JK Audio INNPBX User manual

innkeeper PBX

Desktop Digital Hybrid

User Guide

JK Audio

Introduction

Innkeeper PBX will allow you to send and receive audio
through your multi-line PBX, ISDN or analog telephone.
While this may seem like a simple task that any telephone
can do, the challenge is getting the best quality audio from
such a limited audio path.

What is a Digital Hybrid?

The innkeeper PBX digital hybrid connects audio signals to
and from the handset side of a telephone without the varia­tions in quality found with analog hybrids. The main function
of a hybrid is to bring in the caller’s voice from the phone line
as clear and clean as possible. In the real world, when you
send your voice down the telephone line it has a tendency to
bleed over into the caller’s audio. The hybrid must adapt to
the audio signals from the telephone in order to properly
separate transmit and receive audio. We use a 16 bit DSP
(Digital Signal Processor) to continuously monitor the phone
line and local audio signals to deliver excellent trans-hybrid
loss, also known as separation. Our dual-convergence algo­rithm can achieve excellent separation, typically exceeding
50 dB.

Ready to go?

The innkeeper PBX controls and connectors are clearly
marked and ready for operation. The Features diagrams and
Operation sections on the following pages will help you pin­point any minor questions that you may have. If this is your
first exposure to a hybrid, we suggest that you read the entire
manual to allow you to take advantage of all these features.

Any Questions?

Before you pick up the phone... Please thumb through the
rest of this manual. You might find those deep technical
questions are covered on later pages.

2

Features

1 2 3 4 5 6 7
8 9

10 11

1. Handset Button - Press this button to use the handset as if you
were on a normal telephone call.

2. Broadcast Button - Press this button to disable the handset
and activate the innkeeper PBX for use as a digital hybrid.

3. Send 1 Level - Adjusts the signal level that you are sending
down the telephone line, through the female XLR input.

4. Send 2 Level - Adjusts the signal level that you are sending
down the telephone line, through the 3.5mm mini jack input.

5. Caller Level - Adjusts the level of the signal coming in from the
telephone line, as it is going out the output jacks.

6. Headphone Level - Adjusts the signal level coming from the

3.5mm front panel headphone jack.

7. Headphones - The 3.5mm stereo headphone jack contains a
mix of both the Send input audio and the Caller audio.

8. ON LED - Lit when you are on line with a call using the hybrid.

9. Send LEDs - Displays the signal level going to the phone line.

10. Power LED - Lit when unit is plugged in and receiving power.

11. Receive LEDs - Displays the signal level coming from the
phone line, after the DSP. This signal level will not change
when you adjust the Caller knob.

3

Features (continued)

12 13 14 15 16 17 18 19 20

12. Handset Jack - Connect your telephone handset to this jack.

13. Phone Jack - Connect this jack to the handset jack on your
telephone using the supplied handset jumper cable.

14. Handset Type Selector Switch - Use this switch to select the
correct type of handset microphone that your telephone uses.
A=Electret, B=Carbon, C=Dynamic

15. Caller Output - Male balanced XLR output contains only the
caller’s voice.

16. Send 1 Input - Female balanced XLR input for audio going into
the phone line. Mic or line level input.

17. Mic / Line switch - Sets the front end sensitivity of the Send 1

XLR jack. Set to Mic if you intend to connect a dynamic micro­phone directly to the Send 1 jack. Set to Line if you are con-

necting to the output of a mic mixer.

18. Send 2 Mono Input - 3.5mm mono mini jack input for signals
going into the phone line. Line level.

19. Stereo Output - 3.5 mm stereo mini jack output contains Send
and Caller audio determined by the Send 1 and Send 2 levels
and the Caller level controls. Left channel contains your local
Send audio and right channel contains the Caller's audio from
the telephone line.

20. Power Jack - For connection only to the supplied 9VDC regu­lated power supply only.

4

Connection

Although each application may require a slightly different setup,
there are two primary configurations.

For a direct connection to innkeeper PBX:

• Handset cable - Connect the supplied RJ-22 handset cable be-

tween the jack marked "Phone" on the back of innkeeper PBX
and to the handset jack on the base of your telephone.

• Handset - Connect your telephone handset to the RJ-22 jack on

the back of the innkeeper PBX marked "Handset".

• Send Audio - Connect a dynamic microphone cable to the Send

1 jack on the innkeeper PBX. Be sure to set the Mic/Line switch
to the “Mic” position.

• Output - Connect a stereo cable from the mini jack “Stereo Out”

on the innkeeper PBX to the “Line Input” on your computer
sound card, mini disk recorder or other equipment.

• Power - Connect the supplied DC power supply to the back of

the innkeeper PBX and then to an AC power outlet.

• Place a test call to a quiet location. Set the “A-B-C” switch on

innkeeper PBX for best audio.

