Frequenty Asked Questions

Why Discrete, and why Class A?

In the golden age of audio, all electronic devices were assembled using separate parts, such as resistors, capacitors, and transistors. These individually soldered components create an operational amplifier, a Discrete Operational Amplifier (Op-Amp). As a foundation of our rotaries, we use the discrete op-amps in the Phono inputs, EQs, Summing, Sends/Return, and all the Outputs.

We can design a discrete op-amp with various output stage types, such as Class A. A benefit of a Class A output stage in audio is reducing crossover distortion. In some designs, the signal can get slightly distorted when transitioning between positive and negative voltage swings. Class A keeps the output transistors constantly conducting, minimizing this distortion. It particularly appeals to us, as our in-house-developed discrete op-amp directly addresses this. Besides, we're simply in love with a transparent, undistorted sound.

Sound quality is paramount in audio. However, fitting everything onto a single chip can sometimes affect that. With a discrete circuit, we have more control. It's like building our high-end stereo system from scratch. We can pick each component individually, the best for sound quality, and only use the exact parts needed for the job. That means a simpler circuit, but the one that lets the pure, unadulterated sound of the music shine through.

So, next time you listen to your favorite records, think about the journey the sound takes. It travels through a maze of carefully crafted discrete circuits built with the love of music in mind.

3 Band Master Isolator

We have installed a 3 Band stereo Isolator on our models 2525, 2533, and 2533 FX. This Isolator uses 24 dB / Oct Linkwitz-Riley filters and has crossover frequencies set at 310 Hz and 3100 Hz. Additionally, we have included a true bypass option for your convenience, which completely removes the Isolator from the audio signal chain.

The Isolator is IC-based, and designed to be highly transparent, meaning it won't noticeably alter the audio quality, and it has a "full-cut" feature that provides over -90dB of signal attenuation.

When all three pots (potentiometers) are set to the center position (0 dB), the frequency response of the Isolator is flat, meaning it doesn't boost or cut any frequencies.

Channel Equalizer

Each channel has two rotary controls that allow you to adjust the frequency response. The first control is a shelving Treble control that operates at 10kHz, with 12 dB boost and cut, and the second control is a shelving Bass control that operates at 150Hz, with 18 dB boost and cut.

In our model 2525M, a 3-band Equalizer has Bass control, which operates within +/- 15 dB at 150 Hz, Mid within +/- 12 dB at 800 Hz, and Treble within +/- 12 dB at 10 kHz.

These controls are not "full-cut" EQs. They attenuate the frequencies to a certain level, preserving the tracks' dynamics and energy.

When both controls are set to their center positions, the audio's frequency response remains flat, meaning there is no boosting or cutting of frequencies.

Channel Rotary Fader

Each channel has a rotary fader that allows precise and tactile control over its level during mixing. We have incorporated the ALPS RK27 Blue Velvet potentiometer for its exceptionally smooth movement, accurate control, and long lifespan.

The fader has a range that extends from entirely off when turned counterclockwise (completely off) to 0 dB or Unity Gain (this is the 7th mark around the knob) and up to a maximum level of +12 dB when turned fully clockwise. It means you could amplify your low-level pressed records significantly by turning the fader up.

  • Our Audio Grade Power Supply Unit can operate from any part of the World. Check that the mains power switch is in its off (O) position. Plug in the IEC mains lead. Plug in the DC power lead to the mixer, but ensure it is correctly orientated in the socket and secured with a nut.

    To avoid damage to the internal circuits of the mixer, do not plug in the DC power lead while the Power Supply Unit is turned on.

  • We are using the PPM (Peak Program Meter) instead of the classic VU meter.

    The difference and the advantage of PPM against the VU meter is the acuracy. The PPM accurately registers the peak voltage of the waveform of almost all audio signals. While the deflection of the needle at the classic VU meter depends upon the energy of the waveform and not the peak voltage, making them very inacurate and hard to read due to their very short fall time.

    We want our meters to be as acurate as possible to truthfully display the sound wave. When you have 4 meters as on the picture here (or two) you're sure to have the correct values displayed. Not to have them jumping around without showing any useful sound information.

  • Wood as a building material has very unique features. It always has different shades, patterns and grains. So, if you see any of these natural marks on the wooden box be sure that due to the nature of wood we can’t guarantee the perfectly smooth surface. After all, everything is built by hand and that is very valuable and special. That gives your mixer a very special and unique look.

  • Your new rotary mixer has the capability to produce sounds which when monitored through headphones can be really loud. Never operate at the high levels, never switch the mixer On or Off with a signal present, and while wearing your headphones.

    We recommend starting at minimum, increasing and keeping at the comfortable level.

  • It’s available as an additional modification to the following models: 2500, 2525, 2525M, 2533 and 2533FX. We have added an input TRS connector on the rear side.

    On the 2500, 2525 and 2525M mixers we have a separate volume control, while on 2533 and 2533FX it is selectable on Channel 4. The best results are with a professional quality balanced dynamic vocal type (Sennheiser, Shure…).

  • Water and dust protected according to IP67. The case series from the industry leader has features you look for in others. Water- and dust-proof according to IP67 certified! This means that the contents of these cases remain dry even after 30 minutes at a water depth of 1 meter.

