Here is a screenshot of the ReaGate settings that were used to perform MIDI KEYING of the sine wave VST PLUGIN - Bipper - ( using the audio output of FLdigi to "key" the midi note on the output of ReaGate - which in turn "keys" the MIDI INPUT of  the sine wave VST PLUGIN - Bipper -)

An extreme qrq cw sending test was used to see how well this setup does at accurately producing perfectly timed, morse code audio tones, from the original MIDI INPUT source.

To test the ability of this system, FLdigi was used to send a continuous stream of the letter "s" at 150 wpm to the MIDI VST's.  The final MIDI-2-AUDIO was recorded.  The midi accuracy is very close to perfect:

Audio to Midi

To further test - AUDIO TO MIDI -  function for regenerating a cw audio waveform, a Logikey K-1 cw keyer was used with paddles.  An audio cable was connected to the Logikey's speaker and a 1k to 8 ohm radio shack audio transformer.  The output (8 ohm) from the transformer was connected to the MICROPHONE INPUT jack with another audio cable. [this transformer provides, GROUND LOOP ISOLATION, COMPUTER MIC JACK VOLTAGE ISOLATION, and lowers the voltage so you don't overdrive the MIC INPUT of the soundcard, helping to prevent damage to the components and distortion of original Logikey audio signal which would effect the ReaGate MIDI OUT performance.   After adjusting the ReaGate's knobs and sliders to "best by ear" settings,  the final regenerated cw was virtual identical to the original.

This picture shows the original LOGIKEY cw audio on top and the regenerated MIDI NOTE on the bottom

The AUDIO TO MIDI function of  ReaGate,  performed extremely well in reproducing the original waveform of Logikey's original cw element length without glitches in timing whatsoever.

Audio TO Midi - MIDI KEYING - for a morse code sine wave oscillator

This video demonstrates how to key a software sine wave oscillator using MIDI CONTROL.. AUDIO to MIDI conversion is performed by the ReaGate VST PLUGIN, to convert morse code audio tones input from a laptop MICROPHONE JACK - into MIDI DATA output. This ReaGate output MIDI DATA, then sends [ midi ON - OFF data ] to key a software sine wave VST signal generator to recreate exactly the original morse code audio tones element length. ReaGate can also send any pitch/frequency data to tell the following SINE WAVE SIGNAL GENERATOR what pitch/frequency to use, independent of the original pitch coming into the MIC JACK and then to the input of ReaGate. Using MIDI to key a sine wave oscillator for function as a code practice oscillator or to create near perfect raised cosine morse code audio tones for QSO on HF or OVER THE INTERNET, is very accurate and stable. It has also been more stable, and more precise, in practical use for this purpose, than using a SERIAL PORT to key a software CPO. AUDIO to MIDI conversion bypasses the need for an actual hardware midi interface. A midi interface would still work the same way as shown in the video for the AUDIO to MIDI conversion technique.

NOTE: JACKROUTER is used, see this video tutorial for more info on how to setup JACKROUTER https://www.youtube.com/watch?v=h883l3PUJ50

HERE ARE THE LINKS MENTIONED IN THE VIDEO:
1. REAPLUGS for ReaGate
http://www.reaper.fm/reaplugs/
2. MELDA PLUGS for Mequalizer and Mfreqshifter
http://www.meldaproduction.com/download.php?bundle=MFreeEffectsBundle
3. BIPPPER and GAIN VST PLUGS
http://www.mindthepressure.org/plugz.php
4. SPECTRUM ANALYZER PLUG - SPAN -
http://www.voxengo.com/product/span/
5. C TUNER VST AUDIO PITCH READER VST PLUG
http://www.samplerchan.com/
6. ENGINEERS FILTER VST PLUG
http://www.rs-met.com/freebies.html
7. ASIO BRIDGE from VB-AUDIO
http://vb-audio.pagesperso-orange.fr/Cable/
8. jackrouter CATIA and CARLA connection bays
http://kxstudio.sourceforge.net/Downloads

