The concept behind the SMP-1 tube preamplifier is simple: take the audio and power supply circuits from the BF-1 and adapt them to a single-channel SEPIA format. The signal path of the SMP-1 is identical in every respect to that of the SFP-30. This gives you the best and most versatile tube preamplifier available – featuring the legendary variable second harmonics of the SFP-60, in SEPIA format.