Manley MOVING COIL & MOVING MAGNET PHONOGRAPH PREAMPILFIER - Manual (Page 7)

LOADING, continued....
If the cartridge manufacturer specifies a load capacitance of 150 pF then it is best to subtract the cable's portion,
i.e. 90 pF. This yields a balance of 60 pF. Thus, the audition should start with the termination capacitance switches
set to 50 pF.
Each cartridge manufacturer's product will work best in a laboratory sense when terminated (loaded) with a
certain amount of resistance and capacitance. A good place to start is with those values recommended by the
cartridge manufacturer, less the interconnect cable capacitance. A good default value, if the recommended
cartridge load capacitance is unknown, is 150 pF, the sum of cable and termination capacitance switch settings.
This value reflects a de-facto standard as used by pre-amp manufacturers past and present. From there, we
encourage you to try a range of switch settings until you find those values which best suit you and your
accompanying components.
Also notice that the audible affects of varying the termination capacitance can differ substantially between
cartridge types and brands. This is to be expected due to the greatly varying source impedance characteristics of
the cartridges available today. In general, you may expect the termination capacitance value to alter, at one
extreme, subtle imaging and spatial cues, and at the other high-frequency content, forwardness and speed of the
reproduced sound. As with the load Z switch, feel free to tune the termination capacitance switches for maximum
sonic satisfaction even though the final setting differs from the cartridge manufacturer's specifications.
5. HIGH PERFORMANCE FRONT END
Your CHINOOK preamplifier makes the best use of active and passive component and circuit developments
generated over the past half-century. The hybrid cascode gain blocks simultaneously deliver wide-band high-gain,
low noise and low distortion performance without overly complex circuitry.
The multiplicative aspect of the cascode devices output (anode) impedance means that the most important
characteristics of each gain stage are preserved even though the local negative feedback used in each block is
quite small. This approach makes the amplification factor of each stage insensitive to tube gain variations due to
device production tolerance allowances or aging. In addition, a precision servo network automatically biases the
input stage to correct for device differences and component tolerances.
Other design elements include high quiescent operating currents in each gain stage. This lowers the static and
dynamic impedances found within each stage while raising the system bandwidth. This is done to insure
maximum headroom is available for the most dynamic musical performances as well as high-level pressings.
6. ACCURATE “4-CORNER” RIAA EQUALIZATION
In the spirit of high fidelity, all four RIAA phono equalization corner frequencies or time constants have been
specifically addressed in the CHINOOK preamplifier. Historically, most designs have concentrated on the “big
three” time constants of 3180, 318 and 75 microseconds. This ignores the fourth corner of about 3.2 us, which
when ignored, causes most phono stages to continue rolling off the highest octave signals coming from the phono
pickup, rather than turning the final “corner” and shelving to flat response at about 50 kHz.
As with all equalizing amplifiers intended to correct a frequency-selective emphasis curve, attention must be
given when building the inverse compensation networks. Care must be exercised if the goal is to produce a highly
accurate passive network coupled to low-feedback amplifiers. Experience has shown that the effort spent in
faithfully adhering to the inverse RIAA equalization curve produces results that easily justify the additional
procurement and manufacturing costs. To this end, only hand-selected and/or 1% tolerance components are used
throughout the RIAA equalization network. This yields impeccable inter-channel phase and gain matching.
In short, the CHINOOK will magnify the differences in the character and personality of your vinyl recording
collection, cartridge, tonearm and turntable. A microscope for the ear! Be prepared to hear previously
undiscovered musical content as you play back your favorites!
Chinook Owners Manual 5
MANLEY
LABORATORIES, INC.