HX3 Board Installation
"Hammond on a Xilinx FPGA," HX3 single-board sound engine for connecting any keyboard, for installation into existing organs or MIDI control
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.
Detailed information on HX3 usage can be found on Bedienungshinweise page (sorry, german language - use Google translation service).
Installation
HX3 should be installed by a qualified technician only. You should be familiar with ribbon cable mounting, crimp contact installation and soldering of delicate parts. Important: HX3 contains static sensitive components. Be shure to use anti-static tools and grounded soldering toolset.
Please refer to board placement diagrams in our Github repository, directories PLATINEN (PCBs) and DOCS_PDF. You should have received your board with proper firmware installed and configurated for your key scanning board or MIDI input only. If you ordered a kit from distributor segor, follow soldering instructions on page Inbetriebnahme der Bausatz-Platine (sorry, german only).
First Test: Connect PL2 power connector to +5V stabilized DC supply, capable of at least 300mA. Be shure not to swap polarity; follow silk print on circuit board! You may alternatively use a wall wart type 5V supply with jumper JP12 (near DC jack) installed or 9 to 12V with jumper JP12 removed. Voltage regulator must be mounted to small heat sink for the latter case. PL2 must not be used with external power applied to DC jack. Overvoltage or interchanged polarity will destroy HX3 circuitry.
After connecting power, LED1 (red) should light up for a few seconds, subsequentially followed by LED2 (yellow) flickering. If LED1 (red) blinks fast for a while or LED2 (yellow) does not light up, FPGA image data in flash memory has been tampered or is corrupted. Please return HOAX to manufacturer for repair. Flickering or "breathing" LED2 (on HOAX2) shows that HOAX engine is working. Switch off before connecting anything else.
For normal operation, only JP6 must be inserted as required (MONO/2-CHANNEL), despite JP12 for 5V operation of DC jack. Use AGND and DGND pins as a "jumper rest" for spare jumpers.
Only connect/disconnect cables or optional boards when power is off!
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.
Connecting Drawbars
At least connect 9 drawbars or slider pots and volume control pot to PL9 Analog upper. R value should be in the 10kOhm to 47kOhm range, taper B (audio). All inputs are DC controlled. Input voltage range is from 0V (off or minimal volume) to +3.3V (max. volume). Connect MAIN/BASS audio output to amplifier. Level is in the 300 mV range.
Loud noise may be heard on MAIN/BASS output if you ordered HOAX with Fatar scan board firmware driver, as no scan board is connected yet. Otherwise, connect a MIDI keyboard to MIDI in (PL18/PL20). HX3 accepts MIDI channel 1 for upper, channel 2 for lower (both 61 notes C-C) and channel 3 for bass (25 notes C-C). Plain organ sound should be heard when playing on channel 1. Check function of all drawbars. HX3 will accept MIDI controller messages conforming to MIDI CC setting (5 to choose from). Important: You may omit those switches/connections/drawbars/pots you don’t plan to use.
PL9 Analog Controller A (Upper Manual)
Pin - function
1: Drawbar 16
2: Drawbar 5 1/3
3: Drawbar 8
4: Drawbar 4
5: Drawbar 2 2/3
6: Drawbar 2
7: Drawbar 1 5/9
8: Drawbar 1 1/3
9: Drawbar 1
10: Tone Pot (by special order only)
11: Leslie Volume Pot (HOAX3 only)
12: Swell Pedal (no connect if jack used on HOAX3; may also be disabled by special order)
13, 14: Drawbar/Pot Gnd
15, 16: Drawbar/Pot End 3.3V+ (Reference)
PL13 Analog Controller B (Lower Manual)
Pin - function
1: Drawbar 16
2: Drawbar 5 1/3
3: Drawbar 8
4: Drawbar 4
5: Drawbar 2 2/3
6: Drawbar 2
7: Drawbar 1 5/9
8: Drawbar 1 1/3
9: Drawbar 1
10: Drawbar Bass 16
11: Drawbar Bass 8
12: Drawbar/Pot Bass Sustain
13, 14: Drawbar/Pot Gnd
15, 16: Drawbar/Pot End 3.3V+ (Reference)
DC swell/volume control is active also on pin 12 of PL9. Even with MIDI control, a swell pedal should be connected to SWELL jack. This overrides MIDI volume control. You may connect a swell pedal like Yamaha FC-7 or a simple volume pot to the SWELL jack.
HX3 may be ordered with tone/treble control input active. Tone pot center is connected to pin 10 of PL9. If digital Leslie emulation is licenced on HX3, pin 11 becomes the Leslie amp volume/drive control (mandatory). Both pots begin with Gnd and end with Ref 3.3V+.
