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Sure Electronics AA-AB32261 Stereo 2 x 150mW Class AB LM4881 Headphone Amplifier Board

Brand:|Model: AA-AB32261|Part # 320-321
Step up the output of your smartphone to drive high impedance headphones with this Class AB headphone amplifier board. The LM4881 IC is used to provide up to 15.7 dB of high quality gain to power even the most power hungry headphones.
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Part # 320-321
  • High quality Class AB output that uses the LM4881 Boomer IC
  • Up to 150 mW of power per channel (15.7 dB of gain)
  • Able to drive 8 ohm speakers
  • Operates on 8 to 24 VDC

Product Details

Sure Electronics AA-AB32261 Stereo 2 x 150mW Class AB LM4881 Headphone Amplifier Board

This compact, self-contained headphone amplifier board is built around the Texas Instruments designed LM4881 Boomer® dual headphone amplifier IC. The LM4881 features high quality, Class AB output (up to 15.7 dB of gain) with minimal components and is able to operate with a wide array of power supplies from 8 to 24 VDC without the need for a heat sink.

Additional to its use as a headphone amplifier, this amplifier board may also be used as a preamplifier or a small loudspeaker power amplifier, with output of up 150 mW per channel at 8 ohms. An exceptionally low total harmonic distortion and noise rating of 0.1% @ 150 mW into an 8 ohm load ensures clean output with lower impedance loads. Distortion and noise are even lower for high impedance headphone loads; 0.02% @ 75 mW into a 32 ohm load.

Locations for the addition of screw-down wire terminals are provided for signal inputs and power outputs. A two-conductor screw-down terminal is included for power supply connection. See related items for two-conductor screw terminals. Gain settings are provided for each channel, as-is stereo 3.5 mm input and output jacks, as well as a 2.1 x 5.5 mm DC power jack.

Features and Specifications:
• Input power requirements: 8 to 24 VDC, 500 mA (minimum recommended current capacity)
• Powre output: 150 mW @ 8 ohms (0.1% THD+N), 120 mW @ 16 ohms (0.025% THD+N), 75 mW @ 32 ohms (0.02% THD+N)
• Frequency response: 20 to 20,000 Hz (±3 dB)
• Gain settings: 9.6 dB (low), 15.7 dB (high)
• Input impedance: 1.7k ohm (with gain set to high), 3.3k ohm (with gain set to low)
• Thermal shutdown protection circuitry built-in
Dimensions: 3" L x 2" W x 5/8" H 

Sure Electronics AA-AB32261 Stereo 2 x 150mW Class AB LM4881 Headphone Amplifier Board
  • BrandSure Electronics
  • ModelAA-AB32261
  • Part Number320-321
  • UPC848864012216
  • Product CategoryAudio Amplifier Boards & Modules
  • Unit of MeasureEA
  • Product Rating
    (8 Reviews)
  • Weight0.1062 lbs.
  • California Prop 65

    Warning: California residents only. Please note per Proposition 65 that this product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

