The γ1 modular miniature DAC

Parts list

The table below is a complete parts list for all main configurations of the γ1. See the sections below for specific parts recommendations and options. For parts not offered by AMB audio shop, Mouser, Digi-Key, Newark, Farnell, RS Components or another vendor's stock numbers for the recommended parts are listed for your convenience.

The A through E columns denote the γ1 configuration. "Y" means the part is required, "N" means that the part should not be populated, and "O" means optional (see corresponding notes below).
  • A: Full configuration (USB and DAC boards)
  • B: Lite configuration (USB and DAC boards)
  • C: USB-to-S/PDIF converter (no DAC board)
  • D: USB-to-I²S converter (no DAC board)
  • E: S/PDIF DAC-only configuration (no USB board)
  • F: Full++ configuration (combination of A and C)
All parts on the DAC board have a "D" suffix, and all those on the USB board have a "U" suffix.

A B C D E F Part ID Description Mouser # Digi-Key # Farnell # RS # Notes
Circuit board
Y PCB γ1 PCB set AMB audio shop -
Resistors
Y N N N Y Y R1D miniature 1% thin film or metal film resistor 75Ω 270-75-RC S75CACT-ND 9343555 - -
Y N N N Y Y R2D miniature 1% thin film or metal film resistor 47KΩ 270-47K-RC S47KCACT-ND 9343261 - -
Y N N N Y Y R3D miniature 1% thin film or metal film resistor 47KΩ 270-47K-RC S47KCACT-ND 9343261 - -
Y N N N Y Y R4D miniature 1% thin film or metal film resistor 3KΩ 270-3.0K-RC S3KCACT-ND 9342990 - -
Y N N N Y Y R5D resistor network SIP-6 bussed 47KΩx5 AMB audio shop -
Y N N N Y Y R6D resistor network SIP-6 bussed 47KΩx5 AMB audio shop -
Y Y N N Y Y R7D resistor network SIP-8 isolated 68Ωx4 AMB audio shop -
Y Y N N Y Y R8D miniature 1% thin film or metal film resistor 47KΩ 270-47K-RC S47KCACT-ND 9343261 - -
Y Y N N Y Y R9D miniature 1% thin film or metal film resistor 47KΩ 270-47K-RC S47KCACT-ND 9343261 - -
Y Y N N Y Y R10D miniature 1% thin film or metal film resistor 47KΩ 270-47K-RC S47KCACT-ND 9343261 - -
Y N N N Y Y R11D miniature 1% thin film or metal film resistor 220Ω 270-220-RC S220CACT-ND 9342826 - -
Y N N N Y Y R12D miniature 1% thin film or metal film resistor 22KΩ 270-22K-RC S22KCACT-ND 9342842 - -
Y N N N Y Y R13D miniature 1% thin film or metal film resistor 22KΩ 270-22K-RC S22KCACT-ND 9342842 - -
O O N N O O R14D miniature 1% thin film or metal film resistor 47KΩ 270-47K-RC S47KCACT-ND 9343261 - See note 1
O O N N O O R15D miniature 1% thin film or metal film resistor 47KΩ 270-47K-RC S47KCACT-ND 9343261 - See note 1
O O N N O O R16D miniature 1% thin film or metal film resistor 1.5KΩ 270-1.5K-RC S1.5KCACT-ND 9342621 - See note 1
Y N N N Y Y R20D miniature 1% thin film or metal film resistor 47KΩ 270-47K-RC S47KCACT-ND 9343261 - -
Y Y Y Y N Y R1U miniature 1% thin film or metal film resistor 22Ω 270-22-RC S22CACT-ND 9342869 - -
Y Y Y Y N Y R2U miniature 1% thin film or metal film resistor 1.5KΩ 270-1.5K-RC S1.5KCACT-ND 9342621 - -
Y Y Y Y N Y R3U miniature 1% thin film or metal film resistor 22Ω 270-22-RC S22CACT-ND 9342869 - -
Y Y Y Y N Y R4U miniature 1% thin film or metal film resistor 47KΩ 270-47K-RC S47KCACT-ND 9343261 - -
Y Y Y Y N Y R5U miniature 1% thin film or metal film resistor 1.5KΩ 270-1.5K-RC S1.5KCACT-ND 9342621 - -
Y Y Y Y N Y R6U miniature 1% thin film or metal film resistor 1MΩ 270-1.0M-RC S1MCACT-ND 9342435 - -
