beginner amp builder questions

[begginerampguy]

hello! I am new to guitar amp building and have some questions about how to go about building amps.

1. how do I figure out how much voltage I need to create 100/ 150 watts of power?

2. how do I select a power transformer and a power rectifier to create the voltages I need for something that will create that much power?

3. how do I pick tubes that will give me enough energy to power a 100 watt output section?

4. how do I pick tubes that will power a pre amp section?

what are the voltage formulas that I will need for each section to figure out what I need for each section based on what I would like in each section of the amp

[Enzo]

HI there...

It sounds like you have never built an amp and are not familiar with the processes. 100 watts is a large tube amp, 150 watts is exceptionally large. I would relate this to building a car. One ought to start out by building a little GO-Kart first, rather than starting out by building a NASCAR racer right off the bat. In other words, you might try building a small amp first, just to get a feel for such construction, and also decide if such work is really as much fun as it seems now.

There are numerous project amps for building from scratch, plus there are some excellent kit amps to build. They include ALL the parts and materials,

There are two things going on here. You want to build an amp, but it also sounds like you want to design it yourself as well. That makes the whole process doubly complex.

[TomCarlos]

Before you do anything else, check out Uncle Doug's two part videos.

How Tube Amplifiers Work, Part 1: The Power Supply

How Tube Amplifiers Work, Part 2: The Pre-Amp and Power Amp

These two video's should give you some insight as to what you are seeking to do.

[Helmholtz]

These two video's should give you some insight as to what you are seeking to do.

Be careful. The guy tends to mix up current and voltage all the time. Not a tutorial I would recommend.

[J M Fahey]

hello! I am new to guitar amp building and have some questions about how to go about building amps.

1. how do I figure out how much voltage I need to create 100/ 150 watts of power?

2. how do I select a power transformer and a power rectifier to create the voltages I need for something that will create that much power?

3. how do I pick tubes that will give me enough energy to power a 100 watt output section?

4. how do I pick tubes that will power a pre amp section?

what are the voltage formulas that I will need for each section to figure out what I need for each section based on what I would like in each section of the amp

You started the wrong way

99.9% of builders out there get a well known schematic first, get all the parts as needed and build it.

The original schematic *already* has all that figured out.

Here: a 50 Watt tube amp, with all parts values and voltages already solved, tubes chosen, everything.
Ignore the silly "mods" drawn in red.

[eschertron]

Just what Juan said. If you're interested in the theory and practice behind the design, look at a lot of schematics. I compared hundreds of schematics when I started with this hobby and have now designed and built... exactly three amps. Think of it like building an airplane. Find out what's good, and what's safe, and what to avoid to prevent a 'crash and burn'.

Oh, and if you don't change your handle now, you'll forever be "Beginner Amp Guy" on the forum

[Chuck H]

bag (beginnerampguy, can I call you bag )

The questions you're asking are VERY rudimentary. The tube electronics environment uses fatally high voltages and some knowledge of safety protocols should be well learned before you start. There are A LOT of books on the basics of electronics and even tube amps specifically. I will take the position that you should acquire two or more and read them cover to cover before you even begin. This is not like building a model airplane or crafting a yard table with benches. To be sure there ARE amateurs with the knowledge and skills necessary to build a functional and even good sounding 100W tube amp from scratch. But these would be hobbyists that have been in the genre for many years. Learning electronics along the way having started with amplifier modification or kit amps or clone builds and then the troubleshooting involved. Consider what questions you will have once you have acquired a suitable 100W transformer and tubes. Putting it all together includes considerations of power supply construction, filtering, grounding scheme, layout for stability, etc. You will also need a preamplifier to drive a 100W power amplifier effectively. You didn't ask about that. There is simply too much to know to assume that one could just "insert part A into slot B". The myriad of specifics and potential complications are in the thousands and specific knowledge in each regard can be necessary to achieve success.

Please trust me on this, if you do not want to read about and learn tube electronics then you actually do not want to scratch build a 100W tube amplifier. Please consider what you actually want. Do want a tube amplifier cheaper than it can be purchased otherwise? Do you want a project with a useful end result? The level of commitment that accompanies a scratch build 100W tube amp is (in my opinion) far beyond these basic impulses we tend to get.

If there is a known amplifier model you think would satisfy your desires I think cloning that model is the best approach for you. While STILL reading and learning from well respected literature. Any amp model you could choose will have 90% of the information you need in the schematic. If you don't know how to interpret that information then you should start by learning THAT.

JM2C