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Sure Electronics AA-AB32261 Stereo 2 x 150mW Class AB LM4881 Headphone Amplifier Board
Sure Electronics AA-AB32261 Stereo 2 x 150mW Class AB LM4881 Headphone Amplifier Board is rated 4.125 out of 5 by 8.
Rated 4 out of 5 by from Good, but audio source may effect hiss/noiseJust came in today and did some basic testing.Used the 12V DC adapter suggested and it works just fine. There are two switches on the amp - each for either the left or right channel. In the 'off' position you get a low gain boost, and in the 'on' position a higher gain boost (15.7db i think).With no source plugged in, its dead quiet. That much seems fine. But with my Galaxy Note 3 and Macbook Pro, the gain on the high settings definitely accentuated any floor noise produced by the source. At least, that's my guess. On my Note 3, I could actually hear the clicks as the notification LED turned on and off - never noticed that before. It was probably always there, but the gain boost amplified what was normally too low to be picked up.I need to do more testing - also ran this off a 9V battery and it worked just fine, so I don't think its necessarily noise from the power source. It's possible having a source for audio that is built to have little/no noise might produce better results. The Note 3 seems to have some obvious noise issues, and I'm not sure how the Macbook Pro's sound card is as far as quality of output.That said, it does what it says it does - gives a nice little kick to the gain. I can't immediately tell if it alters the audio in any noticeable way other than giving you more room to play with. I'm hoping to try it out with a pair of Oppo PM-3s in the future - will update the review depending on how they work.
Date published: 2016-01-14
Rated 3 out of 5 by from Decent for the priceIt gets the job done for $9. It pushes my Superlux 668b's to levels that are uncomfortably loud without audible distortion. My biggest complaint is that there's a noticeable hiss at low volumes. It goes away at normal listening volumes but it's still an annoyance. Highs also seem harsher with this amp but I haven't broken in my headphones yet so it could very well just be a deficiency with the headphones themselves.
Date published: 2015-06-23
Rated 4 out of 5 by from Great BuyNeeded a little more headroom for my headphones for gaming/music/movies but I didn't want to spend a fortune for a amp. I tend to add a little (3 to 5dB) bump in all of my music audio based around 25Hz purely for personal preference and my pc sound card just didn't have enough punch to be able to meet the demand not to mention it just couldn't drive even 32-ohm headphones worth a darn even without the bass boost. I am using a pair of Behringer HPM1000's that I bought on a whim with this amp because they were only $10 and I just wanted to try them out. Good combo, not the best out there but this set for under $20 investment? Sold. Not quite Turtle Beach mind you, but for 1/5 the price... It is well worth it. Since I am into R/C planes/trucks I have an abundance of Lipo 3s batteries (11.1V) so I made up a plug that allows me to use them to power it. I can imagine my 2200mah battery will get me about 6 hours worth of sound pretty easily. I have only had it plugged in for the last hour so I can't really give any input on longevity. I did not have the "hiss" problem another had (possibly because I am using battery and not a psu?). I plan to buy another just for giggles cause they are cheap and work well.
Date published: 2015-05-15
Rated 5 out of 5 by from Nice little heaphone ampUsing this as a headphone/pre-amp. Like another reviewer noted, my 2x15w class D amp wasn't reaching full power when using my phone/tablet as a signal source. This amp provides a little more input boost to fix that. I also wired in a DPDT output switch and headphone jack to allow me to switch between headphones or an external amp, and a 5kΩ audio-taper potentiometer (#023-644) for fine tuning the volume. The Hammond 4.7" x 2.6" x 1.6" project box (#320-708) was the perfect size to fit the board, all the input/output jacks, and potentiometer.With the gain on low, the output seems just a little louder than straight from the signal source. With the gain on high, there is a much more noticeable difference and gives me a little more headroom for low volume recordings. Output is quiet with no hiss that I can hear.The recommended power supply is stated as 8-24v at 500mA. Well, even when using an 8 ohm load (which is the load that results in the highest power draw), current draw is no more than around 200mA. There is a LM317 linear regulator on board set to around 5.5v, so anything more than 8-9v input voltage is being wasted as heat. But this also means that you don't need a "regulated" power supply. A 9v DC supply rated for 200mA (or more) is really all that's needed.I really wanted to run this straight off a 5v phone charger, but the LM317 dropout voltage reduces the usable voltage to the amp chip to around 2.5v, which is no good. I could have modified the board by removing the regulator IC and wiring in a jumper between the in/out solder pads, but I didn't want to modify the board.
Date published: 2015-04-27
Rated 5 out of 5 by from Great board for price!I am currently working on a potable boombox. I have a T-AMP TRIPATH TA2024 2X15W AUDIO DIGITAL AMPLIFIER BOARD that is hooked up to 2 FOUNTEK FE83 3" FULL RANGE DRIVER 8 OHM with a 12v 7ah SLA battery. It sounded great but i noticed with my phone it was a lot less quite than when i played from my laptop. So I figured i would give this part a try since it was so cheap. works fantastic boosted the volume so i can get full potential from the amp plus no distortion. i really like the ability to change the high pass filter as well. easy to wire and small enough to fit almost anywhere.
Date published: 2015-04-16
Rated 4 out of 5 by from Breathed new life into my Yamaha OrthodynamicsI bought this headphone amp in the hopes it would allow me to use my power hungry vintage Yamaha Orthodynamic headphones with my laptop (and other devices that lack the power to drive them properly.) I am pleasantly surprised with how well this tiny little amp works. Very clean noise free operation. I (somewhat crudely) constructed a little plastic box to contain the unit and the 1/4 TRS jack I connected to the amp. Using a 12v 1.5 amp power supply. Also considering adding 2 RCA jacks.This is exactly what I wanted and the price was unbeatable.
Date published: 2015-01-22
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Product Q&A

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Sure Electronics AA-AB32261 Stereo 2 x 150mW Class AB LM4881 Headphone Amplifier Board

I would like to add a volume pot to this unit how would I go about wiring it up and what pot to use?

Asked by: 357mag
You will need to use a stereo pot and have it wired in line with the speaker output. You will need a pot like this one:
Answered by: MattW
Date published: 2015-04-20

is there a Wiring diagram for this board? also is this board for stereo output (left and right speaker) or is this mono output(either left or right but not both)? 

Asked by: dday
No, we currently do not have a wiring diagram and the board Is for stereo output.
Answered by: MattW
Date published: 2015-04-09

Is the Stereo 2 x 150mW Class AB LM4881 Headphone Amplifier Board a bare board or are the parts included?

Asked by: Toddr30
The LM4881 is an assembled amplifier board. The power supply is not included.
Answered by: TomI
Date published: 2015-03-04

Ok so, I'm new at this so bear with me. Besides the power supply, what else do I need to buy to start using this amplifier?

Asked by: Rodgl
Other than cables to connect from your music source and headphones, the power supply is really all you need to get this amp to function.
Answered by: MattP
Date published: 2015-03-04

Is the amp able to be bridged to get more power?

Asked by: ochocki
This amp is not bridgeable.
Answered by: MattP
Date published: 2015-03-04

Does this unit come with its own power supply?

Asked by: TheDavel
No these do not include power supplies. The adapter we recommend is below.
Answered by: MattP
Date published: 2015-03-04
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