Audio Research SP20 Pre Amplifier
The all new Audio Research SP20 vacuum-tube preamplifier which the company say is influenced by some of their classic SP preamplifiers but with performance that is only achievable their best LS- and PH-series.
The front panel has a new 4.3″ LCD touchscreen, with two large rotary knobs on either side. For the first time ever on an Audio Research preamp, there is a ¼” headphone jack
Through the touchscreen you can change inputs, select stereo or mono, Mute, adjust Phase, adjust left-right balance, and adjust the phono input Load (50, 100, 500, 1000 or 47k Ohms). Through a Settings menu, you can customize other items. When the tube hour meter reaches 4,000 hours, the settings icon will turn red to warn the owner it is time to change the tubes.
In addition to the Phono input, there are four other single-ended inputs, two balanced inputs, separate Monitor-in and Record-out, and two pairs of balanced outputs. There is also an RS-232 port, IR-input, 12V trigger, and a 15A IEC connector. The SE4 input can be configured as a home theater pass-through.
The SP20 is fully balanced, pure Class-A with zero feedback. There are seven levels of voltage regulation, a large power supply, and a very low-noise R-core power transformer. Both the line and phono stages feature low-noise JFET inputs and 6H30 (2 per section) outputs.
6H30(2 per section) outputs.
Line -3dB 0.8Hz – 220kHz,
Phono+/- 0.4dB 5Hz—80Hz
gain of the line section 13.8dB (BAL)
gain of the phono section 58dB,