Artistic EQ - Amplifier Fredenstein - Free user manual and instructions

Product Type	Three Band Equalizer for 500 Series Racks
Brand	Fredenstein
Model	Artistic EQ
Technology	Proprietary SMT design with OPA2 discrete audio operational amplifier
Output Transformer	American-made steel-core transformer
Number of Filter Bands	3 (Low, Mid, High)
Filter Shape Selection	Bell or Shelf per band (via HI SHELF and LOW SHELF switches)
Gain Range per Band	±14 dB
High Frequency Range	2 kHz – 20 kHz
Mid Frequency Range	300 Hz – 3000 Hz
Low Frequency Range	30 Hz – 300 Hz
Frequency Response	20 Hz – 20,000 Hz ±0.2 dB
Total Harmonic Distortion	< 0.02%
Signal-to-Noise Ratio	> 90 dB at 0 dB gain
Input Impedance	> 10 kOhm
Maximum Input Level	+24 dBu balanced
Output Impedance	600 Ohm
Maximum Output Level	+26 dBu balanced
Power Requirements	±16 V, max ±70 mA (600 Ohm load)
Power Indicator	PWR LED
Clip Indicator	CLIP LED (output > +24 dBm)
Bypass	True hard bypass when EQ IN switch is disengaged
Color Circuit	Emulates tube amplifier characteristics (level-sensitive)
Compatibility	All standard 500 series racks with ±16V power
Manufacturer	Fredenstein Professional Audio (Orion Communication)
Country of Manufacture	Taiwan

Frequently Asked Questions - Artistic EQ Fredenstein

How do I install the Artistic EQ in my 500 series rack?

Power down your 500 series rack before inserting the module. Ensure the rack can supply ±16V at up to ±70mA. The module is keyed for correct orientation.

What does the COLOR switch do?

The COLOR switch emulates tube amplifier characteristics, adding level-sensitive artifacts such as harmonic distortion and compression. Higher signal levels increase the effect. In the 'norm' position, the circuit is completely disabled.

How do I bypass the EQ for comparison?

Press the EQ IN switch so the LED is off. This activates a true hard bypass, routing the signal directly from input to output with no EQ circuitry, allowing immediate comparison with the equalized signal.

What is the difference between Bell and Shelf filter shapes?

A Bell filter is a band-pass filter that boosts or cuts frequencies around a center frequency. A Shelf filter boosts or cuts all frequencies above (high shelf) or below (low shelf) the corner frequency, resulting in a flat boost/cut beyond that point.

What are the power requirements for the Artistic EQ?

The module requires ±16V DC from the rack’s power supply and draws a maximum of ±70mA when driving a 600 Ohm load. It is compatible with most 500 series racks.

What is the maximum input level before clipping?

The maximum input level is +24 dBu balanced. The CLIP LED illuminates when the output level exceeds +24 dBm.

Can I use the Artistic EQ in any 500 series rack?

Yes, as long as the rack provides ±16V power rails and can supply the required current. The module is designed to fit all standard 500 series racks.

What is the OPA2 operational amplifier?

The OPA2 is a discrete audio operational amplifier proprietary to Fredenstein, socketed for easy exchange without tools. It uses matched integrated dual input transistors for improved specifications compared to older designs.

How do I clean and maintain the unit?

Use a soft dry cloth to wipe the front panel. Avoid using liquids or solvents. No internal maintenance is required; if the OPA2 op-amp needs replacement, it can be swapped without tools.

What are the frequency ranges for each band?

Low band: 30 Hz – 300 Hz; Mid band: 300 Hz – 3000 Hz; High band: 2 kHz – 20 kHz. Each band has independent gain control (±14 dB) and shape selection.

USER MANUAL Artistic EQ Fredenstein

Black silhouette of a human ear with the letter F inside, no text or symbols present.

