Three MIDIbox SID-NUXX Mainboards

Overview

The MIDIbox SID-NUXX's mainboard is six of the MIDIbox Hardware Platform modules and a simple dual-voltage power supply all fit on to one PCB. The PCB is also designed to fit cleanly into the grooves in the side of a Hammond 1455T1601-series enclosure. One side of the PCB also provides connectors for power input, audio in/out, MIDI in/out/thru, and a power switch.


The six modules implemented on the MIDIbox SID-NUXX mainboard are the Core, DINX1, BankStick, LTC, SID, and IIC MIDI modules.


Features

These modules allow for a single PCB which uses a SID for audio filtering and generation. Other features include:

  • Power, MIDI In, and MIDI Out LED connections.
  • Support for up to eight switches (pushbuttons, rotary encoders, etc).
  • Header to alow more input modules to be connected, supporting more switches.
  • Storage of 128 or 256 patches. (In order to store 256 patches, a Microchip 24LC512 must be for IC6. This part is denoted as IC6 alternate.)
  • Display connector to allow for easier selection of patches, programming of synthesis parameters, etc.
  • MIDI output handled by IIC MIDI module to work around bug in PICs currently used in the Microchip PIC18F4620. This workaround allows the newer PIC to be used in the core module. (Note that per a Microchip errata document silicon versions B4 and higher will not have this bug.)
  • Header to allow addition of memory (BankStick) modules.


Additionally, the MIDIbox SID-NUXX has some design features which I don't believe are found on other MIDIbox implementations:

  • All audio in and out lines run isolated, not crossing any on-board signal nor power lines.
  • Audio in jack shorts input line to ground when a 1/4" plug is not inserted, helping to eliminate noise which could be picked up and fed into the SID.
  • Per MOS SID 6581 specification, Vcc, Vdd, and GND lines are run to the power supply separately. I do not believe this makes much of a difference on such a small board, but as it was in the specification, it was done.
  • ICSP (In-circuit Serial Programming) header to allow reprogramming of Core PIC, should it be needed.


MIDIbox SID-NUXX Mainboard PCB v1.1 in CADsoft EAGLE (More...)

Design

The PCB was designed by me based on the aforementioned MIDIbox Hardware Platform Reference Designs in CADsoft EAGLE. While I had previously made the original CAD files and photoplotter files available, I have chosen to no longer make them publicly available.


The schematic can also be viewed as a 300dpi PNG export or a printer-ready letter-sized PDF.


A 300dpi export of the PCB layout (minus the upper ground plane for clarity) is also available.


PCB

To start, I do not have any of these PCBs for sale. For a vareity of reasons I am not making them available, nor am I allowing them to be a sold in a commercial capacity. However, if you would like to have some of these PCBs made for youself (and maybe a few close friends), feel free. Just don't sell them.


In order to have PCBs manufactured one generally needs to send photo plotter and drill files to a manufacturing facility. To create these files one must render them from their PCB CAD software. In my case I used EAGLE's CAM tool to generate the required files.


These files are ready to be uploaded to a company such as PCBFABEXPRESS or Advanced Circuits for manufacturing. They also have been confirmed to pass Advanced Circuit's FreeDFM checks. The plotted output from these checks in PDF format can be viewed here.


Pinouts / Header Information

J1

ICSP (In-circuit Serial Programming). Connected to IC10 (Core PIC – PIC18F4620) so that it may be reprogrammed without removal from board. Pin compatible with Microchip’s PICkit 2.

Vp: Vpp/MCLR
Vd: Vdd Target
Vs: Vss (Ground)
PD: ICSPDAT/PGD (Programming Data)
PC: ICSPCLK/PGC (Programming Clock)
NC: Auxiliary / Not Connected (Not Needed)


J2

DINX4 Inputs. Each labeled pin D0-D7 provides one digital input. VS is Vss, the common pins which D0-D7 connect with to signal an input.


J3

LED Connection. Hardware power, MIDI Input, MIDI Output LEDs. Does not rely on MIOS being loaded in order to function. Replace R12, R13, and R14 to vary the brightness of the LEDs if the default is not acceptable.

PW: Power LED
IN: MIDI Data In
OU: MIDI Data Out
+5V: 5VDC for LEDs. Anodes connect here.


J4A

BankStick Connection. Essentially the equivalent of J4 in MBHP_CORE. Know that if more BankSticks are connected, addressing of new BankSticks should begin with 1.