N Y Y Y N N R7U miniature 1% thin film or metal film resistor 560Ω 270-560-RC S560CACT-ND 9343350 - -
N N Y N N Y R8U miniature 1% thin film or metal film resistor 220Ω 270-220-RC S220CACT-ND 9342826 - -
N N Y N N Y R9U miniature 1% thin film or metal film resistor 110Ω 270-110-RC S110CACT-ND 9342460 - -
Capacitors, ferrite beads & inductors
Y Y N N Y Y C1D multilayer ceramic capacitor X7R 1µF 25V 810-FG18X7R1E105KRT0 or
810-FG18X7R1E105KRT6
445-180204-ND or
445-173261-1-ND
3288102 or
3416643
811-8364 See note 2
Y Y N N Y Y C2D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y N N Y Y C3D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y N N N Y Y C4D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y N N Y Y C5D multilayer ceramic capacitor X7R 10nF 50V 80-C315C103K5R 399-4148-ND 1457653 538-1196 -
Y Y N N Y Y C6D conductive polymer electrolytic low-ESR capacitor 47µF 10V 661-PSA10VB47M 565-3051-ND - - -
Y Y N N Y Y C7D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y N N Y Y C8D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y N N Y Y C9D multilayer ceramic capacitor X7R 10nF 50V 80-C315C103K5R 399-4148-ND 1457653 538-1196 -
Y Y N N Y Y C10D conductive polymer electrolytic low-ESR capacitor 47µF 10V 661-PSA10VB47M 565-3051-ND - - -
Y Y N N Y Y C11D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y N N N Y Y C12D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y N N N Y Y C13D multilayer ceramic capacitor X7R 10nF 50V 80-C315C103K5R 399-4148-ND 1457653 538-1196 -
Y N N N Y Y C14D multilayer ceramic capacitor X7R 10nF 50V 80-C315C103K5R 399-4148-ND 1457653 538-1196 -
Y N N N Y Y C15D multilayer ceramic capacitor X7R 10nF 50V 80-C315C103K5R 399-4148-ND 1457653 538-1196 -
Y N N N Y Y C16D multilayer ceramic capacitor X7R 10nF 50V 80-C315C103K5R 399-4148-ND 1457653 538-1196 -
Y N N N Y Y C17D multilayer ceramic capacitor X7R 10nF 50V 80-C315C103K5R 399-4148-ND 1457653 538-1196 -
Y N N N Y Y C18D multilayer ceramic capacitor C0G/NP0 1nF 100V 80-C315C102J1G 399-4143-ND 1457635 538-1382 See note 2
Y N N N Y Y C19D multilayer ceramic capacitor X7R 22nF 50V 80-C315C223K5R 399-4169-ND 1457654 538-1326 -
Y N N N Y Y C20D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y N N Y Y C21D multilayer ceramic capacitor X7R 1µF 25V 810-FG18X7R1E105KRT0 or
810-FG18X7R1E105KRT6
445-180204-ND or
445-173261-1-ND
3288102 or
3416643
811-8364 See note 2
Y Y N N Y Y C22D audio grade electrolytic capacitor 22µF 6.3V+ 647-UKW1H220MDD or
647-UES1E220MEM
604-1051-ND 8766762 or
8766959
215-5691 or
521-1738
-
Y Y N N Y Y C23D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y N N Y Y C24D audio grade electrolytic capacitor 22µF 6.3V+ 647-UKW1H220MDD or
647-UES1E220MEM
604-1051-ND 8766762 or
8766959
215-5691 or
521-1738
-
Y Y N N Y Y C25D audio grade electrolytic capacitor 22µF 6.3V+ 647-UKW1H220MDD or
647-UES1E220MEM
604-1051-ND 8766762 or
8766959
215-5691 or
521-1738
-
Y Y N N Y Y C26D film capacitor MKT or MKS 1µF 63V AMB audio shop -
Y Y N N Y Y C27D film capacitor MKT or MKS 1µF 63V AMB audio shop -
Y N N N Y Y C28D multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y N N N Y Y C29D film capacitor MKT or MKS 1µF 63V AMB audio shop -
Y Y Y Y N Y C1U multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y Y Y N Y C2U multilayer ceramic capacitor X7R 1µF 25V 810-FG18X7R1E105KRT0 or
