True PT2-500 User Manual

pT2-500

OPERATION MANUAL

PRECISION MICROPHONE

PREAMPLIFIER

with Direct Input and Thru

500 series compatible module

Version 1.0

pT2-500 Microphone Preamplifier OPERATION MANUAL

True Systems pT2

-

500

RoHS

True Systems pT2

-

500

pT2

-

500

Declaration of Conformity

Sunrise Engineering and Design Inc. hereby declares the
single channel microphone preamplifier module to be in material conformity with the
following EC directives and related standards:

 2006/95/EC Low Voltage Directive
 2004/108/EC EMC Directive

Technical files are maintained at corporate headquarters of Sunrise Engineering and
Design Inc., 1630 S. Research Loop, Suite 150, Tucson, Arizona 85710, U.S.A

Certificate of Compliance

This is to certify that the
requirements and specified limits of restricted substances according 2002/95/EC
directive.

WEEE

is marked with the WEEE symbol to comply with the European Union’s Waste
Electrical & Electronic Equipment (WEEE) Directive 2002/96/EC. The symbol indicates
that this product should not be treated as household waste. It must be disposed and
recycled separately as electronic waste. Please assist to keep our environment clean.

Above declarations are void by modification of the device without approval, or unau­thorized servicing.

is RoHS compliant and meet the

Tucson, 06-01-2010

Tim Spencer, president

Version 1.0 2 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

SAFETY & OPERATING PRECAUTIONS

Important symbols:

This symbol appearing on the product or in this manual indicates the
presence of dangerous voltage within the product enclosure that presents
the risk of electric shock injury. When this symbol appears next to an
operation discussed in this manual, only qualified technical personnel should
perform that operation.

This symbol indicates important operating or maintenance instructions that
should be read carefully. Failure to observe these instructions could result in
damage to this product or other equipment.

WARNINGS:

While no hazardous voltage is present within this product during normal
operation, please observe the following warnings regarding any AC-powered
equipment into which this product is installed:
 To reduce the risk of electric shock injury, do not remove the access

covers on AC-powered equipment. Refer servicing to qualified personnel.

 This unit is intended for indoor operation only
 Do not operate this unit in the presence of rain, liquids or condensing

moisture.

 Do not expose the unit to dripping or splashing liquids.
 Do not place liquid-filled objects on the unit.
 Do not defeat the earth ground connection in the AC power cable.
 Do not defeat intended AC power connection polarization.
 Do not use a damaged or excessively worn cord to connect the equipment

to AC power.

CAUTIONS:

 Severe damage to pT2-500 will occur if incorrect power supply voltages

are applied to the card edge connector. Please consult the
“CONNECTIONS” section in this manual for proper power supply
specifications/connections.

Disclaimer:
Product failure caused by improper voltage application cannot be
covered under warranty.

 Liquid entering the product enclosure is likely to cause performance

degradation or failure. Failures due to moisture entering the enclosure
cannot be covered under warranty. Should liquid spill on the unit,
immediately disconnect it from the AC power source and contact TRUE
Systems for servicing instructions

 This product is designed to operate in an ambient temperature range of

10C to 50C (50F to 122F).

Version 1.0 3 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

CONTENTS

CERTIFICATIONS…………………………………………………………...

CE
RoHS
WEEE

SAFETY and OPERATING PRECAUTIONS…………………………….

TABLE of CONTENTS……………………………………………………...

PRODUCT OVERVIEW……………………………………………………..

New Type 2 Circuit Design
Features

INSTALLATION……………………………………………………………...

Unpacking
Card Rack Installation

Card Edge Connections

Ventilation

OPERATION………………………………………………………………….

Connections

Output
Microphone Input
Instrument Input and Thru (DI)…………………………………………………..

A Word About Cables……………………………………………………………………
Cable Types

Instrument cables
Microphone and Line Level cables

Front Panel Layout……………………………………………………………………….
Controls

Gain, LO/HI
High Pass Filter
Phantom Power

Instrument Input
Level Indicators

2

3

4

5

6

7

8
9

10

SPECIFICATIONS…………………………………………………………...

TROUBLESHOOTING………………………………………………………

WARRANTY & SERVICE INFORMATION……………………………..

Registration and Warranty
Service and Support……………………………………………………………………..