Vd: Vdd
SD: Serial Data
SC: Serial Clock
Vs: Vss


J9A/J8

J8 half of connector is equivalent of J8 in MBHP_CORE. J9A is essentially the equivalent of J9 in MBHP_CORE, except it has already been connected and passed through a DINX1. Therefore, SI of J9A connects to SER (Pin 10) of IC8 (the 74HC165) in the DINX1 instead of directly to RD1 (Pin 20) of the Core PIC as it would in the reference design. (See schematic for more information.)


J15

Display Connection. Equivalent of J15 in MBHP_CORE.


Cost

All prices are in US dollars and were calculated on 03-Aug-2006.

From Mouser: All parts except for the alternate TO-220 heatsinks and alternate IC6 (24LC512), with minimum quantities for resistors fulfilled: $51.68

From Jameco: Wall-Mount Transformer: $4.89

From PCBFABEXPRESS: Single PCB: $13 (Minimum Order is Five Pieces)

Shipping: ~$13 (~$5 from Mouser, ~$5 from Jameco, $3 per board from PCBFABEXPRESS)


Parts to assemble a Mainboard

Bill of Materials

Notes

  • Almost all parts are required in the quantity detailed, except for those labeled alternate. Read on for information as to when these parts are needed.
  • Some parts (such as resistors) may have minimum orders greater than the required quantity. Fortunately this minimum is typically ten (10) pieces, which does not add significant cost to the project.
  • If using a MOS 6581 SID, be certain to use an LM7812 for IC9 and 470pF caps for C2 and C3.
  • If using a MOS 8580 SID, be certain to use an LM7809 for IC9 and 6.8nF caps for C2 and C3. (These parts are designated alternate in the Component List.)
  • The 532-579302B00 heatsink from Mouser is for TO-220 parts (such as the LM78xx series) with beveled sides. This is the correct part to use with the voltage regulators specified in the BOM. An alternative part, the 532-579402B00, is available for TO-220 packages with straight sides. If you use voltage regulators other than those specified, be sure to order the correct heatsink for your regulators. Aavid's published mechanical specifications for the heatsinks on the BOM can be used to help determine which parts you need. Or, just order two of each part and see which fits best. Be careful, using the wrong heatsink will cause a poor fit and improper cooling of the regulators.
  • The 16PJ031 power jack has a 2.1mm center pin, while the 16PJ032 has a 2.5mm center pin. Be certain to order the appropriate part to mate with your power supply. The listed power supply from Jameco (309884 has a 2.1mm center pin, and thusly the standard part for PWR1 (16PJ031) should be used with this supply.
  • Individuals outside of areas which use Type A / NEMA 1-15 power outlets will have to select a different power supply which is appropriate to their area. It should output ~12VAC or ~15VDC and have an appropriately sized barrel connector.
  • R12-R14 values may vary depending on the LEDs used for Power, MIDI In, and MIDI Out. Calcuation and / or experimentation with the chosen LEDs will allow one to establish a proper value.
  • For IC6, a 24LC256 should be used if one bank of patches (128 patches total) are desired. If two banks of patches (256 patches total) the alternate part 24LC512 should be selected.


PCB

The MIDIbox SID-NUXX's mainboard is a custom designed 159mm x 80mm PCB. I designed this implementation in late June and July 2006. The first run of boards, v1.0 S1, was manufactured by PCBFABEXPRESS in a quantity of five pieces for my personal use. Changes from these boards have been implemented in the the aforementioned v1.1 design.


