IHF-1 is a high-quality, affordable interface solution for converting from consumer to pro audio.  This compact assembly may be treated exactly as a pair of high-performance transformers—but with gain.  The same assembly is used for balanced to unbalanced, and unbalanced to balanced configurations.  The IHF-1 also makes an excellent line amplifier—just use it in a balanced to balanced configuration.


The unique cross-coupled precision feedback design used in the output amplifier means that if an unbalanced input or output is needed, just pull either side to ground—as you would with a transformer.  The precision circuitry used will sense that the line is at ground potential, shut down that line and increase the gain on the complementary line by 6 dB to compensate.  Laser-trimmed low-noise thin-film precision input components are used (matched to within  0.005%), resulting in excellent CMRR performance.  Devices are protected against surges and overvoltage conditions by additional circuitry.  Effective RFI suppression techniques have also been employed.  Audio performance is excellent, and gain is continually adjustable from -40 to +40 dB using precision multiturn trimmer potentiometers.  Gold-plated gain-setting jumpers are included to optimize the amplifiers’ performance for a particular gain range.


Each circuit assembly consists of two discrete channels and a power supply regulator mounted on a small printed circuit board, with integral edge connector and card guide bracket.  The assembly may be conveniently mounted inside consumer equipment, or mounted inside console cabinetry as desired.  The assembly may be powered with an AC adapter (a CSA/UL approved unit capable of powering up to 6 IHF-1 assemblies is available from DTL under separate cover; specify IHF-1 PS), or its flexible power requirements often allow it to be powered by the equipment it is interfacing.


Each unit comes a complete schematic diagram and parts list.  Integrated circuits are socketed.  Circuit board edge connector contacts are gold-flashed.  Finest quality circuit board materials are used.  In short, this device is a superior product, designed to provide years of trouble-free service. 


Installation Information




Frequency Response                            20 Hz-20 kHz +/- 0.25 dB

                                                            5 Hz-100 kHz +/- 1.00 dB


Input Level                                           - 40 dBu to +28 dBu


Input Impedance                                   24 kW


Output Level                                        + 24 dBu maximum into 600 W


Output Impedance                                600 W nominal, 50 W actual


S+N/N                                                 > 90 dB


THD                                                    < 0.006 %


IMD                                                     < 0.006%


CMRR                                                 > 95 dB below 10 kHz

> 80 dB to 20 kHz


Phase lag/lead                                       < 2 degrees, 20 Hz-20 kHz


Physical dimensions                              3” x 3.13” printed circuit board in card-edge

                                                            connector assembly.  Mounts on 3.38” centres.


Power requirements                              15-24 VAC unregulated @ 50 mA maximum,

                                                            or +/- 20-35 VDC unregulated @ 50 mA maximum.




IHF-1 PS:  CSA/UL approved AC adapter.  120 VAC in; 16 VAC, 300 mA out.


Warranty Information


DAV TRONICS / S.W. Davis Broadcast Technical Services Ltd.

200-1543 Venables Street

Vancouver, BC


V5L 2G8


Telephone 604 255 2200

Fax 604 255 4083