Version 1.0 4 ©2010 TRUE SYSTEMS

11

12
13

14

15

pT2-500 Microphone Preamplifier OPERATION MANUAL

PRODUCT OVERVIEW

Thanks for using our product! We appreciate the confidence you place in TRUE
Systems by purchasing the pT2-500 microphone preamplifier/instrument DI. We

design our products to deliver stunning musical accuracy, uniquely useful features,
exceptional value, and reliability. Every aspect of this product design was determined by
careful listening tests and extensive user feedback. Please feel free to contact us with
questions or comments. And, we always appreciate hearing about (and hearing)
successful projects you’ve completed!

NEW TYPE 2 CIRCUIT DESIGN

The pT2-500 is the first instance of our new-technology Type 2 circuit design. Our Type
2 design provides the traditional ultra-resolution musicality of our original design

preamps, but adds serious analog depth and warmth. In short: It sounds BIG!

New technology alone certainly doesn’t guarantee better sonic performance (frequently,
just the opposite). But, frankly, neither do transformers, Class A circuit topology,
through-hole components, etc., etc. We’ve spent great effort designing, refining, and
working with major component manufacturers in order to implement the Type 2 design.
And, we believe you’ll be very pleased with the results!

FEATURES

 API™ 500 series module format
 Totally Balanced Topology for:

 insensitivity to ground noise/loops
 Insensitivity to EMI, both external and from adjacent modules/power supplies
 reduced distortion

 Rail-to-Rail design for:

 higher internal headroom
 higher maximum input level without pad (up to +22dBu)
 higher output level without transformer and excessive power supply current

 0.1% precision resistors for:

 exceptional Common-Mode and Output Signal Balance performance
 excellent unit-to-unit sonic consistency

 “Real DI” IN and THRU jacks for:

 Easy hookup to amps for simultaneous DI and amp’d tracking or live sound
 Easy hookup to other DI’s or effects for simultaneous tracking or live sound

 Detented, continuous Gain Control and Dual Gain Ranges for:

 easy gain resetability
 easy gain setting over wide gain ranges

 Steel Enclosure for:

 protection from EMI and RFI
 protection from ESD and handling contamination/damage

 80Hz High Pass Filter
 4-Level Signal Meter

Version 1.0 5 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

INSTALLATION

Unpacking

Please read and follow instructions on the Caution sticker on the anti-static bag
enclosing the pT2-500:

 Please ground yourself to dissipate static electricity before opening anti-static bag

and handling the pT2-500.

 Save the anti-static bag, carton, and foam supports for future storage or ship-

ment.

Card Rack Installation

1. Turn off card rack AC power and remove AC power cord.

2. Carefully align the pT2-500 with the desired card slot edge connector. This is a

blind installation, so take your time in order to avoid scratching this unit or adjacent
units in the card rack.

3. Press the unit firmly and evenly until you feel it seat in the card edge connector.

4. If you have difficulty inserting this unit, check for debris in the card rack edge

connector. It may help to rearrange adjacent modules in the card rack.

5. Secure the front panel with two 4-40 flat head philips mounting screws (supplied with

API™ card racks and Lunchbox™).

6. Reconnect the AC power cord and turn on the rack power.

Card Edge Connections

If you are using a custom card rack, or a
card rack not manufactured by API™, please
verify the following power supply

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15 +48VDC

CHASSIS GROUND
+OUTPUT
NC

-OUTPUT
AUDIO COMMON
NC
NC

-INPUT
NC
+INPUT
NC
+16VDC
POWER COMMON

-16VDC

Note:

Disclaimer:

terminations:

Pin 12 = +16VDC
Pin 13 = Power Common
Pin 14 = -16VDC
Pin 15 = +48VDC

Pin 1 is located at the top of the card edge
connector.

Damage caused by incorrect power
supply termination or voltage cannot be
covered under warranty.

Ventilation

We recommend that the card rack containing the pT2-500 have adequate ventilation to
maintain the unit within an operating ambient temperature range of 10C to 50C (50F
to 122F).

Version 1.0 6 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

OPERATION

Connections

Read “Safety and Operating Precautions” on page 3, and “Installation” on page 6 of
this manual before making any connections to the pT2-500.

