Tuesday, March 11, 2008

DIY a $20 Dollars Hi-End Heaphone Amp

DIY Gwado RA1 Headphone Amplifier

Some people like you and me who can't afford to pay high price for this "state-of-the-art performance" Grado RA1 Headphone Amplifier, so what we can do is self DIY it, althought it might not be equal sound quality compare to the Grado RA1, but is up to you to tweaks it by changing the component like capacitor and resistor or even use a higher grade soldering lead, so at the end of the day, is still your own judging of the sound quality has gone worst or better then Grado RA1.

The DIY Instruction layout;



Gwado Ra1 Headphone Amplifier






Hopefully so far you can understand the layout as shown above, next we will need to purchase the part list.

Part list;

Resistor:
2 x 100K Ohm 1/2W $0.49 Parts Express Code: 002-100K
2 x 120k Ohms 1/2w $0.49 Parts Express Code: 002-120k
2 x 470k Ohms 1/2w $0.49 Parts Express Code: 002-470k
2 x 4.7k Ohms 1/2w $0.49 Parts Express Code: 002-4.7k

Capacitor:
2 x Dayton 4.7uF 250V Polypropylene Capacitor $2.79 EA- Parts Express Code: 027-422
2 x Dayton .10uF 250V Polypropylene Capacitor $0.67 EA- Parts Express Code: 027-400
2 x 330uF 35V Radial Electrolytic Capacitor $0.27 EA- Parts Express Code: 020-1164

IC:
1 x NJM 4556 $0.40 EA Mouser Part Number: 513-NJM#4556AL

Other Parts:
1 x 100k Dual Volume Pot
On/Off Switch
2 x 9Volt Battery Cell

Optional Upgrade of the PSU to a Virtual Ground with an TLE 2426 (3pin) IC

Optional Upgrade Parts
1 x TLE 2426 IC
1 x 220uf 25v Capacitors

Alright that's all, the rest shall leave it to you to complete it
Wish you all the best!

William Neo

Do you like this tutorial?
If yes, would you mind helping me to promote to other reader by Stumble Up!


Amazon is selling Grado RA1@ $425USD.

19 comments:

Anonymous said...

Hey, nice simple headamp...

Something to consider is using a buffered virtual ground instead of resistor divider:

http://tangentsoft.net/elec/vgrounds.html

In my 2 x 9v project I *was* all set to use the same power supply you show, but for my application a single 220uf & 3-pin TLE2426 (as shown in Tangent's "Simple Buffered Virtual Ground" on left) works great. Less parts, better V balance & possibly longer batt life.

William Neo said...

Thanks for e comment Man! I have added the virtual ground Power Suppy upgrade layout. Cheer!

Anonymous said...

Why not go buffered ground?

William Neo said...

Actually this project is meant for beginner to kick start on Simple Diy Amp. Will not go into complicated circuit for the time being. :)

lem said...

Hello there, I was wondering if the IC mattered much for example, for a CMOY the usual is a Burr Brown OPA132, I heard that this was a high impedence op-amp while your op amp is a low impedence op-amp suited better for low impedence loads.

Anonymous said...

There are a lot of these opamp based headphone amplifiers but little knowledge of the opamps themselves except the notion that the mre expensive they are the higher end and louder they will sound. Well it is not as easy as that. Most opamp knowledge out there comes unfortunately from reading other people's subjectivity.

You see opamps are not perfect and even though they all fit in the same socket they are not 100% circuit comparable! So a good expensive opamp can sound and act like crap, get hot an oscillate when rolled into a circuit designed for a cheap opamp.

The "most" important factor ignored by almost everyone is the lowest impedance an opamp can handle. Just like typical power amplifiers opamps misbehave, get hot and distort like crazy when faced with a lower impedance than it was designed to handle. This is the reason why some people get totally disappointed when testing an opamp which is highly regarded by the diy crowd. Opamps must be matched to the headphones they'll be connected to be able to get optimal sound quality out of the combination. Looking at the datasheets for opamps like the LM4562, OPA604, NE5532, OPA2134, AD797 one can easily see that their lowest distortion number are given at a minimum of about 600 ohms! Impedance in commercial headphones vary from 8 ohms and over 600 ohms. It would take a litte bit of more homework to build a decent than just throw a few pieces together around an expensive opamp.

