Routes and merges midi data between two USB devices and one TRS midi device.
USB Bridge A features two midi USB hosts and conventional TRS midi (type A) input and output.
Midi data is routed between the connected devices and merged if necessary. Routing is very fast with very low latency.
Data received from a USB device will be send to the other USB device and to the TRS output.
Data received on the TRS input will be sent to the two USB devices.
Depending on the kind of data it will be merged, see below.
You can use this to:
Connect one or two midi USB midi controllers/keyboards to a conventional midi device
Connect a keyboard to a module with only USB device capability
Connect a cheap USB midi interface and get more conventional midi IOs
Use your phone to control your Eurorack or as a synthesizer
Connect a synthesizer via USB
LEDs show the status of USB and midi:
OFF: NO USB device connected:
BLUE : USB device connected successfully
MAGENTA : Receiving midi
RED : USB device connected, but not compatible
BLINKING RED : Overcurrent detected
The TRS midi LED is BLUE, when the module is turned on and blinks purple when receiving midi.
We use blue and red LEDs so colors are distinguishable for people with red/green color blindness. If you prefer your module with green/red instead of blue/red, please let us know when ordering.
Merging and routing
If all three midi inputs are used (2xUSB, 1x midi TRS), it is necessary to route and merge midi data.
Here, USB Bridge A differentiates between several types of midi data:
NOTE AND CONTROLLER DATA
These are all the midi messages that can be merged without any issues. If two devices send midi at the same time, data will be interleaved and sent to the receiving device.
CLOCK DATA
Clock data can not be merged, only one midi clock stream can be used at a time. When USB bridge A receives clock data, it will lock the receiver to this clock source. Once you press stop, the receiver is freed and clock data can be received from an other device.
SYSEX DATA
Sysex data is even trickier to handle than clock data, because sysex messages can have an arbitrary length. if multiple sysex streams are received simultaneously, USB bridge A buffers the data and will forward it to the receiver as soon as possible. This way sysex messages are merged as well.
Voltage converter
USB bridge A includes an optional DC/DC converter to convert 12V to 5V. This means eurorack cases without a 5V supply are also supported. A jumper on the back selects between 5V or 12V input. The DC/DC converter topology means current draw is less on the 12V supply. For example: If your USB device draws 500mA, USB bridge A will only draw about 220mA from 12V.
The supplied power cable features a 26 AWG conduction diameter and can carry more current than the typical eurorack cables. This allows you to connect midi devices with large current draw, such as charging two phones simultaneously. Your eurorack power supply should of course be able to handle the charging currents.
Voltage selector
Compatibility
USB bridge A is compatible with all Class Compliant devices. It also supports some gear that is not quite Class compliant.
Rule of thump: If your device does not need a special driver in Windows, Linux or OSX, it will work.
So far it has been tested with the following gear, but of course it works with many more:
KEYBOARDS / CONTROLLER
Korg Nanokontrol 2, Korg Nanokey 2
Korg microKEY 37 MkII
Roger Linn Design – Linnstrument
AKAI Professional LPK 25
Alesis Q49
SYNTHESIZERS / SEQUENCERS
Korg SQ-1
Novation Launchpad Mini MK2
Novation Peak
Teenage Engineering OP-1
Arturia Beatstep Pro
USB MIDI INTERFACES
Roland UM1-G
Thomann Midi USB 1×1
RME Fireface UFX
Tubbutec µTune
Low latency
USB bridge A has an extremely low latency between input and output:
Sending note-on from USB to USB: 0.08ms
Sending 64bytes sysex from USB to USB: 0.12ms
Sending note-on from USB to TRS-midi: 0.03ms (until TRS midi transfer starts)
For comparison: Usually USB midi clocks at 1kHz / 1ms, so the minimum latency between two devices is usually 1ms.
USB bridge A is about 10 times faster.
A TRS/DIN midi note on message is about 1ms long. The latency here is about 33 times lower.
Technical specs
Printed aluminum front panel, 2mm thickness
2x USB type A host socket
1x input, 1x output TRS midi type A
Voltage supply 12V or 5V
Includes 12 to 5V converter
Supply current: +12V: 10mA , -12V: 0mA, (5V: 20mA) + current drawn by USB devices
USB devices may draw up to 500mA current each
Dimensions: 3HE, 2HP, 128.5mm x 10mm, Depth: 25mm
Weight: 30g
How much is my shipping?
Shipping is automatically calculated before you submit your payment information. Simply add items to your cart and proceed to the checkout page, where you'll be offered shipping options and their prices. In the UK it's normally around £4 for order values under £150, and free above that. Shipping to mainland EU is typically between £7 and £20, depending on the shipping method and the size and weight of the order.