Fredenstein

Professional Audio

Artistic EQ Three Band Equalizer

Operating Manual

Fredenstein Artistic EQ

The Fredenstein Artistic EQ, a three band equalizer for 500 series racks, provides best-in-class audio performance and flexibility. Open sounding, easy to use, and with our Color technology Artistic EQ can handle any program material in live and studio applications. Centerpiece of the Artist EQ is the OPA2 discrete audio operational amplifier. As all Fredenstein products, it is not a copy of an older design, but a proprietary design manufactured in SMT technology. Matched and integrated dual input transistors guarantee vastly improved specifications compared to older designs. The OPA2, following the tradition of well known manufactures, is socketed and can be exchanged without tools. The sound is further defined by the American-made steel-core output transformer, which is known for its smooth vintage sound without being dark or just “mid-rangy”. The low and high frequency filters can be switched between Bell or Shelf. The gain range for each filter is +- 14 dB. To facilitate sound comparisons, a true “hard” bypass is available when EQ IN is not engaged. As all Fredenstein products, the Artistic EQ is designed by a German-American team and manufactured in Taiwan.

Overview:

Indicators:

PWR : Power On Indicator

CLIP : Output level > +24 dBm

Rotary Controls:

HI FREQ:

-0+ : High Frequency Gain (dB)

KHz : High Filter Frequency

MID FREQ :

-0+ : Mid Frequency Gain (dB)

KHz : Mid Filter Frequency

LOW FREQ:

-0+ : Low Frequency Gain (dB)

Hz : Low Filter Frequency

Switches:

HI SHELF : selects the HI filter band characteristic: Shelf or Bell

COLOR : emulates tube amp characteristics

LOW SHELF: selects the LOW filter band characteristic: Shelf or Bell

EQ IN : EQ activated when lit, otherwise hard bypassed

Fredenstein Artistic EQ

Installation:

Please power down your rack or box first before inserting the Artistic Pre Plus. The power requirements are not very demanding at a maximum of +/-70mA. The Artistic Pre Plus should work in weaker racks as well.

User Controls:

High Frequency Control:

Select the desired corner frequency of the high frequency filter between 2000 Hz and 20 kHz.

High Frequency Gain:

Boost or cut the high frequency signal by 14 dB.

High Frequency Shelf or Bell:

Select the high frequency filter characteristics: Bell – Band Pass Filter, Shelf – High Pass Filter

Mid Frequency Control:

Select the desired corner frequency of the mid frequency filter between 300 Hz and 3000 Hz.

Mid Frequency Gain:

Boost or cut the mid frequency signal by 14 dB.

Color:

emulates tube amp characteristics, another significant way to alter the program material. If activated, a sensible amount of tube-style amplification artifacts are added. These are level sensitive like tube gear, higher levels increase the amount of artifacts. In “norm” this circuit is completely disabled.

Low Frequency Control:

Select the desired corner frequency of the low frequency filter between 30 Hz and 300 Hz.

Low Frequency Gain:

Boost or cut the low frequency signal by 14 dB.

Low Frequency Shelf or Bell:

Select the low frequency filter characteristics: Bell – Band Pass Filter, Shelf – Low Pass Filter

EQ IN:

EQ activated when lit, otherwise it is hard bypassed. Allowing for immediate comparisons of the eq'ed and original program.

Fredenstein Artistic EQ

Technical Data:

Frequency Response : 20 Hz – 20,000 Hz, +/- 0.2dB

Distortion : < 0.02%

S/N Ratio : > 90 dB at 0dB gain

Input Impedance : > 10KOhm

Max. Input Level : + 24 dBu balanced

Output Impedance : 600 Ohm

Max. Output Level: +26 dBu balanced

High Freq Filter : 2 KHz – 20 kHz

High Freq Gain : +/- 14 dB

Mid Freq Filter : 300 Hz – 3000 Hz

Mid Freq Gain : +/- 14 dB

Low Freq Filter : 30 Hz – 300 Hz

Low Freq Gain : +/- 14 dB

Filter Q : Frequency dependent

Power Consumption : +/- 16 V, +/- 70 mA (600 Ohm load)

Contact Info:

Fredenstein Professional Audio

by Orion Communication

7F-1, No. 582, Ruei Guang Rd.

Neihu District

Taipei 114

Taiwan

Phone : [phone]

Email: [e-mail]

Web : www.fredenstein.com