Desk-top tuner, amp and speakers

[AIA]

I am interested in building a desk-top amp (10 watts, or so) and tuner to drive a pair of small, full-range speakers. I could buy something like this at Target for $30, but that's not the point.

Does anyone have any sources for the design and parts?

I think that I have a basic grip on the speakers, although any suggestions will help. I have also seen a few books and websites touting amp designs, but this is my first project so ditto the suggestion request. What I really can't find is a source for a small FM tuner to build in to the system.

Thanks.

[pinkmouse]

Hi AIA, and welcome to diyAudio.

I tried something similar a few years ago, but had to give up, there are just no straightforward tuner circuits around. In the end, I used an old walkman with a burnt out motor, I just ripped out the pcb and adapted it to fit in with the amp.

However, you should have more luck with the amp and speakers here! Do you have any ideas on size, budget, preferred brands at all?

[dnsey]

How experienced are you in electronics?
Design and, to a lesser extent, of an FM tuner is quite involved to say the least.
If you want to have a go though, I suggest sticking to one of the 'single chip' designs or a ready-made RF module.

[AIA]

Thanks for replying, and, thanks, it's good to be here.

Regarding budget, well, I'm not quite sure what my options are.... I figure the speakers will run around $50-75 US the pair; I am hoping the amp parts can be had for for about the same and I have no idea what the RF parts will cost. Research is clearly in order!

Regarding experience in electronics, this is my first project. I do like the suggestion of a ready-made RF module. On the first go-'round, it may be best to keep it simple.

thanks again!

AIA

[lineup]

What kind of power supply will you use?
Normal Mains AC or something else?

[lineup]

In-depth project details:

* Circuit design - Implementing the LM4780, including a thermal shutdown feature.
* Construction - Pictures of the point-to-point wiring and details of the enclosure.
* Power Supply construction - More constructional pictures.
* Sound quality and conclusions - It's early days, but this little amp sounds pretty good!

* Full Schematic - Complete circuit details.
==============================================


This "stacked" view shows how they are almost the same size as a CD.


M. Hennessy 'microamp' project is a really compact amplifier!
He uses a wellknown two amplifier (stereo) IC called LM4780.
The LM4780 contains two LM3886 dies (reference) giving 60 watts per channel,
which is rather more than required this application.

M. Hennessy is a member of this forum: mhennessy - profile
Great pictures to show in detail how he built this little amp.

More info LM4780 Micro-Amp


Complete Schematic PDF

[dnsey]

Quick edit of my previous post - I meant that construction of an FM tuner was not quite as involved as its design.

If this is your first project though, I'd leave the tuner for a while. It really is quite a difficult thing to do, even with ready-aligned modules. For example, everything has to be correctly positioned - even the curve of a wire connection can make a big difference.

As an intermediate step, why not take a pocket radio and add a stereo decoder, probably rehousing it too? You'd learn quite a lot about multiplex decoding, de-emphasis etc. that way, and if you get hooked you could then try for a scratch build.

Do the amp first though, to get your hand in!