1. Connect output signal cables from the XLR OUTPUT connectors on your 500-series
compatible card rack to the analog line-level inputs of your DAW, recorder, mixer,
A/D converter, signal processor, etc.

 XLR outputs used with unbalanced cable configuration must be wired correctly. 

See page 9 “Output Cable Connection – unbalanced”.

DAW, Recorder, Mixer, A/D Converter, Signal Processor, etc.

2. Connect microphone cables to the XLR INPUT connectors on card slots that contain

Version 1.0 7 ©2010 TRUE SYSTEMS

Microphones

(for card slots with Mic Preamps installed)

your pT2-500 or other mic preamp.

 Do not attempt to connect unbalanced microphones to the pT2-500 

It is not intended to operate with this type of microphone.

NOTE: The input and output connector locations on some 500-series
compatible card racks are different than on API™ units. In order to prevent
time-consuming errors and possible damage to your equipment, please
consult the manufacturer’s documentation for the particular card rack you are
using.

pT2-500 Microphone Preamplifier OPERATION MANUAL

CAUTION:

We recommend that you avoid “hot-patching” microphone inputs when using
a patch bay at the microphone inputs of the pT2-500. Please TURN OFF
phantom power and turn down the gain prior to connecting or re-patching
microphone inputs routed through a patch bay. Failure to do so may result in
transients that can damage the pT2-500 or equipment that is connected to
its outputs-not to mention your ears!

Instrument Input and Thru (DI)

1. Connect your instrument cable to IN. This interrupts the microphone input on the rear
panel and routes your instrument to the discrete FET DI in the pT2-500. This input
is intended for unbalanced signal sources.
 DO NOT use TRS plugs for this input or the DI will not be activated 

2. If desired, connect a cable from THRU to a guitar/bass amp, another DI, or additional
signal processing device.

3. The IN and THRU jacks are directly connected as in any typical standalone DI. Since
the input impedance of the pT2-500 FET DI is 2.5 Megohms, it does not provide
any significant electronic load to the instrument pickup. When connection is made via
the THRU jack to an amp or other device, the input impedance of that device will
essentially determine the electronic load on the instrument pickup. Keep in mind that
lower impedance may alter the tonal character of your instrument.

Version 1.0 8 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

tip

sleeve

pT2

-

500

A Word About Cables…

Most users of the pT2-500 have invested much time and money in their selection of
microphones and preamplifiers. We recommend that you give some consideration to the
microphone, instrument and output cables you select, as well.

 Use high-quality, low capacitance cable. Braided shielding and “star quad” type mic

cables will perform better in electrically noisy environments. Manufacturers such as
Canare, Mogami (and others) make high performance cable of this type.

 Some “house brand” cables are made by quality manufacturers, but others can be

inferior. Be careful. Use cables with high-quality connectors (Neutrik, Switchcraft,
etc.).

 Our studio testing has shown that some of the more esoteric guitar/instrument

“super-cables” do, indeed, sound better. Noticeable improvement, but at a stiff price.
Try before you buy!

 Avoid excessive cable length.
 Replace damaged connectors.

Cable Types

There are two styles of audio cables used for connections to the pT2-500 in a 500­series rack:

 Shielded / single-conductor type for unbalanced signals (Instrument cables)
 Shielded / twisted-pair type for balanced signals ( Microphone / Line level cables)

We recommend that all interconnecting cables are wired according to the following
standards. Failure to do this can result in malfunction or audible distortion.

For Instrument cables (unbalanced)

on TS connectors:

 Tip = positive (+) signal

 Sleeve = shield

TS connector (¼” plug, mono)

For Microphone and Line level cables (balanced)

on XLR connectors:

 Pin 1 = shield
 Pin 2 = positive (+) signal
 Pin 3 = negative (-) signal

female male

XLR connector (front side)

Output cable connection – unbalanced

NOTE: When connecting an XLR output from

to a subsequent
audio device with an unbalanced input, the negative signal lead (from Pin 3)
must be wired to shield (Sleeve) at the TS connector. For this type of
connection, the Maximum Output Level is reduced to +23dBu.