810-FG18X7R1E105KRT6
445-180204-ND or
445-173261-1-ND
3288102 or
3416643
811-8364 See note 2
Y Y Y Y N Y C3U multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y Y Y N Y C4U multilayer ceramic capacitor C0G/NP0 33pF 100V 80-C320C330J2G 399-4172-ND 1216408 538-1253 See note 2
Y Y Y Y N Y C5U multilayer ceramic capacitor C0G/NP0 33pF 100V 80-C320C330J2G 399-4172-ND 1216408 538-1253 See note 2
Y Y Y Y N Y C6U multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y Y Y N Y C7U multilayer ceramic capacitor X7R 10nF 50V 80-C315C103K5R 399-4148-ND 1457653 538-1196 -
Y Y Y Y N Y C8U conductive polymer electrolytic low-ESR capacitor 47µF 10V 661-PSA10VB47M 565-3051-ND - - -
N N Y N N Y C9U multilayer ceramic capacitor X7R 0.1µF 50V 80-C320C104K5R 399-4264-ND 1457655 or
1141775
538-1310 -
Y Y Y Y N Y C10U multilayer ceramic capacitor X7R 1µF 25V 810-FG18X7R1E105KRT0 or
810-FG18X7R1E105KRT6
445-180204-ND or
445-173261-1-ND
3288102 or
3416643
811-8364 See note 2
N N Y N N Y C11U film capacitor MKT or MKS 1µF 63V AMB audio shop -
Y N N N Y Y L1D miniature inductor 47µH AMB audio shop -
Y Y N N Y Y L2D ferrite bead, axial-lead AMB audio shop -
Y Y N N Y Y L3D ferrite bead, axial-lead AMB audio shop -
Y Y N N Y Y L4D ferrite bead, axial-lead AMB audio shop -
Y Y Y Y N Y L1U ferrite bead, axial-lead AMB audio shop -
Y Y Y Y N Y L2U ferrite bead, axial-lead AMB audio shop -
N N Y N N Y L3U miniature inductor 47µH AMB audio shop -
Semiconductors
Y N N N Y Y Q1D 2N3904 NPN transistor TO-92 512-2N3904BU 2N3904FS-ND 9846743 294-312 -
Y N N N Y Y Q2D 2N3904 NPN transistor TO-92 512-2N3904BU 2N3904FS-ND 9846743 294-312 -
O O N N O O U1D Texas Instruments TPS2115APW power multiplexer TSSOP-8 595-TPS2115APW 296-16940-1-ND 3124061 665-8866 See note 1
Y N N N Y Y U2D Cirrus Logic CS8416-CSZ S/PDIF receiver/multiplexer SOIC-28 777-CS8416-CSZ 598-1123-5-ND 1023451 491-5675 -
Y Y N N Y Y U3D Wolfson WM8501GED/V stereo DAC SOIC-14 AMB audio shop -
Y Y N N Y Y U4D Microchip Technology MCP100 or
Maxim/Dallas DS1818
reset manager TO-92
579-MCP100-315DI/TO or
579-MCP100-300DI/TO
MCP100-315DI/TO-ND or
MCP100-300DI/TO-ND or
DS1818-10+CT-ND
1212673 667-4124 -
Y Y N N Y Y U5D LP2985AIM5-3.3 or TPS79333DBVR LDO voltage regulator SOT23-5 926-2985AIM53.3/NOPB or
595-TPS79333DBVR
LP2985AIM5-3.3/NOPBCT-ND or
296-12961-1-ND
1469134 652-0033 -
Y Y N N Y Y U6D LP2985AIM5-4.5 or TPS793475DBVR LDO voltage regulator SOT23-5 926-LP2985AIM545NOPB or
595-TPS793475DBVR
LP2985AIM5-4.5/NOPBCT-ND or
296-12160-1-ND
1685756 761-6488 -
Y N N N Y Y U7D Toshiba TORX147PL fiber-optic receiver AMB audio shop -
Y N N N Y Y U8D Texas Instruments SN74AHC1G02DBVR logic NOR gate SOT23-5 595-SN74AHC1G02DBVR 296-1088-1-ND 1287441 - -
Y Y N N Y Y U9D Microchip Technology MCP101 or
MCP101-300DI/TO or
Maxim/Dallas DS1817
reset manager TO-92
579-MCP101-315DI/TO or
579-MCP101-300DI/TO
MCP101-315DI/TO-ND or
MCP101-300DI/TO-ND or
DS1817-5+-ND
1332052 667-4143 -
Y Y Y Y N Y U1U Texas Instruments/Burr-Brown PCM2707PJT or
PCM2706PJT stereo USB DAC
595-PCM2707PJT or
595-PCM2706PJT
296-15276-5-ND or
296-15275-ND
1755016 or
1755015
662-5510 or
662-5501
-
Y Y Y Y N Y U2U Texas Instruments SN74AHC1G08DBVR logic AND gate SOT23-5 595-SN74AHC1G08DBVR 296-1091-1-ND 1105918 - -
Y Y Y Y N Y U3U LP2985AIM5-3.3 or TPS79333DBVR LDO voltage regulator SOT23-5 926-2985AIM53.3/NOPB or