    Quality according to EN ISO 9001. This guarantees precision and fitting accuracy of all parts from the stainless hinges, the all-round lid seal, the robust, two-stage latches to the impact resistance of the scratch-resistant case material.

    Integrated, automatic pressure regulating valve. The perfect travel insurance. For example, in the event of pressure changes in the hold of an airplane, the internal pressure of the case adjusts automatically without damaging sensitive electronics.

    Absolutely safe during transport! High-quality case shell made of impact-resistant special plastic. Robust, strong two-stage folding latches and additional side safety latches on the larger cases ensure absolute tightness and maximum transport safety even in rough handling during travel, assembly or leisure.

  • To prevent damage to the controls and cosmetics avoid placing heavy objects on the unit surfaces, scratching the surface with sharp objects, or rough handling and vibration. Protect the controls from damage during transit. We provide the protective case and use it if you need to move the unit.

  • Use only the highest grade professional cables. Avoid using consumer grade cables.

  • Locate the unit away from direct, sunlight and any equipment which produces heat such as power supplies, amplifiers and heaters. Protect from excessive dirt, dust, heat and vibration when operating and storing. Avoid tobacco ash, drinks spillage, and smoke, especially that associated with smoke machines. 

  • The prices on the website are displayed without VAT. Your local country VAT will be added to the final price.

    For customers from Germany 19% VAT will be added to the final price.

    Deliveries outside the EU are free of VAT, but you remain responsible for any VAT and/or customs duty that may apply in destination countries outside the EU.

    Deliveries to entrepreneurs within the EU but outside Germany may be free of German VAT. Please contact us.

    We accept:

    • Bank transfer (IBAN, SEPA)

    • Paypal

  • Resør Electronics is not responsible for additional costs due to customs and service fees when shipping abroad. Your country will likely require you to submit fees upon receipt at your local customs office. If you know ahead of time your local authorities require more detailed paperwork, then please let us know.

  • Our shipping partner is UPS. We ship both EU and Internationally. You will get tracking information emailed to you when the label is created. All shipments are insured and with tracking number. As a safety precaution, we require a signature upon delivery.

  • The warranty period for all products purchased from us is 36 months from the date of shipment. For any repairs, the customer must provide us with a reasonable time to repair the damage. This time is determined by the type and scope of the work required and the delivery time of the parts needed for this, if not in stock.

    Excluded from any warranty are; Defects caused by damage, incorrect connection, or incorrect operation by the customer; damage caused by force majeure, e.g. lightning; defects caused by wear and tear due to overloading of mechanical or electromechanical parts caused by improper use or defects caused by contamination; damage caused by extraordinary mechanical, chemical or atmospheric influences such as comet impacts.

    All our shipments are insured by the respective parcel service provider. If any damage occurred during the shipping time, the customer undertakes to help in the clarification, if necessary. If a package is already delivered with external damage, please open the package directly in front of the eyes of the parcel service provider, if possible - or refuse to accept.

    Shipping damage must be reported to us immediately - please never try to repair the damage yourself.

  • Warranty

    We guarantee that every DJ mixer from our workshop is of outstanding quality. That is why we offer a 3-year warranty for repairs or replacements in case of faulty products or deviations from the advertised specifications. Even beyond the 3-year warranty, we are happy to provide support, service, and replacement parts.

    Cancellations

    Purchases may be returned during a 14-day cooling-off period. To exercise this right, send us an email within the 14-day timeframe. You may return the purchase for any reason at all. Please note: Given the personalized nature of our product DJ mixers, the 14-day cooling-off period does not apply to custom units.


    Upon receipt, customers are encouraged to thoroughly inspect their purchases and promptly contact our customer service team for any concerns.

Technical Specifications

Line Inputs

Discrete, Class-A Op-Amps
Measured Line In to Master Out:
Frequency response +/- 0,3 dB, 20 Hz to 20 kHz
THD+N better than 0,004 %
SNR better than -95 dB

Phono Inputs

Discrete, Class-A Op-Amps, Gain 40 dB
Passive RIAA Equalization, polypropylene capacitors, close tolerance
Input impedance is 47 kohm
Input capacitance is 47 pF
Measured Phono In to Master Out:
RIAA accuracy within +/- 0,3 dB (20 Hz - 20 kHz)
THD+N better than 0,02 %
SNR better than -77 dB
Maximum input signal level before distortion 100 mVRMS

Master Output

Balanced XLR
Unbalanced RCA L and R
Impedance < 300 ohm

Booth Output

Balanced TRS
Impedance < 300 ohm

Record Output

Nominal level -10dBV
Impedance < 300 ohm

Crosstalk
Channel Fader offness < -100 dB
Channel L/R separation <-70 dB
Isolator offness < -90 dB

Dimensions

(please note that the measurements do not include Knobs, Headphone Jack on the front side, RCA's and Sockets on the rear side of the mixer)

Resør Model 2500 / 2525 / FX / M

Width - 250 mm

Depth - 250 mm

Height - 98 mm (measured from the faceplate and including the rubber feets)

Resør Model 2533 / M / FX

Width - 330 mm

Depth - 250 mm

Height - 98 mm (measured from the faceplate and including the rubber feets)