Build low power Transistor Amplifier

[BasicHIFI1]

That all depends on your sense of what audio should look like. DIYs tend to leave aesthetics to individual tastes, skills and resources which vary a lot around the world.

A CD player here is a large 2 Unit rack sized device. Putting a 1 watt amplifier in a matching 2U rack case to suit it would be an hilarious mistake for a device about the size of 2 matchboxes 😀 If you said 100W amplifier, you probably would match the appearance of the cases but that is for you to consider and make personal decisions for your time, abilities, cost and availability of parts and finishes.

Indeed. I just wanted to find out what the practice of other DIYers was, especially if you leave out the power supply with its beautiful toroidal transformers (to reduce noise and em?) and the huge capacitors.

a search for "Hi-Fi Systems" netted the following image :

Hi Fi Systems San Antonio | Stereo Systems San Antonio

I guess the components don't have to be the same size.page:

See images further down this

http://www.astrasuite.com/astrablog/voxativ-ampeggio-due-shanghai-show-2012/



Searching for "High-end Hi Fi systems" gave better results.

You have to have a good rack, though, the kind that makes your sound so transparent.

 

[Mrcloc]

That looks manageable, thanks. Nice touch showing the ground rail. Says 24V can it be run off 12? I know when you run a 12 V PC speaker amp off 6 volts it sounds awful, but maybe I can limit the gain of the circuit so this does not happen? Or add a resistor to the volume control.

You can't run this off 12V. You must trim it to obtain 13V at the positive side of the output capacitor to achieve full swing.

If you need a power supply for this, a 24V regulator or a dual supply running a +12V and -12V regulator can be used (this is how I did it), then take 24V from +12 and GND from -12 and leave the center tap internal to the supply.

7812 regulators worked fine for me, but they need a big heatsink. I would rather use a buffered regulator. I can send you a schematic for one if you would like - it will be useful for any class A power supply anyway.

A class A amplifier will generally be fairly large because you will need big heatsinks and a big power supply. You can't easily run a class A amplifier off a power adapter; you will need to clean that power up a bit. A 1 A power adapter could be used for a 1 W mono class A amplifier, but at a push.