Connecting Switches or Buttons
Vibrato/chorus V1 to C3 is selected by a rotary switch:
Pins PL5 Vibrato rotary switch
Pin Number - Function (active low – switch to Gnd)
nc: Vib1 (no connection)
1: Cho1
2: Vib2
3: Cho2
4: Vib3
5: Cho3
6: not used
7: not used
8: MEM LED- (optional)
9: MEM LED+ (optional)
10: Common Gnd
Pins PL7 buttons (momentary contact, optional LED) or PL8 tab switches
Pin Number - Function (active low – switch to Gnd)
1: Perc ON, like B3
2: Perc SOFT
3: Perc FAST
4: Perc THIRD
5: Vib ON upper
6: Vib ON lower
7: Leslie ON (connected LED blinks with Leslie speed)
8: Leslie FAST
9: (+5V, used only for button LEDs supply, e.g. on Panel16)
10: Common Gnd
Up to 16 buttons or tab switches may be connected to PL7, PL11 or PL11/PL12. You may either use a buttin or a tab switch for each function, also mixed, but not both on same function.
Pins PL11 buttons (momentary contact, optional LED) or PL12 tab switches
Pin Number - function (active low – switch to Gnd)
1: Common Preset 1 (only button with LED indicator on PL11 - do not use pin 1 of PL12!)
2: Common Preset 2 (only button with LED indicator on PL11 - do not use pin 1 of PL12!)
3: Common Preset 3 (only button with LED indicator on PL11 - do not use pin 1 of PL12!)
4: Common Preset 4 (only button with LED indicator on PL11 - do not use pin 1 of PL12!)
5: EFX 1 / Reverb 1
6: EFX 2 / Reverb 2
7: Bass on Leslie (routes pedal bass also to Leslie simulation if ON)
8: Split ON
9: (+5V, used only for button LEDs supply, e.g. on Panel16)
10: Common Gnd
Every function may be activated by a button on PL7/PL11 or a switch on PL8/PL12. Pin functions are equivalent, but PL7/PL11 toggle status on every push and drive indicator LEDs (see schematic). You may omit those switches you don’t plan to use or connect corresponding pins of PL8 and PL12 permanently to Gnd if function should be ON as default.
A button panel named Panel16 with 16 LED buttons is available if you want to have a hassle-free compact solution. It connects directly to PL7 and PL11. It also contains the 4 common preset buttons.
Connecting Preset Switches
HX3 may be extended to 2x8, 2x12 or 2x16 presets with optional boards Preset12 (obsolete), Preset16 (one or two) or Preset24. All connect to HX3 PL4 by 10-wire flat ribbon cable. HX3 PL4 is a I2C bus system, so all boards connect in parallel (use multiple 10-pin plugs on one cable if necessary); Preset12 and Preset16 yield an extension route-through connector for adding more boards. Cable length on HX3 PL4 should not exceed 75 cm (30") in total. See description of each product for details.
Optional Boards
Connecting MenuPanel
Connect optional HX3 MenuPanel to HX3 PL4 using a 10-wire flat ribbon cable. HX3 firmware from version 3.41 and up will recognize the MenuPanel and act accordingly. HX3 MenuPanel may be used in parallel/simultaneously with Preset12 (obsolete), Preset16 and Preset24 boards connected to HX3 PL4. Extend a flat ribbon with additional connector to your cable on HX3 PL4 or use unoccupied 10-pin header on (last) Preset16 board which also carries the PL4 signal.
Connecting OrganScan61 board set
A set of up to 3 "daisy-chained" OrganScan61 boards are connected to PL14 if HOAX was ordered with OrganScan61 firmware driver. Refer to picture. Be shure not to twist connectors (red marked ribbon lead must match with pin 1 of all ribbon cable connectors, indicated by a triangle marking). Total cable length should not exceed 1,5m. First board in row is upper manual, second is lower manual and third (rightmost in picture) is bass pedal (not completely populated since only 25 keys are present). Bass25 board may be used as an alternative to last OrganScan61 board; it has the same functionality (but different key connectors). See page Anschluss der Scan-Platine OrganScan61 (KlangComputer) (german) for more pictures.
Inputs are active low (switch to ground), so connecting them to Gnd pins 13 to 16 of PL33 (PL31 on bass) on OrganScan61 board should yield the appropriate note. See OrganScan61 schematic for connector pinout.
