Project FAQ
Here are some questions people often ask when first looking at building a META42.
I've never built a headphone amp before. Can I build a META42?
Before jumping in, first read my article Getting Started in Audio DIY.
You may want to build a CMoy Pocket Amp to get some basic skills before proceeding to the META42. A META42 isn't particularly hard to build, but the build will go smoother if you have these basic skills before starting. It's a whole lot less painful to screw up a CMoy amp than it is a META42, especially if you buy a lot of expensive parts for your META42.
There's an awful lot of stuff to read here. Do I have to read it all?
The more you read, the more likely you'll build the amp correctly.
At minimum you'll need to read through the Part Selection Guide. There are no parts kits available, so you need to read this page to learn how to choose the parts you'll use to build the amplifier. There is no single "correct" set of parts, but there are infinite wrong choices you could make. This section will tell you what works and why. You don't have to read everything on that page; many of the longer items on that page have short answers up front and details below that which aren't essential to understand. Please read all the details about a part before you ask a question about it; you may be surprised at how often the answer is in the documentation.
You may also find the Part Lists page handy. This page lists almost everything you need to build a working META42. You still need to read through the Part Selection Guide to learn how to choose among the alternatives given on that page. Also, you need other parts that cannot be listed on that page because they depend too much on your particular situation so I cannot recommend anything specific.
Once you've chosen your parts, you probably need to read the Step-by-Step Assembly Guide and Assembly Tips pages to learn how to assemble those parts into a working amplifier. If you're new to building amps, you may even wish to skim these sections first, because the Part Selection Guide will make more sense when you know how the parts will be used. If you are an experienced DIYer, you may be able to skip these sections entirely.
Once the amp is working, you may wish to read through the Tweaks page.
That's pretty much all the documentation. So the short answer is, "yes". :)
I'm confused by the number of choices I have in choosing parts. Help!
If you don't want to think about part values, just use the ones given on the schematic. The schematic shows a working configuration, though arguably not the best configuration for any given purpose. There is no substitute for knowledge and experience.
There are many "optional" parts. How do I know if I need them?
The amplifier will function without the optional parts, but there is always a good reason for that part to be used. If you populate the board only with mandatory parts, you end up with basically a CMoy amp, which is probably not what you wanted.
The parts most likely to be left out or jumpered are, in more or less descending order: C5, ZNR/CRD, R8/R9, R10/Q1/Q2, C4, 2001G. While there are other parts that are technically optional, they should always be used unless you know what you're doing.
What's the best way to save money on parts?
Leave out all the optional parts I mentioned at the end of the previous item.
If that doesn't save enough money, be careful about choosing cheaper parts. It would be better not to build the amp at all than to go too far down the quality scale.
Can I use parts not mentioned in your parts list?
The parts table doesn't list everything that will work. It's more a list of examples than anything. Before buying a part not mentioned on these pages, do a search in the DIY archives on Headwize and Head-Fi; someone else may have used the part and reported on it, or there may be advice there saying why a given part is a bad choice for a META42. If you can't find any information there on the part and you aren't savvy enough to be able to pick parts on your own, please ask on the forums about it. Often a part that looks like it will work, won't.
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 sell the hard-to-find parts along with the amp board, and you can get everything else you need with a single order to one of the major electronic parts distributors. If for some reason you do not have access to a major parts distributor, you may be able to ask for someone to send you some parts; please don't ask me, though, because I'm already offering everything I wish to on my ordering page.
Will you build the amplifier for me?
If you've looked through the docs and have concluded that you'd really rather not build the amp yourself, you can look for a builder on the forums. There are several active builders.
I have a question. Who do I ask?
First, look through this documentation. It has been improved continuously since the introduction of the META42, so the answer is often here if you look carefully enough.
Next, look through my articles list. I've written quite a few of these articles now, one of which may answer your question. Naturally I don't wish to repeat myself here in the META42 documentation, and sometimes I don't point to a suitable article when I should.
If you can't find it here, do a search in the Headwize and Head-Fi DIY forum archives. Asking a question that's been answered before (sometimes many times before) is a waste of the other forum members' time and yours. If the answer is in the archives, it's quicker to search the archives than to post the question and wait for people to answer.
If the answer is not in the archives, go ahead and post the question to the forum. It's better to post publically than ask people via email or private messaging because you get more answers by posting publically, and the answers are archived for future builders to find.
This space intentionally left blank. :)