The Best Byerdynamic A1 Headphone Amplifier DIY Kit,4 Pairs Output Transistor

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The best Byerdynamic A1 headphone amplifier DIY kit,4 pairs output transistor,Low cost but high performance.

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Up for sale is a DIY kit of headphone amplifier,Not yet assembled and you will need to build by youself or you can buy assembled product if you want,The headphone amplifier is based on famous Byerdynamic A1 headphone amplifier, We make some improvements for better performance with better control and stressing mid-range when working with AKG / Sennheiser headphones.


  • ALPS potentiometer is NOT included,Pls select in drop-down list.
  • We also supply assembled amplifier unit with high quality alum. enclosure,Pls contact us for pricing.

1. Two pair output transistors in parallel connection to improve better control and drive ability,Make solid low range and bigger soundstage, Original A1 headphone amplifier only use one pair output transistor for each channel, It can not work perfectly with AKG and Sennheiser headphones.
2. Special 300mv headphone amplifier with discrete components,No like other A1 headphone amplifier with UPC1237 protective IC which designed for speakers and act at 1.2V DC output.
3. Genuine OMROM relay with lower contact resistance and signal loss
4. Using separate power regulator for OPamps,Make better crosstalk.
5. Optimized layout with ground,Archive better S/N ratio.

Materials of the headphone amplifier
1. High quality dual side fiber PCB board with 10 ounce copper.
2. 1% high precision matal film resistor
3. Capacitor:  Main filter capacitor is Panasonic FK series 3300UF
                       Decoupling capacitor is Panasonic NXL audio
4. ST 33078N dual OP-amps and BD139/140 output transistor,They are same as original A1 headphone amplifier.
5. Use RIFI 840 4.7UF coupling capacitor,Better than WIMA/ELNA/Nichicon electrolytic capacitor.<BR

Packing List:

  • One headhone amplifier DIY based on Byerdynamic A1 circuit

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