Components on PCB

Part Name on PCBValuePart NumberQuantityPhotoCatalog Description
AUDIO_IN, AUDIO_OUT 568-NYS2162 Neutrik Phone Jacks 1/4" STEREO SWITCHED
C1, C4, C8, C12, C14, C15, C18-C21, C26, C30100nF80-C412C104K5R12 Kemet Conformally Coated Axial Ceramic Capacitors 50V X7R .1uF 10%
C2, C3470pF23PS1472 Xicon Polystyrene Film Capacitors STRENE 50V 470PF
C2, C3 (alternate)6.8nF23PS2682 Xicon Polystyrene Film Capacitors STYRENE 50V .0068uF
C51uF140-HTRL50V1.0-RC1 Xicon Hi-Temp Radial Electrolytic Capacitors 50V 1.0uF 105C
C6, C131nF80-C410C102K5R2 Kemet Conformally Coated Axial Ceramic Capacitors 50V X7R 1000pF 10%
C7, C10, C11, C25, C2910uF140-HTRL25V105 Xicon Hi-Temp Radial Electrolytic Capacitors 25V 10uF 105C
C9470pF581-SA101A471JAR1 AVX Axial Ceramic Capacitors 100V 470pF NPO 5%
C16, C1715pF81-RPE5C1H150J2P1Z032 Murata Monolithic Radial Lead Capacitors 15pF, 50volts, C0G
C22, C2733pF81-RPE5C1H330J2P1Z032 Murata Monolithic Radial Lead Capacitors .1LS 33PF 50V 5%
C232200uF140-HTRL25V2200-RC1 Xicon Hi-Temp Radial Electrolytic Capacitors 25V 2200uF 105C
C24, C28330nF581-SR215E334MAR2 AVX Radial Monolithic Capacitors 50V .33UF Z5U 20%
D11N4148512-1N41481 Fairchild Diodes - Small Signal DO-35 100V Io/200mA
D2-D51N4004512-1N40044 Fairchild Rectifiers DO-41 Vr/400V Io/1A T/R
IC16N138512-6N1381 Fairchild Optocouplers DIP-8 DIP-8 HG PHOTO DARL
IC2MOS 6581 1  
IC2 (alternate)MOS 8580 1  
IC3, IC474HC595512-MM74HC595N2 Fairchild High Speed CMOS HC/HCT Logic DIP-16 8-Bit Shift Register
IC574HC00512-MM74HC00N1 Fairchild High Speed CMOS HC/HCT Logic DIP-14 Qd 2-Input NAND Gate
IC624LC256579-24LC256-I/P1 Microchip Serial EEPROM - 256k PDIP-8 32kx8 - 2.5V
IC6 (alternate)24LC512579-24LC512-I/P1 Microchip Serial EEPROM - 512k 64kx8 - 2.5V
IC7PIC16F88-I/P579-PIC16F88-I/P1 Microchip PICmicro - PIC16Fxxx Flash MCU's PDIP-18 7KB 368 RAM 16 I/O
IC874HC165512-MM74HC165N1 Fairchild High Speed CMOS HC/HCT Logic DIP-16 8-Bit Shift Register
IC9LM7812511-L7812ACV1 ST Voltage Regulators TO-220AB 12V 1.0A Positive
IC9 (alternate)LM7809511-L7809ACV1 ST Voltage Regulators TO-220AB 9.0V 1.0A Positive
IC10PIC18F4620-I/P579-PIC18F4620-I/P1 Microchip PICmicro - PIC18Fxxx Flash MCU's PDIP-40 64KB 3804 RAM 36 I/O
IC11LM7805511-L7805ACV1 ST Voltage Regulators TO-220AB 5.0V 1.0A Positive
IC1, IC6Socket575-1933082 Mill-Max DIP Low Profile Sockets 8P TIN PIN GOLD CONT
IC2Socket575-1936281 Mill-Max DIP Low Profile Sockets 28P TIN PIN GLD CONT
IC3, IC4, IC8Socket575-1933163 Mill-Max DIP Low Profile Sockets 16P TIN PIN GLD CONT
IC5Socket575-1933141 Mill-Max DIP Low Profile Sockets 14P TIN PIN GLD CONT
IC7Socket575-1933181 Mill-Max DIP Low Profile Sockets 18P TIN PIN GLD CONT
IC10Socket575-1936401 Mill-Max DIP Low Profile Sockets 40P TIN PIN GLD CONT
J1 571-10323961 AMP AMPMODU Breakaway Headers 6 P HEADER GOLD 30u, single row
J2, J9A/J8 571-10324052 AMP AMPMODU Breakaway Headers 10P HEADER GOLD 30u, double row
J3 571-10324031 AMP AMPMODU Breakaway Headers 6P HEADER GOLD 30u, double row
J4A 571-10323941 AMP AMPMODU Breakaway Headers 4 P HEADER GOLD 30u, single row
J15 571-10324081 AMP AMPMODU Breakaway Headers 16P HEADER GOLD 30u, double row
MIDI_IN, MIDI_OUT, MIDI_THRU 161-05043 Kobiconn DIN Jacks 5 PIN DIN PCB
PWR1 16PJ0311 Kobiconn DC Power Jacks PCB 2.1mm
PWR1 (alternate) 16PJ0321 Kobiconn DC Power Jacks PCB 2.5mm
R1, R2, R8, R10, R11220Ω291-220-RC5 Xicon 1/4W 5% Carbon Film Resistors 220ohms 0.05 (Red - Red - Brown)
R3, R17, R20-R26, R28-R30, R32, R3310KΩ291-10K-RC14 Xicon 1/4W 5% Carbon Film Resistors 10Kohms 0.05 (Brown - Black - Orange)
R4, R18, R19, R31, R341KΩ291-1K-RC5 Xicon 1/4W 5% Carbon Film Resistors 1Kohms 0.05 (Brown - Black - Red)
R5, R910KΩ531-PT6KV-10K2 Piher Trimmer Potentiometers 10Kohms 6mm Rnd Top adj
R61.2KΩ291-1.2K-RC1 Xicon 1/4W 5% Carbon Film Resistors 1.2Kohms 0.05 (Brown - Red - Red)
R75.6KΩ291-5.6K-RC1 Xicon 1/4W 5% Carbon Film Resistors 5.6Kohms 0.05 (Green - Blue - Red)
R15, R16100KΩ291-100K-RC2 Xicon 1/4W 5% Carbon Film Resistors 100Kohms 0.05 (Brown - Black - Yellow)
R12-R14, R27470Ω291-470-RC1 Xicon 1/4W 5% Carbon Film Resistors 470ohms 0.05 (Yellow - Violet - Brown)
SW1 108-1MS1T2B4M7QE-EVX1 Mountain Switch Miniature Toggle Switches SWITCH TOGGLE SPDT
T1BC337512-BC3371 Fairchild Small Signal Transistors TO-92 NPN 45V 800mA HFE/63
T2BC547625-BC547A1 Vishay Semiconductors Small Signal Transistors TO-92 NPN 45V 100mA HFE/220
XTAL120MHz73-XT49S2000-201 Vishay/Dale HC-49/S Microprocessor Crystals 20.0 MHZ 20pF
XTAL210MHz73-XT49S1000-201 Vishay/Dale HC-49/S Microprocessor Crystals 10.0 MHZ 20pF


