Chipamps Lead and Everything

[Elmosslave No.437917]

So my plan is to build a chipamp. I honestly don't know very much, but I've been researching and figure I shouldn't have too many problems..... :S

I was wondering if anyone had any experiences or advice they could give me and also hoping someone could let me know why the lm3886 chips seem to come in lead or lead free (nopb) varieties but there doesn't seem to be info on it......

So ya chipamps, any wisdom /diy/nosaurs?

[Elmosslave No.437920]

Hmmm probably should have posted at a better time ..... lol sleepy /diy/nosaurs

[Anonymous No.437922]

>come in lead or lead free (nopb) varieties

Tin-lead was the old standard pin coating. The components were soldered using tin-lead solder.
Then it was realized that electronics contains all kinds of toxic shit and not all of it is absolutely necessary. Lead was one of those "not absolutely necessary" chemicals and it was decided that lead-containing solder (and pin coatings) will be phased out.

Too bad the old lead-containing solders are better than the new solders. It's still used in applications where reliability is important, like in medical devices.

Tl;dr? Get lead free variant, it should be easier to get nowadays.

[Elmosslave No.437924]

Thank you so much, you sir are fantastic
>>437922

[Anonymous No.437942]

3886's are fucking rad. You only need 9 components to make a sweet as fuck high power, super low distortion power amp.

i've built piles of them for power amps, sub amps (parallel a couple or them), guitar amps.

amazing things!

the basic circuit in the datasheet from NatSemi is pretty much all you need.

Lead or lead free makes no difference really. Lead free is slightly more of a pain to solder as it doesn't flow onto the pins as nicely. Also, don't use lead free solder as it sucks ass.

[Anonymous No.438131]

Working on a chipamp myself right now. It doesn't use the LM3886, I'm using its brother, the LM3875.

I'll try to get some pics up of the heads later when I get off work.

[Elmosslave No.438209]

>>438131
That would be neat.

just curious but, what are the benefits of the lm3875 over the 3886 ?

[Anonymous No.438545]

>>438209
Forgot to take some photos, I'll have some time tonight to get them.

The LM3875 doesn't have an advantage over the LM3886, it's the other way around.

The LM3886 can drive a 4 ohm load up to 68 watts (within specific supply voltages) and also has a muting function built in.

The LM3875 can only drive 8 ohm loads, and is good until 56 watts. It also has no built in muting.

I'm using the LM3875 because I scored some off ebay for dirt cheap.

Outside of that, they are pretty much identical.

[Anonymous No.438819]

>>437924
>>437922
The whole RoHS thing was such a crock. Lead in leads doesn't leak out nearly enough to be a health concern. The actual problem was shit like CRTs using on the order of POUNDS of fucking lead for shielding.

[Anonymous No.439200]

Finally got some pics taken.

This one uses 6 chips, all independent. Six inputs, six outputs. Nothing fancy on the board, just straight amplification.

It's part of a larger system that does more with the signals coming into the amp, but this is the part that does the heavy lifting.

[Anonymous No.439201]

>>439200
This is the other head, designed to drive 4 ohm speakers. There are six LM3875's, but there are three pairs, each pair wired in parallel. Three inputs, three outputs.