NE5532 TDA 7293 Newbie Help

[balaberda]

Hi Guys,

I am new to these forums and by the sounds of reading other posts I really lack a basic set of knowledge about this stuff.

I love electronics and I want to learn how to start building my own amps but every post I have read is already over my head. I started fixing and modding consoles a year ago and I love it. I know my way around a soldering iron and electronics but obviously lack some knowledge when it comes to building them.

Here is what I want to do: I want to build my own amp that powers my 15 inch home JL Sub. My home reciever obviously does not power it enough and I want to run a sub preout from my reciever into the amp (I am hoping to build) that will power my sub.

I have found some things on ebay and dont know exactly what they are:

350W Mono NE5532 + TDA7293 BTL Power Amplifier Kit -New - eBay Power Amplifiers, Amplifiers, Home Audio, Electronics. (end time 27-Jan-10 19:40:36 AEDST)

If I bought this how far away am I from reaching my objective discussed above?

How would I install a volume control ( doesn't have to be nice but I want to control the gain to the sub). How would I power it?

I appologize for the newb post as I have answer several newb posts on my modchip forums and now I am the newb.

I really want to learn this stuff and would appreciate some guides or basic guides/faq's that will get me caught up with the lingo/knowledge.

Thanks,

[Minion]

If it mono then you just put a pot at the input 10k is good .......

Your going to need about a 500va transformer to power it and i suggest you use some speaker protection circuitry./..

[balaberda]

Thanks for the response.

Where is the best place to get a 10k pot?

And whats the easiest way to get a 500va transformer?

Is that all I need to get it powered?

[gootee]

Depends. Where are you located?

In the USA, for buying new, I would suggest mouser.com, allied-elec.com, and digikey.com . Definitely would order mouser and allied paper catalogs, too: Much easier and quicker to see what's available with the paper catalogs. And they are huge, with lots of pictures, making them excellent references and resources. Then use the websites for getting datasheets, checking availablility, and ordering, while also remembering that there are always products on the websites that are not shown in the catalogs.

[Minion]

You will need the Transformer and a Power supply , the Power supply will consist of the Power supply PCB , a Bridge rectifier (25amp) anywere from 2 to 4 10,000uF caps and a few assorted Resistors , caps and even LED"s .....

I would also look into getting a speaker protection kit , this will protect your speakers in case of a fault ......


Cheers


For a cheapo transformer Look for a 500va 28v , 0v , 28v ...... Try Apex JR in a the vendors section or contact him personally and see what he has got in stock ......

[jtktam]

I had just finished building my amp using the same board..

350W Mono TDA7293 X 4 + NE5532 POWER AMPLIFIER KIT - eBay (item 200429073332 end time Jan-26-10 20:12:12 PST)

buy the amp + power supply combo.. it works wonderfully..

I used a 28v/0/28v 400va tranformer.. after the power supply section it outputs 35v DC so it's just perfect for this board

-joe

[AndrewT]

is that TDA7293 PCB based on a 4 chip bridged parallel arrangement?
If so then don't use a 4ohm speaker. Stick to 8ohm.

[balaberda]

So if I buy the power supply unit that it can come with I still need a transformer?

I may just build my own power supply as I was reading through the guide and I have some good electronic stores that people will help me through.

It says something about the aluminum heat sink. How and where do you mount it? I assume this is just for heat right?

Can I just use fans to cool it intead?

I am thinking about building my own power supply and installing a few fans ext and putting it in an empty xbox 360 case. I have tons as I mod and repair them.

I appreciate the help I am learning much more and very quickly (but obviously a large newb).

Is it worth buying the DIY PCB and then just building it with Capactitors/resistors etc etc (ordering the tda chips separate)

or...

Is it better to just buy these kits already made up and worry about the power supply (and whatever the aluminum heatsink is for)?


Thanks again

[Minion]

A heatsink is a "Must" and you are going to need a big one !!!

The amp it"s self will probably dissapate 150w of heat ....

Without a heatsink the amp will fry it"s self in a matter of seconds ....


The chips them selves attach to the heatsink Via the holes in the Chips , You are also going to need Thermal insulators (Mica or sil pad) and Insulators for the mounting bolts and get some heatsink compound....

The Insulators are to isolate the chips from the heatsink as there is voltage on the metal parts of the chip , the insulators and the heatsink compound also efficiently transfer the heat from the chip to the heatsink....

You probably won"t find a heatsink that has the mounting holes for the chips in the right spot and the right spaceing so when you get yourself a big heatsink (and I don"t mean one from a PC CPU , something 4 times that big) you will have to drill the mounting holes yourself


From building a few of these ebay kits it is better to buy the whole kit with parts as and Populateing the PCB with the parts and soldering it all yourself as opposed to buying the PCB and then trying to source the parts yourself ......
For the PSU you can buy a PSU PCB or whole PSU Kit probably from the same seller for pretty cheap ......

The Transformer though is generally the most expensive part of the amp and the Heatsink can also get pricey thats why I usually scavenge my heatsinks from old amps and stereos and recievers ......

Good luck

[balaberda]

Thanks for the help. I have an endless supply of xbox 360 heatsinks that I might be able to rig something up with.

If I wanted to add a pot I just add it across the power?

I will try and find a PSU board or kit.

I stopped by my local electronic store and his 35v (8 amp and up) power supplies are brutally expensive.

What is this part all about? All I need after this is the transistor correct?

I don't think I want this big of an amp for my first project and I might just play around with a smaller one. I was thinking about this one and it seems like I don't really need a PSU is that true? Just a transformer or will I still need a PSU.

TDA7294 x 2 Power Amplifier + Speaker Protect UPC1237 on eBay.ca (item 330398065984 end time 25-Jan-10 19:30:08 EST)


Thanks again