595-TPS79333DBVR
LP2985AIM5-3.3/NOPBCT-ND or
296-12961-1-ND
1469134 or
1470478
652-0033 or
661-4490
-
N N Y N N Y U4U Texas Instruments SN74HCU04D logic hex invertor SOIC-14 595-SN74HCU04D 296-9819-5-ND 9592148 - -
N N Y N N Y U5U Toshiba TOTX147PL fiber-optic transmitter AMB audio shop -
N Y Y Y N N LEDU T-1 (3mm) red LED 78-TLHR4401 751-1128-ND 1045456 826-515 -
Miscellaneous
Y N N N Y Y T1D pulse transformer 1:1 580-DA101C or
673-PE-65612
470-1003-ND or
470-1006-ND
1362398 - -
Y N N N Y Y SW1D NKK G13JVCF bicolor illuminated toggle switch 633-G13JVCF or
633-G13JVCF-RO
360-1772-ND - 453-7893 Can use G12JVCF (2-pos) for config E
Y Y N N Y Y J1D DC power jack, 1.3mm center pin, PCB-mount AMB audio shop -
Y N N N Y Y J2D RCA jack, PCB-mount AMB audio shop -
Y Y N N Y Y J3D 3.5mm miniature stereo phone jack, PCB-mount AMB audio shop -
Y Y N O O O J2U, J3U 9P long pin header, break-apart AMB audio shop See note 7
Y Y N O O O J4D 3P pin receptacle AMB audio shop See note 7
Y Y N O O O J5D 5P pin receptacle AMB audio shop See note 7
N O N N N N JP1D 2P short pin header 517-647-01-36 (break apart) S1011E-02-ND or
S1011E-36-ND (break apart)
1097955 (break apart) - See notes 3, 4 and 6
O O N N O O JP2D 3P short pin header 517-647-01-36 (break apart) S1011E-03-ND or
S1011E-36-ND (break apart)
1097955 (break apart) - See notes 1 and 3
N N Y N N Y T1U pulse transformer 1:1 580-DA101C or
673-PE-65612
470-1003-ND or
470-1006-ND
1362398 - -
Y Y Y Y N Y X1U HC-49USX 12.000MHz crystal 20pF AMB audio shop -
Y Y Y Y N Y J1U Mini-B USB connector, PCB-mount 538-54819-0519 WM17115-ND 9786465 515-2005 -
N N Y N N Y J4U RCA jack, PCB-mount AMB audio shop -
O O O O N O JP1U 3P short pin header 517-647-01-36 (break apart) S1011E-03-ND or
S1011E-36-ND (break apart)
1097955 (break apart) - See notes 3, 4 and 5
N O N O N N JP2U-1 2P short pin header 517-647-01-36 (break apart) S1011E-02-ND or
S1011E-36-ND (break apart)
1097955 (break apart) - See notes 3 and 4
N O N O N N JP2U-2 2P short pin header 517-647-01-36 (break apart) S1011E-02-ND or
S1011E-36-ND (break apart)
1097955 (break apart) - See notes 3 and 4
N O N O N N JP2U-3 2P short pin header 517-647-01-36 (break apart) S1011E-02-ND or
S1011E-36-ND (break apart)
1097955 (break apart) - See notes 3 and 4
Y Y Y O Y N Hammond
Enclosure
1455C802 or
1455C802BK or
1455C801 or
1455C801BK or
1455C801BU or
1455C801RD
546-1455C802
546-1455C802BK
546-1455C801
546-1455C801BK
546-1455C801BU
546-1455C801RD
HM970-ND
-
HM969-ND
1455C801BK-ND
1455C801BU-ND
-
4272936
9287906
4272810
9287787
2361583
-
458-0730
773-3047
613-8353
773-2956
-
-
-
N N N N N Y Box
Enclosure
B2-080BK or
B2-080BL or
B2-080GD or
B2-080GR or
B2-080RD or
B2-080SI
- - 1015173
1015174
1418582
1418583
1015176
1015172 or 1549967
2508349218
2508349224
2508349230
2508349246
2508349252
2508349202
Newark
26K9019
26K9020
26K9021
26K9022
26K9023
26K9024
O O N N Y O Power supply regulated AC adapter, 5VDC 300mA+, 1.3mm plug, center-positive See "AC adapter or power supply" section below -
O O O O O O - 2P jumper shunts 649-68786-202LF (single) S9001-ND (10-pack) 1097979 (10-pack) - See note 4
Y Y Y Y N Y - USB-A to Mini-B cable 562-3021003-03 or
538-68806-0019
- - - or buy locally
O O O O O O - imperial #6-32 or metric M3.5 flat-head socket cap screws (for front and rear panel) - - - - McMaster-Carr or local hardware store

