This chip was brought to my attention via the Midibox forums and is produced by a company called Ploytec (
Ploytec GmbH . USB Audio and more) out of Germany who produces various midi odds and ends. They also offer the PCB for this project but I opted for the Midibox (
tk_gm5_bulkorder [MidiBox.org]) version which has the correct jumper pinout for connecting to a Core module. The uC itself is an Atmel AVR AT90USB162 which is a very high performance 8 bit chip with 16kb of FLASH and a onboard 512b EEPROM. The price of the chip is 4.50 € and the 1x1 pcb is another 3.00 € ($ 10.50 US). Parts from Mouser came to another $12.00. It is worth mentioning that this chip is a TQFP32 package which is a SMD so you will need an appropriate iron to solder this in.
The chip is class compliant so it runs without and drivers under win32/win64/mac/linux but also has a dedicated driver for win32 to overcome the shortcomings of the generic windows midi driver. 5 in/out ports are available per chip and a 5x5 PCB is in the works but for my tests I am only using the 1x1 PCB which was the only thing available at that time.
Test Setup: Vista32, same USB port, same midi cable with a loop back using Miditest 4.6. I run 2 Midiex 8s and also had some other interfaces (my Novation controller and a Midisport 1x1) to test against. For those who don't know how to interpret these results, low numbers and tight groupings are what you want to see.
To summarize that rather long list, the GM5 bests the Midex 8 by about a factor of 2 pretty much down the board and by about a factor of 3 for the midisport. The max deviation is also very impressive with max of 1.67 (!) ms making this the tightest timed midi interface I have used to date. For less than $25, I really dont think it gets any better than this..
The GM5: Quote:
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MidiTest Results
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================ Info ====================================================
Date: 19 Dec 2008
Time: 07:16:20
AppVersion: 4.6.231
OS: Professional, Service Pack 1 (Build 6001)
Processor(s): Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz
Speed: 2400 MHz
Number: 4
API: MultiMedia Extensions (MME)
Test type: Advanced
Use timestamp: yes
Errors: None
================ Tested Message Types ====================================
Note off: yes
Note on: yes
Key aftertouch: yes
Controller: yes
Program change: yes
Channel aftertouch: yes
Pitchbend: yes
System exclusive: yes
MIDI time code quarter frame: yes
Song position pointer: yes
Song select: yes
Tune request: yes
MIDI clock: yes
MIDI tick: no
Start: yes
Continue: yes
Stop: yes
Active sensing: yes
System reset: yes
System exclusive mixed with realtime messages: no
================ Ports ===================================================
MIDI Output: GM5 port 1
Description: midibox.org GM5
Provider: midibox.org
DriverDate: 11-20-2008
DriverVersion: 1.0.6.0
MIDI Input: GM5 port 1
Description: midibox.org GM5
Provider: midibox.org
DriverDate: 11-20-2008
DriverVersion: 1.0.6.0
================ Results Per Message =====================================
MESSAGES Snd Rcv Snd+Rcv
Message TotalTime: 2026.36 ms 10170.38 ms 12196.74 ms
Message MaximumTime: 0.18 ms 1.67 ms 1.73 ms
Message MinimumTime: 0.03 ms 0.00 ms 0.04 ms
Message AverageTime: 0.06 ms 0.33 ms 0.39 ms
SysexTime: 22.56 ms 2473.62 ms 2496.18 ms
SysexAverage: 0.00 ms 0.25 ms 0.25 ms
< 1 ms: 31250 28461 27792
1 - 2 ms: 0 2789 3458
2 - 3 ms: 0 0 0
3 - 4 ms: 0 0 0
4 - 5 ms: 0 0 0
5 - 10 ms: 0 0 0
10 - 20 ms: 0 0 0
20 - 50 ms: 0 0 0
50 - 100 ms: 0 0 0
> 100 ms: 0 0 0
Message count: 31250 Sysex count: 155
Sysex size: 9999 Sysex passed: 9999
Message latency: 0.39 ms Total time: 64.520 sec
Message jitter: 0.41 ms
Message max deviation: 1.34 ms
================ Results Per Byte ========================================
BYTES
Byte TotalTime: 4862.94 ms
Byte MaximumTime: 1.18 ms
Byte MinimumTime: 0.01 ms
Byte AverageTime: 0.16 ms
