Orange Amps Forum

Hey all!

I know it's not impossible, as many great techs are self taught. What reference material would be the best in which to start learning all I can?

I can already do soldering pretty well, and I have made some minor mods to amps in the past. I bias on my own, etc. But, I struggle with schmatics, and lack a thorough understanding of electronic theory, although the basics make good sense to me.

Anyone else attempted this journey?

I'm going to assume you mainly want to work on valve amps, as you mention biasing.

It is really important to get the fundamentals firmly in place.
If you do this properly the schematics will start to make sense.
It might seem boring at first but it is worth it.

Firstly learn DC circuits just involving voltage sources and resistors/resistive components.
Learn and get your head round Ohm's law. Learn how resistances in series & in parallel work.
Then move on to circuits with only inductors/capacitors/resistors and voltage sources. Learn how a capacitor in series with a resistor behaves when connected to a voltage source. Learn how an inductor in series with a resistor behaves when connected to a voltage source.

Then do AC circuits with inductors/capacitors/resistors/transformers/diodes.
Learn how inductors and capacitors behave at different frequencies. Learn how simple filters work. Understand how transformers work. Understand how diodes work - get your head round the bridge rectifier.

Finally, learn how transconductive (amplifying) components work - i.e. valves and transistors.

Once you have done all of the above - go here: http://www.freewebs.com/valvewizard/ and start with the triode gain stage. Don't bother trying to understand the valve stuff if you haven't learnt the basics because it will get really confusing. Then do simple single ended output stages, then push-pull output stages with phase inverters.

Even if you fully understand everything on the Valve Wizard website, it still doesn't make you a tech. You need to learn how to fault-find, and to be good at that requires experience. You also need decent test equipment - oscilloscopes, signal generator, dummy loads etc.

I finished my Electronics Degree in 1997 and worked as a electrobiomedical engineering tech for several years after that. I only got into valve amps about 5 years ago - my degree taught me nothing about valves at all so I had to teach myself about all that. A lot of my valve theory comes from the Valve Wizard website.

jontheid wrote:I'm going to assume you mainly want to work on valve amps, as you mention biasing.

It is really important to get the fundamentals firmly in place.
If you do this properly the schematics will start to make sense.
It might seem boring at first but it is worth it.

Firstly learn DC circuits just involving voltage sources and resistors/resistive components.
Learn and get your head round Ohm's law. Learn how resistances in series & in parallel work.
Then move on to circuits with only inductors/capacitors/resistors and voltage sources. Learn how a capacitor in series with a resistor behaves when connected to a voltage source. Learn how an inductor in series with a resistor behaves when connected to a voltage source.

Then do AC circuits with inductors/capacitors/resistors/transformers/diodes.
Learn how inductors and capacitors behave at different frequencies. Learn how simple filters work. Understand how transformers work. Understand how diodes work - get your head round the bridge rectifier.

Finally, learn how transconductive (amplifying) components work - i.e. valves and transistors.

Once you have done all of the above - go here: http://www.freewebs.com/valvewizard/ and start with the triode gain stage. Don't bother trying to understand the valve stuff if you haven't learnt the basics because it will get really confusing. Then do simple single ended output stages, then push-pull output stages with phase inverters.

Even if you fully understand everything on the Valve Wizard website, it still doesn't make you a tech. You need to learn how to fault-find, and to be good at that requires experience. You also need decent test equipment - oscilloscopes, signal generator, dummy loads etc.

I finished my Electronics Degree in 1997 and worked as a electrobiomedical engineering tech for several years after that. I only got into valve amps about 5 years ago - my degree taught me nothing about valves at all so I had to teach myself about all that. A lot of my valve theory comes from the Valve Wizard website.

Thanks for the post! I am wanting to focus on valve amps. I don't intend to work or maintain anything but my own amps, but I want to be able to do it well. I have several amps ranging from as old as 1972 to present day, and I'm tired of having to send things off all the time if work needs to be done. Oh, yeah, and it's fun to think about and work on. I'd love to begin building my own circuits at some point, whether it be simple low wattage amps, or just effects pedals.

Ironlung is good branding for the stoner rock genre. Go build it.

