Audiophile neophyte here, please bear with my possibly inane questions. Have a pair of PC-350s. Onboard sound on my motherboard is actually quite good, I just want a bit more oomph out of my headphones, where at high volumes it doesn't sound like it is straining to get there as much. The amps in the OP seem more or less tailored to bypass the onboard sound, which adds a bit of cost to the DAC/amp purchase. So, is there something that is *just* an amplifier that is recommended? I did a bit of searching on amazon, but was a bit overwhelmed with the options.