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SPECIAL DESIGN FEATURES

MACHINED ALUMINUM CHASSIS:

 Precision-machined chassis with integrated heat-sinks, 

milled from a solid block of aircraft grade aluminum, provides exceptional thermal 
heat transfer/dissipation, RFI/EMI shielding, and resonance control.. 

COMPOSITE CIRCUIT ARCHITECTURE:

 Unique composite circuit architecture incorporating 

separate Class AB voltage and current gain blocks with no overall negative feedback, 
delivers a sensuous grain-free musicality of unparalleled transparency and low level 
resolution.

BALANCED TOPOLOGY:

 Inherent cancellation effects of balanced topology implemented 

throughout all power and input/output circuits ensures greatly reduced distortion and 
noise under dynamic signal conditions.

HIGH-CURRENT COPPER BUS-BARS: 

High-current, dual polarity, ultra low impedance 

copper bus-bars distribute both power supply input current and signal output current, 
virtually eliminating intra-circuit EMI signal contamination, greatly reducing internal 
wiring, while increasing circuit board rigidity.

HIGH-PRECISION SURFACE MOUNT COMPONENTS: 

Extensive use of Lead (Pb)-free, low 

temperature coefficient, active and passive surface-mount components results in 
significantly smaller loop areas, reduced circuit capacitance and inductance, and 
introduces less noise than conventional leaded components.

TRANSFORMER-COUPLING AND ISOLATION: 

Transformer coupled input circuitry provides 

universal component compatibility and virtually eliminate ground loop noise and RFI/
EMI. Transformer coupling ensures identical amplifier overall gain when using 
unbalanced input adapters.

POWER FACTOR CORRECTION: 

Power Factor Correction (PFC) in the power supply reduces 

AC line harmonic noise pollution and increases AC line power utilization to 99%.

HIGH-EFFICIENCY SWITCH-MODE POWER SUPPLY: 

Highly efficient, compact, light weight, 

1500 watt DC switch-mode power supply provides optimum voltage regulation for all 
circuits and operating conditions, and allows for quiet operation over a wide range of 
AC mains power sources.

DUAL-POSITION SPEAKER TERMINALS: 

Dual CE approved speaker output terminals, in both 

horizontal and vertical orientation, require no tools for secure, low resistance 
connections, and allow for easy bi-wiring applications.

 

PAGE  6

Summary of Contents for 625

Page 1: ...MODEL 625 STEREO AMPLIFIER Operational Manual REVB1 Jeff Rowland Design Group 2011 All Rights Reserved...

Page 2: ...properly grounded AC receptacle should be used A potential shock hazard may result if the supplied 3 wire grounded AC cable ground terminal is defeated or lifted or the unit is connected to a 2 wire...

Page 3: ...is non transferable to any secondary or other purchaser In order to have this product repaired or replaced the original purchaser must first obtain the prior authorization of Jeff Rowland Design Group...

Page 4: ...rized to do so Warranty registration cards must be completed and mailed to Jeff Rowland Design Group Inc within thirty 30 days of the date of purchase If this product is used in a commercial or indust...

Page 5: ...u to gain the maximum performance and ease of use for which this amplifier was designed Please note that your MODEL 625 STEREO AMPLIFIER serial number begins with the letters SB Please include this nu...

Page 6: ...TABLE OF CONTENTS Special Design Features 6 Maintenance and Care 8 Unpacking and Placement 9 Initial Inspection 9 Unpacking 9 Front Panel 10 Rear Panel 11 Specifications 12 PAGE 5...

Page 7: ...ty HIGH PRECISION SURFACE MOUNT COMPONENTS Extensive use of Lead Pb free low temperature coefficient active and passive surface mount components results in significantly smaller loop areas reduced cir...

Page 8: ...panel push button switches the amplifier into standby mode 1 watt consumption REMOTE ON OFF A 1 8 3 5mm mini plug connector on rear panel permits amplifier power on standby switching in remote and ho...

Page 9: ...6 MONTHS BEFORE ATTEMPTING TO CLEAN IT THIS WILL PREVENT SMALL SCRATCHES FROM MARRING THE SURFACE BEFORE THE SURFACE COATING HAS HAD A CHANCE TO HARDEN COMPLETELY WARNING THE FRONT PANEL OF THE UNIT...

Page 10: ...r immediately We strongly suggest that you save all of the packing materials If the amplifier is returned to your dealer or Jeff Rowland Design Group the original packing materials must be used for sh...

Page 11: ...t Panel 1 FRONT PANEL POWER BUTTON Press this button to operate the amplifier Press again to place the amplifier in Standby mode 2 POWER INDICATOR RING This white ring will illuminate when the amplifi...

Page 12: ...e usually red loudspeaker cable spade terminal to the positive binding post and the negative usually black spade terminal to the negative binding post of either horizontally or vertically oriented LEF...

Page 13: ...ms THD Noise 0 005 1 kHz 8 ohms Damping Factor 200 20 Hz 20 kHz Overall Gain Bal or Unbal 27 dB Common Mode Rejection Ratio 90 dB 20 Hz 20 kHz Absolute Phase Non inverting Pin 2 Positive Inputs 1 pair...

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