HX3 Board User Manual

"Hammond on a Xilinx FPGA," HX3 single-board sound engine for connecting any keyboard, for installation into existing organs or MIDI control

Sample installation of HX3 in a B3-like console. Preset keys have LEDs from Preset24 LED board.

Optional Panel16 board (here with bezel) may be installed as user panel.

Features

• Compact organ emulator module on single PCB, 200 x 100 mm, for OEM installation
• Authentic reproduction of generator, tapering, key contacts, percussion and vibrato by FPGA (Field Programmable Gate Array)
• Extremely low latency of 50 microseconds Key-to-Audio (not >20 ms as with other MIDI expanders and software emulation)
• Natural key click by "rattling" contacts
• Accurate Leslie simulation with separate outputs
• MIDI IN accepts 5 different MIDI CC sets
• Drawbar connection by 9 to 24 analog control voltages
• Connection for switches (active low) or digital switch control voltages (Percussion ON, Soft / Normal, 2nd/3rd, vibrato, vibrato ON upper/lower, chorus / vibrato)
• MIDI-in/out (accepts different MIDI CC sets)
• Connection of any type of keyboards (key contact to ground or matrix) with additional scan board (optional)

Jack Connections

The HX3 module has two "stereo" type 1/4" audio output jacks, one DC input jack and two accessory jacks. Signals are also availabe on four 3-pin header solder pads located under jacks on PCD solder side.

• MAIN/BASS: Separate output for main organ manuals (plug tip) and pedal (plug ring) on jack if 3-pin jumper JP6 set to 2-CHANNEL. Use Y-cable or stereo cable to obtain all channels. Outut is mono (mix of manuals and bass) if JP6 set to MONO (only plug tip connected). Output level is approx. 150 mV at full swell.
• LESL/AMP: Leslie simulation (mono, plug tip) and leslie amp simulation (122 amp without speakers, but with overdrive capabilities, plug ring). Output level is 300 mV (full "Leslie Volume"). The separate AMP output (plug ring) may be used with transistor leslies to obtain the nice tube overdrive effect provided by HX3. On higher "Leslie Volume" levels, you will notice the tube overdrive/distortion of simulated 6550 output stage.
• SWELL: Expression pedal input is compatible with Yamaha FC-7 and similar expression pedals (direct connection preferred for speed/accuracy, but may also be remoted by MIDI CC 11).
• FOOTSW: Single or double footswich controls simulated Leslie speed as well as Leslie I/F control bits (pin 1 to 4 on HX3 PL12): SLOW/FAST on plug tip, RUN/STOP on plug ring. Please use latching foot switches; momentary (button type) switches are not supported. If single footswitch used, Leslie is always on RUN (no plug ring, input grouded by plug sleeve).
• DC IN: Use stabilized DC wall wart 9 to 12V with at least 800mA current output, inner/outer plug diameter 2.1/5.5 mm on DC input jack. Regard jumper setting of JP12 (see below - must be removed for 9 to 12V voltages). Alternatively, use stabilized DC wall wart 5V/1A with jumper JP12 installed or use internal 5V power connector PL2.

Despite complex modeling and switchable reverb, the simulation cannot replace a "room" atmosphere. If necessary, in recording before mixing a miked instrumental amplifiers provides this; the direct mixing of the output signal is rather unsatisfactory.

Detailed information on HX3 usage can be found on Bedienungshinweise page (sorry, german language - use Google translation service). Please see Using HX3 with MIDI controllers for further details on MIDI implementation. You may leave all drawbar/pot/switch connectors open if you plan to remote by MIDI only with analog control inputs disabled.

User Panel

When using LED buttons, pressing the push button switches alternately on and off, which is indicated by the LED. If using optional Panel16 board instead of separate switches, function layout is as follows:

Perc ON	Perc SOFT	Perc FAST	Perc THIRD		Vib ON upper	Vib ON lower	Leslie RUN	Leslie FAST
Preset 1	Preset 2	Preset 3	Preset 4		Reverb I	Reverb II	BassOnLeslie	SplitLower

Same functions can be obtained with rocker tab switches, dependant on your installation.

Reverb/BassOnLeslie

There are four reverb levels available: OFF, REV 1, REV 2, REV 1 + 2. Another switch/button determines whether the bass signal from the pedal is sent (internally) to Leslie sim/amp out or not. The pedal signal is otherwise available only on the organ output (see above) for separate amplification.

Split Function

Only valid for HX3 with scan cores from Rev. # 0B and up: Keyboard split can now be done with a selectable split point and also on the lower or upper manual - as some clones only have one manual.

• Press the button of the desired split point on the lower manual, hold while turning Split on: Pedal to lower manual below note pressed. Or:
• Press the button of the desired split point on upper manual, hold while turning Split on: Lower to upper manual below note pressed. Lower manual is now turned off. Or:
• Press two buttons side by side on upper manual, hold while turning Split on: Pedal to upper manual below notes pressed. Pedal is now off.

Such a setting will remain even after switching off and switching on the split function, but only up to turn off the HX3. See for advanced options also connect the scan board FatarScan2 . These functions are gradually introduced to the other scan cores.