The Microdesignum MIDI Presto BassExtractor is a small MIDI processor that takes an incoming MIDI data stream, finds the bass line in it, and sends that bass line out on a different MIDI channel1. Microdesignum positions it as a very low-cost substitute for a MIDI pedalboard: instead of playing bass parts from a separate pedal controller, a keyboard or organ player lets the BassExtractor derive the bass part automatically from what is being played2. It belongs to the Czech maker's MIDI Presto line of MIDI converters, described as an effect for keys and organs2.
What it does to a MIDI stream
The BassExtractor analyzes the MIDI data arriving at its single MIDI input, identifies the lowest sounding note, and sends that note to the MIDI output on a different channel12. In practice, a player feeding it a full keyboard part gets a separate bass line on its own channel, ready to drive a bass sound or another instrument without splitting parts by hand.
A switch selects how the extracted note is shifted: the BassExtractor lowers the lowest sounding note by 1, 2 or 3 octaves, or raises it by 1 octave, depending on the switch position12. That covers the common registers a bass part needs, set on the unit rather than in a menu. There is no display on the unit at all, so the switch is the only control1.
| Control | What it does |
|---|---|
| Octave shift switch | Shifts the extracted lowest note down 1, 2 or 3 octaves, or up 1 octave12 |
In short, the unit's job breaks down into three steps:
- Receive MIDI data at its single MIDI input1.
- Find the lowest sounding note in that data12.
- Send that note out on a different MIDI channel, shifted by the chosen octave setting12.
Availability and development status
Microdesignum's shop lists the BassExtractor as temporarily unavailable as of 26 October 2026, and the maker describes the converter as still in development and open to further suggestions12.
The unit is sold as a final product, not a kit1. The maker's product page notes that the converter is still in development and that further suggestions and comments are welcome, so its behavior may continue to evolve2.
Where it sits in the MIDI Presto line
The BassExtractor is one of Microdesignum's MIDI Presto converters. Its closest named relative is the MIDI Presto Organium, a converter for organ keyboards; the BassExtractor instead works on incoming MIDI data and extracts a bass line from it2. Players comparing the two are choosing between converting an organ keyboard and deriving a bass part from a MIDI stream. For other jobs in the same family, Microdesignum also makes foot controllers such as the Microdesignum MIDI Grande and relay loop switchers such as the Microdesignum MIDI Agente Relay Loop 4L2R1D, and the MIDI pedals page covers the wider category.
Questions
What does the Microdesignum MIDI Presto BassExtractor do?
It is a MIDI processor that analyzes incoming MIDI data, finds the bass line in it, and sends that bass line out on a different MIDI channel. Microdesignum describes it as a very low-cost substitute for a MIDI pedalboard: instead of playing bass parts on a separate pedal controller, a keyboard player can let the BassExtractor derive the bass part from whatever is being played.
Which octave shifts does the BassExtractor offer?
The BassExtractor takes the lowest sounding note in the incoming MIDI data and shifts it by an amount chosen with a switch: down by 1, 2 or 3 octaves, or up by 1 octave. That lets the extracted bass line sit in the register the player wants without any editing of the MIDI data itself.
How many MIDI inputs does the BassExtractor have?
The BassExtractor has one MIDI input, according to Microdesignum's product page. It also has no display, so all of its operation is set with the physical switch rather than a menu.
Is the MIDI Presto BassExtractor currently available?
As of 26 October 2026, Microdesignum lists the BassExtractor as temporarily unavailable on its shop page. The maker also notes on its product page that the converter is still in development and welcomes further suggestions and comments, so the design may continue to change.
What is the difference between the BassExtractor and the MIDI Presto Organium?
Both belong to Microdesignum's MIDI Presto line of MIDI converters. The BassExtractor works on incoming MIDI data and extracts a bass line from it, while the MIDI Presto Organium is a converter for organ keyboards. They are related products in the same family, aimed at different jobs.
Sources (2)
- MIDI Presto BassExtractor vyextrahuje basovou linku, Microdesignum
- MIDI efekt pro varhany, Microdesignum (www.microdesignum.cz)
