Headphone Amplifier With TPA6120A Part II – Finished Product

Somehow I forgot to translate this second part of the Headphone Amplifier project from Bulgarian to English. Better late then never 🙂 The project has been finished in March 2010 and all relative time references should be linked to that date. That was quite a while ago. It seems I have lost track of time or I’m just getting older. I am building an updated version at the moment and I will post an article about it soon. Now let’s go back to the finishing of the first version.

Time has come to finish the project, started long ago, headphone amplifier with TPA6120A. After I finished the assembly of the PCB for the amplifier and performed some tests in August 2009, I just didn’t have an opportunity to finish what I have started. Now everything came in its place and one PCB became a finished product. The final version combines the amplifier together with toroidal transformer, voltage regulator and circuit for delayed output enabling in a nice aluminum enclosure.

Headphone Amplifier With TPA6120A

The following article is devoted to a HiFi headphone amplifier project of mine based on BurrBrown’s (Texas Instruments company now) integrated circuit TPA6120A . This IC consists of two high power operational amplifiers in one package. Both amplifiers have separate power supply pins, placed symmetrically on both sides of the package so developing a high density PCB will be easy. TPA6120 has impressive parameters, which make it fit the usage mentioned in its datasheet. The main parameters as follows:

• 80 mW into 600 Ω From a ±12V Supply at 0.00014% THD + N
• Current-Feedback Architecture
• Greater than 120 dB of Dynamic Range
• SNR of 120 dB
• Output Voltage Noise of 5 μVrms at Gain = 2 V/V
• Power Supply Range: ±5 V to ±15 V
• 1300 V/μs Slew Rate
• Differential Inputs
• Independent Power Supplies for Low Crosstalk
• Short Circuit and Thermal Protection