Notes

See the parts list table above, which refer to specific notes here.
  1. This part may be omitted if the USB board will never be attached to the DAC board, or if you want to hardwire for external DC power or USB power only (See jumper settings in the instructions section). Omitting these parts is not recommended. U1D provides controlled voltage ramp-up during turn-on and current limiting protection that would be defeated if it's not used.
  2. Straighten formed capacitor leads to fit if necessary.
  3. If you use the "break apart" 36P pin headers and receptacles, only one of each type is enough for all positions.
  4. If you don't plan to change jumper settings, there is no need to populate the jumper positions with pin headers and jumper shunts. You may leave an "open" jumper completely unpopulated, and you can solder a piece of clipped resistor lead to make a "shorted" jumper. See "Jumper settings" in the instructions section for details.
  5. If you plan to mate your γ1 board to a γ2 board, you should hard-wire JP1U with a clipped resistor lead. Do not use a jumper block and pluggable shunt, because they will not fit when the two boards are mated.
  6. If your γ1 is a Full (A), S/PDIF-only (E) or Full++ (F) configuration, and you will be mating it to a γ2 board, then you should install the "leftover" pin from the supplied 9P pin header in JP1D pin 2. This will mate with γ2's J3 receptacle.
  7. Also required if mating to a γ2 board.

Parts selection guide

Due to the tight spacing within the enclosure, and to ensure proper fit when the DAC and USB boards are plugged into each other, please observe the following recommendations. Do not use oversized parts or mount parts in a manner that was not intended. Since the γ1 is mostly a digital circuit, with the exception of the output coupling capacitors, there is no benefit to using "boutique grade" parts. Also, do not substitute parts values unless you know what you're doing. Many of the parts are carefully selected and tuned for optimum operation.

Resistors

All discrete resistors (except the resistor networks R5D, R6D and R7D) are miniature through-hole axial-lead types with a body length no longer than about 4mm (the recommended Xicon, Panasonic and Multicomp resistors are 3.5mm or 3.2mm), and no wider than 1.9mm. Metal film or thin film 1% resistors are recommended for their thermal stability.
R5D and R6D are SIP-6 "bussed" resistor networks, each with five internal resistors, one pin of each of them are connected to a common bus. R7D is a SIP-8 "isolated" resistor network, with four independent internal resistors. The lead pitch is 0.1" (2.5mm) for all of these.

Capacitors

There are four types of capacitors used in the γ1: conductive polymer electrolytic, audio-grade electrolytic, film and multi-layer ceramic.

