The need for a high-gain stereo preamp has diminished, because the CD has replaced the LP record in most audiophile homes.
1. All tube, no semiconductors if possible;
2. No electrolytic capacitors, if possible;
3. Best possible insulation materials;
4. Best possible tube types without resorting to rarities;
5. Regulated power supply;
6. Low output impedance without iron to drive 600 load;
7. Sufficient voltage gain of 10-20;
8. No feedback, stable, minimalistic.
Visit Here for more.