Other Components

PartPart NumberQuantityPhotoCatalog Description
TO-220 Heatsink532-579302B002 Aavid Thermalloy Heatsink TO-220 HORIZ/VERT SNAP DOWN 16.8 TR
TO-220 Heatsink (alternate)532-579402B002 Aavid Thermalloy Heatsink BLACK ANODIZE TO-220
Wall-Mount Transformer3098841 TRANS,WALL,12VAC/1A,2.1X5.5MM,F,UL/CUL


Mouser BOM Import Tool

This list can be copy and pasted into Mouser's BOM Import Tool (requires a My Mouser account) to facilitate easy ordering of all required parts. This list does not include a SID, alternate TO-220 heatsinks, alternate IC6 (24LC512), wall-mount transformer, or PCB:

568-NYS216 2
80-C412C104K5R 12
23PS147 2
23PS268 2
140-HTRL50V1.0-RC 1
80-C410C102K5R 2
140-HTRL25V10 5
581-SA101A471JAR 1
81-RPE5C1H150J2P1Z03 2
81-RPE5C1H330J2P1Z03 2
140-HTRL25V2200-RC 1
581-SR215E334MAR 2
512-1N4148 1
512-1N4004 4
532-579302B00 2
512-6N138 1
512-MM74HC595N 2
512-MM74HC00N 1
579-24LC256-I/P 1
579-PIC16F88-I/P 1
512-MM74HC165N 1
511-L7812ACV 1
511-L7809ACV 1
579-PIC18F4620-I/P 1
511-L7805ACV 1
575-193308 2
575-193628 1
575-193316 3
575-193314 1
575-193318 1
575-193640 1
571-1032396 1
571-1032405 2
571-1032403 1
571-1032394 1
571-1032408 1
161-0504 3
16PJ031 1
16PJ032 1
291-220-RC 5
291-10K-RC 14
291-1K-RC 5
531-PT6KV-10K 2
291-1.2K-RC 1
291-5.6K-RC 1
291-100-RC 3
291-100K-RC 2
291-470-RC 1
108-1MS1T2B4M7QE-EVX 1
512-BC337 1
625-BC547A 1
73-XT49S2000-20 1
73-XT49S1000-20 1


Changes

The current revision of the mainboard PCB is 1.1. Changes from v1.0 S1 (set 1) to the current v1.1 are as follows:

  • Indicator / part outline for D1 (1N4148 as part of MIDI IN) was reversed in v1.0 S1. This has been corrected.
  • Pin TN on AUDIO_IN has been connected to ground. This helps eliminate excess noise from entering the SID when an audio input is not connected.
  • Slight rearrangement / clarification of trace routing in center of PCB, near version tag.
  • General readability improvements in the schematic.
  • Note regarding variability of values for R12-R14 added to schematic.
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