What decides components?

[maxmigax]

I am new to this and have done lots of research but cannot seem to find what I am looking for. I want to understand how to build an amp from scratch, but I don't understand how you are supposed to know which components to use (.22uF Cap or .022uF cap, etc.) and what is the bare minimum you need for an amp to work? Also, what each component does for the amp's tone? I would like to make my own personal amp and was wondering if anyone could enlighten me on these subjects.

[hesamadman]

Oh god man. This is like if a Dr posted on a forum to get some overnight info on how to perform open heart surgery. I have good and bad news. The bad news is this. Its going to take years for you to fully understand all of the questions you just asked. Theres A LOT to it all. Probably more than anyone getting into building ever thought. But heres the good news. If you truly want to do it, there is enough literature on the web and in books to get you where you want to go. Also, there are more than enough people willing to help you and answer questions. Ive learned every single thing I know from reading on the internet and from the guys at this forum.

I would like to make my own personal amp and was wondering if anyone could enlighten me on these subjects.

Now you could start with a small kit amplifier like the fender champ style. Thats a great place to start. There will be lots of people willing to help you with that to get you started.

[John]

how you are supposed to know which components to use (.22uF Cap or .022uF cap, etc.)

Very generally speaking, with your coupling caps you want to use the lower value. I typically use .01, Fender's are normally .022. If you want the amp to let more bass through, say to play harp through, then the bigger values are good, like the .22, even .47.


With the cathode bypass caps in the preamp, the same applies. For "more treble or headroom" (how it often gets described) use lower value caps, like a 1, 2.2 or 4.7 uf. Even on the first gain stage - the input stage - a lot of guys, myself included, like a lower value, usually around 4.7 uf. It all gets down to personal taste.


I highly recommend Merlin Blencowe's book on designing tube preamps, ver. 2. Runs about $40 with shipping, worth every penny.


And read, read, read the threads on here. :)


Also, you'd be surprised how effective a simple Google search will be at directing you to a message board where someone has already asked your specific questions, and someone else has answered them.


Download Express SCH. Learn to use it (pretty easy), learn to make your own custom components, and use it for creating layouts. Being able to attach a schematic to your question posts is, IMO, invaluable.


Good Luck. Be warned, this hobby is like crack. 

[Willabe]

1st off, Welcome Maxx!!!!!   

I am new to this and have done lots of research but cannot seem to find what I am looking for. I want to understand how to build an amp from scratch, .......

Most if not all (has to be all) have learned how to 'build an amp from scratch' (which is different than designing/engineering an amp from scratch) started out on either repairing or copying some amp engineers already built and proven (ie, tested out on stage) work.

We all need to learn to crawl before we can walk and learn to crawl before we run, it's just a part of life. 1st addition/subtraction, then multiplication/division, then fractions/decimals, then algebra, then........          

And I agree with hesamadman. Many guys for a 1st build, go with either a Fender Champ or a Fender tweed Deluxe amp. Both of these amps have pre punched chassis, combo speaker cab's and eyelet/turret boards that are available. Doug has these, except for the combo speaker cab's in his store.     

I don't know what you've found and read in your searching but here's a very good reading link for you, our host Doug's 'Tube Amp Library of Information' is a great place to start;

http://el34world.com/schematics.htm

You could get lost in there for weeks just reading it, digesting it and asking questions about it.   

Hang around here and read the different threads, both new and old and you'll start to put things together in your mind.

There's more links I could post but they really are only helpful after you understand more of the basic foundation information.


                            Brad     

[shooter]

make my own personal amp

don't know your electronic skills soooo.....
I'll 2nd, read, study, figure out which commercial amp, regardless of price, you like best, get a schematic, study it, figure out why "they did it that way" then build a fender SE tweed for practice.  But most of all have fun

[robrob]

max, I have an intro level "How Tube Amps Work" webpage: https://robrobinette.com/How_Amps_Work.htm

And the next level, "How the 5E3 Dexule Works": https://robrobinette.com/How_The_5E3_Deluxe_Works.htm

My "5E3 Modifications" page discusses changing components to change the amp's voice, add gain, etc. that will help get to the next level. I try to explain what the mods do and why they work: https://robrobinette.com/5e3_Modifications.htm

My "5F6A Bassman Mods" page has a "How the 5F6A works" and "How the Long Tail Pair Phase Inverter works" section for more advanced topics: https://robrobinette.com/5F6A_Modifications.htm

[PRR]

> how you are supposed to know which components to use

Same way you build a house. You are not the first to walk this path. You copy an existing house.

Just the fact that you copied it with your own two hands makes it "personal".

Exploring "all" possible variations of tone is more than one lifetime's work. And the search starts with building *something*.