C6D, C10D and C8U are conductive polymer electrolytic type for their ultra low ESR characteristics. They are through-hole with radial leads, 2.5mm lead-pitch, a maximum diameter of 6.3mm and a maximum height of 12.5mm.
  • United Chemi-Con PSA
  • Nichicon PLF
  • other similar
C22D, C24D and C25D are "audio grade" electrolytic capacitors. They are through-hole with radial leads, 2mm or 2.5mm lead pitch, a maximum diameter of 6.3mm and a maximum height of 12.5mm. C24D and C25D are the DAC's analog output coupling capacitors. See the film capacitor descriptions below for C24D/C25D options. If you plan to drive headphones directly from the γ1, then you should use Nichicon KW or FW 470µF 6.3V or 10V capacitors to avoid low-frequency roll-off. Note that some of these "for audio" electrolytic capacitors are non-polarized.
  • Elna RFS (Silmic II)
  • Nichicon ES (Muse)
  • Nichicon KW
  • Nichicon FW
  • Rubycon Black Gate NX Hi-Q
  • Panasonic AK
  • Elna ARD(ROD) (Starget)
  • CapXon NK
  • other similar
C26D, C27D, C29D and C11U are through-hole, radial-lead 1µF "box"-style film capacitors with a lead spacing of 5mm. You may use metallized polyester (MKT or MKS) types (or metallized polypropylene (MKP) in a lower capacitance for C26D and C27D), but be sure that the footprint is no larger than 7.5mm x 5.5mm and the maximum height is 12.5mm. C26D and C27D are "bypass" capacitors for the C24D and C25D audio-grade electrolytic output coupling capacitors. Depending on your preference, you may omit C26D/C27D and run C24D/C25D unbypassed, or you may omit C24D/C25D and run C26D/C27D alone (but increase their capacitance of C26D/C27D to 3.3µF or higher to avoid low-frequency rolloff and phase shift within the audio band). If you choose the latter option, the Wima MKS2 3.3µF 50V or 4.7µF 16V capacitors are the only known ones that would fit.
All remaining capacitors are multi-layer ceramic type, with through-hole, radial-leads and 2.5mm lead-spacing. Some capacitors have 2.5mm pitch leads but come pre-bent to 5mm, you must straighten them to fit the board. The TDK FG18 series 1µF multi-layer ceramic capacitor specified have smaller size and lower profile than most others of comparable specifications, ensuring that they will fit without hitting other parts when the DAC and USB boards are mated.

C4U and C5U are C0G/NP0 grade, which provides the best thermal stability and is important for the crystal oscillator circuit. C18D is also C0G/NP0 but all other multi-layer ceramic capacitors are X7R grade because C0G/NP0 is only available in small capacitances. Do not use Z5U, Y5V or other lower grades.

Inductors and ferrite beads

L1D and L3U are miniature 47µH through-hole axial-lead inductors with a maximum body length of about 4mm and no wider than 2.3mm. L2D, L3D, L4D, L1U and L2U are through-hole ferrite beads.
  • L1D, L3U: JW Miller 79F470K-TR-RC (available from AMB audio shop)
  • L2D, L3D, L4D, L1U, L2U: Panasonic EXC-ELSA35 (available from AMB audio shop)

Pulse transformers

A 1:1 pulse transformer is used for T1D and T1U. The recommended transformers are as follows:

Semiconductors

The integrated circuits in the parts list table above should be used, with alternatives as specified below. Some ICs come in several package styles, be sure to use the correct ones that the board is designed for.

The default U3D stereo DAC chip is Wolfson WM8501GED/V which outputs 1.5Vrms at 0dBFS when the supply voltage is 4.5V. The Wolfson WM8759GED/V is pin-compatible and may be substituted, but the output voltage is 1Vrms under the same conditions. It is otherwise identical to WM8501GED/V.

For U1U, the "technically-correct" USB DAC chip is the PCM2707PJT. The PCM2706PJT has the same TQFP-32 package, but several pins have different functions. These pins are unused in the γ1, thus the PCM2706PJT may be substituted and will function correctly.

You may use either the LP2985 series or the TPS793xx series LDO voltage regulators for U5D, U6D and U3U, as shown in the parts list table above.

For U4D, you may use MCP100 or DS1818 in TO-92 package. Each of these come in several "threshold voltage" variants. It is recommended that you use the 3.15V or 3.00V versions if available (see their datasheets for the meaning of the part number suffix). Similarly for U9D, the options are MCP101 or DS1817.

