I'll start, maybe someone can add more and put to meta or something.
- What can be built as a DIY-project for the average builder?
* If you find a help thread for the project and there is finished builds found (go to the end of the build thread and browse couple of pages back and you'll know if anyone has actually built it). Check what kind of problems people have if they have any. Problems with PCB indicate it is not for beginners.
* If you don't know how to wire mains transformer or don't know how to wire controls and connectors without wiring guide one should read more or build a kit with a building manual first.
-- What are the popular projects? What are their features?
* What you see in The Lab on couple of first pages, or if the project help thread has tens of pages of discussion.
* Features: You should be able to know if the project is preamp or eq or whatnot. Try googling the project name. If there is photos look the front panel.
- What kind of sound-quality could I expect?
* As good as you can build. Depends on what components you use and you know how to use them and if you know how to keep hum and buzz out. The kits around generally have good or excellent sound quality with the parts they list. What is sound quality? You will develope personal preference by trying out different transformers and capacitors etc. in time. The circuit topology will affect most how it sounds. Changing capacitors and resistors don't affect that much (at least don't buy very expensive parts if you can get cheap, unless you have heaps of money). Aim for low noise and finishing the unit without bankruptcy.
- How expensive is it?
* Bulk Chassis + powersupply components generally add up to 100€ or more.
* Miscelaneus bits and pieces (wire, screws, connectors, stickers, new tools) can add easily tens of euros.
* Transformers are the most expensive stuff. As are discrete operation amplifiers (DOA), some tubes, Grayhill brand rotary switches, meters... Sometimes the PCB might cost over 100e.
* Only few projects cost less than 200e to finish and most are more than 500e per box. Depends what parts you use and how much of it is recycled televisions and so on. No answer here. Expect to spend several hundred euro.
* DIY is not cheap. If you go to audiophile foolery you can douple or triple your cost. If you count your working hours DIY is more expensive than buying ready made units. DIY is a hobby and shouldn't be judged by the cost. Be sure to keep good notes what you have done so after 1 to 40 years your unit breaks down you can still fix it
-- Buying the parts?
* Mouser and digikey you can find most of the electronic parts. Meters, transformers, some switches, some potentiometers (rev log for example), tubes, chassis, custom front panels need to be bought elsewhere (look White market, tube amp stores etc.).
* Usually I buy tubes from ebay, passive and active parts from Mouser or some local electronics store, transformers depending on the project, meters from white market or black market here at groupdiy.com. Frontpanels from White Market or do my own. Chassis from local store or for example from modushop.biz in Italy. Knobs from Farnell, Banzai music, recycled from old kitchen aid, what ever you like
Most often it takes at least 2-5 different sources for parts depending on project of course.
* Combine parts of two projects to save on bulk and postage.
*
Tip: Don't get greedy, buy parts only one or two projects not for 10 projects since that way you'll end up 10 half finished projects instead of two finished
-- Shipping and VAT-handling?
* Order from outside EU to EU you'll pay customs and VAT. If your parcel is small there is no customs and VAT. Customs are from 1-2% here in finland, VAT here is 23%. You'll pay customs and VAT for the shipping as well.
-- Getting the tools needed?
* Soldering iron, solder, wrench or some third hand to keep parts still while soldering, some metalworking tools such as power drill, drill bits (unibit for bigger holes). Maybe hole punch for XLR. Screwdrivers, pliers etc. You notice when you need more tools and can then go to local hardware store and buy one.
- How difficult is it?
* More wiring = more difficult
* Poor PCB layout = more difficult
* Less documentation = more difficult
* The most difficult thing might be the metal work and trouble shooting if you don't have enough support. Check every solder joint you do and triple check all wiring! It is a lot of work to trouble shoot non working unit. Don't hurry, take it easy and quadruple check everything!! Measure all resistors, check orientation of electrolytics and tantalums, semiconductors... Do couple of projects and you'll find it out yourself
- Do I have to expect a lot of troubbles and problem-solving?
* Yes if you are not careful
* Yes if you don't have detailed instructions nor experience about similar projects
* Yes if you don't know grounding concepts
* The more parts you have, the more wiring you have, the more changes to do a mistake. Be patient, check everything you do, concentrate, take your time.
* If you run into problems, breath and start troubleshooting in a logical manner to accurately spot the error. Consult the help thread before starting another since most propably some one else has ran into same or similar problems before.
- What kind of knowledge is needed?
-- To choose pcb, psu and case.
* PCB you can buy. People who have provided PCB's to manyu projects do good PCBs. Check out if the PCB is the first version they have often some minor issues. Second batch, much better (propably). Read help thread, all problems are found there if any. You can roll your own PCB. Check out PCB software and google about how to make PCB layout. Simple projects you can do on veroboard.
* PSU: depends on the project. There are plenty of examples, just search and read.
* Case: Experience. Measures what will fit into what enclosure. Bigger enclosure is easier to work with but take more space in your rack / table. Check out what other people use. Tube projects are generally 2u high or more. Some fit into 1u so no rules here either. Aluminium is easier to work with than steel. Full aluminium cases are expensive so most often only the frontpanel is aluminium. Sometimes the back panel as well. Full aluminium encolusers are more expensive than steel counterparts but they don't rust. Steel provides better shielding (was it magnetic or electrical or both? home work for you to find out
-- To choose parts?
* Experience. Read a lot. Check out BOMs (parts list for the project, bill of materials ?) and compare to the PCB and schematics. Most trouble will come from choosing right type and size of capacitors I think.
-- To get parts?
* Just order from your favourite source some of which are already listed above somewhere.
-- Safety and fire?
* This is your own risk. Read a lot and ask. One hand in pocket. Wear safety classes. Always keep power cord disconnected when working with the project. If it is a tube project the PSU capacitors can hold lethal charge several minutes after disconnecting the power cord! Check with multimeter there isn't any voltage left in big capacitors before you start poking. READ A LOT. I'm not responsible. Maybe some link for resource here?
-- Building, soldering, connecting?
* Youtube, instructables. Google is your best friend. Some tips can be found from the forum some times. Check meta.
* Molex and screw type PCB connectors are the most used, try googling. Most often you can use the same parts (hole spacing in PCB)
* Use shielded wire, twist wires when possible to minimize loop area (varying magenetic field going through a loop will introduce current to that loop). Read how you should hook up the shield in the shielded wire. Check rane notes about hooking up stuff http://www.rane.com/library.html
- How do I get a nice looking unit?
* Take your time for the assembly and plan properly. Measure thrice and drill once. Get some front panel engraved. Depends if you have taste for good looking units
* for drilling, use smallest bit you have and gradually use next drill size until you are on your target size hole. Too big drill bit will wander and your hole will end up off. Use center punch to make the first dent in the correct spot.
-- What's the options and costs?
* If options are not listed, ask. If the project "owner" sells PCBs or anythign he'll help you gladly. Otherwise only experience tells you what you can do.
* From 0 to 1000000, depends how many liters of snake oil you want to have.
Free tips:
* Aim for durability and low noise, this is the benefit doing it your self.
* It takes a lot of effort to finish a build. Keep good notes so you know what is in your box. This way you are able to repair it after several years or revisit the build you started last year.
* Build stuff you need, not what you want. This keeps you motivated and gives the most satisfaction eventually.
* Concentrate on one or two builds at a time so you'll get something finished. There is many half built projects in black market.
* Keep your stuff organised so you can build / order parts when ever you have time. These aren't one week projects here...
* My projects from start to finished unit have lasted a year or more. My pockets are empty so one month I buy transformers, one month the chassis and so on...