• Set the “Send” level control so that while you are speaking into

the microphone, the Send LEDs on the hybrid light the -20 dB
green LED consistently and flash the -9 dB green LED. If you
flash the -3 dB red LED, lower the level. Set the “Caller” control
for good recording level of the caller audio at the output jack.

Computer

Set to
“Mic”

Sound Card

Line

Line

Mic

in

out

in

5

Connection (continued)

To connect innkeeper PBX through a mixer—Mix Minus Setup

Connect Caller to any
line level input on mixer

Number of microphones
depends on mixer

Connect Aux (or FX) Send on
mixer to Send 1 on innkeeper
PBX, Mic/Line button out (Line)

Use Main Outputs,
USB or Firewire
connectors to
send audio to
recording device
or broadcasting
equipment inputs

For whichever input channel you have the Caller connected to, turn the
corresponding Aux control to minimum (usually hard left). All other Aux
controls should be set for what you want to send to the phone line. Each
Aux Send bus is completely separate from all other outputs, so these Aux
controls will not affect what is heard on the Main outputs or on any other
Aux buses. This Aux Send bus should be pre-fader, so you can use the
fader controls to set the levels of each channel to the main output.

6

Operation

• Using balanced XLR cables (not included) with 1/4” TRS adapt-

ers if necessary for your mixer, make all connections as shown.

• On your mixer and on innkeeper PBX, set all controls to nominal

levels, usually 12:00.

• On your mixer, set local microphone channel input gain for good

microphone level.

• On your mixer, set all output faders and the main mix control for

good recording level of the local audio.

• On your mixer, set the headphone level for comfortable listening.

• On your mixer, set the Caller channel input gain to line level, if

there is a selector switch. If there is no line level input and you
must connect the Caller to a Mic in, turn the input gain way down.

• On your mixer, set the Aux control for Caller channel only to mini-

mum (zero or ∞). Aux controls for all other channels should ini­tially be set at 12:00. Set Aux Send Master for good overall level.

• Place a test call to a quiet location. Set the A-B-C switch on the

innkeeper PBX for best audio.

• On your mixer, set the Aux Send control so that while you are

speaking into the microphone the Send LEDs on the hybrid light
the -20 dB green LED consistently and flash the -9 dB green
LED. If you flash the -3 dB red LED, lower the level.

• On your mixer, set the Caller channel output level for good re-

cording level of the caller audio. If you need more control of this
level, on the mixer first adjust the caller channel input gain (if ap­plicable), then adjust the Caller control on the innkeeper PBX.

Mix-Minus Setup

A mix-minus signal is an audio signal that contains a mix of your
local microphones plus any other audio, minus the Caller's own
voice. Sending the Caller’s audio back to the innkeeper PBX
through Send 1 will cause an echo, or feedback.

If your mixer does not have an Aux Send bus, you can achieve the
same results using Pan controls with the Left and Right outputs.
Simply pan all the microphones, etc. to the Left output and pan the
Caller to the Right output. Then connect only the Left output to the
innkeeper PBX Send 1. Or, you may use an external Mix-Minus
box that will create this signal for you.

7

Operation (continued)

Telephone Handset

Innkeeper PBX will disable the microphone in the telephone hand­set when you press the Broadcast button. Use your telephone to
place or screen a call. When you are ready to take the call on inn­keeper PBX, simply press the Broadcast button. Innkeeper PBX

will automatically release the Hold (if Hold is used). Make sure

you do not put the telephone handset back in it's cradle while
you are on a call. This will still drop the call. Do not disconnect
or remove the handset during your call as this will change the

input impedance from the phone line and change the audio level.

If you need to take the call back on your telephone, press the
Handset button on innkeeper PBX. This will disable the inputs and
outputs on innkeeper PBX and connect your handset back to the
telephone. Your telephone will operate as a normal telephone any­time you are in Handset mode. Leaving the hybrid connected to the
handset jack on your telephone will not affect normal use of your
telephone. Audio will only pass through the hybrid when you press
the Broadcast button.

Optional Jumper Settings

There is a jumper located inside the innkeeper PBX at J9 that af-

fects handset operation. The factory default closed position
(jumper covering both pins) disables only the handset microphone
when the Broadcast button is pressed. Changing the jumper to the
open position (either remove the jumper or cover just one pin) al­lows you to completely disable both the handset microphone and
speaker when the Broadcast button is pressed.

If the incoming audio level from your telephone is too high and you
are consistently lighting the red –3dB Receive LED, first try de­creasing the volume using the controls on the base of your tele­phone. If you still cannot drop the incoming audio level enough,
and your unit was purchased after February 2007, you may need

to change jumper J10 inside innkeeper PBX. There are three pos-

sible settings to adjust Caller receive level:

Pins 1 & 2 closed = 0dB (factory default)
Pins 2 & 3 closed = -6dB
Pins 1-3 left open = -12dB

To change the jumper settings, first disconnect power from the inn­keeper PBX, then remove the cover and locate the appropriate
jumpers on the printed circuit board.

