Here's what Lehle say about the Sunday Driver
The Lehle Sunday Driver is a high end preamp with a convenient compact format.
It features JFET-based circuitry and provides two modes of operation, with selection via a mode selector switch with gold-plated contacts: "D" stands for Driver; in this mode, the guitar signal is amplified, with absolutely no modification, at the input impedance of a guitar amp, efficiently eliminating losses on the route through leads and effects; the signal remains strong and clear, retaining its full dynamics.
The second setting "S" - as in Sunday - multiplies input impedance by four, bringing out previously inaudible details and, as gain increases, imparting to the guitar sound a characteristic and unmistakable warmth that has given this preamp its name - the result is a sound as mellow as a sunny Sunday afternoon! Even at a 15dB gain setting, the Lehle Sunday Driver always stays clean and absolutely free of background noise, thanks to its studio-standard signal-to-noise ratio of over -100 dB.
To exploit the dynamics of tube amplifiers to the full, the input voltage is also rectified from the power supply socket, then filtered, stabilized and doubled to 18V. With its broad output range of 20 to 100,000 Hz, the Lehle Sunday Driver, powered by a standard 9V (PP3) battery, can be used anywhere, whether as a cable driver for stadium and other large stages, in complex effects set-ups, or as a recording preamp - and not just Sundays!
Q: What is the effect of an impedance converter?
A: The sound will be freshened up and signal loss through long cable runs will be compensated.
Q: What is the benefit of a buffer/impedance converter before my effects chain?
I heard about the SD, but I am uncertain how this works and whether I need this for my pedal board.
A: A high impedance / HiZ signal can be weakened by an increasing number of fx-pedals, even true bypass effects. The difference can be felt by connecting your instrument with a short cable directly to your amplifier and focus on the details in sound and dynamics.
Q: How can I compensate the signal loss on my effects board?
A: By using an impedance converter, which provides a high impedance input socket for the instrument signal and a low impedance output signal that is more resistent against loss.
Q: My doublebass pickup delivers a weak signal, can I increase the level without any coloration or distortion?
A: The Sunday Driver can increase the signal gain up to 15dB without any loss or alteration of your original signal.
Q: What’s the difference between the Lehle Julian and the Lehle Sunday Driver?
A: The EQ section makes the difference! The Lehle Julian offers additional controls like the parametric mids and treble which allow individual sound shaping.
The S-Mode: The Lehle Julian does not have an S (= Sunday) Mode whith a higher input impedance.
SW as in Switcher: The Lehle Julian has an On /Off footswitch included as a standard, which comes along with the big LED showing its status. Besides the classical Lehle Sunday Driver without switch there is a switchable version, the Lehle Sunday Driver SW.