DIY500 PCB Component Explanations

Component designations, referring to the schematic, are silk-screened onto the DIY500 PCB. This table explains which component(s) will fit in each place. Information is current as of DIY500v3 (June 2006).

LS = Lead Spacing, the distance between holes on the PCB.

A value of 0Ω indicates a short, and that either a zero ohm jumper resistor or a piece of jumper wire should be used. Leads clipped off of installed components are fine for this purpose.

Open means leave that component out.

Note how resistor values are witten, e.g. 2k4 means 2400 ohms, for clarity.

Component Type Package Possible Values Function

R1 Resistor 0.5" LS, ≥1/2W between 0 and 1kΩ 48V series resistor

R2, R3 Resistor 0.4" LS, 1/4W 6k8 or 6k81Ω, matched pair phantom power application

R4, R5 Resistor 0.4" LS, 1/4W 680Ω, many others, matched pair U pad series resistance

R6 Resistor 0.4" LS, 1/4W 150, 200Ω, etc. U pad shunt resistance

R7 Resistor 0.4" LS, 1/4W open, short, anything in between input xfmr secondary zobel network

R8 Resistor 0.4" LS, 1/4W open, many values input xfmr secondary loading

R9 Resistor 0.4" LS, 1/4W usually ≥100Ω, otherwise short optional input load isolation

R9a Resistor 0.4" LS, 1/4W 100k, 1MΩ, others op amp +IN shunt to GND -- bleeds C3 when inadvertantly charged, can also help with stabilization

R10, R11 Resistor 0.5" LS, ≥1/4W between 0 and 47Ω, usually 10 +/-16V series resistors

R12 Resistor 0.4" LS, 1/4W between 10k and 20kΩ, or greater negative feedback series resistance

RV1 Potentiometer Clarostat 388 10k or 25kΩ RZ (reverse log) negative feedback shunt resistance variable

R13 Resistor 0.4" LS, 1/4W between 20Ω and 1kΩ negative feedback shunt resistance cutoff

R14 Resistor 0.4" LS, 1/4W between 0 and 100Ω, or OLI optional output load isolation

OLI Inductive Resistor 0.85" LS JT-OLI-3, JH OLI output load isolator for driving capacitive loads (e.g. LONG cable runs)

R15 Resistor 0.4" LS, 1/4W open, typically 100kΩ or higher op amp output shunt to GND -- bleeds C9 in the event that a DC charge has been stored, can also help with stabilization

R16 Resistor 0.4" LS, 1/4W open, short, anything in between output xfmr secondary zobel network

R17 Resistor 0.4" LS, 1/4W usually 620 or 1k2Ω output xfmr secondary loading

D1, D2, D3 Diode 0.4" LS, DO-41 1N4003 or short optional PSU polarity protection

J1, J2 Jumper 0.1" or 0.4" LS 0.1" pin headers, 1/4W resistor, or short short out C3, C9 or add parallel resistors

J3 Jumper 0.1" LS 2-way 0.1" pin headers jumper R17 in/out

Component Type Package Possible Values Function

C1 Capcitor, electrolytic 3.5mm LS, 8mm dia, radial ≥47µF/50V optional 48V decoupling (local filtering)

C2 Capacitor, film or C0G ceramic 5mm LS, radial many, open input secondary xfmr zobel network

C3 Capacitor, electrolytic or film 2.5 or 5mm LS, radial ≥1µF/10V, could be bipolar input coupling, usually optional

C4 Capacitor, film or C0G ceramic 5mm LS, radial 1000pF, others limit input bandwidth, HF stabilization -- forms low pass filter in combination with R9

C5, C6 Capacitor, electrolytic 3.5mm LS, 8mm dia, radial ≥47µF/16V +/-16V decoupling

C7 Capacitor, C0G ceramic or film 5mm LS, radial usually between 10 and 120pF phase lead compensation

C8 Capacitor, electrolytic 5mm or 0.85" LS, radial or axial ≥100µF/6.3V, could be bipolar negative feedback shunt C, DC blocking

C9 Capacitor, electrolytic 5mm or 1.3" LS, radial or axial ≥470µF/16V, could be bipolar output coupling, DC blocking

C10 Capacitor, film 5mm LS, radial many, open output xfmr secondary zobel network

C1, C5, C6 bypass Capacitor, film 5mm LS, radial 0.01µF bypass power supply decoupling Cs

C8, C9 bypass Capacitor, film 5mm LS, radial ≥0.01µF HF bypass

SW1 Switch, pushbutton DPDT proprietary C&K F2UEE or equivalent phantom power switching

SW2, SW3 Switch, pushbutton DPDT proprietary C&K F2UEE AU or equivalent input pad and polarity switching, gold contacts

CONN1 Connector, 1/4" female TRS switching Neutrik NMJ6HCD2 front panel direct input

A1 Operational Amplfier 2520/990, 0.04" dia pins many op amps, Mill-Max 0344-2-19-01-34-27-10-0 sockets amplification

