but we are here to help as well.

Finally, do not worry about output power and adequate volume. Get it running correctly first. measure the output voltage after you have played with it a while and you'll find that much of your listening is done with 1Vac to 3Vac being fed to your speaker.