LATENCY OF JACKROUTER for AUDIO to MIDI technique to key a software CPO

This picture shows the inside routing audio delay from a cw sidetone going into the computer sound card MICROPHONE INPUT JACK, then over to the SOUND CARD OUTPUT,  when using JACKROUTER,  measured to be about 17 milliseconds,  this is considered to be - NEAR ZERO LATENCY - 

the first wave is MIC AUDIO from the CW KEYER entering the MIC JACK, the 2nd wave is when that same wave reaches the sound card after going through jackrouter WITHOUT any VST PLUGINS - 17milliseconds

17 milliseconds is just below the human sensory threshold for being able to notice any latency at all

often quoted in the music industry for LIVE PERFORMANCE:

"sounds are perceived as coming from a single source when they occur within 25-35 ms time window"

In this picture, we show the delay between the output of the software CPO - BIPPER - , and the output of the same audio going through all the VST PLUGS, in this example, it only takes another 3 milliseconds to go through 5 VST PLUGINS...to the sound card...the FIRST WAVE on top, is the immediate output of BIPPER, the second waveform on the bottom is the start of the FINAL filtered audio as it outputs from the last VST plugin

When you add these two numbers together, you get a TOTAL OF 20 MILLISECONDS of latency/delay from when the cw keyer sidetone enters the MICROPHONE JACK until it reaches the SOUND CARD OUTPUT.

This is still below the  25 -35 ms human hearing threshold for being able sense any latency at all...

This is outstanding performance from JACKROUTER and ASIO4ALL and the REALTEK HD AUDIO soundcard of this laptop.  Every computer has different soundcards, and drivers, and may have different results than these. Make sure your sound card drivers are up to date for best outcome when using a setup like this for LIVE PERFORMANCE in audio applications.  The jackrouter settings used were 48k sample rate/256 frame buffers.

HERE IS A PICTURE OF the CW PADDLE HANDLE TAP TEST

- testing the time from when you "tap" the paddle handles until you hear the tone.  This measured to be less than 30ms, still considered to me near zero latency. This is very good performance when using ASIO4ALL, and the computer's own soundcard.  

HERE IS ANOTHER VIEW OF THE TWO WAVEFORMS

- K1 CW KEYER AUDIO input on top, and MIDI note 79 from Bipper CPO vst plugins on bottom.  The cw audio pitch/frequency of input and output can be any audio frequency and differ from each other by any range desired.

HERE IS AN ADVANCED SETUP FOR AUDIO to MIDI CW KEYING

Here are the results from testing the MIC INPUT JACK to the AUDIO to MIDI converter from k1el keyer sidetone

The k1el sidetone keyer audio output was connected by an audio cable,  to the MIC INPUT of the laptop's soundcard.  The K1el was set to 149wpm, and a dit stream was sent and recorded after the AUDIO to MIDI conversion,  as you see above.  The dit stream produced by the AUDIO to MIDI converter, is very accurate and steady... an extremely precise copy of the original wave length and timing,  of the original  k1el sidetone output.

HERE IS A VERY SHORT VIDEO EXAMPLE OF A MIDI KEYED SOFTWARE MORSE CODE OSCILLATOR

This video demonstrates a software code practice oscillator being "keyed" by a MIDI MESSAGE, from a virtual midi keyboard and a mouse.  The same performance can be expected from an actual hardware midi interface setup, where your IAMBIC PADDLES and CW KEYER would send a normal "keying output signal" to a hardware "MIDI INPUT DEVICE".  MIDI OX is shown that visualizes the midi messages, NOTE ON, and NOTE OFF.  Midi messages are fast and accurate, duplicating the timing of the original input - such as - - an iambic cw keyer's output that would normally key a rig, could be used to key a hardware midi interface and the MIDI OUTPUT would then key this software CPO.

There are many VSTi plugins besides Bipper, that can produce a SINE WAVE.  I have been testing another free one called Satyr.  It produces a sine wave cw audio note that I like better than the previously described Bipper. Here is a picture of Satyr.  The only controls needed to adjust from default settings are marked in RED LINES.  

Satyr creates sine waves with exponential edges on RISE and FALL.  Adjusting ATTACK and RELEASE TIME is all that is needed to "dial in" the desired milliseconds of edge shaping for producing a high quality cw note.

Here is a picture of the SATYR wave shape for a single DIT.