Keybed Connection
Pin 1 PL30 = Note 1 = lowest C 1
Pin 16 PL30 = Note 16 = D# 2
Pin 1 PL31 = Note 17 = E 2
Pin 16 PL31 = Note 32 = G 3
Pin 1 PL32 = Note 33 = G# 3
Pin 16 PL32 = Note 48 = H 4
Pin 1 PL33 = Note 49 = C 5
Pin 13 PL33 = Note 61 = C 6
Pin 14, 15, 16 PL33 = Gnd/Busbar
Pedals Connection
(or use Bass25 scan board)
Pin 1 PL30 = Note 1 = lowest C 1
Pin 16 PL30 = Note 16 = D# 2
Pin 1 PL31 = Note 17 = E 2
Pin 9 PL31 = Note 25 = C 2
Pin 14, 15, 16 PL31 = Gnd/Busbar
If unconfigured, OrganScan61 boards are activated by serial command:
wen=1 519=0
Refer to serial interface command description (syntax table), Excel sheet in our Github repository, directory DOCS_PDF.
Connecting Scan16 board set
As an alternative to OrganScan61 a set of Scan16 strip boards may be used which yields easier installation on some keybeds. For each manual you need 3 (44 or 49 keys) or 4 (61 keys) strip boards. Please refer to schematics and part placement in out Git repo. Connection is somewhat different to OrganScan61: All Scan16 equipped manuals are wired in parallel with one 10-wire flat ribbon cable (multiple connectors attached) to HX3 PL15. Bass25 may be used as convenient alternative to pedal scan board. A jumper on "lowest" Scan16 board determines if keybed is upper, lower or bass pedal:
JP1 = Upper manual
JP2 = Lower manual
JP3 = Pedal notes
If unconfigured, Scan16 boards for one or two 61-key manuals are activated by serial command:
wen=1 519=5
Scan16 boards for one or two 49-key manuals (spinett type organs) are activated by serial command:
wen=1 519=4
Please note: lowest key contact pad on Strip16 is always "C" key. On 61-key manuals, upper part of rightmost Scan16 board may be cut off as marked on PCB silk screen printing (or pads are left open). On 44-key manuals, lowest 5 pads are left open, manual(s) start with "F". On 49-key manuals, connect pad PL20 to highest "C" note.
As on OrganScan61, all contacts must switch to ground. Boards provide ground lugs for connection to busbar.
Connecting FatarScan2 board
A single FatarScan2 board is connected to HX3 PL14. One or two Fatar 61 key manuals (type TP/8O or similar) may be connected to one FatarScan2 board using a special cable set (MicroMatch connectors to keyboard scanning strips). See page Anschluss der Scan-Platine FatarScan2 (german) for more pictures. We recommend buying to FatarScan2 cable set for connection to MicroMatch headers on Fatar keybeds; see page Anschluss der Scan-Platine FatarScan2 (german) for more pictures.
Bass pedals may be connected to an additional OrganScan61, OrganScan16 or Bass25 board wired to HX3 PL15 (!). FatarScan2 board is are activated by serial command:
wen=1 519=2
Refer to serial interface command description (syntax table), Excel sheet in our Github repository, directory DOCS_PDF.
Connecting LDR/Leslie Interface Board
The LDR/Leslie Interface (see also german page LDR/Leslie-Interface-Platine and documents in Github repo folder ADAPTER) is required for direct connection of Leslie families 715, 760 and 147 without need of Combo Preamp. It contains a two-channel preamp for organ main (manuals) and pedals, a mixing stage and relais switches for Leslie control, also a power supply capable of 5V/500mA. This board is intended for skilled technicians, as it might require adjustments and re-wiring to fit your needs.
Main channel is routed either from HX3 main organ output or Leslie tube amp simulation output (recommended for use with transistor Leslies) to LDR/Leslie Interface Board's preamp. A volume pot might be inserted between preamp and mixing stage. To control Leslie speed relais, 10-pin header connect to HX3 PL12 (also additionally in parallel to other switches). Connection to HX3 PL7 on second 10-pin header is required only when a Leslie button switch is to be used (momentary "button" contact, often found on organ's swell pedal).
Green power connector carries 5V DC to supply HX3 board. Note wire jumpers for 117V or 230V mains and set operating voltage trimpot to 5.0V on green power connector.
We recommend Yamaha FC-7 type expression pedal plugged into HX3 SWELL jack, but for OEM installations in older organ consoles the LDR-to-voltage converter on Leslie I/F board may also be used. It translates swell pedal's LDR resistance to swell control voltage of HX3. SWELL jack has to be removed for this purpose. LDR stage requires proper calibration of GAIN and OFS trimpots to obtain a control voltage range of approx. 0 (soft) to 3.3V (full swell) on HX3 swell input.