T1 Transformer, microphone input several many impedance bridging, unbalancing

T2 Transformer, line output EI625 x 5/8�? many balancing

Component Type Package Possible Values Function

Specifications subjec to change without notice. GMT

Component	Type	Package	Possible Values	Function
R1	Resistor	0.5" LS, ≥1/2W	between 0 and 1kΩ	48V series resistor
R2, R3	Resistor	0.4" LS, 1/4W	6k8 or 6k81Ω, matched pair	phantom power application
R4, R5	Resistor	0.4" LS, 1/4W	680Ω, many others, matched pair	U pad series resistance
R6	Resistor	0.4" LS, 1/4W	150, 200Ω, etc.	U pad shunt resistance
R7	Resistor	0.4" LS, 1/4W	open, short, anything in between	input xfmr secondary zobel network
R8	Resistor	0.4" LS, 1/4W	open, many values	input xfmr secondary loading
R9	Resistor	0.4" LS, 1/4W	usually ≥100Ω, otherwise short	optional input load isolation
R9a	Resistor	0.4" LS, 1/4W	100k, 1MΩ, others	op amp +IN shunt to GND -- bleeds C3 when inadvertantly charged, can also help with stabilization
R10, R11	Resistor	0.5" LS, ≥1/4W	between 0 and 47Ω, usually 10	+/-16V series resistors
R12	Resistor	0.4" LS, 1/4W	between 10k and 20kΩ, or greater	negative feedback series resistance
RV1	Potentiometer	Clarostat 388	10k or 25kΩ RZ (reverse log)	negative feedback shunt resistance variable
R13	Resistor	0.4" LS, 1/4W	between 20Ω and 1kΩ	negative feedback shunt resistance cutoff
R14	Resistor	0.4" LS, 1/4W	between 0 and 100Ω, or OLI	optional output load isolation
OLI	Inductive Resistor	0.85" LS	JT-OLI-3, JH OLI	output load isolator for driving capacitive loads (e.g. LONG cable runs)
R15	Resistor	0.4" LS, 1/4W	open, typically 100kΩ or higher	op amp output shunt to GND -- bleeds C9 in the event that a DC charge has been stored, can also help with stabilization
R16	Resistor	0.4" LS, 1/4W	open, short, anything in between	output xfmr secondary zobel network
R17	Resistor	0.4" LS, 1/4W	usually 620 or 1k2Ω	output xfmr secondary loading
D1, D2, D3	Diode	0.4" LS, DO-41	1N4003 or short	optional PSU polarity protection
J1, J2	Jumper	0.1" or 0.4" LS	0.1" pin headers, 1/4W resistor, or short	short out C3, C9 or add parallel resistors
J3	Jumper	0.1" LS	2-way 0.1" pin headers	jumper R17 in/out
Component	Type	Package	Possible Values	Function
C1	Capcitor, electrolytic	3.5mm LS, 8mm dia, radial	≥47µF/50V	optional 48V decoupling (local filtering)
C2	Capacitor, film or C0G ceramic	5mm LS, radial	many, open	input secondary xfmr zobel network
C3	Capacitor, electrolytic or film	2.5 or 5mm LS, radial	≥1µF/10V, could be bipolar	input coupling, usually optional
C4	Capacitor, film or C0G ceramic	5mm LS, radial	1000pF, others	limit input bandwidth, HF stabilization -- forms low pass filter in combination with R9
C5, C6	Capacitor, electrolytic	3.5mm LS, 8mm dia, radial	≥47µF/16V	+/-16V decoupling
C7	Capacitor, C0G ceramic or film	5mm LS, radial	usually between 10 and 120pF	phase lead compensation
C8	Capacitor, electrolytic	5mm or 0.85" LS, radial or axial	≥100µF/6.3V, could be bipolar	negative feedback shunt C, DC blocking
C9	Capacitor, electrolytic	5mm or 1.3" LS, radial or axial	≥470µF/16V, could be bipolar	output coupling, DC blocking
C10	Capacitor, film	5mm LS, radial	many, open	output xfmr secondary zobel network
C1, C5, C6 bypass	Capacitor, film	5mm LS, radial	0.01µF	bypass power supply decoupling Cs
C8, C9 bypass	Capacitor, film	5mm LS, radial	≥0.01µF	HF bypass
SW1	Switch, pushbutton DPDT	proprietary	C&K F2UEE or equivalent	phantom power switching
SW2, SW3	Switch, pushbutton DPDT	proprietary	C&K F2UEE AU or equivalent	input pad and polarity switching, gold contacts
CONN1	Connector, 1/4" female	TRS switching	Neutrik NMJ6HCD2	front panel direct input
A1	Operational Amplfier	2520/990, 0.04" dia pins	many op amps, Mill-Max 0344-2-19-01-34-27-10-0 sockets	amplification
T1	Transformer, microphone input	several	many	impedance bridging, unbalancing
T2	Transformer, line output	EI625 x 5/8�?	many	balancing
Component	Type	Package	Possible Values	Function