Quicksilver KT Series User manual

Quicksilver Audio KT Mono Amplifier
Operating Instructions
Thank you for purchasing the Quicksilver Audio KT Mono Amplifiers.
These amplifiers have been engineered to have a very wide band width, extremely low distortion,
and superior dynamic range.
The output transformer used in this amplifier is based on the best designs of the past but uses
superior new materials to achieve a very high level of performance. The high frequency
characteristics of this transformer are very stable. Any KT series output tubes may be used
without the need for circuit changes or compensation adjustments.
This is an all-tube design and used no circuit boards or transistors.
PLACEMENT
The KT Mono Amplifiers should have at least 6 inches of ventilation space on either side and at
least 6 inches oabove them. If this is not possible, then use a fan for colling.
SPEAKER CONNECTION
Five-way binding posts are used for speaker connection. For a better sonic performance, we
recommend using the screw-down part of the post rather than banana plugs to connect your
speaker wire. Make sure the ends of the speaker leads do not touch each other. The rating on the
back of your speaker system will determine whether you use the 4 or 8 ohm tap for the positive
lead. Connect the negative or ground to the black post.
There is a diagram on the bottom of the amp that identifies the three posts labeled 4 ohm, C, 8
ohm:
Use the 4 ohm tap for speakers from 4 to 8 ohms impedance or the 8 ohm tap for speakers from 8
to 16 ohms.
4 AMP SLO-BLO FUSE
Standard fuse value must not be exceeded. If a fuse blows, replace and check out tube bias. If
there is a large change, then an output tube is probably damaged. If the bias has not changed,
then the cause of the fuse blowing may be due to other problems, such as poor system grounding,
unstable preamp, shorted speaker, etc. Interchanging the amps between channels will help
localize the problem to either the system or the amplifier.
TUBES
The input tubes in this amplifier were chosen for their specific performance characteristics.
These tubes should last between one and two thousand hours. We can only guarantee the
performance of this unit when used with input tubes supplied by Quicksilver Audio.
4 C 8
Input
100K

Quicksilver ships the KT Mono Amplifiers with matched KT88 tubes but any KT series output
tubes can be used. The output tubes should be matched.
Output tubes will need to be replaced periodically. When a degradation in sound occurs, the fuse
blows repeatedly, or the tubes will not hold their bias anymore, it is time for new output tubes.
We recommend purchasing tubes from Quicksilver Audio or your dealer and we recommend
keeping extra fuses and an extra output tube on hand.
OUTPUT TUBE BIAS SETTING
Output tube bias should be set immediately when new tubes are put in; then again in 15 minutes;
and periodically the first few times of using the amplifiers. After that the bias should be checked
monthly.
The bias control is located between the output tubes near the power transformer.
To adjust the bias you will a slot-head screwdriver and a multimeter that reads millivolts. Adjust
by turning clockwise to increase bias; counterclockwise to decrease bias.
Set the meter to read millivolts (not milliamperes.) Insert the black and red probes from your
meter into black and red pin jacks on the amp. The millivolt reading on the meter is actually the
bias current in ma through the output tubes. Efficient speakers will sound better with lower bias
(60ma) and inefficient speakers may require higher bias (80ma.) Bias should not be set higher
than 100ma.
If the bias cannot be set low enough, then an output tube may be shorted and the amplifier should
be turned off immediately. If the bias cannot be set high enough, then one output tube may be
dead. In either case, the output tubes need replacing. Replace the output tubes as matched pairs—
matched pairs will sound better and last longer.
KT Mono Amplifier
Fuse
4 amp
slo-blo
4 ohm
Ground
8 ohm
12AX7 12BH7

KT Mono Amplifier Specifications
Power Output 80 watts into 4 or 8 ohms
Power Bandwidth 14 Hz to 70 KHz
Damping Factor 20
Input Sensitivity 1.2 volts
Inout Impedance 100 K ohms
Power Consumption 105 watts at idle
250 watts at full power
Tube Complement 1 -12AX7 input
1 -12BH7 driver
2 -KT77, KT88, KT90, KT120 or KT150 outputs
Dimensions 5 ½” high x 14 ½” deep x 9 1/8”wide
Finish Black chassis
Chrome transformer covers
Weight 38 lbs, 44 lbs shipping
Warranty 3 years parts and labor
90 days tubes
POWER SUPPLY
CAPACITOR
INPUT TUBE
12AX7
DRIVER TUBE
12BH7
OUTPUT TUBES
INSERT METER PROBES
TO CHECK BIAS
OUTPUT
TRANSFORMER
POWER
TRANSFORMER
INPUT
CONNECTOR
100k
SPEAKER
TERMINALS
POWER
CORD
4 AMP
FUSE
POWER
SWITCH
Push in at
top to
turn on
8
C
4
Quicksilver Audio KT Mono Amplifier
Bottom View

WARRANTY
Quicksilver Audio warranties your amplifiers for a period of 3 years from the date of purchase
(90 days on tubes.) Parts and labor are provided free of charge as long as the failure was not
caused by misuse, accident or negligence. Shipping to the factory is not included.
Retain at least one packing carton in case a unit needs to be returned for service.
Quicksilver Audio
7475 Murray Drive., Suite 17
Stockton, CA 95210
[phone]/fax [phone]
[email protected]
www.quicksilveraudio.com