How to make an Headphone amp on breadboard...?

ron24 · 30th January 2012, 08:09 AM

I have a headphone which I use with my desktop pc for gaming, watching movies,..... However I wanted to some how increase the sound output and many users suggested to make an Amp... I wanted to know about the electrical components to be used and I even wanted to know about the circuit. It would be great if sum1 cud post me a diagram of the circuit and could let me know about the components required...Thanks you in advance...!!!

jtavrisov · 31st January 2012, 03:21 AM

How to Build the CMoy Pocket Amplifier

jcx · 31st January 2012, 03:41 AM

Gilmore's projects are somewhat advanced but you can see from the pics that they are built up on perfboard

HeadWize Library - Projects

GloBug · 31st January 2012, 03:50 AM

I also dig the ChuMoy.

Both are great links for you to get started. Build the CMoy first on perf-board.

ddietz · 1st February 2012, 03:13 PM

Yup, CMOY tutorial by Tangentsoft sounds good and gets a lot of people started in DIY audio. I've built a few. I'm working on a more powerful desktop headphone amp right now the uses an output buffer (BUF634). This uses about 6 more parts and sounds much better, IMO. Based almost entirely off of Fig 5 on the datasheet: http://www.ic72.com/pdf_file/b/20822.pdf

Why do you want to increase the sound output. Most normal sources should get sufficiently loud enough to cause hearing damage, unless you are using really expensive high impedance headphones that need more power and current to drive them. If that is the case, you might need more power than a basic CMOY. generally, headphone amps are used to add more power (current) capability and/or to improve sound, not to make it louder.

Antoinel · 1st February 2012, 03:28 PM

Wise choice. One matter bothered me with the writeup for BUF634 is the abscence of a performance Figure which relates %THD versus its output current (from ~+/-15 mA at idle to +/-250 mA peak) in a stand alone circuit. Figure 5 forces the DIYer to use a front end OPA to correct for potential inaccuracy in it. By the way the circuit of BUF634 was originally invented/used by National Semiconductor.

ddietz · 1st February 2012, 03:59 PM

Antoinel,

I'll admit that I'm not much of a designer of circuits at this point

I have found the BUF implemented generally same in a great many circuits shared here at DIYAudio, such as
YardBird OPA627/637 BUF634 preamp/headphone amp and OPA627 + BUF634 Preamp PCB Design and I't sounds great sitting open on my desk right now. Do you have suggestions for improving its sound, other than using a good PSU and proper bypassing at the chip's pins? This may be off topic though so if the OP minds, we can move elsewhere.

Antoinel · 1st February 2012, 04:35 PM

One possibility is to "discrete" the circuit of BUF 634. Operate the new complementary output stage at an idle current (Class A) which will be commensurate with your design specifications. The circuit of BUF 634 and its discrete version have a voltage gain of unity!

ddietz · 1st February 2012, 04:53 PM

Are you talking about a discrete Diamond buffer?

I thought the Buf634 in the arrangement shown on Fig 5 was already biased Class A?

Would there be a benefit to biasing the OPAx (in my case 2132) to Class A by using a resistor from the negative rail to the output of the OPAx?

Antoinel · 1st February 2012, 05:23 PM

I do not know what a diamond buffer is?

30th January 2012, 08:09 AM	#1
ron24 diyAudio Member Join Date: Jan 2012	How to make an Headphone amp on breadboard...? I have a headphone which I use with my desktop pc for gaming, watching movies,..... However I wanted to some how increase the sound output and many users suggested to make an Amp... I wanted to know about the electrical components to be used and I even wanted to know about the circuit. It would be great if sum1 cud post me a diagram of the circuit and could let me know about the components required...Thanks you in advance...!!!

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31st January 2012, 03:21 AM	#2
jtavrisov diyAudio Member Join Date: Jun 2011	How to Build the CMoy Pocket Amplifier

31st January 2012, 03:41 AM	#3
jcx diyAudio Member Join Date: Feb 2003 Location: ..	Gilmore's projects are somewhat advanced but you can see from the pics that they are built up on perfboard HeadWize Library - Projects

31st January 2012, 03:50 AM	#4
GloBug Banned Join Date: Jun 2011	I also dig the ChuMoy. Both are great links for you to get started. Build the CMoy first on perf-board.

1st February 2012, 03:13 PM	#5
ddietz diyAudio Member Join Date: Mar 2011	Yup, CMOY tutorial by Tangentsoft sounds good and gets a lot of people started in DIY audio. I've built a few. I'm working on a more powerful desktop headphone amp right now the uses an output buffer (BUF634). This uses about 6 more parts and sounds much better, IMO. Based almost entirely off of Fig 5 on the datasheet: http://www.ic72.com/pdf_file/b/20822.pdf Why do you want to increase the sound output. Most normal sources should get sufficiently loud enough to cause hearing damage, unless you are using really expensive high impedance headphones that need more power and current to drive them. If that is the case, you might need more power than a basic CMOY. generally, headphone amps are used to add more power (current) capability and/or to improve sound, not to make it louder.

1st February 2012, 03:28 PM	#6
Antoinel diyAudio Member Join Date: Jan 2012 Location: Pennsylvania Blog Entries: 1	Wise choice. One matter bothered me with the writeup for BUF634 is the abscence of a performance Figure which relates %THD versus its output current (from ~+/-15 mA at idle to +/-250 mA peak) in a stand alone circuit. Figure 5 forces the DIYer to use a front end OPA to correct for potential inaccuracy in it. By the way the circuit of BUF634 was originally invented/used by National Semiconductor.

1st February 2012, 03:59 PM	#7
ddietz diyAudio Member Join Date: Mar 2011	Antoinel, I'll admit that I'm not much of a designer of circuits at this point I have found the BUF implemented generally same in a great many circuits shared here at DIYAudio, such as YardBird OPA627/637 BUF634 preamp/headphone amp and OPA627 + BUF634 Preamp PCB Design and I't sounds great sitting open on my desk right now. Do you have suggestions for improving its sound, other than using a good PSU and proper bypassing at the chip's pins? This may be off topic though so if the OP minds, we can move elsewhere.

1st February 2012, 04:35 PM	#8
Antoinel diyAudio Member Join Date: Jan 2012 Location: Pennsylvania Blog Entries: 1	One possibility is to "discrete" the circuit of BUF 634. Operate the new complementary output stage at an idle current (Class A) which will be commensurate with your design specifications. The circuit of BUF 634 and its discrete version have a voltage gain of unity!

1st February 2012, 04:53 PM	#9
ddietz diyAudio Member Join Date: Mar 2011	Are you talking about a discrete Diamond buffer? I thought the Buf634 in the arrangement shown on Fig 5 was already biased Class A? Would there be a benefit to biasing the OPAx (in my case 2132) to Class A by using a resistor from the negative rail to the output of the OPAx?

1st February 2012, 05:23 PM	#10
Antoinel diyAudio Member Join Date: Jan 2012 Location: Pennsylvania Blog Entries: 1	I do not know what a diamond buffer is?