Version 1.0 9 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

Front Panel Layout

CONTROLS

Gain

The detented rotary gain control along with the
HI GAIN button setting determines the overall
gain through the preamp. When HI GAIN is off,
the rotary gain control range is from 6dB to
58dB and maximum input level is
approximately +22dBu. When HI GAIN is on,
the rotary gain control range is from 18dB to
70dB with maximum input of +10dBu.

Polarity

Output signal polarity is reversed when the

POL button is depressed.

High Pass Filter

The HPF/80Hz button activates the high pass
filter (-3dB at 80 Hz).

Phantom Power

The +48V button activates phantom power for
microphones that require it.

CONNECTIONS

Instrument Input

Discrete FET Instrument Direct IN. Connect
your instrument cable to the IN jack
(unbalanced instrument cable only). If desired,
connect a cable from THRU to a guitar/bass
amp, another DI, or additional signal
processing device. See previous section for
details.

LEVEL INDICATORS

The level indicators show output signal level. SIG illuminates at -24dBu and indicates
that a signal is present on the channel. +4 illuminates when the output signal reaches
normal operating level of +4 dBu. +12 illuminates when the output signal reaches
+12dBu. OL illuminates when the output signal level exceeds +26dBu which is 3dB
below actual preamp overload.

Version 1.0 10 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

SPECIFICATIONS*

Frequency Response

@ 40dB gain (-3 dB)

THD+N

@ 40dB gain,+26 dBu out, 20Hz to 20kHz BW

Intermodulation Distortion

SMPTE/DIN 4:1 (60Hz/7kHz), @40dB, +26dBu

Noise (E.I.N)

Rs = 0 Ohms

CMRR

@40dB gain, Vcm = +10dBu

Slew Rate

Microphone Input

Maximum Input Level

Input Impedance

Gain

Instrument Input (DI)

FET discrete circuit

Maximum Input Level (DI)

Input Impedance (DI)

1.5 Hz – 600 kHz

0.0004%

0.0009%

-133 dB

85 dB

50 V/us

1x balanced (XLR-type)

(via card edge connector)

+ 22 dBu

5.5 kOhm

+6 to +58 dB (LO gain)
+18 to +70 dB (HI gain)

1x unbalanced, (jack type)

(IN jack on front panel)

+11 dBu

2.5 MOhm

Gain (DI)

-14 to +38 dB (LO gain)

-2 to +50 dB (HI gain)

Output

1x balanced (XLR)

(via card edge connector)

1x unbalanced (TS jack)

(THRU jack on front panel)

Output Impedance

Maximum Output Level

Power Requirements

100 Ohm

+29 dBU

±16 VDC, +48 VDC
(power supply - 500 format rack)

(via card edge connector)

Power Consumption

65 mA = 1.04 W (±16V)
2 mA = 0.01 W (+48V)

Dimensions

1.5“ x 5.25“ x 6.05“ (W x H x D)

38.1 x 133.4 x 153.8 mm

Weight

1.4 lbs. (0.64 Kg)

*Typical performance. Specifications subject to change without notice.

Version 1.0 11 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

TROUBLESHOOTING













Symptom Solution

No signal output. Main power switch
on rack power supply is ON, but no
LED’s illuminate on pT2-500.

Check AC power source and cord connection

 Check fuse on rack power supply.
 Check that preamp card edge connector is

properly seated.

No signal output. Main power switch
on rack power supply is ON and
appropriate LED’s illuminate on
pT2-500.

Output signal is distorted. Outputs
are connected for balanced
operation.

Output signal is distorted. Outputs
are connected for unbalanced
operations.

Check status of phantom power.

 Check continuity of mic and electric

instrument cables.

 Check continuity of output cables.
 Make sure GAIN control is adjusted.

Make sure GAIN is adjusted so that the OL
indicator does not activate during the audio
program.

 Make sure the high output capability of this

unit is not overloading the device or
monitoring system to which it is connected.

 Check continuity of output cable.
 Make sure outputs are not connected to a

load impedance of less than 600 ohms.

Make sure the minus (-) output signal pins
are connected to the shield and not left
unconnected. See “Output Cable
Connection” section, page 9.

 Check troubleshooting tips for balanced

operation (above).

Hum can be heard in the audio
program.

Electric instrument connected to a
Direct Input does not produce a
signal or signal is distorted.