The Q1D and Q2D transistors are specified to be 2N3904, but you may subtitute them with just about any NPN TO-92 transistor with the same pin-out. Some examples are 2N4401, PN2222, 2N5088 or MPS8099 just to name a few.

Use a T-1 (3mm) high brightness red LED for LEDU. You may also use green or yellow, but do not use blue or white, because blue or white LEDs typically require around 4V or more and we only have 3.3V here. If you get insufficient brightness, decrease the value of R7U. The default value of 560Ω will run 2.7mA through a red LED, which usually has a forward voltage of around 1.8V. If you change R7U's value, do not exceed 10mA to keep the USB power consumption reasonable. Use this online LED resistor value calculator.

Connectors

  • J1D: CUI PJ-053DH DC power jack, PCB-mount 1.3mm center pin
  • J2D, J4U: CUI RCJ-041 RCA jack, PCB-mount (a gold plated version of this is available from AMB audio shop).
  • J3D: CUI SJ1-3533NG 3.5mm stereo mini phone jack, PCB-mount
  • J4D: 3P single-row pin receptacle (available from AMB audio shop)
  • J5D: 5P single-row pin receptacle (available from AMB audio shop)
  • J1U: Molex 54819-0519 Mini-B USB connector, PCB-mount
  • J2U, J3U: 3M 929705 series 9P single row pin header, 0.318" mating length.
  • (available from AMB audio shop)

Chassis / case

The γ1 is designed specifically for the Hammond 1455C80x series extruded aluminum cases.
The γ1 full++ configuration (F) uses the Box Enclosures B2-080 series extruded aluminum case.
  • Hammond 1455C801 anodized with aluminum end-panels
    The default color is silver. Add BK suffix for black, BU suffix for blue, or RD for red.
  • Hammond 1455C802 anodized with plastic end-caps
    The default color is silver. Add BK suffix for black.
  • Box Enclosures B2-080 anodized with aluminum end-panels
    Add the following suffix to specify the color:
    BK - black
    BL - blue
    GD - gold
    GR - green
    RD - red
    SI - silver
    Box enclosures are available from Newark, Farnell and RS Components.

AC adapter or power supply

A 5V DC regulated AC adapter ("wallwart") or external 5V DC regulated power supply may be used to provide power to any γ1 configuration equipped with U1D and the 1.3mm DC power jack.

The AC adapter or power supply's output plug should be a barrel-type with 1.3mm ID female, the polarity is center-positive. A compatible plug for the 1.3mm DC power jack is the CUI PP3-002D (Digi-Key CP3-1003-ND).

The appropriate input AC mains voltage, frequency and plug style depends on your country. The output voltage should be between 4.85V and 5.4V DC, with a minimum current capacity of 300mA.

A linear regulated power supply is preferred over a switching type for lowest noise. You may purchase one that is pre-built, or build your own.

The σ25 regulated power supply is a suitable DIY option, and offers clean, linear-regulated power. For the γ1 (and γ2 upgrade), set up the σ25 to output 5V DC, and use a 2.8VA or higher power transformer with 9V secondary. The following is a partial sampling of such transformers:

TransformerPrimary voltageVendor and part numberNotes
Pulse BV030-7597.0 2.8VA EI-30115VDigi-Key 567-1040-5-NDFor γ1/γ2, mount on σ24 board
Pulse BV030-7585.0 2.8VA EI-30230VDigi-Key 567-1042-5-NDFor γ1/γ2, mount on σ24 board
Myrra 44698 2.8VA EI-30230VFarnell 1689068For γ1/γ2, mount on σ24 board
Pulse BV030-7151.0 1.5VA EI-30115VMouser 673-030-7151-0For γ1 only, mount on σ24 board
Amveco/Talema 62011 3.2VA toroidal115V/230VAllied 70065727 or Digi-Key 1295-1105-NDFor γ1/γ2
Amveco/Talema 62021 5VA toroidal115V/230VAllied 70065733 or Digi-Key 1295-1110-NDFor γ1/γ2

The σ11 regulated power supply is another DIY alternative, providing the best in low-noise, high-current performance. It is more costly and complex than σ25 but merits consideration if you're also building the γ2 upgrade. See the σ11 website for details.


Main: γ1 Main | Prev: Boards & panels | Next: Instructions