Hafler DH-101 preamplifier

The Hafler DH-101 is the control center of your high fidelity system. 

Its extremely low distortion and noise level provides very accurate control of the following functions:

Preamplification and equalization for such sources as tape recorders, tuners, and the like;

Control of tonal balance of all signals;

Adjustment of volume level and balance;

Switching facilities for all signal sources;

Tape copying facilities and monitoring capability while tape recording.

Special features:

Lowest distortion from phono input to preamp output

Extraordinary pulse and square wave response

Widest power bandwidth

Highest phono input acceptance level  - 1,8 volts at 20 kzh

High slew rate both phono section and tone control stage

Fast rise time

Human engineered with self-indicating push buttons

All discrete transistors, no ICs in audio circuits

Tape dubbing facilities

Provision for internal moving coil pre-preamp

Sub-sonic filter meets latest RIAA standard

Easiest kit construction

No cartridge interaction

Precision RIAA equalization all push pull design

Regulated power supply

International power transformer

Complete tape record, monitor, and duplicate facilities

Feedback tone controls with defeat switch

Prefabricated and pretested circuit modules carry all components, operating controls, and switches

Finest quality components including tantalum capacitors and film resistors where useful

Provision for patching external equipment such as a noise reduction unit or graphic equalizer

 

 

Specifications

Phono Preamp Section

Type:  Discrete transistor (No integrated circuits)

Rated Output:  3 volts, 10 Hz to 100 kHz

Max. Output:  7 volts, 20 Hz to 20 kHz

Total Harmonic Distortion :  less than 0,0006% at 1 kHz and 3 volts out

Slew Rate: 12 volts per microsecond

Phono Overload:  180 mV at 1 kHz ; 1,8 V at 20 kHz

Phono Cartridge Interaction at 20 kHz:  Unmeasureable

Hum and Noise:  86 dB below 10 mV, 1khz input (A weighted)

Frequency Response:  complies with RIAA sepcification 40 Hz to 15 kHz ±0,5 dB

Hi-pass Filter:  In accordance with proposed RIAA revision

Gain:  34 dB at 1 kHz

Input impedance:  47 k Ω  in paralel with 250 pf

Tone Control Section and High Level Amplifier

Type:  Discrete transistor (no integrated circuits)

Rated Output:  3 volts 10 Hz to 100 kHz

Max. Output:  7 volts, 10 Hz to 100 kHz

Total Harmonic Distortion less than 0,001%, 20 Hz to 20 kHz at rated output

Slew Rate:  12 volts per microsceond

Rise Time:  2 microseconds

Hum and Noise:  90 dB below 1 volt (A weighted)

Frequency Response:  20 Hz to 20,000 Hz +0 dB,  -0.25 dB

Gain:  20 dB ±1 dB

Input Impedance: better than 25 k Ω 

Bass Control: 

Type:  Moving Inflection with variable turnover frequency

Amount:  ±12 dB at 50 Hz

Treble Control:

Type:  shelving with fixed turnover frequency

Amount;  ±10 dB at 20 kHz

General Specifications

Semiconductors:  28 Transistors; 4 Diodes; 1 LED; 2 ICs power supply regulators

Inputs:  Two phono, tuner, auxiliary; two tape recorders

Outputs:  Two tape (buffered) and one profram

Provision for patching in external equipment

Controls: Volume, balance, bias, trebl, tape dubbing, input switching, mono-stereo, tone control engage, power on-off

Intermodulation Distortion:  at normal levels of operation, IMD, whether SMPTE or CCIF, from phono iput to preamplifier output is below the residual of currently available instruments

AC Convenience Outlets:  2 switched; 5 amp continuous, 72 amp surge; 2 unswitched, 5 amp continuous

Power Requirements:  AC 100/120/200/220/240 50/60 Hz

Power Consumption:  3,5 watts

Dimensions (W x H x D):  350 x 82,5 x 215 mm (13,75" x 3,25" x 8,5")

Weight: 3,6 kg (8 lbs )