Vectronics VEC-1680K - Manual (Page 4)

VEC-1680K Owner’s Manual Vacuum Tube Preamp
4
groups by multiplier band (make a pile of 10s, 100s, Ks, 10Ks, etc.). Next, sort
each group by specific value (1K, 2.2K, 4.7K, etc). This procedure makes the
inventory easier, and also makes locating specific parts more convenient later on
during construction. Some builders find it especially helpful to arrange resistors
in ascending order along a strip of double-sided tape.
Reading Capacitors: Unlike resistors, capacitors no longer use a color code for
value identification. Instead, the value, or a 3-number code, is printed on the
body.
Multilayer
271
(270 pF)
Ceramic Discs
|
| 1uF
35V
+ -
104
Electrolytic
1 uF
10 pF = 100
100 pF = 101
1000 pF = 102
.001 uF = 102*
.01 uF = 103
.1 uF = 104
Value Code
102
(.001 uF) (.1 uF)
As with resistors, it's helpful to sort capacitors by type, and then to arrange them
in ascending order of value. Small-value capacitors are characterized in pF (or
pico-Farads), while larger values are labeled in uF (or micro-Farads). The
transition from pF to uF occurs at 1000 pF (or .001 uF)*. Today, most
monolithic and disc-ceramic capacitors are marked with a three-number code.
The first two digits indicate a numerical value, while the last digit indicates a
multiplier (same as resistors).
Electrolytic capacitors are always marked in uF. Electrolytics are polarized
devices and must be oriented correctly during installation. If you become
confused by markings on the case, remember the uncut negative lead is slightly
shorter than the positive lead.
Danger---High Voltage Warning: Although your pre-amp runs from a 12-
volt wall adapter, a second internal transformer boosts voltages back up to
lethal levels to supply plate voltage to the 12AX7 tube! This voltage can
painfully shock, injure, or even cause death if you touch it! Never work on
tube-type equipment without first turning off and un-plugging the power
source from the AC mains! Also, you should discharge power supply filter
capacitors before working on tube amplifier circuitry. This added safety
procedure will be described in the Testing and Alignment section of the
manual.
PARTS LIST
Your kit should contain all of the parts listed below. Please identify and
inventory each item on the checklist before you start building. If any parts are
missing or damaged, refer to the manual's warranty section for replacement