How did I learn/you can learn

IT IS PRUDENT TO UNDERSTAND THE DANGERS OF ELECTRICITY. THERE IS ENOUGH CURRENT IN VINTAGE ELECTRONICS TO SERIOUSLY INJURE OR KILL YOU AND I DO NOT TAKE ANY OWNERSHIP OVER WHAT YOU CHOOSE TO DO WITH YOUR ELECTRONICS OR YOUR WELL BEING.

I got into stereos around the age of 14 around 2009 or so. My parents let me use an all in one stereo with separate speakers in my bedroom and naturally, I started going to thrift stores to find other speakers and components to upgrade said stereo. Back then, vintage gear was easy to find and very cheap so I amassed a collection of it over the next few years and spent hundreds of hours reading on forums to learn about it. I only ever did a few basic repairs and by the time I was 20 I had sold most of the gear and moved onto other things. Five years later I found a set of speakers that I had always wanted in high school at an antique store for a good deal and that reignited the desire to tinker with stereos. I pieced together a few stereos for friends and eventually one of them said I should make videos about it so here I am haha. I've always enjoyed tinkering with things and thought I'd go to college for electrical engineering but ended up finding a good job in Marketing and never went to college. 

Over these last few years I specifically delved into repairing gear and still have a lot to learn. My main resources were the forums (Audiokarma, DIYaudio, etc.), Videos (Novalux Stereophonic, XrayTonyB, Mend it Mark, and Mr. Carlson's Lab), and some books. 

*There are affiliate links below for products from which I earn a small commission if you buy them through the link. 

My general advice for restoring gear is first, build a dim bulb tester (hundreds of videos and forums posts about these). They're very simple to build and cost around $15-20. Get a decent soldering iron. (I really like my Hakko FX-888D but there are some cheaper options out there that are nearly identical in performance). Then practice soldering on something you don't care about. A keyboard is a great thing to start on and the old wired ones are abundant for cheap at thrift stores. Get some solder flux and some good solder. Kester 60/40 or 63/37/2 silver bearing solder are great to work with. A quarter pound of it or less will last you for a very long time. It's good to note that those solders contain lead which will work it's way into your bloodstream if left on your skin long enough so I always recommend wearing nitrile gloves when handling it. You don't always need to use flux if your soldering iron tip is properly tinned as there is flux in the solder but it lowers the melting point of the solder which is good for sensitive components like transistors and can help to tin new solder pads on PCBs.

I buy most of my electronics parts from Mouser.com or Digikey.com. Both are reputable sites that don't sell garbage. If you buy capacitors from amazon for cheap, don't expect them to last very long or perform well. I look on eBay for custom parts or cosmetic parts and will occasionally buy a unit to use for parts if needed. 

Avoid NTE transistors for the most part. I typically use onsemi/fairchild or other brands available on mouser/digikey. I use Nichicon, Panasonic, Rubycon, and Wurth Elektronik for most of my electrolytics caps. For big filter caps I also use cornell dubilier, Kemet, and Epcos. It's important that the replacement is the same microfarad (uF) rating but the voltage can be one or two steps higher ie. a 10uF 10V capacitor could be replaced with a 10uF 35v. The only time where that differs is in power filtering caps or specific upgrades that people might offer on sites like Audiokarma. For the main power filter capacitors, increasing their uF by up to 20% is also usually ok and can help with bass response at higher volumes. The main importance with replacing them is that they are the same diameter and lead spacing so that they will fit in the clamps that hold them in place or into the holes in the PCB they are attached to. For smaller value capacitors 4.7uF and below, I typically replace them with WIMA, Panasonic, TDK, or Kemet polypropylene, polyester, or PET film capacitors in that order depending on what sizes are available. Metalized Polypropylene (MPP or PP) is the best for sound quality but they are also very large and small sizes are becoming scarce. 

As for actually refurbishing your component, before you dive in or order any parts, Google the make and model and read every forum entry on diyaudio and Audiokarma as well as any other blog posts you can find about your piece to get an idea of what parts you'll need and common issues as well as any possible upgrades for that model or service bulletins. A service bulletin is a change that the manufacturer issued part way through production of a component to make it more reliable. Earlier production models would need to be updated to the recommended configuration. Also watch videos on restoring your piece. Expect that if you are doing a full recap and doing the research that there will be just as much time spent prepping to do it right as there will be spent actually working on the piece. It make take you upwards of 100 hours of time. If you want to do it right, you need to have patience and understand that there will likely be things that you do wrong that might cause other issues. I find that going into a project with no expectation for when you will have it completed lowered my stress/frustration levels when I inevitably messed it up. If you find yourself no longer enjoying the process, set it aside until you feel ready to work on it again. 

 It may be tempting to just rush in and replace everything and hope that it fixes the problem, this is not a good tactic because you will probably install other parts incorrectly and will then be trying to fix another issue that you created for yourself. Focus on getting your piece working, then go in and board by board replace components testing for shorts with your dim bulb tester then sound out of all inputs and both L & R speakers between each board. If you do multiple boards at once and then have an issue, you would have to spend hours of time figuring out what board you messed up on.

There aren’t many courses available for learning stereo repair specifically but Mend it Mark has a great course on troubleshooting and this book (https://amzn.to/3KEVveq) are some of the best options I’ve seen. The creators that I mentioned earlier also all have Patreons which are wealths of knowledge. I specifically really love what Ben (Novalux Stereophonic) does with his. 

I hope this is helpful, happy restoring ✨