Do you ship to my country?
Almost certainly - the site will give you an estimate of shipping costs if you add an item to the cart and then enter your country and postcode. If you have specific requirements (such as if you prefer UPS over FedEx, for example) then let us know in advance and we'll try to work something out for you.
Shipping methods
We use a combination of Parcelforce, DPD, Royal Mail and UPS for the UK, and for international orders it's either Royal Mail, UPS, DHL or FedEx depending on where you are in the world. If you have a particular preference then try to let us know BEFORE you order so we can look into it for you. Please note that there may occasionally be additional shipping charges if you live in a remote area, depending on what surcharges are applied by the shipper. We'll get in touch to discuss this with you in such cases.
Dispatch times
For UK orders, we normally dispatch the same working day if we get the order before 15:00. If you have a really urgent situation then of course drop us an email before ordering and we'll always do our absolute best to accommodate you.
For international orders, we normally dispatch the same day if we get the order before 13:00 but again, occasionally it might be the next day before we can send it out, and sometimes FedEx or UPS may come a little earlier than scheduled which would also push an order into the next day.
Shipping times
Since April 2020 the couriers we use have suspended guarantees for shipping times, so even though we're paying them for priority services - 24-48 hours for most of the world - in practice it's often an extra day on top and sometimes it can be longer.
There is absolutely nothing we can do about this unfortunately. If you are outside the UK and it's a life-or-death situation where you absolutely MUST have that passive mult for the next day then... it may be better to find a local supplier.
Saturday shipping
If you're in the UK and you order before 15:00 on a Friday then we can send something for a Saturday delivery (NB: this applies to UK mainland addresses only). The success rate with DPD is about 95% so it's worth a punt most of the time. Please note that if you select Saturday shipping on an order placed earlier in the week, we'll wait until Friday to ship it.
Pre-orders
If a product is listed as a pre-order, it means we've ordered it from the supplier but it's not physically in stock yet. The product listing will include an estimated shipping date based on the best information we have from the supplier, but do bear in mind this is subject to change and is not a guaranteed date.
If you place an order containing a mixture of in-stock and pre-order items, we'll normally hold off on shipping anything until the pre-order item(s) have arrived, rather than splitting it into multiple shipments. If you need the in-stock items sooner, we'd recommend placing separate orders. As always, please get in touch if you have questions.
Product Overview
Routes and merges midi data between two USB devices and one TRS midi device.
USB Bridge A features two midi USB hosts and conventional TRS midi (type A) input and output.
Midi data is routed between the connected devices and merged if necessary. Routing is very fast with very low latency.
Data received from a USB device will be send to the other USB device and to the TRS output.
Data received on the TRS input will be sent to the two USB devices.
Depending on the kind of data it will be merged, see below.
You can use this to:
Connect one or two midi USB midi controllers/keyboards to a conventional midi device
Connect a keyboard to a module with only USB device capability
Connect a cheap USB midi interface and get more conventional midi IOs
Use your phone to control your Eurorack or as a synthesizer
Connect a synthesizer via USB
LEDs show the status of USB and midi:
OFF: NO USB device connected:
BLUE : USB device connected successfully
MAGENTA : Receiving midi
RED : USB device connected, but not compatible
BLINKING RED : Overcurrent detected
The TRS midi LED is BLUE, when the module is turned on and blinks purple when receiving midi.
We use blue and red LEDs so colors are distinguishable for people with red/green color blindness. If you prefer your module with green/red instead of blue/red, please let us know when ordering.
Merging and routing
If all three midi inputs are used (2xUSB, 1x midi TRS), it is necessary to route and merge midi data.
Here, USB Bridge A differentiates between several types of midi data:
NOTE AND CONTROLLER DATA
These are all the midi messages that can be merged without any issues. If two devices send midi at the same time, data will be interleaved and sent to the receiving device.
CLOCK DATA
Clock data can not be merged, only one midi clock stream can be used at a time. When USB bridge A receives clock data, it will lock the receiver to this clock source. Once you press stop, the receiver is freed and clock data can be received from an other device.
SYSEX DATA
Sysex data is even trickier to handle than clock data, because sysex messages can have an arbitrary length. if multiple sysex streams are received simultaneously, USB bridge A buffers the data and will forward it to the receiver as soon as possible. This way sysex messages are merged as well.
Voltage converter
USB bridge A includes an optional DC/DC converter to convert 12V to 5V. This means eurorack cases without a 5V supply are also supported. A jumper on the back selects between 5V or 12V input. The DC/DC converter topology means current draw is less on the 12V supply. For example: If your USB device draws 500mA, USB bridge A will only draw about 220mA from 12V.
