First project - the Mini-CMoy Amp - Page 2

Quote:

Originally Posted by mmcaleer 

Do you have a Mouser Project BoM link?

The parts list page includes a Mouser column.

From the project FAQ:

I don’t want to chase down all these parts. Can I buy a kit?

Sorry, no one’s offering kits right now, and I have no plans to ever offer kits. I offer the hard-to-find parts in the parts shop along with the PIMETA v2 circuit board. You can get everything else you need with a single order to one of the major electronic parts distributors.

Quote:

Originally Posted by mmcaleer 

Actually I was just on you site researching that amp as a possible next amp.  Do you have a Mouser Project BoM link?  I didn't see any kits available on your site.  I used Mouser on my last order and didn't realize they are just outside of Dallas, I live in North Dallas.  I received my order overnight with regular USPS shipping.

Mouser is absolutely one of the finest resources for DIY-ers, anywhere.

You did a great job on that CMoy.  The first one I built worked the first time out, but I had so much length on all of my wire leads that you couldn't even see the perf board in the mint-tin once I packed it all in.

Tangent is right about the PIMETA. It's a great amp and a perfect 2nd build.  Once you have the PCB, all you're talking about really are a few opamps/sockets, some resistors and capacitors, then the connectors and the pot.  Seriously, it's one of the most un-intimidating, yet most rewarding DIY projects you can take around here.  The only complaint in the past was the historically scarce availability of the BUF634.  Now that he's updated the buffer section to more readily available, superior chips, I'm sure it's even better.  My 2nd project after the CMoy was Tangent's orginal PIMETA.  You can see the two I built in the Trickle Charger thread in my signature:
http://www.head-fi.org/t/185377/trickle-chargers/15#post_2278954

BTW, Tangent has implemented a trickle charger circuit native onboard with the new PIMETA version.

P.S. Old school DIY meant a PCB and documentation.  Kits were "cheating."  It's true that these days, there are kits availble from several sources for different designs (I have some, as a matter of fact).  Don't that led dissuade you, though.  Learning to make up an order from a BOM on Mouser (or DigiKey, Newark, Allied, etc.) is one of those essential skills you should learn as a DIY-er.  In the case of the PIMETA, it's much simpler than it seems.

Even a cheap socket should work at any angle when new.

When an amp has to be held at a particular angle to make it work, this often indicates a poor solder joint.

Soldering is straightforward, but if you are inexperienced you can make problems for yourself.

Use a cored (multicore) solder.

Make sure the parts to be joined are clean (bright metal). If necessary scrape them with a blade or polish them with emery paper. Failing anything else, rub them on the sandpaper on a box of matches. You can tin the parts to be joined as per the instructions for tinning the iron if you want to be doubly sure.

Set the parts and board up so that the surfaces to be joined are in contact and unlikely to move or slip apart. You can just hold them (and the solder) with your free hand in most cases although this requires a little dexterity and practise. 

Tin the hot soldering iron. Apply solder to it until it has a thin layer of bright solder all over the working surface. Shake or wipe off any surplus solder.

Heat the joint, not the solder. Push the tip of the iron firmly against the 2 parts to be joined, as close as possible to the point where they meet.

Push the tip of the solder against the junction of the parts to be joined. It will probably contact the iron too. Wait for the solder to flow over the surfaces. When enough solder has covered the joint remove the remaining solid solder from contact with the joint.

Remove the iron from contact with the joint. Hold the joint undisturbed until the solder solidifies. This is usually indicated by the surface becoming slightly less reflective. You can blow gently on the joint to speed the cooling.

DO NOT pick up solder on the iron and attempt to transfer it to the joint. This is a recipe for failure.

That's all she wrote.

Noise in a pot often indicates that DC is flowing in the pot. A good design avoids having DC flow in the pot, so a noisy pot may indicate faulty construction or a poor design.

w

Quote:

Originally Posted by tomb 

P.S. Old school DIY meant a PCB and documentation.  Kits were "cheating."  It's true that these days, there are kits availble from several sources for different designs (I have some, as a matter of fact).  Don't that led dissuade you, though.  Learning to make up an order from a BOM on Mouser (or DigiKey, Newark, Allied, etc.) is one of those essential skills you should learn as a DIY-er.  In the case of the PIMETA, it's much simpler than it seems.

 

I agree, choosing parts for an existing design is probably one of the most basic skills to pick up on.

It's just good essential knowledge to be able to look at a schematic and figure out what you need, tangent is one of the best in telling you in plain english what the part does, why you do or don't need it and what to use there. So it is pretty easy with any of his projects to deviate off from his parts list without losing your way. From there it is fairly easy to go to a supplier and search for the parts that you want by entering in what parameters you want.

As an example tangent doesn't list a capacitor for C2 on his Pimeta v2, oh no!

That's a perfect example of choosing for yourself, say if you were to stick to tangents recommendation of a capacitor from Panasonics FM* or FC or Nichicon PW series. Go to your supplier of choice, filter down the results to those series, choose a voltage range and capacitance values you're interested in. Then pick one from the results that suits the application. Also download the datasheet as that will show you the whole range of values available and various case sizes as well as the specifications, compare and see why one series/brand may be better suited to your uses than another.

You'll start to learn some general rules about certain parts and this will help in future with choosing parts for your own projects.

Some disadvantages of kits is that they usually will not include parts for every possible variant of a build, some parts may be of lower quality than you'd like (the opposite is not usually likely but may apply) and it really doesn't help you learn. You have a part and you know where it goes, but it doesn't help you understand why that specific part was chosen, it just was.

* Panasonic FR is a new line with the same specs as FM, but rated to a longer life, only downside is that they don't look as good, not that is should matter.