4th of JULY SALE! ALL GaN Amps on SALE - Extended Through Tuesday July 9th!

Chosen as one of the best products of 2010 by Afforeable Audio Magazine

Class D Audio Amplifier – 125 Watts RMS X Two Channel Stereo into 8 Ohm, 250W RMS X 2 into 4 ohms, and 500W RMS into 8 Ohms in Single Channel Bridge Mode.. Brand New and made by us here in the USA! Only 4 1/4″ X 4 1/2″ Ultra Clean & Thunderous Powerful Sound Lead Free & Energy Efficient This audiophile quality two channel Class D audio power amplifier or single channel in full bridge mode. All housekeeping power supplies are built-in so only a dual voltage +/- 42 to +/- 52 volt power supply is required. Features click and pop noise reduction, over/under voltage protection, over current protection, over temperature protection, and more! The new version of this amp has terminal blocks for input and terminal blocks for power supply and speaker connections. The provided heatsink is enough for most situations, but if you plan to push this amp really hard, then you will have to add additional heatsink or mount it to aluminum plate. Easy to mount… 9/16″ standoffs and mounting screws are also included. No soldering required.


Model CDA-250
Number Of Channels 2
RMS Power Per Channel 8 Ohms 125W RMS X 2
RMS Power Per Channel 4 Ohms 250W RMS X 2
RMS Power in Bridge Mode 500W Into 8 Ohm Only
Input Sensitivity 2V
Total Harmonic Distortion (THD) Better than .02% (normal listening is about .003%)
Frequency Response 10hZ to 35KHz
Input Impedance RCA 10K
Input Impedance XLR N/A
Voltage Gain for RCA Input 30
Voltage Gain for XLR Input N/A
Power Requirements +/- 42 Volts DC to +/- 50 Volts DC
Dimensions (W x H x D) Inches 4.25″ X 1.5″ X 4.5″
Dimensions (W x H x D) Millimeters 108.0 X 38.1 X 114.3
Product Weight (lbs/kg) 1.5/ 0.7
Shipping Weight (lbs/kg) 2/ 0.9
Manufacturer Class D Audio
Weight 1.5 lbs


  1. *

    I’m from Italy.
    I bought the 250 X 2 4 ohm version with his 300VA power supply. Good good good.
    I like it. I drive it with a 10K pot and sounds very very good.
    It’s possible that with a good preamplifier sound will be better, but for me it’s already outstanding.



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  2. *

    I bought this power amp as part of a complete package deal
    (see “KITS” at the top of the page). The amp itself features
    top quality workmanship, superior overall design, and best of all . . . the
    best sounding class D tonal quality I’ve ever heard! Tom also has the best customer service of any amp manufacturer I’ve ever dealt with. You really owe it to yourself to check out this power amp. It will blow you away!

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  3. *

    I put this amp module into a 1U rack project box because I had a flat toroidal transformer. It is so cool to have 500 watts rms in a 1U rack. I have used this amp for some power hungry 4 ohm Bose speakers in stereo and also as a sub amp in bridge mode for a 18″ B-52 subwoofer. Sound great and doesn’t overheat like my other AB class amp projects. And for the money you can’t touch the value you get with any commercial products especially in class D.

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  4. *

    Months of my quest for my dream amp has finally come to an end or rather, it is a beginning of my pursuit for achieving Audio nirvana.

    I received the Class D Amp with it’s ‘low profile’ power supply .

    I connected the amp to the supplied ‘Low Profile Power Supply’ and linked it up to an old 10 Amp Audio Transformer with a secondary output of 30V AC. As a result, the DC output from the power supply would be 42.3V, slightly less than the optimum operating range of 45V to 60V of the Amp.

    I then connected the Amp to two-way tower speakers and played a demo disk from a very reputed speaker manufacturer.

    Wow, my jaw just dropped!!! What a music!!! All the instruments have come alive. Superb vocals, taut percussions, silky smooth strings, lively trumpets and saxophones!! The sound is clean but not clinical musical but not warm. The transients, the decay are so lively that it has to be heard to be believed.

    We listened to all types of music, from Pop to Rock, from Western Classical to Jazz. There is not even an iota of listening fatigue. Hats off to Tom of Class D Audio.

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  5. *

    I received this model today and promptly installed it into an original (mine) Crown D150 Power Amp chassis from the 70’s. This proved a decent high-current +- 45 Vdc supply with 9400mfd in each leg. This is enough supply to show off the assets of this Class D module. I have been involved in mid & high-end equipment sales and manufacturing for several decades including modifications and the like both in speakers and amplification (line-level & power). In planning my next small studio, I have decided on building or modifying everything I need since that is the most efficient path for me to get what I want. I can not come up with a better choice than this class D module. The middle range is at least as clean as the finest tube amplifiers I have heard or used. The bass control and depth is as good as any bipolar design I have used or modified . The harmonic range (above 4000Hz) is as uncluttered and extended (and actually better) than anything I could imagine. This design can handle any dynamics or subtleties I can throw at it whether it is powering high-efficiency full-range designs or average-efficiency mini-monitors. My first impressions are nothing short of superb! The next time I come across a power amplifier in need of output stage repair… I’m not bothering – I will install one of these modules instead. It makes no sense to do otherwise! Thanks for making available a competent design!

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  6. *

    This CDA254 amp board used paired with the theirs Heavy Duty DC Power Supply and a Breve Tufvassson 600VA dual 35V secondaries toroidal. Carefully compared against a Marantz MM7025 class AB power amp costing more than 850 bucks… night and day difference better this classD. What can I say more? And made in USA!!!

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  7. *

    With Dynaudio speakers, transformer volume control preamp and silver-plated OFC unshielded twisted interconnects and really high gauge speaker cable this power amp bettered in transparency, slam and dynamics even to expensive heavy class-A power amps. This is trully a bargain in high end amps. Antonio M. Europe.

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