Frankfurt (Oder), Sauer op. 2025

Frankfurt a/Oder, Sauer organ, op. 2025 (1975)

The Carl Philipp Emmanuel Bach Concert Hall in Frankfurt (Oder) was originally a Franciscan monastery. The organ in the hall was built by Sauer in 1975 as Opus 2025. The Sauer company is world famous for top-quality Romantic instruments (such as the Chemnitz organ modeled by Sonus Paradisi). But few people know that the organ building at the company continued throughout the 20th century, and even today the company builds and services pipe organs. In the second half of the 20th century, the company built neo-baroque instruments. as was the current fashion. The Opus 2025 is an excellent representative of this movement. Unlike many instruments of the period, which often have lackluster voicing and a sound that borders on boring, this instrument stands out with its meticulous voicing, especially in the labial stops. For this reason, we have decided to include it in the Sonus Paradisi portfolio.

The organ's layout is typical of its time, based strictly on the "Werkprinzip" hierarchy. Not to be overlooked are the strange aliquots, including septimes and nones, the high-pitched mixtures, and the characteristic dominant flute sound of the foundation stops. The reed registers are rather narrow in sound, always needing to be paired (covered) by a labial stop. Also very successful is the Holzprincipal in the swell, which is essentially a "secret" Flute Harmonique. Thanks to the Sauer tradition of voicing and the craftmanship of this organ, it transcends the narrow confines of the neo-baroque sound ideal. 
The organ was overhauled in 2019/20, and a new mobile console has been added to allow the organ to be easily used together with the orchestra. Fortunately, the voicing of the organ was not altered during this restoration, so we can still hear the mastery of Sauer's voicers today.

For the sample set we decided to stick to the layout of the original old console, and from the new console only the newly added couplers were incorporated. Also, we decided to add a single register, namely the Schwebung on the III manual, which can be used together with the Salicional to obtain the typical undulating effect. Although not normally found on the mid-1970s organs in this style, just a few years later Sauer began to build undulating registers into their new organs. This greatly expanded the organ's usefulness for a variety of repertoire.




The samples are offered in 48kHz/24bit resolution. The multiple releases have three levels: short, mid and long. Hauptwerk v4.2 and higher supported. The sample set is offered in a plain wave format, no encryption.

Reverb time

The reverb time is ca. 3 seconds.

Keyboards, pedalboard

The original compass of the keyboards is 61 keys (full 5 octaves). The original compass of the pedal division is 30 keys. The pedal was extended virtually to 32 keys (activation of the pedal extension is achieved through the mixer tab).


All ranks were recorded with and without tremulants for the most convincing tremulant behavior. However, loading the authentic tremmed ranks consumes large amount of RAM. It is possible to select to use the artificial tremulant instead to save RAM (the switch is located on the mixer tab).


RAM consumption: 6-channel surround

16-bit, other settings default:  28 GB

20-bit, other settings default:  45 GB

24-bit, other settings default:  53 GB

* loading in 16-bit depth is NOT recommended due to high amount of digital hiss emerging, since the noise floor of the 16-bit depth is too high and very audible with the many samples sounding simultaneously.

RAM consumption: the semi-dry channel solo

20-bit, other settings default:  16 GB

Screen resolution 1280x1024 px or more.

Polyphony of 10.000 voices recommended for the full suround.

Surround format

The sample set is offered in a Surround variant (6 channels). There are two direct channels, two diffuse channels and two rear channels.

The semi-dry channels were recorded at short distance from the organ.

To reproduce the surround format, an audio card with at least 4 output channels is required, dedicating the direct and diffuse channels for the front speakers, and other two channels for the rear speakers.

1. Rückpositiv C–c4
Holzgedackt 8'
Quintadena 8'
Praestant 4'
Rohrflöte 4'
Oktave 2'
Terz 1 3/5'
Quinte 1 1/3'
Gemshorn 1'
Scharff IV
Holzregal 8'
2. Hauptwerk C–c4
Pommer 16'
Prinzipal 8'
Gemshorn 8'
Oktave 4'
Kleingedackt 4'
Nasat 2 2/3'
Oktave 2'
Blockflöte 2'
Mixtur V-VI
Zimbel III
Fagott 16'
Trompete 8'
3. Swell C–c4 (enclosed)
Bordun 16'
Holzprinzipal 8'
Rohrgedackt 8'
Salizional 8'
Oktave 4'
Spitzflöte 4'
Waldflöte 2'
Septime 1 1/7'
Oktävlein 1'
Sesquialtera II
Quintan 1 1/3'+8/9'
Mixtur V-VII
Dulzian 16'
Oboe 8'
Helltrompete 4'
Schwebung* 8'
Pedal C-f1 [-g1]
Untersatz** 32'
Subbass* 32'
Prinzipal 16'
Subbass 16'
Oktavbass 8'
Pommer 8'
Hohlflöte 4'
Rohrpfeife 2'
Gr. Sesquialtera III
Mixtur VII
Sordun 32'
Posaune 16'
Bombarde 8'
Corno 4'
Singend Kornett 2'

* - stop added virtually by Sonus Paradisi.