> the bare minimum you need

Older commercial designs "can" be a guide. Audio companies have to carefully consider every part. However there are times when 3 parts are cheaper than 1 part to do the same job. But in DIY, part-count is NOT a big issue.

[Willabe]

As always so well phrased PRR.   

[eleventeen]

Take a step or two back.

If you wish to build an amp "from scratch", what's "scratch"?

Do you want, for example, to mine iron ore, melt it, convert it to steel, roll it to a particular thickness, plate it, then cut it, bend it, weld the corners, punch the big holes and drill the small ones?

Probably not,  but I don't know.

Likewise, you're probably not going to get sand, melt it into glass, bend some very thin sheet metal into tube components and make your own tubes.

Nor wind your own transformers.

So, leaving behind that silliness, you're going to be using the work of others, not just somehow, somewhere, but in every single part. That holds equally true for the circuit diagram and topology. There's no way you are going to randomly, by chance, achieve something better than a plain old Fender Champ. And if you go back to the Tweed Champs (anything in the "5E" series) the circuit diagrams for these are almost shockingly simple. This is where and how you start learning abut amps.

[Ed_Chambley]

I actually began learning out of being a poor musician.  I could not keep paying people to Bias, change tubes and such.  So the way I really learned is maintaining my amps.  It all started with a Super Reverb I have had for years.  A 73 model.  Well I knew how to solder and worked part time as a young guy at a TV and Radio repair shop doing odds and ends.  So I had someone who would answer questions, but he would never teach me anything unless I had read and knew something about it.

He said it was a waste of his time to try to teach someone who was not willing to Read, read, read.  I agree.

So I had heard of converting a Silverface amp from bias balance to adjustable fixed bias and Blackfacing them.  This was before the internet, but it still was not that hard.  I had already understood the basics and replacing parts with others that are the same is not hard, but educational.  Doing this I learned inside the amp there were different sections of a circuit.  I had a preamp, a tone control, reverb driver, tremolo and power section.

To me this was more beneficial than building a Champ or other small amp.  No it was not a scratch build, but with my boss answering yes that is your first filter cap and it is in series with the other one so it can handle the voltage.  Prior to that he said probably 50 times, no that is wrong which meant I had to go read more.  He did not stay like that.  After a while he began teaching me and I started fixing TV's instead of sweeping floors.

The old guys were pretty harsh and there are a couple around here that are that way.  If you try, they will help you build anything you want.

Now go download the FREE Jack Darr Amp Book PDF and read it.  It is free and all over the internet.  It will answer most of your questions for FREE!  Now you have no excuse to join in on this addiction.

[maxmigax]

Well thank you all. I'll definitely take all that you guys said into consideration. I appreciate any help/advice that is given to me.

[Ritchie200]

This has been hinted at, but if you really want to see how "this" value interacts with "that" stage, build something very simple - like a Champ and start experimenting.  Certainly don't try to build a 3 channel 13 gain stage with switchable output tubes - amp of your dreams on your first go-round.  Play around, make some mistakes, burn up a few cheap components, try not to shock yourself - too many times.  Pick up the books that have been suggested.  Having your hands on the subject matter will help you absorb what you are reading.  Read all of Tubenit's posts on his homegrown amps and his quest for the perfect tone.  He does a great job of describing the results.  And last, keep asking questions here on the board.  Welcome!

Jim

[Ritchie200]

The old guys were pretty harsh and there are a couple around here that are that way. 

You calling me old?  You get outa my yard and off my grass!

Jim

[Willabe]

The old guys were pretty harsh and there are a couple around here that are that way. 

You calling me old?  You get outa my yard and off my grass!

           

               

[shooter]

You get outa my yard and off my grass

There were signs in VA back in the '70's saying "sailors and dogs stay off the grass", being a sailor, I just wee'd on his sign

[Ed_Chambley]

The old guys were pretty harsh and there are a couple around here that are that way. 

You calling me old?  You get outa my yard and off my grass!

Jim

No Jim, I am not calling you old, but a hit dog always hollers.  I guess you made your own mess.

[Ritchie200]

Not the first time THAT's happened!

Jim

[sluckey]

I am new to this and have done lots of research but cannot seem to find what I am looking for. I want to understand how to build an amp from scratch, but I don't understand how you are supposed to know which components to use (.22uF Cap or .022uF cap, etc.) and what is the bare minimum you need for an amp to work? Also, what each component does for the amp's tone? I would like to make my own personal amp and was wondering if anyone could enlighten me on these subjects.

Stick around a while.

[pinkphiloyd]

Its going to take years for you to fully understand all of the questions you just asked.

I've been doing this as a hobby for ~5 years now, and I feel like I'm just now starting to learn how much I don't know, if that makes any sense.