beautypg.com

Overview – Manley SKIPJACK User Manual

Page 4

background image

OVERVIEW

The Manley Skipjack is a novel little multi-purpose product. In its most basic form, a partial list of what it might be used
for is:

Selector of 4 x Stereo Inputs to 1 Stereo Output.
Selector of 3 x Stereo Inputs to 2 Stereo Outputs.
Routing 1 Stereo source to one of 4 Stereo Destinations.
Routing 1 of 2 Stereo Sources to 1 of 3 Stereo Destinations.

These basic functions may be just what you need to extend the number of Inputs on a typical Hi-Fi Preamplifier or
Receiver which often have too few, especially those Surround receivers that only have one set of “Direct Inputs” that
bypass all digital conversions and processing. It is also intended as a wonderful way to compare multiple audio products
with minimal electronics in the audio path. In fact, the audio only passes through the high end RCA phono connectors, a
few inches of audiophile wire, and is switched by sealed gold contact relays where both the signal sides use 2 switch
elements and the ground uses 2 switch elements for reliable redundant and leakage free connections. In other words, a
stereo pair needs 4 relays and the Skipjack has 40 relays to perform all routing needed.

Switching signals and grounds separately allows us to control the timing to a fine degree to minimize clicks. Of course,
when switching between any two different signals may generate a click, depending on the relative difference between
instantaneous voltages on those two signals. The method we use generates practically insignificant artifacts when the
signals are matched, because both “overlap” and “dead air” are minimized.

A wired simple single button remote control (known as “The Pickle” in recording studios) gives one immediate and
confident A/B (or A/B/C/D) switching. Additionally, the Skipjack is designed with the possibility to accept both infra-red
and radio-frequency remote controls, through the the use of additional modules and remote controls through the same
back panel port. Each Remote Control opens the door to other purposes particularly useful to equipment reviewers, audio
retailers and audio R&D labs, including a variety of A/B/X tests, with various modes of blindness and statistical reports.
This port could also be used (with the appropriate cable adaptor and software) to accept commands from a computer and
report status. The aforementioned extra options have not yet been developed, but should the demand arise in the future...)

Perhaps the biggest use of the port will be to link Skipjacks. For example 3 Skipjacks could be used for some great 5.1
switching and routing. A very low cost adapter allows one to join up to 4 Skipjacks and have them follow one set of
commands.

The Skipjack is surprisingly heavy for a little box. The weight is to stabilize for the heavy and stiff audiophile
interconnects. With 5 pairs of thick wire connected plus the pickle wire (or a Cat-5 cable) and power supply wire we
wanted the Skipjack to sit solidly.

At first glance, one might suppose that the logic required to handle the switching and LEDs might be simple enough to
be accomplished with standard TTL or CMOS logic. Instead there is a simple microprocessor to do this. Before your
“warning bells” sound off, 99.9% of the time the processor is “sleeping” and the clock is shut down. It comes to life
once a button is pushed or it receives an external command, performs the necessary action, stores its state, and goes back
to sleep in a fraction of a second. If power is removed and returned, the Skipjack returns to the last state. The audio paths
are completely isolated from the control electronics and external power supply.

The LED indicators on Skipjack are also a bit more elaborate than one might fist guess. The MANLEY badge can be lit
by a combination of four colors, from an array of LEDs behind it. Button “D” uses a two-color LED to help show which
mode it is in and whether “D” is controlling an INPUT or OUTPUT.

The Skipjack uses a small external supply, followed by linear regulators in the box. The power supply is designed for a
worst-case scenario (1 in, all 4 outputs on), which while a rare and unlikely possibility, does require 32 relays and 4
LEDs to be turned on and requires almost 2 Amps of power.

5