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). HX3 may also be used without any switches/drawbars/pots connected by selecting "Expander Mode" - see page Using HX3 with MIDI controllers. You may leave all internal connectors open if you plan to remote by MIDI only with analog control inputs disabled.

Volume Control

We recommend connecting an expression pedal Yamaha FC-7 or similar (1/4" jack, 10k to 47k resistance) directly to the HX3 SWELL input jack, as it has a higher resolution and acts faster than MIDI control by MIDI CC #11. Despite the swell/expression pedal (or MIDI CC #11) there is a "simulated" total volume control by MIDI CC #7. But: It only reduces "travel" of swell pedal, it is not intended as a volume pot substitute (would reduce resolution and S/N ratio due to internal 16 bit audio handling). Anyway, instead of the ORGAN MAIN output you may use the simulated Leslie Amp 122 output which has a separate volume pot (either real if analog controllers enabled or, for example, by MIDI CC $4C hex, 76 decimal in NI B4 MIDI CC set). Even with 122 Amp pot not connected and disabled, amp volume may be changed by MenuPanel entry "LeslieVolume".

Drawbars

Drawbars will react exactly as on real B3 organ in "live" presets (preset numbers 0 and 15). Switching from preset 1 to 14 to "live" will update drawbar setting immediately to actual positions. Any preset may be changed "on the fly" by changing the desired drawbar or tab/vibrato control (and may be saved with new sound afterwards). On installations with Preset24 board, please note which drawbar set (two per manual) is active.

User Panel

When using LED buttons, pressing the push button (momentary contact, using HX3 PL7 and PL11) toggles 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	Split ON

Same functions can be obtained with rocker tab switches (using HX3 PL8 and PL12), 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.

Split setting will remain even after switching off and switching on the split function without holding a key, but only until power-off.

Presets

The four common presets (for upper and lower manual at the same time) work as follows: If none of the four LEDs is lit, the "live" setting is selected, drawbars and tabs switch or buttons are active. When pressing one of the preset buttons the corresponding preset is called, another press on the same button switches the preset off again (ie. back to "live" setting). If the button is held for more than two seconds, the last accessed setting is stored here. You may save the "live" setting (ie. previously no preset LED lit) as well as another preset (one other Preset LED lit, so you can copy from one to another preset). The saving procedure is signaled by short flickering of all Preset LEDs.

7, 10 or 15 presets separate for each manual are available with supplementary boards Preset16 (one or two, ie. 7 or 15 presets per manual) and Preset24 (10 presets per manual), the latter with switching from two drawbar "live" sets per manual as on real B3. As on common presets, a preset will be saved by pressing a preset button or Preset24 key by more than 2 seconds. See Preset16 and Preset24 pages for details.

From firmware #3.37 and up, presets may be edited by simply altering the tab, drawbar or pot to be changed. Altered presets may be saved again, also on different preset number.