So if I were to design an amp...

[keantoken]

Hello.

I was thinking that I would love to build an amplifier of my own design. The problem, however, is that it doesn't seem like there's much use in designing a new amplifier when there are already so many other great ones out there.

So I was thinking to myself, wondering why people still keep building more amplifiers.

Naturally, they do it because it's fun. I understand that perfectly. Those who remember two years ago will attest that I still loved playing with the simulator even though I had little idea how anything really worked.

However, I still have little idea what in an amplifier makes it desirable, other than low component count, low distortion, high efficiency, and really neat design.

So, asking those who design amplifiers, I would like to know something. If I were to design an amplifier on which to stamp my own signature, what all would I be aiming for? What makes an amp great?

- keantoken

[h_a]

Hi, keantoken!

What makes an amp great?

I do not design amplifiers; however if you start to plough through Self, Slone, Duncan, the articles of Nelson Pass, Walt Jung, Borbely and others you start to get your own ideas how an amp topology should look like. (electronics and electrodynamics knowledge greatly help you with this).

Of course that is not the same as building all famous amps and listen to them yourself. That's also a nice way to make your own mind up (maybe a bit expensive, though).

The only advice I can give you is to find out for yourself! Asking other people for advice on such a war topic gives you more different replies than users registered here

Have fun, Hannes

[nelsonvandal]

Why don't you listen, and read reviews of, amps with known topology, transitor types etc, and try to see some kind of read thread, and then start to design a "new" amp with a type of topology and transistors you find interesting.

[analog_sa]

Originally posted by keantoken
what all would I be aiming for?

It seems some amp designers approach this as a purely intellectual exercise, in the same way they would a crossword puzzle. I don't understand them. As the amp is ultimately only a tool in the reproduction of music, the concept of the design should reflect the designer's attitude towards sound.


Single ended? Negative feedback? Desired distortion spectrum? Clipping behavior?

If you don't know your own preferences, why would you start a new design? Just to kill some time over the weekend? To start a discussion with other similarly bored designers? To publish a magazine article?

[keantoken]

Thanks, Hann.

I've been searching names here for about an hour and haven't gotten anything but books. I can't order books. Or kits. I don't have $$.

Are there any online schematics or resources?

I suppose searching these forums would be a must, since there are 'official' amplifier threads and such.

I'm mainly interested in the schematics and theory involved. Doug Self's site was perfect for me because it's all circuit and theory, and what he says he says so darn well.

Can you point out some quick links?

Thanks,

- keantoken

[h_a]

Sure!

Read all of Nelson Pass' Zen articles and his legacy projects at

http://www.passdiy.com/

Erno Borbelys articles are here

http://www.borbelyaudio.com/special_articles.asp

When a bit advanced, you may find some interesting reading from Walt Jung here (especially his articles on regulators are a must)

http://waltjung.org/Library.html

Further advanced you can read Bob Cordells AES article on his Mosfet amp which features error correction, rarely seen unfortunately

http://www.cordellaudio.com/poweramp/

If you're into opamps, Walt Jungs Op Amp Applications Handbook might give you ideas

http://www.analog.com/library/analog..._handbook.html

and of course Ron Mancinis 'opamps for everyone'

http://focus.ti.com/lit/an/slod006b/slod006b.pdf

I guess this should keep you occupied


Have fun, Hannes

[wakibaki]

The thing about desgining and building an amplifier is that it's concrete evidence that you understood the theory and correctly interpreted the datasheets.

I build a lot of prototypes for a wide variety of functions. Be they ever so simple, I always get a kick when they work. Perhaps it's not very admirable that I feel the need for constant self-reassurance like this, but the understanding of a lot of this stuff felt hard-won in a lot of instances, and although I do not regard myself as stupid, I'll take any encouragement I can get.

The primary consideration in the design of any (linear) amplifier is that it should exactly replicate the input signal at higher power.

How well it works is, however, sometimes secondary to the fact that it works at all...

It's nice to be able to pick up an old tube, or a bunch of components and turn them into something useful.

Modular and discrete amplifiers of more than adequate performance for most purposes are widely available at economic prices. From that point of view there is little to be gained by designing an amplifier, although there are geniune advances taking place in digital and class D amplification.

w

[VHF man]

About 10 years ago I built a well know D. Self based kit amplifier. This measured well and sounded like a D Self amplifier is reported to sound like. This amp has served as a useful reference for subsequent "next amps" which really is a must if your objective is listening to music. If you already have an amplifier and are very familiar with the cct topology then that will also be fine.

A few pointers

1. It's often best to start with a scaled down version of your cct such as a preamp. This is cheaper to build and easier to protect which means less $$$ going up in smoke when something doesn't quite work out as planned. When you're happy with the design after mods etc. you simply up scale the voltage rails and supply currents as required.

2. Some test equipment is mandatory such as DVM, ac mV meter, 1 MHz Audio generator with a nice sqare wave and if you can buy or borrow then a 100 MHz CRO is really handy and in my view a must have. If you're aiming high then things can and usually do oscillate at RF frequencies. I've even had parasitics as high as 400 MHz.

3. The reason people build more than just one amplifier is usually because it is very much a learning curve and we all learn from our design shortcomings and open our eyes to new ideas such as those presented here in DIYA from well respected pro and amateur designers. The holy grail of amplifiers is a limit we can never achieve but nonetheless is one we all strive for.

This is your mission if you wish to choose it.

Good Luck

[traderbam]

Hello Keantoken.

I am an amplifier designer.

I was thinking that I would love to build an amplifier of my own design. The problem, however, is that it doesn't seem like there's much use in designing a new amplifier when there are already so many other great ones out there.

I design them because there are very few out there that are great.

However, I still have little idea what in an amplifier makes it desirable, other than low component count, low distortion, high efficiency, and really neat design.

I only care about how faithfully the recorded music reaches my ears.

So, asking those who design amplifiers, I would like to know something. If I were to design an amplifier on which to stamp my own signature, what all would I be aiming for? What makes an amp great?

To me a great amp is one that has no sonic signature. It is an audibly invisible link in a chain. I do not feel qualified nor do I presume to add my own flavour to a musicians' creation.

Of course, what you should be aiming for depends entirely on what you are trying to get out of this undertaking. What do you mean by "stamp my own signature"?

[ionomolo]

Originally posted by traderbam
To me a great amp is one that has no sonic signature. It is an audibly invisible link in a chain. I do not feel qualified nor do I presume to add my own flavour to a musicians' creation.

That's fine for a commercial design, but i like to build amps that add a little bit of "flavour" to the music, the exact amount to make me feel at home instead of feeling inside a white cold anaechoic chamber, anyways, we are in the sub 0.05% THD, so probably the same musician performing in a different room would sound even more different.