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.