As the title suggests, I am a newbie regarding audio amplification design. Although I am soon to graduate with an electrical engineering degree, to say that amplification was skimmed over during one of my many courses is an under-statment. I'd ultimately like to be able to purchase broken vintage or current amplifiers from people, fix them up, and resell them while also getting to experience a wide range of audio performance through benchmarking. My biggest issue is... where the heck do I start? from different amplifier classes to different era's of design, im finding my self being rather overwhelmed. If anyone has tips, resources, or good places to start by all means throw them my way. Thanks a ton!
Edit: regarding workbench, I own a Siglent SDS1202X-E 200mhz 2-channel digital osciloscope, a cheap 40 dollar smart voltage source with current control, an anti-static mat, and a decent soldering iron (which I can use with self proclaimed skill).
Edit: regarding workbench, I own a Siglent SDS1202X-E 200mhz 2-channel digital osciloscope, a cheap 40 dollar smart voltage source with current control, an anti-static mat, and a decent soldering iron (which I can use with self proclaimed skill).
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I do not know about the selling part. I give refurbished amps away to small churches whose ****ese garbage has worn out. Most music directors in bigger churches prefer new new new which means they are on a purchase to scrap treadmill of about 7 years.
If you are going to be up to date, repair class D or H products. As there are a lot of copyrighted microprocessors in these, you may bang your head into a wall. Secrets may not be copied.
I repair Class AB devices which are well documented. I started with Dynaco, but those have gotten quite pricey. McIntosh was always desired but out of my income bracket. More in the bottom feeder class, Crown QSC BGW and Peavey. Prices of Peavey gear for parts or repair are the lowest in my part of the country. Schematics and parts crosses are public. I've recently been observing threads on Adcom, which made enough mistakes in the 90's to fill a textbook IMHO. Oddly their prices are mid-range. Behringer, lots of hulks out there, no documentation or parts available. If you buy products from the 90's or earlier, you don't have to spend $600 on a surface mount capable workstation. Note in buying used, pay attention to location. USPS cost is the same 48 states, but over 70 lb they do not participate. Freight from the coasts to my midwest location is easily is more than the price of a good hulk.
As I have crawled through melted down hulks, I have learned about op amp circuits, Hi freq compression to avoid blowing tweeters or melting woofer voice coils, VAS, predriver, emitter follower driver and output transistors. VI limiters, idle bias setting, DC offset control, protection circuits, fan control circuits.
I extended my skills a bit by graduating from transformer rectifier filter designs (to 1990) then some of the more reliable switcher supply models. I have stayed away from active speakers and low priced switchers which IMHO are designed to fail in 6 or 7 years.
There is also the guitar/bass amp market, which has similar technology but different goals. I play keyboard so I have stayed away from that. Lots of money in reselling to bar bands. Reliable brands, Fender, Ampeg, Marshall, Crate.
RJ Keene wrote a useful beginners resource. People always tout Ron Elliot in Australia, who sells kits and discusses the theory of his designs. His repair article seems to me to be slanted towards finding the stupid mistakes people make in building kits, and not the problems that happen to performance equipment. For basic theory, electronics books stocked in community college bookstores have more practicle theory than the stuff I was taught in EE & physics courses. Kirchoffs laws, vector algebra were useful in filters. tone controls, speakers.
If you are going to be up to date, repair class D or H products. As there are a lot of copyrighted microprocessors in these, you may bang your head into a wall. Secrets may not be copied.
I repair Class AB devices which are well documented. I started with Dynaco, but those have gotten quite pricey. McIntosh was always desired but out of my income bracket. More in the bottom feeder class, Crown QSC BGW and Peavey. Prices of Peavey gear for parts or repair are the lowest in my part of the country. Schematics and parts crosses are public. I've recently been observing threads on Adcom, which made enough mistakes in the 90's to fill a textbook IMHO. Oddly their prices are mid-range. Behringer, lots of hulks out there, no documentation or parts available. If you buy products from the 90's or earlier, you don't have to spend $600 on a surface mount capable workstation. Note in buying used, pay attention to location. USPS cost is the same 48 states, but over 70 lb they do not participate. Freight from the coasts to my midwest location is easily is more than the price of a good hulk.
As I have crawled through melted down hulks, I have learned about op amp circuits, Hi freq compression to avoid blowing tweeters or melting woofer voice coils, VAS, predriver, emitter follower driver and output transistors. VI limiters, idle bias setting, DC offset control, protection circuits, fan control circuits.
I extended my skills a bit by graduating from transformer rectifier filter designs (to 1990) then some of the more reliable switcher supply models. I have stayed away from active speakers and low priced switchers which IMHO are designed to fail in 6 or 7 years.
There is also the guitar/bass amp market, which has similar technology but different goals. I play keyboard so I have stayed away from that. Lots of money in reselling to bar bands. Reliable brands, Fender, Ampeg, Marshall, Crate.
RJ Keene wrote a useful beginners resource. People always tout Ron Elliot in Australia, who sells kits and discusses the theory of his designs. His repair article seems to me to be slanted towards finding the stupid mistakes people make in building kits, and not the problems that happen to performance equipment. For basic theory, electronics books stocked in community college bookstores have more practicle theory than the stuff I was taught in EE & physics courses. Kirchoffs laws, vector algebra were useful in filters. tone controls, speakers.
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