HERE IS A COMPARISON PICTURE OF AN ORIGINAL FLdigi WAVESHAPE of the LETTER "R" on TOP and a recreated LETTER "R" via this AUDIO to MIDI technique(SATYR CPO)on the bottom- -also THE SATYR CPO is using the FLdigi RT CHANNEL QSK function to trim off a tiny increment of time via negative compensation - a few milliseconds, the same amount off of both the dit and dah.  At your top copy speed I have found this to be a great feature to help "fine tune" the QRQq cw sending to make for better copy.  The AUDIO to MIDI technique (using SATYR as the CPO) followed by a software BESSEL FILTER effectively "clones" the original FLdigi wave shape.  The AUDIO to MIDI technique for regenerating FLdigi cw tones, also allows one to use the RT CHANNEL FLDIGI QSK function to further dial in some desired characteristics of the QRQq sending.

HERE IS THE LETTER "R" at 125 wpm,  FLdigi by itself on TOP and SATYR's regenerated cw on bottom

HERE ARE THE FLDIGI SETTINGS THAT I LIKED for this experiment using QSK RT CHANNEL only

HERE IS THE JACKROUTER SETUP VST PLUGINS FOR this QSK RT channel QRQq CW copy test

THE SETTINGS WERE MODIFIED ON SATYR to these, all TIME to bottom, all LVL to top

HERE IS ANOTHER VST DSP BANDPASS PLUGIN that works well

with less DSP LOAD and less CPU LOAD than the ENGINEERS FILTER VST PLUGIN:

Gband VST PLUGIN

1.  http://www.gvst.co.uk/gband.htm

2.  http://www.gvst.co.uk/gband_manual.htm

HERE ARE THE SETTINGS used for cw audio bandpass in AUDIO to MIDI mode

Here is what the wave shape looks like from a DIT via this Gband bandpass vst plugin

HERE IS THE JACKROUTER SEQUENCE for the VST PLUGins for AUDIO to MIDI for this setup

css555 15khz cw to MICROHPHONE input, converted to any desired cw pitch in excellent wave shaped CW

NEAR ZERO latency from the KEY of the paddles until you hear the tone in the sound card (HD AUDIO) AND you send the same excellent morse code audio tones into the input of the ASIO BRIDGE for sending morse code over the internet on any VOIP like program such as MUMBLE, SKYPE, GOOGLE VOICE, HAMSPHERE, QSO NET, JAMULUS, GOOGLE HANGOUTS, etc...

ASIO BRIDGE  http://vb-audio.pagesperso-orange.fr/Cable/index.htm

HERE IS AUDIO TO MIDI for UBUNTU with the same setup using the FREE MINIHOST MODULAR

Using the FREE VST HOST "MINIHOST MODULAR", you can setup the same vst plugins for AUDIO TO MIDI keying of the css555 chip - as shown for WINDOWS 7.  Get your free version of MINI HOST MODULAR HERE:  http://forum.image-line.com/viewtopic.php?f=1919&t=123031

MINIHOST MODULAR's VST HOST setup will also place a VST PLUGIN VERSION of MINIHOST MODULAR in your folder for VST PLUGINS.  Using the jack audio connection bay from KXstudio - CARLA -  The latest beta CARLA - GIT version,  you can run the VST HOST directly as a VST PLUGIN.  It works great, and performs as well as it does in windows 7.  Here is a picture of MINI HOST MODULAR vst plugin for UBUNTU:

Here is the CARLA-GIT connection bay showing MINIHOST MODULAR's GUI and connection from the MIC JACK through the MINIHOST MODULAR VST HOST directly to the soundcard for monitoring and also directly connected to the MUMBLE INPUT for sending cw over the internet on iCW.

The straight key or iambic paddle latency was amazingly low using this method. [ the time it takes from pressing the paddle handle(s) -  until you actually hear the sidetone from the speaker or headphone ]

     22 milliseconds at 256 frames/48k, n=2

     28 milliseconds at 256 frames/48k  n=3

- This is considered to be 'NEAR ZERO LATENCY' in the PRO MUSIC PERFORMANCE world -

REAL TIME TEST for measured delay -   paddle handle tap test

time it takes from actually hitting the iambic paddle dit handle until you hear the tone

Here is an example of using 48k at 256 buffer frames  n=2   latency = 20 milli seconds

EXTREME audioTOmidi TEST at 200 wpm creates perfect - home brewed - MIDI KEYED - CW NOTES

USING AUDIO to MIDI technique, FLdigi was used to send a continuous stream of the LETTER  "S" at 200 wpm  to the REAGATE audio TO midi VST plugin.  Perfectly constructed cw elements and spacing were made.