8

Operation (continued)

Send Signal Level

The Send LEDs display the signal level as it goes out to the phone
line. The goal is to drive the phone line at high enough levels to
avoid phone line noise, but not so loud as to cause excessive clip­ping. Adjust the Send level control so that you rarely see flashes of
the red -3dB peak Send LED. These flashes should occur only dur­ing loud speech bursts. If the red LED stays lit for extended periods
you can assume that much of your speech is being clipped or dis­torted. In this case you should decrease the Send volume control
for the input that is causing the clipping.

Caller Signal Level

The Receive LEDs only display the strength of the signal coming in
from the phone line just after the DSP. The Caller level control
does not change what you see on these LEDs. Adjust the Caller
level for the best signal at the output jacks of innkeeper PBX.

A-B-C Selector Switch

Use this switch to select the correct type of handset microphone
your telephone uses. A=Electret, B=Carbon, C=Dynamic. Trial and
error seems to work best in determining which handset type to use.
Your innkeeper PBX will only function correctly if the handset type
selector switch is in the correct position. This switch changes sig­nal level, impedance, and wiring to accommodate the differences
in handset microphone types. To determine the correct position,
you should place a call to another telephone line, then try to send
audio to the phone line through the input jack of the innkeeper
PBX . While doing this, switch between the three different handset
type positions. Choose the position that works best by monitoring
the audio quality and Send LEDs.

Although not conclusive, the following guidelines may help:

The majority of newer telephones have electret type microphones
and will use the "A" position.

Older telephones that have the round "screw type" handsets con­tain carbon microphones and use the "B" position.

Many Radio Shack®, Panasonic®, and Nortel® telephones have
dynamic microphone types and use the "C" position.

9

FAQs

?

Will innkeeper PBX work with my ___ PBX phone system?

! Probably yes. We have to say probably because the handset

interface is proprietary and therefore can change from model to
model. We have no way of predicting how a phone manufac­turer will use the handset wires in the future. The three handset
microphone types that we support, electret, dynamic and car­bon, cover every handset microphone type that we have seen in
use, but the wire diagrams can change without notice.

? Will your digital hybrid provide phantom power for a con-

denser mic?

! No, this device will not provide phantom power. If you are con-

necting your microphone directly to the innkeeper PBX, use a
dynamic mic.

? Why can't I dial out on my phone and I hear a lot of noise on

the call?

! The innkeeper PBX will not work with any telephone that has a

keypad in the handset. You need to use a telephone with a stan­dard handset.

? Can innkeeper PBX auto-answer or auto-disconnect?
! No, the handset cord on your phone is only active if the handset

is off-hook. This must be done manually. So there is no way to
auto-disconnect. You must return the handset to the cradle.

? I have everything connected correctly. Why can't the caller

hear me?

! There are two things you should check: First, the position of the

A-B-C switch which will probably use either setting A or C. Next,
you cannot use the speakerphone function on your telephone
during your recording. Innkeeper PBX accesses audio through
the handset cord. With the speakerphone turned on, there is no
audio going through the handset. You must use a microphone.

? Why is there a loud hum on the output of my innkeeper

PBX, even when nothing else is connected?

! Make certain you are using the regulated power supply that was

shipped with this unit. Power supplies are not all the same.

10

FAQs

? Why does my laptop only record half of the conversation? I

am using the Stereo output on the innkeeper PBX and I
have a stereo cable.

! Most laptop computers only have a mic input, which is mono.

You will need to either get a sound card with a stereo line level
input for your laptop or use a USB or FireWire interface product.

? How do I record onto my computer and edit the files?
! You will need to purchase or download any audio editing soft-

ware of your choice. You may also need to edit the audio con­figuration files on your computer or in your software to allow re­cording in stereo. Innkeeper PBX just allows you to access the
audio from your phone line.

? Does innkeeper PBX come with any Talk Show software?
! No, our description "Turn your PBX into a low cost talk show

system" pertains to using a multi-line PBX phone system as a
line selector switch. When the innkeeper PBX is on line, simply
select which phone line you want to talk to, either dropping the
last caller, or putting them back on hold.

? Why is there a Send 2 mini-jack on the back of my inn-

keeper PBX?

! This is a second line level input to innkeeper PBX. Here you can

connect another device, such as a CD player, the Line Out from

your computer or even the output of your personal audio player,
to add audio to the conversation. This enables you to play back­ground music or other sound bites during your discussion. Do
not connect a microphone to this jack. This is a mono input. If
you connect a stereo output here such as a computer Line Out,
you will receive only Left channel audio on this jack.

