Cary Audio Design SLP 03 - Manual (Page 6)

WELCOME
5
THANK YOU
Dear Customer:
We would like to thank you for your decision to buy a SLP 03 vacuum tube preamplifier. The SLP
03 combines the desirable attributes of low noise, low distortion and ease of use making it an
excellent preamplifier choice for your home audio system. This stereo vacuum tube preamplifier
offers one XLR balanced input pair and six pairs of RCA single-ended inputs making it a very
capable preamplifier. The adjustable brightness front panel display shows the current settings
and volume levels during use. The SLP 03, when combined with a power amplifier is capable of
outstanding musical reproduction using your favorite music.
Thank you for your support and enjoy the music!
The Cary Audio Team
PRODUCT OVERVIEW
The new Cary Audio Design SLP 03 preamplifier is a blend of digital computer technology and
pure vacuum tube, analog discrete circuitry. The SLP 03 consists of actually four (4) analog, 16
dB, line gain stages. Two separate gain stages are used for each of the two channels. One gain
stage amplifies the positive phase (+180 degree) and the other gain stage amplifies the negative
phase (-180 degree). Two stages for each channel equal the four active line circuits. All audio
path signals are amplified through 12AU7 vacuum tubes in a class A zero feedback circuit.
The front panel display is a Noritake vacuum florescent display with a blue lens in front. The
display receives and displays the critical control functions from a Motorola CPU incorporated
inside the Cary Audio SLP 03 preamplifier. The Motorola processor is the controller for all
functions of the preamplifier.
Back to the analog side of things, there are a total of eight (8) fully regulated power supplies in
the SLP 03 preamplifier. Separate supplies for each channel’s analog circuit along with multiple
power supplies for the Alphanumeric, Noritake display, along with dual supplies for the Motorola
processor. To power the fully regulated power supplies the SLP 03 has two individual R-Core
shielded power transformers. Dual power transformers, along with separate left and right
supplies, make the SLP 03 a true dual mono preamplifier. In fact, the channel separation is in
excess of 80 dB. This amount of channel independence is a major engineering design
breakthrough in vacuum tune designs.
A word about cinema-bypass is in order. We have discovered with previous Cary Audio
preamplifier designs, when incorporating the cinema bypass, that on occasion the user would
forget that the system surround processor inputting to the preamp could be a very high level.
Thus when the preamplifier power switch is placed in the off position, the default would be a
feed through of the processor signal and could blast the left and right channel loudspeakers. In
the SLP 03 the cinema-bypass only functions when the SLP 03 is powered up with the volume
gain setting set at number 47 on the display. The reading of 47 is unity gain. It might be noted in
the SLP 03 one could have a single ended (RCA) processor input and through the SLP 03 have a
balanced output to the left and right channel amplifiers.
Operating the dual 12AU7 vacuum tubes in a current source configuration, true balanced output
is achieved with both single-ended (RCA) inputs or the balanced (XLR) input selection.