Cheers.

Anonymous said...

BTW, most audio opamps are designed to work as preamps so they pass the signal to a circuit rather than a speaker. If you open a receiver you will notice that the headphone section is connected to the speaker outputs through a switch and a few resistors to reduce the power and avoid frying the headphones. The reason receiver manufactures don't use a particular opamp is because they know too well that headphones aren't made to one impedance.

A preamplifier on the other hand usually has a horrible headphone section because of cost and because the headphone output is usually is running from the same preamp section.

Anonymous said...

If you like a particular opamp and want to build a kick ass headphone amplifier with it then the best solution is to parallel several sections to lower noise to very low leves, increase current drive and low impedance stability to drive any kind of headphones.

By paralleling I mean building a dedicated circuit for each section of the opamp as per manufacturer recommendations and then paralleling the outputs through the proper resistors to avoid them fighting each other.

Btw, paralleling is not "stacking" opamps on top of each other.

If you need to understand more about opamp circuits I recommend the book by Douglas Self called "Small Signal Audio Design".

Anonymous said...

Dear Anonymous

I thank you for that detailed response, I understand most of it due to having taken a couple of ee classes, and oddly enough I was looking to check out that book from the library since it was right next the some audio amplifier books!

Again thanks, Ill be sure to take this into consideration when building my headphone amp!

Anonymous said...

You're welcome.

Another option I didn't include was using a buffer. It is of importance to note that the most significant advantage of using a single opamp is the low power consumption. If it is gonna be connected to the wall I don't see why not do it the right way.

Jhon said...

Sound become little bit blurry. Some time with louder sound it become problem.

- John Devis
Magento Themes

Magento themes said...

thats the nice try but the pitch of the sound is little bit high

Anonymous said...

i confuss le
Counter Depth French Door Refrigerator
How to Get Into Acting
Breville Smart Oven
How to Impress Woman
Picking Lottery Numbers
Canon Powershot A800
Adidas Barricade
Adidas Barricade 6.0
Cuisinart TOB-195
Acne Conglobata
Acer 11.6 Netbook
500 payday loan
acne inversa
VIZIO M261VP
checkmate payday loans
Pengurusan Masa

Counter Depth French Door Refrigerator
How to Get Into Acting
Breville Smart Oven
How to Impress Woman
Picking Lottery Numbers
Canon Powershot A800
Adidas Barricade 6.0
Cuisinart TOB-195
Acne Conglobata
Acer 11.6 Netbook
500 payday loan
acne inversa
VIZIO M261VP
checkmate payday loans
Pengurusan Masa

Stacey said...
This comment has been removed by the author.
jarredjoffe said...

I want to get the most out of my Shure audio SRH750DJ headphones. Is this the right circuit and opamp chip combination to be using?
or would the Cmoy amp (mini pocket amp) work better?

my iphone isnt giving me the loudness that i would expect from these. thats why i want to make the amp.

heres the headphones ratings:
frequency response: 5-30000 Hz
sensitivity: 106 dB/mW
Impedance(at 1 kHz): 32 Ohms
Maximum input power: 3000 mW

Patrick said...

They say that they have best headphones, may be they are right...

Pablo Cassa said...

Hi. Congrats. Nice blog. Could you provide the Grado RA-1 printable proto board layout? Thanks.

Anonymous said...

If you need to get custom PCB boards for your project, try
http://h-instruments.ecrater.com/c/1403757/2-layer-custom-made-pcb-prototype

They are cheap and the quality is professional

Unknown said...

Pay attention to your blog for a long time. Really want to know more about your business.cheap nike nfl jerseys