Interviews

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Our previous preamps (line stage and phono) were $4,000 each, for a total cost of $8,000 for our customers who needed a phono preamp.  Since both preamps are now combined, customers who need a full-function preamp can now save several thousand dollars as the new preamp sells for half the price of the previous two.

Additionally, more modern circuit design technology has reduced distortion and noise figures from those in the earlier preamps.  The styling has been redesigned to better match our amplifiers.  A video processor pass through also is included in the new preamp.  All the previous ergonomic and performance features of the earlier preamps have been retained.

The goal of a true audiophile grade preamplifier is to offer gain, switching, and other conveniences, while at the same time passing the original signal downstream without adding distortion, noise, or a sonic signature of its own.  The Sanders Preamp does exactly that but includes many ergonomic features for convenience and ease of use that are not available on even far more expensive preamps.

The levels of each individual input can be adjusted to get them all matched so that you don't get "blasted" or have to turn up the main level each time you switch sources.  A stereo/mono switch remains standard equipment.  The overall gain, individual gain between devices, and channel balance can be adjusted in precise, 1 dB increments.  Muting by remote control is standard.  A video readout makes it easy to monitor the levels.

Controls are available both by remote control and on the front panel.  Front panel controls are done through micro-touch electronic switches.  Internal switching is done by miniature, sealed, gold relays.  Conventional rotary volume controls have channel matching error of around 20%, which causes the left/right balance to shift as you change the level.  To solve this problem, some preamp manufacturers use discrete, precision resistors on a multi-step switch.

While this solves the channel tracking problem, they introduce new ones.  Specifically, they have very limited resolution due to too few steps (typically 31 steps of 2 dB each).  These "stepped attenuators" produce very annoying switching transients at each step.

The Sanders Preamp solves these problems by using the "volume control" knob to drive an optical comparitor circuit.  The optical circuit operates a microprocessor that controls an electronic gain system.  This controls the level using one hundred, one dB steps, with precision of greater than 0.1% between channels.

The microprocessor monitors the signal voltage and waits for it to cross the zero voltage point between waves before switching to the next level.  This prevents any switching transients.
The volume control knob has detents at each 1 dB point and it rotates continually.  So it as an infinite number of detents and you can feel each 1 dB change in level.

There is a digital display with beautiful, blue, light emitting diodes (LEDs).  The display continually shows the output level of the unit and switches automatically to show level differences between channels, when you adjust the balance, or when you adjust the input levels.  You no longer have to guess at the levels or try to see fine gradations on a knob to know the levels, since you can see them from several feet away.

Most components come with a remote control transmitter that only controls that particular component.  Therefore you end up adding that remote transmitter to the pile of remotes you have for all your other electronics.

Rather than contribute to "remote clutter", the Sanders Preamp comes with a programmable remote that can be used to operate all your components.  You will then no longer have to dig through a pile of remotes every time you want to adjust something in your audio/video system.

The phono preamp offers exceptional flexibility and features, including virtually all the features of the most expensive, dedicated phono preamps.  These include switchable gain for both moving magnet and moving coil cartridges, and user-adjustable cartridge loading for both resistance and capacitance so that users can match their cartridge manufacturer's specifications for optimum performance.  The phono circuit has the benefit of extremely low distortion and an ultra-quiet noise floor.