Duncan KTG-2075 User manual

KTG-2075
Stereo Power
Amplifier
Owners Manual

Caution
To prevent electrical shock, do not operate this unit in wet or moist areas.
There are no user -serviceable parts inside. (See " Maintenance" and "Tube
Chart" sections for user maintenance procedures.)
Performance Specifications
I rack space, 2-channel power amplifier
Power Output –
(Minimum power per channel, both channels driven.)
-75 watts into 8 ohms Crosstalk --68dB
Thd.12%@ 1 Khz Frequency Response -15Hz-5OKhz
-100 watts into 4 ohms ( -3dB + OdB )
Thd.15%@ 1 Khz Input Impedance -30K
Input Sensitivity -.80V
IMD SMPTE (60 Hz/7khz 4:1 ratio)
-15% into 8 ohm at rated power Protection Circuitry -Front panel
-2% into 4 ohms at rated power accessible DC rail fuses giving
short circuit and DC fault protection.
Hum and Noise -referred to rated
8 ohms output Output type -Quasi -complimentary
-60 Hz hum; better Dimensions -Face plate-
than -105 dB 19" x 1.75"
-120 Hz ripple; better Chassis/heat sinks -
than -105dB 17" x 10.5" x 1.75"
-Combined hum noise; better Weight -13.5 lbs.
than –lOOdB

Congratulations on your purchase of the Seymour Duncan Research KTG-2075
TM Stereo Power Amplifier. Each product in the KTG, King Tone Generator
series has been designed and built to generate great guitar sound, now and for
years to come. Read this manual carefully to become familiar with their features
and operation of the KTG -2075 amplifier.

Front Panel
The KTG -2075 is a single rack space stereo power amplifier designed primarily
for guitar although it will also produce excellent results in applications Such as
keyboards or vocal monitors.
Set up
The KTG -2075 can be connected directly to the preamp Source, or after stereo
effects processing.
Volume Control
Like many power amps, the KTG-2075 does not have a Volume control. When
the amp is on, it provides maximum head room & prevents you from unknowingly
clipping any signal processors earlier in the chain. Clipping reduces dynamic
range and can create undesirable distortion.

When you need to reduce your overall volume, use the output level control of
your pre-amp or final signal processor.
Thermal overload indicator
The KTG -2075 is designed for rugged operation under extremes of
temperature. In the event the amp does reach a dangerous degree of
temperature, the thermal overload indicator (see front panel diagram) will light
up, and the amp will automatically shut down until it has cooled enough for safe
operation. When the thermal overload indicator comes oil, turn the amplifier off
and wait for it to cool before restarting.
Hot tips -Being a power amp the KTG -2075 does generate some heat and
requires ventilation for proper operation. It's important to place the unit in the
upper part of your rack with 1/2 rack space above and below the unit. Be sure the
rear heat sinks have good air flow.
Output Protection Fuses
The KTG -2075 is designed with short circuit fuse holders conveniently located
on the front panel of the unit. This means that in the case of a shorted speaker
cable or other short circuit conditions, you won't have to take this power amp to a
service center for changing internally placed fuses. Four spare fuses are supplied
inside the fuse holders.
Important: Make sure all cable connections (input and output) are made before
turning power on. Adding or removing cables when unit is on may blow fuses.

To avoid short circuits (possibly blowing Fuses) use good quality speaker cable
and use a minimum load of 4 ohms.
Note: 2-ohm loads will eventually blow fuses.
In the event of blown output protection fuses, always replace with 4A Fast Blow
type.
Rear Panel
For I 100V and 120V
Use 3A SLO -
For r 22OV and 240V
Use 1.25A SLO -131,0
Speakers Loads
The impedance rating of a speaker or a cabinet (measured in ohms), specifies
flow much current it will let flow through for a given voltage. When you think of
the word "load", think of loadingup your car. The heavier the load, the more work
your car has to do in order to maintain the same speed. The same with your
amplifier; the heavier the speaker load, the more current it has to put out to
maintain the same voltage. Excessive loading overworks the amplifier and may
cause it to overheat or blow afuse To avoid this, the key thing to remember is that
the lower the number of ohms, the more loaded the amplifier is and the more
Current the amplifier has to put out to drive it. Confused? Well, the following is a
handy chart that will let you know for certain the load you're putting on each
channel.

Maintenance
The KTG -2075 has been designed to provide safe and reliable performance
year after year. Treat it with care as you would any piece of high performance pro
gear, preferably rack mounted in a good road case. There are no user -
serviceable parts inside. If your amp should ever require servicing please call us
for the name of your nearest Authorized Service Center.
Troubleshooting
1. No output
a. Check power indicator--is the switch on and AC plugged in?
b. Check main fuse on the rear panel and replace if necessary.
c. Check output protection fuses and replace if necessary. Before using amp
again, check for any short circuits or improper loads (bad speaker cables, loads
heavier than 4 ohm, etc.) If output protection fuses blow again refer to authorized
service center.
d. Check thermal over load indicator if it's on; check for adequate ventilation
around heat sinks (see rear panel diagram). Note: Thermal protection circuit will
automatically re-set after amp has cooled 10 -15 degrees. (Approx. 5 minutes)
2. Excessive distortion at low volumes –
a. Check all cables for intermittent connections.

Reference:KTG-1 Tubes
The KTG-1 uses three tubes in its all-tube design. They are, from left to right
looking from the front of the unit:
Type Comment
Tube 1 I2AX7 Should be a low noise,
low microphonic tube, so
we use a Chinese tube
for this position.
Tube 2 I2AX7
This tube has a metal
shield around it and gives
you most of the
distortion. We use a
Yugoslavian tube here for
the best break-up
characteristics.
Tube 3 12AU7 The 12AU7 will glow brightly when the unit is
first turned on.