Tip of the day: Always keep one hand in your pants while working on valve amps.

I have a good friend who is an amazing tech. He not only fixes amps, keyboards, recording consoles, whatever, but he has also designed his own line of amps. They never got farther than a few prototypes due to a few things not worth mentioning, but anyways, the dude is a genius. He works at a shop in Denver now, and makes really good money for his work. He started off an electrician long before touching amplifiers. I guess my point is, you need to understand electrical circuits before you even move on to amplification. A person that just knows how to build an amp probably won't have the fundamental knowledge to fix things, make innovative mods, etc. The ability to troubleshoot complex circuits for issues seems to be the hard part, and that's what in my mind separates a tech from a guy that knows how to build amps and pedals from kits and execute routine maintenance.

I guess if I were you I'd start learning the basics of electronics from the very beginning, even if you know how to do a few routine tech activities.

yeah, I know I need to crack some books. Just so much out there, it's hard to know where to start.

Randy Bass wrote: Tip of the day: Always keep one hand in your pants while working on valve amps.

Excellent advice... I just hope ironlung realises you are being serious for a change

OrangePaul wrote:

Randy Bass wrote: Tip of the day: Always keep one hand in your pants while working on valve amps.

Excellent advice... I just hope ironlung realises you are being serious for a change

I tried keeping one hand in my pants today, while working on some gear.
Not a bad sensation, though I would recommend working on the gear afterwards.

ironlung40 wrote:

OrangePaul wrote:

Randy Bass wrote: Tip of the day: Always keep one hand in your pants while working on valve amps.

Excellent advice... I just hope ironlung realises you are being serious for a change

I tried keeping one hand in my pants today, while working on some gear.
Not a bad sensation, though I would recommend working on the gear afterwards.

Tip #2: It's always best to discharge your capacitors before you start working on an amp.

ironlung40 wrote:yeah, I know I need to crack some books. Just so much out there, it's hard to know where to start.

I canot recommend anything for SS but for tubes I would recommend:

''Beginner's guide to tube audio design'' by Bruce Rozenblit as nice place to start.

''RCA Tube Handbook'' as THE classic you cannot live without.

You will also need a general book on electricity and magnetism. ''Electronic Device and Circuit Theory'' from Boylestad is as good now as it it was 40 years ago (unless you want to design a smartphone...).

Watch out playing with tubes... I second the ''keep one hand in your pocket'' advice, especially when reading voltages. 650 V at 30 mA is not something you want to get zapped with!

Enjoy the journey!

eBay is a nice place to buy measurement gear for cheap.

My mechatronics teacher in college recommends this book to all his classes, and even used it as a reference for some of his lectures:

Title: The Art of Electronics
Author: Paul Horowitz
http://www.amazon.com/Art-Electronics-P ... 0521370957" onclick="window.open(this.href);return false;

From the description:

It is an ideal first textbook on electronics for scientists and engineers and an indispensable reference for anyone, professional or amateur, who works with electronic circuits.

indianDYsummer wrote:My mechatronics teacher in college recommends this book to all his classes, and even used it as a reference for some of his lectures:

Title: The Art of Electronics
Author: Paul Horowitz
http://www.amazon.com/Art-Electronics-P ... 0521370957" onclick="window.open(this.href);return false;

From the description:

It is an ideal first textbook on electronics for scientists and engineers and an indispensable reference for anyone, professional or amateur, who works with electronic circuits.

Wow, almost $100! Dang. I might get this someday just because I like to know stuff.

just wanted to drop back in and say, thanks for the continuing comments. I'm paying close attention to all, and plan to pickup some of the reference material and follow the advice in here. Please, keep it coming....one might just learn something!

'The Art Of Electronics' is a good, well written book for electronic students, but it won't help you with valve stuff at all.

My 1985 edition doesn't even have the words 'valve' or 'tube' in the index.

I doubt anything in it after chapter 4 is going to be relevant to fixing older type valve amps also - a lot of digital stuff.

N.B. - I am not knocking this book at all! I really like the way it is written, and I used it a lot in my degree. I just think that a lot of the info in it isn't going to be of use, and it isn't exactly cheap!

Cheers
Jon