The supplied power cable features a 26 AWG conduction diameter and can carry more current than the typical eurorack cables. This allows you to connect midi devices with large current draw, such as charging two phones simultaneously. Your eurorack power supply should of course be able to handle the charging currents.
Voltage selector
Compatibility
USB bridge A is compatible with all Class Compliant devices. It also supports some gear that is not quite Class compliant.
Rule of thump: If your device does not need a special driver in Windows, Linux or OSX, it will work.
So far it has been tested with the following gear, but of course it works with many more:
KEYBOARDS / CONTROLLER
Korg Nanokontrol 2, Korg Nanokey 2
Korg microKEY 37 MkII
Roger Linn Design – Linnstrument
AKAI Professional LPK 25
Alesis Q49
SYNTHESIZERS / SEQUENCERS
Korg SQ-1
Novation Launchpad Mini MK2
Novation Peak
Teenage Engineering OP-1
Arturia Beatstep Pro
USB MIDI INTERFACES
Roland UM1-G
Thomann Midi USB 1×1
RME Fireface UFX
Tubbutec µTune
Low latency
USB bridge A has an extremely low latency between input and output:
Sending note-on from USB to USB: 0.08ms
Sending 64bytes sysex from USB to USB: 0.12ms
Sending note-on from USB to TRS-midi: 0.03ms (until TRS midi transfer starts)
For comparison: Usually USB midi clocks at 1kHz / 1ms, so the minimum latency between two devices is usually 1ms.
USB bridge A is about 10 times faster.
A TRS/DIN midi note on message is about 1ms long. The latency here is about 33 times lower.
Technical specs
Printed aluminum front panel, 2mm thickness
2x USB type A host socket
1x input, 1x output TRS midi type A
Voltage supply 12V or 5V
Includes 12 to 5V converter
Supply current: +12V: 10mA , -12V: 0mA, (5V: 20mA) + current drawn by USB devices
USB devices may draw up to 500mA current each
Dimensions: 3HE, 2HP, 128.5mm x 10mm, Depth: 25mm
Weight: 30g
Technical Specs
Shipping Details
How much is my shipping?
Shipping is automatically calculated before you submit your payment information. Simply add items to your cart and proceed to the checkout page, where you'll be offered shipping options and their prices. In the UK it's normally around £4 for order values under £150, and free above that. Shipping to mainland EU is typically between £7 and £20, depending on the shipping method and the size and weight of the order.
Do you ship to my country?
Almost certainly - the site will give you an estimate of shipping costs if you add an item to the cart and then enter your country and postcode. If you have specific requirements (such as if you prefer UPS over FedEx, for example) then let us know in advance and we'll try to work something out for you.
Shipping methods
We use a combination of Parcelforce, DPD, Royal Mail and UPS for the UK, and for international orders it's either Royal Mail, UPS, DHL or FedEx depending on where you are in the world. If you have a particular preference then try to let us know BEFORE you order so we can look into it for you. Please note that there may occasionally be additional shipping charges if you live in a remote area, depending on what surcharges are applied by the shipper. We'll get in touch to discuss this with you in such cases.
Dispatch times
For UK orders, we normally dispatch the same working day if we get the order before 15:00. If you have a really urgent situation then of course drop us an email before ordering and we'll always do our absolute best to accommodate you.
For international orders, we normally dispatch the same day if we get the order before 13:00 but again, occasionally it might be the next day before we can send it out, and sometimes FedEx or UPS may come a little earlier than scheduled which would also push an order into the next day.
Shipping times
Since April 2020 the couriers we use have suspended guarantees for shipping times, so even though we're paying them for priority services - 24-48 hours for most of the world - in practice it's often an extra day on top and sometimes it can be longer.
There is absolutely nothing we can do about this unfortunately. If you are outside the UK and it's a life-or-death situation where you absolutely MUST have that passive mult for the next day then... it may be better to find a local supplier.
Saturday shipping
If you're in the UK and you order before 15:00 on a Friday then we can send something for a Saturday delivery (NB: this applies to UK mainland addresses only). The success rate with DPD is about 95% so it's worth a punt most of the time. Please note that if you select Saturday shipping on an order placed earlier in the week, we'll wait until Friday to ship it.
Pre-orders
If a product is listed as a pre-order, it means we've ordered it from the supplier but it's not physically in stock yet. The product listing will include an estimated shipping date based on the best information we have from the supplier, but do bear in mind this is subject to change and is not a guaranteed date.
If you place an order containing a mixture of in-stock and pre-order items, we'll normally hold off on shipping anything until the pre-order item(s) have arrived, rather than splitting it into multiple shipments. If you need the in-stock items sooner, we'd recommend placing separate orders. As always, please get in touch if you have questions.