** - not a real stop, but an internal coupler drawing the low quint of the engaged pedal stop, to emulate a resultant 32'.

  • All the usual couplers available, including most of the sub- or super- couplers.


  • Tutti
  • Crescendo
  • Swell pedal
  • "Schweller an" switch. It is a servo aid for an easier move of the swell pedal on the real organ, a switch of no use for the sample set. However, there is a function for the switch in the sample set. The switch is used to enhance the swell functionality in a special way. It has been used to enclose the SW Oktave 4' stop. This stop is in the facade on the real organ, unenclosed. Therefore, the swell does not react on the Oktave 4' in the sample set by default. However, the Schweller an switch will make the swell operating on the SW Oktave 4', too.






Console view:

this is the general console view. It serves to define the keyboard MIDI inputs for all the divisions. The only active part of this view are the manuals and the pedals. Specifying the MIDI inputs is done by right-clicking on the desired manual or pedal. All the other screen components are image-only.




Mixer view:

The output levels of the direct, diffuse and rear ranks can be adjusted here. Also the blower and tracker noises can be adjusted.
The pipe coupling and pipe detuning features can be adjusted. The sound gets somewhat mistuned with higher settings, giving the "chorus" effect to the overall sound, often found pleasingly "floating".
The mixer settings can be stored, retrieved, reset. 3 different mixer settings can be stored/recalled any time.
The switches:
Select the sampled (real) tremulant or the artificial (Hauptwerk model) tremulant.
Select the mixtures sounding as recorded (casually mistuned) or purely tuned.
Select the extended compass of the pedalboard (up to g1) with the compass selection switch.



Left+Right Jambs view:

for dual touch screens, split jambs were created. They allow for portrait or landscape orientation, according to the orientation of the touch screens.




Left + Right Jambs Vertical view:

the dual stop jambs offer vertical (portrait) orientation as an alternative.






Simple Jamb:

All the stops and other original controls of the organ can be found here. The jamb has alternative horizontal and vertical (portrait) orientation. 

Physical pistons or draw stops can be assigned to a virtual button on screen by right-clicking on the button.



Single Jamb:

All the stops are available on a single screen.




Pedal Matrix:

MIDI continuous controllers (hardware swell pedals) are freely assignable on this tab to any of the existing swell pedal or crescendo pedal of the virtual organ. One hardware swell pedal can control any number of virtual swell/crescendo pedals which is useful when the physical console has less controllers than needed. The setting can be memorized via 4 dedicated memory pistons and recalled anytime, thus enabling changing the MIDI assignment during performance. For more details, click here.





the crescendo sequence can be adjusted here. By clicking the gray/white box, the stop is enabled/disabled in the given screscendo stage. The crescendo settings is remembered by Hauptwerk via Hauptwerk dedicated combination system (each stage of the crescendo is a memory for the combination system).

If the crescendo sequence gets corrupted by an accident, the Reset button will help you to restore the original crescendo sequence instantly.





The up-to-date version (1.04) is downloadable from the "My Products", the links have been updated.

  1. Frankfurt (Oder), Sauer, Surround, vol.0

    Frankfurt Sample Set vol. 0. (free volume, semi-dry and surround, 8 channels). Minimum Hauptwerk version: 4.2. (Also works in all higher versions.) No encryption. Free volume, selection of stops. Taste the surround and semi-dry variants together in one sample set.
    Price: Excl. Tax: €0.00 Incl. Tax *: €0.00 Excl. Tax

    Detail & order

  2. Frankfurt (Oder), Sauer, Surround, vol.1

    Frankfurt Sample Set vol. 1. Surround channels, 6 channels (direct, diffuse, rear). Minimum Hauptwerk version: 4.2. (Also works in all higher versions.) No encryption. Works together with Vol.0. No semi-dry channels!
    Price: Excl. Tax: €300.00 Incl. Tax *: €363.00 Excl. Tax

    Detail & order

  3. Frankfurt (Oder), Sauer, Semi-Dry, vol.2

    Frankfurt Sample Set vol. 2 (semi-dry channels). Minimum Hauptwerk version: 4.2. (Also works in all higher versions.) No encryption. Works together with Vol.0
    Price: Excl. Tax: €200.00 Incl. Tax *: €242.00 Excl. Tax

    Detail & order

  4. Frankfurt (Oder), Sauer, 8-channels (surround+sedmi-dry), vol.1+2

    All 8 channels of the Frankfurt sample set together, usable in one sample set. Semi-dry, direct, diffuse and rear channels. Minimum Hauptwerk version: 4.2. (Also works in all higher versions.) No encryption.
    €375.00 Excl. Tax

    Detail & order

    Original price: (excl. tax)€500.00
    Bundle sale (25%):
    - €125.00