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Fredenstein HD Reference Preamplifier

Controls and Operation:

Rotary Control:

GAIN

:

Gain Control from

 

0 to 64 dB in  1dB steps
Pressing the Gain Knob Mutes the output and the Gain Display Blinks

Output Peak Level Indicator:

 

-18dB to +20 dB, 2 dB steps (0dB = +4dBu) 

Switches:

P48

:

+48 Volt Phantom Power when lit

POL

    

:

Reverse Output Polarity when lit

LOW Z 300 

300 Ohms Input Impedance when lit

LOW Z 1K        

:

1000 Ohms Input Impedance when lit

With neither 1K and 300 pressed, the input impedance is approximately 200 Kohms
Note: With P48 engaged 200K becomes approximately 13 Kohms. 

Low Cut 39

:

reduces the lower frequency response to 39 Hz

Low Cut 82

:

reduces the lower frequency response to 82 Hz

 

Fredenstein HD Reference  Manual V1.0  Feb 5, 2016    Page 8

Содержание HD Reference

Страница 1: ...HD REFERENCE Operating Manual...

Страница 2: ...efit of bandwidth The HD Reference also has a few added features such as a display that shows gain in dB next to the knob that allows one to set gain in accurate 1dB steps which is great for setting u...

Страница 3: ...e 2012 19 EU this product must not be disposed with household waste This product should be taken to a licensed EEE collection center for recycling If you need to replace the mains fuse make sure the r...

Страница 4: ...r of damaging the microphone Just to complicate matters the length and capacitance and quality of the microphone cable may be the biggest factor for the microphone and its transformer to deal with Thi...

Страница 5: ...but were intended to be simple problem solvers We might characterize the high pass filters in the HD Reference as relatively gentle and safe The filters are 6 dB oct types with minimal phase shift an...

Страница 6: ...ecision APx515 measuring itself Only the 60 dB gain setting red line shows any visual departure from the others 0 5 dB at 5 Hz 2 5 dB at 2Hz With 40 dB gain you can see the HD Reference measured as fl...

Страница 7: ...wing for noise With the noise floor the actual THD N becomes 0 003 near 10 dBu for the 40 dB gain setting and 0 001 near 15 dBu output level for the 0 dB setting The rising slope towards the left simp...

Страница 8: ...ncies and high levels but are sometimes biased them to bring in some 2nd These graphs show a nice onset and harmonic balance Figure 8 shows two tones 200 and 2 kHz at 0 dBu input each at 6 dB to illus...

Страница 9: ...8 48 Volt Phantom Power when lit POL Reverse Output Polarity when lit LOW Z 300 300 Ohms Input Impedance when lit LOW Z 1K 1000 Ohms Input Impedance when lit With neither 1K and 300 pressed the input...

Страница 10: ...DI input is not supplied with Phantom Power Low Cut 39Hz A 39 Hz low cut filter is activated when lit avoiding unwanted low frequencies while tracking Low Cut 82Hz A 82 Hz low cut filter is activated...

Страница 11: ...rs there are graphs and FFT plots that are even more impressive to those familiar with testing high gain audio amplifiers For example the distortion remains low and flat well beyond 20 Khz unlike most...

Страница 12: ...appreciable capacitance into the chain In extreme cases this might attenuate high audio frequencies In less extreme cases cable capacitance can affect phase response at 20K and can be a difficult load...

Страница 13: ...Contact Info Fredenstein Professional Audio by Orion Communication 7F 1 No 582 Ruei Guang Rd Neihu District Taipei 114 Taiwan Phone 886 2 2657 2618 Email info fredenstein com Web www fredenstein com...

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