PEQ-1 DESCRIPTION
The PSIDEX PEQ-1 is a modern version of the famous “Pultec” equalizer popular during the 1950– 1960 period. Like the original, this design employs vacuum tube gain stages and a high quality passive LCR equalizer network, long known for it’s robust, low distortion performance. This modern design, based upon the original EQP-1A, offers lower distortion and noise over the original in addition to more frequency choices. A dual regulated high voltage power supply is used to provide plate voltage along with a regulated heater supply. This power supply uses toroid magnetics to reduce magnetic noise both internally and externally.
Modern features include conductive plastic potentiometers for high frequency boost and width along with stepped switch controls for low frequency boost and cut and high frequency cut. Polypropylene and polystyrene capacitors are used in the signal and frequency determining circuits. The input and output line transformers are wound for low capacitance and leakage inductance and use modern high quality core materials and are magnetically shielded.
The makeup-gain line amplifier is a minimal feedback single ended Class A design. This approach allows for a minimum parts count, which contributes to low noise and distortion. Two vacuum tubes are used in the amplifier. Signal input and output modes are independently switchable for 600 ohm balanced or high impedance, unbalanced, operation.
SPECIFICATIONS
EQUALIZER SECTION
BOOST
FREQUENCIES
L.F
20, 30, 60, 100, 150 Hz, 14 dB in 1 dB steps., shelf
H.F
1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18 kHz, 20 dB +/-1 dB peaking, continuously variable with
variable peak width.
CUT FREQUENCIES (ATTENUATE)
L.F
20, 30. 60, 100, 150 Hz, 18 dB in 1 dB steps., shelf
H.F
5, 10, 15, 20 kHz, 16 dB in 1 dB steps., shelf
LINE AMPLIFIER
GAIN
Unity, with +/- 5 dB Adjustment Range. (Amplifier gain for Eq. make-up typ. 23 dB)
FREQUENCY RESPONSE
10 Hz to 48 kHz +/- 0.5 dB in Balanced Mode.
20 Hz to 50 kHz +/-0.5 dB in Unbalanced Mode.
NOISE
>90 dB below +10 dBm, A weighted.
HARMONIC
DISTORTION
Less than 0.015% at +10 dBm output into 600 ohms.
Less than 0.008% at 0 dBm output into 600 ohms.
MAXIMUM OUTPUT
+26 dBm into 600 ohms.
EFFECTIVE
SOURCE IMPEDANCE
47 ohms for 600 ohm output.
960 ohms for unbalanced hi-z output.
INPUT IMPEDANCE
Balanced input 600 ohms terminated.
Unbalanced hi-z input 100k resistive.
CONTROLS,
FRONT PANEL
EQUALIZER IN/OUT
Lever type Rocker Switch, Gold Contacts
Rotary Elma, Gold Contacts
Rotary Potentiometer, Conductive Plastic
Rotary Greyhill, Gold Contacts
Alternate action Push Button
Red Led
INPUT MODE,
BALANCED- UNBALANCED
Low Profile Rocker Switch, Gold Contacts
Low Profile Rocker Switch, Gold Contacts
Low Profile Rocker Switch, Gold Contacts
Low Profile Rocker Switch, Gold Contacts
Screwdriver Adjust, Conductive Plastic
CONNECTORS, REAR PANEL
INPUT, BALANCED
3 pin XLR Female
INPUT,
UNBALANCED
¼ inch Diameter Phone Jack
OUTPUT,
BALANCED
3 Pin XLR Male
OUTPUT,
UNBALANCED
¼ inch Diameter Phone Jack
Standard 3 Wire IEC Type with Integral Fuse 5 x 20 mm.
120 volts 0.315 Ampere, 240 volts 0.160 Ampere, both to be Time Delay type.
VACUUM
TUBES
Two Nine Pin, Accessible Thru Access Port. Tubes are fully enclosed within chassis.
VACUUM
TUBE COMPLIMENT
One
each, 6414, 12AX7A / ECC83
MISCELLANEOUS
INPUT
POWER
120/ 240 Volts AC 22.6 VA. Input voltage selection via internal jumpers.
PHYSICAL
SIZE
Front Panel, 19 inches wide (48.26), 1.75 inches high (4.445). Equal to 1U rack standard.
Chassis, 17 inches wide (43.18), 11.60 inches behind panel (29.46).
Overall depth, 12.45 inches (31.62) including panel knobs.
( ) Dimensions in cm.
WEIGHT
7.75 pounds (3.52 kg)
FINISH
Panel, Dark Grey textured powder coat.
Chassis, Black anodize.
Markings, white epoxy paint.
MATERIALS/
QUALITY
Panel, aluminum, 0.125 thick.
Chassis, aluminum, 0,0625 thick.
Wiring, MIL M2759/11, MIL M27500, MIL-W- 16878E Teflon.
Soldering, to IPC610A.