[hans030390]

I bought the Creative X-Fi HD USB external sound card a few weeks ago for $50 (after MIR). It seems like a solid device, especially at that price. It has an AKM AK4396VF DAC, SNR is rated at 114dB for the headphone out, etc. I'm fairly sure the Opamp they use for the headphone amp is the JRC4556 (I mean, the JRC4556 is on the board near the headphone out...I can't find any other Opamps). Seeing as how people have modded their older X-Fi cards to use nicer Opamps, I was hoping to do the same for this.
 
So, my first question is what Opamps can directly replace this? The LM4562 seems popular, and is used in the original X-Fi mod. I believe the X-Fi cards also used the JRC4556, so I'd guess it would work for the HD USB as well. I could be wrong, though. Do I need to know specifics of the board layout?
 
Also, I do not have the skill OR the tools necessary to do this. Would anyone be willing to do this for me for a fee? 

 

[joe_cool]

The 4556 is an audio-specific amp with very high output current (70 ma) and there are no obvious replacements as it has good gain (the same GBP (gain vs frequency) as the OPA2134).

 

[hans030390]

I see. So, why then is the 4556 easily replaceable in the older X-Fi cards? Is it because it wasn't used as a dedicated headphone opamp or something? Would someone have to analyze the electronics in the HD USB in order to determine what, if any, opamps could be put there instead?
 
Obviously I'm not very familiar with these types of technical details in electronics, so I appreciate the help.

 

[joe_cool]

When used as a headphone driver, there are few if any good replacements. In low-voltage environments (3-15 volts total) the NJM3414A is sometimes used (+/- 5VDC, etc.) but doesn't have as much gain.