Hifiman HM603 slim

Hifiman HM-603s 

About the Player 

Hifiman is one of the reputed brand in audiophile product industry, that reputation force me to buy one of their product and i selected HM-603 Slim. Two factors influenced me in selecting this particular model one factor i already explained and the second thing is the DAC(digital to analog converter) used in HM-603S , about that i will explain later.

Player hardware enclosed in a glossy plastic with some metal shining beneath it. buttons are of golden texture with a good aesthetics but longtime use cause color fading. Button functions are unusual , it will be ok once if we get familiar with it. on board 16GB of storage with expansion slot(SD card supported).display provided is good enough for an audio player.Battery backup is average. player provided with one headphone out and one line out , USB DAC provision is not available which is actually a down side. DAP is a digital player with some analog signature , main highlight is the analog volume control which i really like.
firmware is free from bugs but minimalistic, audio filters or equalizers are not available giving a sign of less software manipulation over audio, personally i like it. since HM-603S uses analog volume control line out spit audio without any regulation.

Technical Specification:

• D/A Chip:TDA1543
• Simulation filter op-amp: OP275, OPA2604
• Ear put module op-amp: LT1057
• Frequency Response: 20-20KHz
• Distorftion:0.09%
• S/N: 98 DB
• Sound channel separating degree: 74 DB(line output, ground separation)
• Headphone jacks output level: 35 European 2.7 V; 150 Europe 3.2 V; 300 Europe 3.3 V
• Maximum output power: 190 mw
• The built-in flash memory: 4 GB
• The battery life: 10 to 13 hours
• Size: 62mm*103mm*21.5mm or 2.4 * 4.05 * 1.04 Inch
• Weight: About 200g / 7Oz

 Package

• HM-603s Slim 4GB Portable MP3 player
• USB cable
• Power adapter (100-240v )
• Cloth carry pouch
• Manual

                                                                                                       *Technical specification collected from penonaudio.com 

About Audio Quality 

Before entering in to audio quality i like to say something about DAC chip used in HM-603S,
TDA1543 is a 16 bit NOS DAC, NOS or none over sampling DAC  is a technology developed by Philips. industry dominated Sigma-Delta technology is the other one ,like valves and semiconductors this technologies are also a hot topic regarding the sound quality and musicality. NOS DACs production cost is higher because of R2R network integration inside the chip and limits it bit resolution also.

                                                                        Because of the architectural difference audio coming out from HM603s feels musical than Fiio X3(which uses Wolfson WM 8740,24 bit sigma-delta dac). HM603s has a unique sound signature like old CD players ,which is more immersing and influential, if you say about the frequency response fiio X3 is more loyal HM603s has enhanced mid frequency with slight rolloff above 40Hz range and higher frequency with less details.DAC used in HM603s is 16 bit as compare with other DAP's,even if the frequency response is not accurate musicality keep the device more enjoyable.Bass heads will get disappointed by the player.More instruments suffocates the player to spit music with proper layering, what i felt is HM603s is good for country songs and classical musics, sound stage is average with poor imaging.  

Conclusion

Overall the DAP is enjoyable for casual listening but player can never fulfill critical audition.