Beta boards?

[littlerick]

Hi all... I have got the PCB's for the 4780 chips.. Both red and blue. I'm realy itching to get started but need some help.

I have looked up parts on suppliers and to be honest have found myself a little overwhelmed with the list and choice of components. I'm unemployed and dont want to order a stack of stuff thats not upto the job.

Can anyone put a kit together of all parts to populate boards and let me know a price.. I was gonna start with the blue one first and make a stereo single chip amp.... If I do it well maybe the boss... I mean.... the wife will be a little more forgiving with the red kit.

Im in the uk so if anyone can help pm me a price or a very easy to follow part list

[GloBug]

Just populate it with basic parts then upgrade caps and such later if you want. Or search some of the other threads, see what they are using. Lot's of info on chipamps here, you can look at other models to get a feel for what people generlay think works. There is a LM3886 thread that is over 3000 post long now.

For the most part, focus your funds on the capacitors, with the priority being quality audio caps, then power supply caps.

Go to your Radio Shack type store and get some cheap 1/4 or 1/2 resistors packs, or online. If I recall there is at least one 2W resistor you need to get, and have a look to see if there are any other larger ones, order them too.

Here's one of the manuals, check it and see if it is your board, even if it isn't it should help shed some light on the situation. http://chipamp.com/docs/lm3886-manual.pdf

I have not started mine yet, (not here yet), but when I do I will know a little more about it.

[littlerick]

OK... So as long as the resistors and caps are the same value as what i need it doesnt matter what type they are?

I have only built one kit before and all parts were provided.. Just enjoyed it so much i want another go. I am a complete noob, I know nothing about electronics, but I can read instructions. Everybody here is helpfull too. I would like to do a proper job tho and use good parts if i can. The 4780 is easy.. there is only one, but caps and resistors seem like a swamp of choice. I guess MUR860 is the next one i know for sure.

[GloBug]

Pretty much.

The amp would "fuction" fine so long as the values/ratings are meet.

In audio applications though some improvements can be made, particularly with parts in the audio path itself. Example metal film resistors don't make as much noise as say cheaper carbon resistors. That being said, a carbon resistor maybe selected by someone building a vintage guitar amp and wants to be faithful to the original sound.

Capacitors in the audio path are the ones I would upgrade first, generally the more expensive ones are better, you might want to avoid ceramic all together in audio amps.

As far as the big power supply caps, they are pretty much always going to be electrolytic, it's the only material that gives that much power for the dollar. (practical) Just make sure you get known newer ones for these. They should have a life of at least 10 years. (in reality most work for much much longer). -Most of the smaller signal caps can last forever depending on what material they are.

Size is also a consideration as we are building on a board.

I myself am not above harvesting parts from other gear. If it helps you out, go for it.

[littlerick]

Thanks for info

[UrSv]

Originally Posted by littlerick

I have looked up parts on suppliers and to be honest have found myself a little overwhelmed with the list and choice of components. I'm unemployed and dont want to order a stack of stuff thats not upto the job.

All the resistors and caps you need, except the 10.000 uF/50V, are GBP 1.00 in total. The supplier is in Sweden and is called UrSv.

This supplier offers a payment plan up to 50 years for this purchase in case immediate financing is not available. That is an annual tuppence and invoices totalling less than a shilling need not be paid as administrative cost would be prohibitive.

Let the supplier know if you need the stuff.

[GloBug]

Sign me up!

[UrSv]

Originally Posted by GloBug

Sign me up!

Sorry, this is a one-time offer for the unemployed in cooperation with the Dole of the Northpole.

[littlerick]

Hi mate bits arrived this afternoon... Just wanted to check b4 i solder into place...

The Diodes MSR1560's... Do they go into board with plate facing the white line or away from it... I made a big mess last time I used MUR's and got em in wrong way.

And a big thanks for the bits

[UrSv]

Originally Posted by littlerick

Hi mate bits arrived this afternoon... Just wanted to check b4 i solder into place...

The Diodes MSR1560's... Do they go into board with plate facing the white line or away from it... I made a big mess last time I used MUR's and got em in wrong way.

And a big thanks for the bits

Good news and no problem as I had some to spare. Metal surface towards white line i.e. white line and metal on the same side of holes. Check pics at ChipAmp.com for the same type of diodes: