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 regulated high voltage power supply is used to provide plate voltage along with a regulated heater supply. The 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 transformers are hand wound for low capacitance and leakage inductance using modern high quality core and dielectric 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

EQUALIZER LF BOOST, CUT; HF CUT

Rotary Elma, Gold Contacts

EQUALIZER HF BOOST, WIDTH

Rotary Potentiometer, Conductive Plastic

FREQUENCY SELECT

Rotary Greyhill, Gold Contacts

POWER

Alternate action Push Button

 POWER INDICATOR

Red Led

CONTROLS, REAR PANEL

INPUT MODE, BALANCED- UNBALANCED

Low Profile Rocker Switch, Gold Contacts

          OUTPUT MODE, BALANCED- UNBALANCED

Low Profile Rocker Switch, Gold Contacts

OUTPUT PHASE, BALANCED MODE

Low Profile Rocker Switch, Gold Contacts

OUTPUT TERMINATION, BALANCED MODE

Low Profile Rocker Switch, Gold Contacts

          GAIN ADJUSTMENT

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

POWER

Standard 3 Wire IEC Type with Integral Fuse 5 x 20 mm.

            FUSE RATING

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.

                                    Control Knob Inserts: Color Coded or Black (PEQ-1B)

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.

The PEQ-! is sold with a one year warranty against all defects. Vacuum tubes warranted for 45 days.

Replacement or repair at the option of PSIDEX

Design and Product specifications may change without notice to maintain quality and performance.