Version 1.0 12 ©2010 TRUE SYSTEMS

Check continuity of output cables
(particularly shields).

 Alternatively, disconnect shields on one end

of output cables (not appropriate for
unbalanced connections).

Check continuity of electric instrument
cables.

 Check the batteries or AC power source of

any “foot pedal” effects processors
connected to the Direct Input.

 Make sure that the instrument cables have

standard tip-sleeve ¼” phone plugs.

pT2-500 Microphone Preamplifier OPERATION MANUAL



Symptom Solution

DO NOT use TRS plugs!

Radio Frequency Interference can
be heard in the audio program
(swishing sound or audio from a
radio transmitter)

Make sure that mic cables are of good
quality and that the shield is properly
connected. Avoid excessive length.

 Make sure that earth ground connection is

maintained via the AC power cord.
DO NOT use an isolator!

 Make sure the unit is located away from

known sources of radio frequency energy.
(e.g. cell phone, walky-talky etc.)

Version 1.0 13 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

WARRANTY & SERVICE INFORM

ATION

REGISTRATION

Don’t forget to register your pT2-500 by completing the registration form online at our
website www.true-systems.com (Tech Support/Product Registration). Alternatively, fill
out the enclosed Registration Card and return it to us. This allows TRUE Systems to
contact you regarding any updates, upgrades or applications information that may
become available.

WARRANTY
SUNRISE ENGINEERING and DESIGN INC. (“SUNRISE”) warrants the TRUE
systems pT2-500 to be free from defects in material and manufacture, when properly

installed and used according to instructions in the Operation Manual, for a period of one
year from the date of sale to the original purchaser. Units returned for warranty repair to

SUNRISE or an authorized TRUE Systems repair facility will be repaired or replaced at
the manufacturer’s option, free of charge. Supplementary shipping charges will apply to
units returned to addresses outside the continental USA. All units returned to SUNRISE
or authorized TRUE systems repair facility must be prepaid, insured and properly
packaged. Purchaser must obtain a Return Authorization (RA) number from SUNRISE
prior to returning a product. SUNRISE may require proof of the purchase date in the
form of a copy of a dated original retail invoice.

This warranty is void if, in the sole judgment of SUNRISE, the product has been abused,
neglected, misapplied, or has been damaged by an accident, modification, or attempted
repair by unauthorized personnel. This warranty will not apply to cosmetic damage
incurred due to normal handling and use. SUNRISE reserves the right to change or
improve the product design at any time without prior notice. Incorporation of design
changes in future versions of the product does not imply the availability of upgrades for
existing units.

This warranty is in lieu of all other warranties, expressed or implied, and SUNRISE
specifically disclaims all implied warranties, including, but not limited to, warranties of
merchantability and fitness for a particular purpose. The purchaser acknowledges and
agrees that in no event shall SUNRISE be held liable for any special, indirect, incidental
or consequential damage, or for injury, loss or damage sustained by any person or
property, that may result from the use of, or failure of this product to operate correctly at
any time. In the USA, some states do not allow the exclusion or limitation of implied
warranties or liability for incidental or consequential damage, so the previous exclusion
may not apply to you. This warranty gives you specific legal rights, and you may have
other rights which vary from state to state.

Version 1.0 14 ©2010 TRUE SYSTEMS

pT2-500 Microphone Preamplifier OPERATION MANUAL

SERVICE and SUPPORT

Other than cleaning the exterior surfaces of your pT2-500 and occasional inspection of
the audio cables for damage, no maintenance procedures should be attempted by the
user. Cleaning can be performed using a lint-free cloth dampened with Windex.

There are no user-serviceable components inside the product enclosure. Many of the
electronic components are selected and matched at the factory. For this reason, as well
as personal safety considerations, we recommend that you refer service requirements to
TRUE Systems or authorized repair facilities.

All units returned to TRUE systems or authorized TRUE systems repair facility must
be prepaid, insured and properly packaged. Purchaser must obtain a Return
Authorization (RA) number from SUNRISE prior to returning a product.

Sunrise Engineering and Design Inc. Tel: [phone]
1630 S. Research Loop, Suite 150 Fax: [phone]
Tucson, Arizona 85710 USA Email: [e-mail]

Version 1.0 15 ©2010 TRUE SYSTEMS