< 1 ms: 31249
1 - 2 ms: 1
2 - 3 ms: 0
3 - 4 ms: 0
4 - 5 ms: 0
5 - 10 ms: 0
10 - 20 ms: 0
20 - 50 ms: 0
50 - 100 ms: 0
> 100 ms: 0
Byte count: 78863
Byte latency: 0.16 ms
Byte jitter: 0.16 ms
Byte max deviation: 1.02 ms
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Midex 8 with Directmusic Driver: Quote:
--------------------------------------------------------------------------
MidiTest Results
--------------------------------------------------------------------------
================ Info ====================================================
Date: 19 Dec 2008
Time: 07:09:37
AppVersion: 4.6.231
OS: Professional, Service Pack 1 (Build 6001)
Processor(s): Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz
Speed: 2400 MHz
Number: 4
API: DirectMusic
Test type: Advanced
Use timestamp: yes
Errors: None
================ Tested Message Types ====================================
Note off: yes
Note on: yes
Key aftertouch: yes
Controller: yes
Program change: yes
Channel aftertouch: yes
Pitchbend: yes
System exclusive: yes
MIDI time code quarter frame: yes
Song position pointer: yes
Song select: yes
Tune request: yes
MIDI clock: yes
MIDI tick: no
Start: yes
Continue: yes
Stop: yes
Active sensing: yes
System reset: yes
System exclusive mixed with realtime messages: no
================ Ports ===================================================
MIDI Output: Midex8 8
Description: Steinberg Midex 8 USB Midi Driver
Provider: Steinberg
DriverDate: Not available
DriverVersion: 1.9.0.3
MIDI Input: Midex8 8
Description: Steinberg Midex 8 USB Midi Driver
Provider: Steinberg
DriverDate: Not available
DriverVersion: 1.9.0.3
================ Results Per Message =====================================
MESSAGES Snd Rcv Snd+Rcv
Message TotalTime: 2698.02 ms 21399.95 ms 24097.97 ms
Message MaximumTime: 1.53 ms 4.17 ms 4.26 ms
Message MinimumTime: 0.05 ms 0.00 ms 0.05 ms
Message AverageTime: 0.09 ms 0.68 ms 0.77 ms
SysexTime: 27.38 ms -375.34 ms -347.97 ms
SysexAverage: 0.00 ms -0.04 ms -0.03 ms
< 1 ms: 31249 25264 24461
1 - 2 ms: 1 2570 3210
2 - 3 ms: 0 2080 1985
3 - 4 ms: 0 1323 1566
4 - 5 ms: 0 13 28
5 - 10 ms: 0 0 0
10 - 20 ms: 0 0 0
20 - 50 ms: 0 0 0
50 - 100 ms: 0 0 0
> 100 ms: 0 0 0
Message count: 31250 Sysex count: 153
Sysex size: 9999 Sysex passed: 9999
Message latency: 0.77 ms Total time: 347090.001 sec
Message jitter: 0.88 ms
Message max deviation: 3.49 ms
================ Results Per Byte ========================================
BYTES
Byte TotalTime: 9820.41 ms
Byte MaximumTime: 3.47 ms
Byte MinimumTime: 0.02 ms
Byte AverageTime: 0.31 ms
< 1 ms: 28684
1 - 2 ms: 2294
2 - 3 ms: 221
3 - 4 ms: 51
4 - 5 ms: 0
5 - 10 ms: 0
10 - 20 ms: 0
20 - 50 ms: 0
50 - 100 ms: 0
> 100 ms: 0
Byte count: 78795
Byte latency: 0.31 ms
Byte jitter: 0.40 ms
Byte max deviation: 3.16 ms
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Midex 8 with MME Driver: Quote:
--------------------------------------------------------------------------
MidiTest Results
--------------------------------------------------------------------------
================ Info ====================================================
Date: 19 Dec 2008
Time: 07:13:57
AppVersion: 4.6.231
OS: Professional, Service Pack 1 (Build 6001)
Processor(s): Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz
Speed: 2400 MHz
Number: 4
API: MultiMedia Extensions (MME)
Test type: Advanced
Use timestamp: yes
Errors: None
================ Tested Message Types ====================================
Note off: yes
Note on: yes
Key aftertouch: yes
Controller: yes
Program change: yes
Channel aftertouch: yes
Pitchbend: yes
System exclusive: yes
MIDI time code quarter frame: yes
Song position pointer: yes
Song select: yes
Tune request: yes
MIDI clock: yes
MIDI tick: no
Start: yes
Continue: yes
Stop: yes
Active sensing: yes
System reset: yes
System exclusive mixed with realtime messages: no
================ Ports ===================================================
MIDI Output: 2- Midex8 8
Description: Not available