? Can I still use my phone to take regular calls or do I have to

disconnect the innkeeper PBX when I am not using it?

! You can leave the innkeeper PBX in place and your telephone

will continue to operate normally. Audio will only pass through
the hybrid when you press the “Broadcast” button.

11

Specifications

Inputs:

Send 1: Balanced Female XLR, 1k ohm,

-10 mV RMS (-35 dBv nom)

Mic/Line pad switch = +4 dBv max

Send 2: 3.5mm mono, 20k ohm, 250 mV RMS
(-10 dBv nom)

Outputs:

Balanced: Male XLR, 200 ohm, 500 mV RMS
(+4 dBv max)

Unbalanced: 3.5mm stereo, 50 ohm,
250 mV RMS (0 dBv max)
Left = Send, Right = Caller

Headphone: 3.5mm stereo, 8 ohms, 250 mW
mixed send and receive

Phone Line:

Aux Phone: RJ11C

Phone Line: RJ11C

Isolation: 1500 VAC

Ringer: 0.5B REN

Frequency Response: Telephone side 200 Hz - 3600 Hz

Power: 120-240 VAC power supply (included)

Size: 7" x 6" x 1.6" (18 x 15 x 4.2 cm)

Weight: 2.2 pounds (1 kg)

12

Notes

13

FCC Part 15 Compliance

This equipment has been tested and found to comply with the
limits for a Class A digital device, pursuant to Part 15 of the FCC
Rules. These limits are designed to provide reasonable protection
against harmful interference when the equipment is operated in a
commercial environment. This equipment generates, uses, and
can radiate radio frequency energy and, if not installed and used in
accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment
in a residential area is likely to cause harmful interference in which
case the user will be required to correct the interference at his own
expense.

Changes or modifications not expressly approved by JK Audio can
void the user's authority to operate the equipment.

FCC Registration

Your new JK Audio product has been registered with the Federal
Communications Commission (FCC). This product complies with
the standards in Part 68 of the FCC rules.

1. Connection and use with the nationwide telephone

network

The FCC requires that you connect this telephone equipment

to the national telephone network through a USOC RJ-11C
modular telephone jack.

This equipment may not be used with Party Line Service or

Coin Telephone Lines.

This equipment is hearing aid compatible.

2. Information for the telephone company

Upon request from your local telephone company, you are

required to provide the following information:

a) The "line" to which you will connect the telephone equipment

(that is, your telephone number), and

14

FCC Registration (continued)

b) The telephone equipment's FCC registration number. This

can be found on the bottom of your telephone equipment,
and,

c) The ringer equivalence number (REN) for this equipment.

The REN is used to determine the quantity of devices which will

be connected to the telephone line. Excessive RENs on the
telephone line may result in the devices not ringing in response
to an incoming call. In most, but not all areas, the sum of the
RENs should not exceed 5.0. To be certain of the number of
devices that may be connected to the line, as determined by the
total RENs, contact the local telephone company.

3. Repair Instructions

If it is determined that your telephone equipment is

malfunctioning, the FCC requires that it not be used and that it
be unplugged from the modular outlet until the problem has
been corrected. Repairs to this telephone equipment can only

be made by the manufacturer or its authorized agents or by
others who may be authorized by the FCC. For repair

procedures, follow the instructions outlined under the warranty
section of the manual.

4. Rights of the telephone company

If telephone equipment is causing harm to the network, the

telephone company may temporarily discontinue your telephone
service. If possible, they'll notify you before they interrupt
service. If advanced notice isn't practical, you'll be notified as
soon as possible. You'll be given the opportunity to correct the
problem, and you'll be informed of your right to file a complaint
with the FCC.

Your telephone company may make changes in its facilities,

equipment, operations or procedures that could affect the
proper functioning of your JK Audio product. If such changes
are planned, you'll be notified by your telephone company.

15

Warranty

Innkeeper PBX is covered by a 2-year warranty to be free
from defective workmanship and materials. In the event that
the innkeeper PBX needs repair, you must call us to get an
authorization, and then carefully pack and ship it to us. You
will pay for shipping to us and we will pay for return back to
you, UPS ground. No free repairs will be made if the defect
was caused by misuse, weather conditions, or other cause,
except for defective workmanship or materials. THERE ARE
NO EXPRESSED OR IMPLIED WARRANTIES WHICH
EXTEND BEYOND THE WARRANTY HERE MADE.

03/07

JK Audio, Inc. 1311 E 6th Street, Sandwich, IL 60548 USA

Voice: [phone] Toll Free: 800-JK-Audio Fax: [phone]

[e-mail] www.jkaudio.com

Copyright © 2007 JK Audio, Inc. All Rights Reserved.