DOEPFER Midi Bass Pedal Electronic Kit MBP25 User's Guide © 2008 by Doepfer Musikelektronik GmbH Geigerstr. 13 82166 Graefelfing Deutschland / Germany Phone: + 49 89 89809510 Fax: + 49 89 89809511 Web Site: www.doepfer.com Email: sales@doepfer.
Electrical safety / EMC compatibility MBP25 is a so-called OEM product (OEM original equipment manufacturer) that cannot be used independently but has to be combined with additional electrical or electronical equipment to become a working device (suitable keyboard, pitch bend and modulation wheel, rotary or fader potentiometer, power supply, case/housing). The manufacturer of MBP25 does not know the final assembly of the complete device in which the MBP25 is used as a part of the complete device.
Table of contents Electrical safety / EMC compatibility ........................................................................................2 Warranty...................................................................................................................................2 Table of contents......................................................................................................................3 Introduction............................................................................
Introduction MBP25 is an electronic kit that has been developed for midi bass pedal applications. Unfortunately our supplier (Fatar) does not offer bass pedals with 25 or more keys but only versions with 13 or 17 keys. As many customers have been asking for a basspedal with 25 keys we decided to develop an electronic kit that can be used to connect two bass pedals with 13 keys each (Fatar PD/3) to obtain a 25 key bass pedal in a very economic way.
These are the most important features of the MBP25: • • • • • • • • • • • • • • • • three versions available: • elektronic kit only • elektronic kit with one 13-key bass pedal and connection cable • elektronic kit with two 13-key bass pedals and connection cables 6 black rectangle momentary buttons (about 12 x 22 mm) with integrated LEDs to adjust the parameters (e.g.
Connections Please refer to the picture on the next page. (1) Power Supply The MBP25 does not have a built-in power supply. Instead it uses a plug-in type external power supply (AC adapter). One reason for this feature is electrical safety. Keeping danger voltages (main) out of the MBP25 increases the electrical safety. Therefore an external power supply of high quality and safety should be used. If the device is used in Germany the external power supply has to be VDE approved.
feedback terminal for optional third pedal (MK4) (4) bass pedal connectors ST1 (lower) and ST2 (upper) (5) connector for volume control (ST3) (2) midi out (BU1) (3) midi in (BU2) alternative alternative connector for midi connector for midi out socket in socket (JP4) (JP3) (1) power supply 7-12V/100mA DC (BU3) alternative connector for power supply (JP2) trimming potentiometer for voltage range adjustment of the volume control connected to ST3 User's Guide page 7 MBP25
(4) Bass Pedal Connectors These female connectors are used to connect the bass pedal(s). The connectors are compatible to the connectors of the Fatar PD/3 bass pedals and the same type of connectors are used (AMP micromatch 16 pins). To connect MBP25 with the bass pedal(s) 16 pin ribbon cables with a 16 pin male connector on each end is used. The connectors are equipped with code pins that have to fit into the corresponding hole on the MBP25 and PD/3 pc boards. Otherwise the pin may break off.
The potentiometer connected to ST3 generates midi volume data (control change #7). If no potentiometer is connected to ST3 the center pin has to be connected to +5V. For this ST3 is equipped with a jumper in the factory. An open center pin of ST3 will cause the transmission of random midi volume data ! By means of a trimming potentiometer the maximal voltage value for the potentiometer connected to ST3 can be adjusted in a range of about +3.5V...+5V. This value corresponds to midi data 127.
Controls The three-digit display is used to show the value of the currently selected parameter, i.e. midi channel, transpose, program change number or mode. The LEDs indicate the currently selected menu. The four left buttons are used to select one of the four menus. The two right buttons are used to decrease or increase the value of the currently selected parameter. In addition each menu button can be used to increment the parameter of the menu in question. E.g.
2. Transpose In this menu the midi note number assigned to the lowest key on the lower pedal is adjusted in octave intervals. The value (0,12,24,36,48 and 60) is displayed and can be changed with the up/down buttons. The lowest note key is always a "C". Only the octave of the "C" can be changed. To avoid midi note hang ups the transpose can be changed only if no key is pressed on the pedal. Otherwise the note off message would be sent on a different note number causing a never ending tone. 3.
Parameter Storage Whenever one changes from one menu to another the parameter of the preceeding menu is stored non-volatile in the MBP25 memory. After the next power on these values are chosen. These values are stored: midi channel, transpose, program change number and mode. Configuration Mode In this special mode all parameters can be adjusted that have basic functions and are normally adjusted once only.
Shortening the second bass pedal If a 25 keys bass pedal has to be made by the combination of two 13 keys pedals one of the two pedals has to be shortended as one of the "C" keys is redundant. Fortunately the PD/3 pedals use a plastic frame and can be shortened with passable effort. From our experience it's easier to remove the upper key of the lower pedal though it would be possible too to remove the lower key of the upper pedal. In the following the shortening procedure is described.
Cut also the black plastic bar which holds the pedal contacts with a suitable saw. One of the screws has to be removed before. remove this screw View after the pc board and the black plastic bar are cut off Mark a cutting line with a distance of about 40-42 mm from the edge to the bottom of the pedal frame.
Cut off the pedal frame at this line with a suitable saw. View after the pedal frame is cut off The two bass pedals can be mounted on a common base, e.g. made of wood. On the left side the bass pedal with the removed upper key is mounted. In the rear area the pedals have to mounted about 8-10 mm higher to have sufficient lift for the vertical movement of the keys. For this a small board (about 12 cm width and 10 mm thickness) over the whole lenght can be used (about 93,5 x 12 cm for two pedals).
Schematics PD/3 If another bass pedal or single contacts/switches are connected to the MBP25 they have to be wired identically to the PD/3. This is the pin-out of the MBP25 connectors (ST1, ST2) for the bass pedals (top view): nc nc MK0 nc T3 T2 T1 T0 code hole nc nc MK1 nc T7 T6 T5 T4 Doepfer Musikelektronik www.doepfer.