Provider: Not available
DriverDate: Not available
DriverVersion: Not available
MIDI Input: 2- Midex8 8
Description: Not available
Provider: Not available
DriverDate: Not available
DriverVersion: Not available
================ Results Per Message =====================================
MESSAGES Snd Rcv Snd+Rcv
Message TotalTime: 1913.16 ms 29946.21 ms 31859.37 ms
Message MaximumTime: 0.40 ms 4.14 ms 4.20 ms
Message MinimumTime: 0.04 ms 0.00 ms 0.04 ms
Message AverageTime: 0.06 ms 0.96 ms 1.02 ms
SysexTime: 21.78 ms 3269.69 ms 3291.46 ms
SysexAverage: 0.00 ms 0.33 ms 0.33 ms
< 1 ms: 31250 18288 17842
1 - 2 ms: 0 6924 6959
2 - 3 ms: 0 4562 4805
3 - 4 ms: 0 1464 1614
4 - 5 ms: 0 12 30
5 - 10 ms: 0 0 0
10 - 20 ms: 0 0 0
20 - 50 ms: 0 0 0
50 - 100 ms: 0 0 0
> 100 ms: 0 0 0
Message count: 31250 Sysex count: 157
Sysex size: 10001 Sysex passed: 10001
Message latency: 1.02 ms Total time: 147.798 sec
Message jitter: 1.04 ms
Message max deviation: 3.18 ms
================ Results Per Byte ========================================
BYTES
Byte TotalTime: 12895.09 ms
Byte MaximumTime: 3.11 ms
Byte MinimumTime: 0.01 ms
Byte AverageTime: 0.41 ms
< 1 ms: 27910
1 - 2 ms: 3083
2 - 3 ms: 250
3 - 4 ms: 7
4 - 5 ms: 0
5 - 10 ms: 0
10 - 20 ms: 0
20 - 50 ms: 0
50 - 100 ms: 0
> 100 ms: 0
Byte count: 78979
Byte latency: 0.41 ms
Byte jitter: 0.44 ms
Byte max deviation: 2.70 ms
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Midi sport 1x1: Quote:
--------------------------------------------------------------------------
MidiTest Results
--------------------------------------------------------------------------
================ Info ====================================================
Date: 22 Dec 2008
Time: 18:03:52
AppVersion: 4.6.231
OS: Professional, Service Pack 1 (Build 6001)
Processor(s): Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz
Speed: 2400 MHz
Number: 4
API: MultiMedia Extensions (MME)
Test type: Advanced
Use timestamp: yes
Errors: None
================ Tested Message Types ====================================
Note off: yes
Note on: yes
Key aftertouch: yes
Controller: yes
Program change: yes
Channel aftertouch: yes
Pitchbend: yes
System exclusive: yes
MIDI time code quarter frame: yes
Song position pointer: yes
Song select: yes
Tune request: yes
MIDI clock: yes
MIDI tick: no
Start: yes
Continue: yes
Stop: yes
Active sensing: yes
System reset: yes
System exclusive mixed with realtime messages: no
================ Ports ===================================================
MIDI Output: Out USB Midi 1x1
Description: Not available
Provider: Not available
DriverDate: Not available
DriverVersion: Not available
MIDI Input: In USB Midi 1x1
Description: Not available
Provider: Not available
DriverDate: Not available
DriverVersion: Not available
================ Results Per Message =====================================
MESSAGES Snd Rcv Snd+Rcv
Message TotalTime: 194.48 ms 67939.69 ms 68134.17 ms
Message MaximumTime: 0.03 ms 5.95 ms 5.95 ms
Message MinimumTime: 0.00 ms 0.00 ms 0.00 ms
Message AverageTime: 0.01 ms 2.17 ms 2.18 ms
SysexTime: 15.54 ms 505.73 ms 521.27 ms
SysexAverage: 0.00 ms 0.05 ms 0.05 ms
< 1 ms: 31250 7511 7466
1 - 2 ms: 0 6833 6825
2 - 3 ms: 0 7313 7324
3 - 4 ms: 0 6627 6630
4 - 5 ms: 0 2868 2906
5 - 10 ms: 0 98 99
10 - 20 ms: 0 0 0
20 - 50 ms: 0 0 0
50 - 100 ms: 0 0 0
> 100 ms: 0 0 0
Message count: 31250 Sysex count: 152
Sysex size: 10000 Sysex passed: 10000
Message latency: 2.18 ms Total time: 178.830 sec
Message jitter: 1.32 ms
Message max deviation: 3.77 ms
================ Results Per Byte ========================================
BYTES
Byte TotalTime: 29007.20 ms
Byte MaximumTime: 4.43 ms
Byte MinimumTime: 0.00 ms
Byte AverageTime: 0.93 ms
< 1 ms: 18111
1 - 2 ms: 11136
2 - 3 ms: 1595
3 - 4 ms: 399
4 - 5 ms: 9
5 - 10 ms: 0
10 - 20 ms: 0
20 - 50 ms: 0
50 - 100 ms: 0
> 100 ms: 0
Byte count: 78871
Byte latency: 0.93 ms
Byte jitter: 0.66 ms
Byte max deviation: 3.50 ms
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