HERE IS A CLOSE UP of one group of  3 dits  that make up the letter "s" at 200 wpm - not only is every dit exactly the same length,  every space between the dits in the letter "s" is perfectly constructed too

This test was conducted using  AUDIO to MIDI technique using REAGATE VST PLUGIN to perform the AUDIO to MIDI function,  receiving the letter "s" stream from FLdigi at 200 wpm,  and then converting it to a midi note out with exactly the same cw element dit length and spacing between dits and spacing between the letter "s"

The VSTi PLUGIN  TX16Wx that constructed the HOME BREWED cw note, was using a SINE WAVE SF2 FILE from a general user SOUND FONT that is free to download:  http://musescore.org/en/handbook/soundfont

Here is the latest MORSE CODE VSTi SYNTHESIZER for extreme QRQ CW

This video demonstrates how to use some vst plugins and FLdigi to create your own customized QRQ CW code practice oscillator. FLdigi QSK Right Channel audio output, is used to "key" a specialized software VST INSTRUMENT called MPowerSynth which creates a very clean and high fidelity code practice oscillator.

The morse code sending text is from W4BQF's famous article:
https://sites.google.com/site/tomw4bqf/copyingcwover70wpm

MINIHOST MODULAR VST HOST is used for this to input the RT CHANNEL audio from FLdigi and send it to "key" MPowerSynth.

MPowerSynth is very accurate in qrq cw timing, and has a great sound that you can customize to your preferences for QRQ CW in pitch and rise/fall time and even weight by percentage and weight by "compensation" using the FLdigi QSK CONTROLS.

Reagate VST plugin receives the RT CHANNEL audio output from FLdigi and then creates an extremely accurate conversion to a midi message which then "keys" MPowerSynth.

HERE ARE THE LINKS :
1. http://www.w1hkj.com/Fldigi.html
2. http://www.meldaproduction.com/plugins/product.php?id=MPowerSynth
3. http://www.kvraudio.com/product/reagate_by_cockos
4. http://www.image-line.com/support/FLHelp/html/plugins/Minihost%20Mo...
5. http://www.voxengo.com/product/span/

NOTE: an extreme qrq speed is used to demonstrate and show how effective this setup is for producing a very good QRQqCW note. FLdigi of course can send great cw on its own, but you can not adjust COMPENSATION using FLdigi by itself, and for QRQcw, sometimes being able to use negative "compensation" is helpful to bring out better copy...the MPowerSynth also has a final polishing AUDIO BAND PASS filter , which makes a huge difference in edge noise at the higher speeds.

HERE IS A CLOSE UP OF THE SPECTRUM READOUT down to -175 db

MPowerSynth creates an excellent cw note by itself

Here is the latest setup on LINUX, for an audio to midi software cw keyer:

- uses two standalone linux audio apps:(using the JACK AUDIO CONNECTION KIT Linux audio engine)

1.  Trigger Midi Mono http://lsp-plug.in/?page=manuals&section=trigger_midi_mono

2.  midiCW  from: https://github.com/recri/keyer

what is notable about this setup, is the extremely low latency for CW REGENERATION...it only takes @300 micro seconds to re-create a raised cosine cw element from the "original sidetone"

here is a picture demonstrating this:  The GREEN waveform is the "original sidetone from a 555 timer chip being keyed by a typical cw keyer,  the RED waveform is the new recreated cw sidetone from midiCW...

Basically, the audio output of the 555 goes to the mic jack input and then to the first Linux audio app called  TRIGGER MIDI MONO,  TRIGGER MIDI MONO only has to measure the incoming volume levels of the 555 cw sidetone....then it takes the top peaks of those 555 cw elements at their start and finish, keyDOWN, keyUP, etc...and converts them into a midi message data output,  that keys the second Linux audio app....midiCW.......midiCW operates just like a hardware cw keyer... the waveform output of midiCW is a raised cosine set to whatever rise & fall time you desire.... 

here is a picture of what the setup looks like inside the JACK AUDIO CONNECTION BAY - Catia