HX3.7 Mainboard

HX3.7 – Preliminary Draft

HX3.7 Part/Connector designators (available as PDF also, see our Documentation and Update Server)

HX3.7 JackExtension dimensions

Common Features with HX3.5/HX3.6

• Same firmware and same FPGA sound engine
• Same PCB size, same mounting holes
• Same location of DC, USB, audio and MIDI connectors
• MenuPanel/Preset Bus Connector (I2C)
• Analog MPX Bus for newer DBX, PTX and ANX boards
• Auxiliary MIDI out, Fatar scan and pedal scan connectors

Omitted Features

• No onboard drawbar inputs
• No onboard button/switch inputs

Note: HX3.7 does no longer offer "legacy" button/switch inputs (Panel16) and classic analog drawbar inputs (old DB9/DB9-MPX boards). Instead, it relies on I2C interfaces on external panels (like Preset16, Extern16 or VibSw) and analog scanning circuits as found on PTX, ANX, DBX9 and DBX12 drawbar boards. For existing OEM installations, we may offer an interface (LegacyBoard) providing connectors for legacy hardware.

However, we strongly recommend I2C bus (Panel connector) and MXP bus (analog scanning) circuits as this greatly reduces wiring effort. Refer to our DBX, ANX and PTX schematics for MPX bus interfacing (using 74HC164 shift registers and 4066 analog switches) and Preset16/VibSw schematic (using PCA9554A and PCA9555 port devices) for I2C bus interfacing.

See HX3.7 Schematics Directory.

Additional Features

• All ExtensionBoard features integrated
• Integrated 11-pin Leslie control, ExtensionBoard pinout on 14-pin box header
• Additional DAC, outputs for plain organ and pedal signal, total of 4 audio output channels
• Headphone amp
• Improved DACs and audio amps/filters
• Insert loop (mono effects insert between tube amp simulation and rotary simulation)
• 3 onboard MIDI connectors (2x IN, 1x OUT)
• Onboard audio output jacks may be jumpered as L/R mono jacks or stereo L/R and stereo headphone jack
• Additional output signals and effect loop input available on 16-pin box header and 3-pin wire-to-board connectors
• JackExtension PCB available for additional MIDI and audio input/output jacks, same jack location as old extension board

MIDI output jack may be mounted on mainboard (new hole for connector necessary) or custom JackExtension board (old location of MIDI OUT connector) alternatively. Note: JackExtension board may be customized for OEM use as it only contains passive components (jacks, optional level potentiometer).

See HX3.7 Schematics Directory on our Update Server for details.

PL1 Leslie 11pin Connector
Pin	Funktion
1	Rotary audio channel, to pin 1
2, 3, 10	Stationary audio channel, to pin 2 resp. 3 and 10
4	Audio ground, to pin 4
5	Common ground for control signals, to pin 5
6	Power ON (MOSFET switches positive voltage to ground), to pin 6
7	Fast (MOSFET switches positive voltage to ground), to pin 7
9	Slow/Run (MOSFET switches positive voltage to ground), to pin 8
11	Leslie +30V supply (clamping), to pin 11
12	Aditional analog Gnd output, not connected
13	Auxiliary Gnd output for relays if needed
14	Auxiliary +5V supply output for relays if needed

PL2 Extension Jacks Connector
Pin	Funktion
1	Headphone Left
2	Headphone Right
3	Ext Out L (plain ORGAN signal)
4	Ext Out R (plain PEDAL signal)
5	Ext In L (Effect Loop Input, mixed to mono)
6	Ext In R (Effect Loop Input, mixed to mono)
7	Sustain Footswitch
8	Sostenuto Footswitch
9	MIDI OUT (-, DIN pin 5)
10	MIDI OUT (+, DIN pin 4)
11	Efx Jack Insert Switch (open when inserted, Gnd when not)
12	Vcc +5V
13, 14	Analog Ground
15, 16	Digital Ground