Other two trimpots set preamp gain. Adjust gain for full Leslie volume. We can supply a set of 3-wire cables with plugs to connect to HX3 audio and swell. Inportant: Plug polarity reqires 3-pin headers to be installed from HX3 component side instead of 1/4" jacks. If installed from solder side, reverse pinout accordingly. Leslie connection is described in schematics of LDR/Leslie Interface Board.
Connection of Leslie interface board to 11 pin Leslie
| PL12-1 | PL12-2 | PL12-3 | PL12-4 | PL10-1 | PL10-2 | PL10-3 | Remark |
| Leslie pin 8 (slow) | Leslie pin 7 (fast) | Leslie pin 6 (power) | Leslie pin 5 (common) | Leslie pin 1 (rotary) | Leslie pin 4 (Gnd) | Leslie pin 2 (stationary) | Set HOAX JP6 to STEREO |
Connection of Leslie interface board to 9 pin Leslie
| PL12-1 | PL12-2 | PL12-3 | PL12-4 | PL10-1 | PL10-2 | PL10-3 | Remark |
| Leslie pin 7 (slow) | Leslie pin 6 (fast) | not connected | Leslie pin 1 (Gnd) | Leslie pin 2 (audio) | Leslie pin 1 (Gnd) | not connected | Set HOAX JP6 to MONO |
Connection of Leslie interface board to 147 Leslie 6-pin
| PL6-1+2 | PL6-4+5 | PL10-1 | PL10-2 | Remark |
| Leslie pin 4 | Leslie pin 5 | Leslie pin 6 (audio) | Leslie pin 1 (Gnd) | Set HOAX JP6 to MONO |
Note: Additional power relay recommended for 230V HV on 147 Leslie pin 4 and 5. Bridge pin 2 to pin 3 of Leslie 6-pin connector.
Connecting Serial USB cable
For custom configuration, entering licence codes and FPGA/firmware updates, a USB-to-serial adaptor cable FTDI TTL-232R 5V must be used. Communication is established by simple clear-text commands by terminal emulation software TeraTerm 4.7x (recommended).
Parameters are 57600/8n1, send CR, receive CR+LF. As +5V is supplied by USB, external power supply may be disconnected. Do not use unpowered USB hubs as HOAX needs 250mA to run (note: on newer HX3 boards, 5V pin of PL26 may be cut off, HX3 power supply must be on). See HOAX3_syntax MS Excel table in our Github repository, directory DOCS_PDF, for command details. Update of FPGA configuration and scan cores are also done by TeraTerm macros in Github TERATERM_MACRO folder. Update of firmware is done by AVRdude command batch "hoaxflash.bat".
Connect FTDI TTL-232 5V cable header to PL26 so black cable sits on GND pin and red cable sits on +5V pin. Plug in PL26 cable first, then connect to USB. Test connection by pressing ENTER a few times, HX3 should answer with "#0:255=0 [OK]" if connection os OK and cable driver properly installed. Please see page Inbetriebnahme der Bausatz-Platine for details on driver installation (sorry, german language - use Google translation service).
HX3 will restart on serial command
9999
ollowed by ENTER key and HX3 will output some status messages. Restart every time you change scan routine setting like below.
Some serial settings that might be useful
Set "MIDI only" keyscan mode (no scan board connected):
wen=1 519=1
Disable own analog controllers for MIDI expander use (no drawbars/pots connected):
wen=1 521=255
Set Customer info (will also be displayed on MenuPanel):
wen=1 9990="John Doe"
Get serial number:
9952?
Enter Organ Licence code (use your purchased licence number):
wen=1 9950=1234567
Enter Leslie Licence code (use your purchased licence number):
wen=1 9951=1234567
Controller Firmware updates
For AVR firmware update, make shure TeraTerm was working properly and quit. Place reset jumper to adjacent 10-pin header as shown on page Firmware- und FPGA-Update. Start "hoaxflash.bat" with your cable's COM port number (i.e. "hoaxflash 3" for COM3) and remove reset jumper same time. Supplied AVRdude utility will flash ATmega644 MCU with given file "HOAX_main.hex" and HOAX_main.eep" in your "C:\HOAX" directory. Do not try if you are not familiar with command line tools; same applies for updating the FPGA configuration and scan cores with TeraTerm macros. Refer to page Firmware- und FPGA-Update (sorry. german - use Google translation service).
MIDI Usage
Please see Using HX3 with MIDI controllers for further details on MIDI.
