SS3601 Discrete Op-Amp
The SS3601 is a discrete op-amp in an 8 pin DIP compatible package optimized for high-performance audio applications. This device is a drop-in replacement for many common, yet inferior audio operational amplifiers and is uniquely compensated for trouble-free swap out into virtually any circuit. Having a footprint of a mere 0.33 square inches, this device is one-third the size of any other discrete op-amp on the market. The SS3601 boasts a very high open-loop gain (140dB) and utilizes 2 pole compensation to maintain said gain deep into the audio band.
You can find the data sheet HERE.