Bandwidth Audio Kaskode One User manual
Kaskode One Rev 1.1 2
WARNING
Configuration of the Kaskode One will require removing the
cover of the unit. Before removing the cover for any reason,
make sure to power off the unit and unplug from mains wall
outlet.
Wait a minimum of 60 seconds for all voltage to dissipate before
opening the cover.
FAILURE TO READ OWNER’S MANUAL BEFORE FIRST USE CAN
VOID YOUR WARRANTY
Kaskode One Rev 1.1 3
CONTAINS LETHAL VOLTAGES
High voltage can be lethal. Do not remove cover while preamplifier is connected to the
Mains power source. For service, contact Bandwidth Audio.
HIGH VACUUM TUBE TEMPERATURES
Vacuum tubes can get extremely hot with bulb temperatures capable of reaching 200ºC. Do
not touch or attempt to remove the tubes while they are hot.
DO NOT ENCLOSE
This preamplifier will get warm from use. Make sure to place the equipment in a non-
enclosed area with good ventilation and air flow.
Kaskode One Rev 1.1 4
Table of Contents
1.0 Kaskode Connections and Setup .................................................................6
1.1 Phono Preamplifier Placement ........................................................................................................... 6
1.2 Mains AC Grounding ............................................................................................................................... 7
1.3 Powering ON & OFF................................................................................................................................ 7
1.4 Installing Optional (MC) Moving Coil Module........................................................................... 8
1.5 Moving Coil Input Connections......................................................................................................... 9
1.5.1 Balanced / Unbalanced Input................................................................................................ 9
1.6 Moving Magnet Input Connections.............................................................................................. 10
1.7 Kaskode One Input Wiring Diagram............................................................................................ 10
1.8 Tonearm and Turntable Wiring....................................................................................................... 11
1.8.1 RCA Connection......................................................................................................................... 11
1.8.2 XLR Connection (MC Only) .................................................................................................. 12
1.9 Subsonic Filter.............................................................................................................................................. 14
2.0 Cartridge Loading........................................................................................ 15
2.1 MM Cartridge Loading Options ..................................................................................................... 15
2.1.1 MM Input Resistance .............................................................................................................. 15
2.1.2 MM Input Capacitance........................................................................................................... 15
2.2 MC Cartridge Loading Options....................................................................................................... 19
2.2.1 MC Input Resistance................................................................................................................ 19
2.2.2 Selecting the MC Step-up Ratio ....................................................................................... 22
2.2.3 Selecting the Rsl value for Cartridge Loading........................................................... 25
3.0 Controls and Layout.................................................................................... 27
3.1 Front Features .......................................................................................................................................... 27
3.2 Back Features............................................................................................................................................ 28
4.0 Typical Specifications.................................................................................. 30
5.0 Notes:............................................................................................................. 32
Kaskode One Rev 1.1 5
List of Figures
Figure 1: white markers indicate correct MC orientation................................................................................... 8
Figure 2: Input Wiring Diagram ................................................................................................................................. 10
Figure 3: Turntable Wiring for RCA Input.............................................................................................................. 11
Figure 4: XLR Pinout (Front View)............................................................................................................................ 12
Figure 5: Turntable Wiring for XLR Option 1........................................................................................................ 13
Figure 6: Turntable Wiring for XLR Option 2........................................................................................................ 13
Figure 7: Location of J3/J4 subsonic filter jumpers............................................................................................ 14
Figure 8: MM frequency response with input capacitances............................................................................ 15
Figure 9: Location of S2 and S5 switches for setting the input capacitance ............................................. 16
Figure 10: S2/S5 setting for 150pF........................................................................................................................... 17
Figure 11: Input Network for MC Input................................................................................................................... 19
Figure 12: Location of Step-up ratio switches ...................................................................................................... 23
Figure 13: Location of Rsl selection switches S1 and S4 .................................................................................. 25
Figure 14: S1/S4 Rsl setting for 10000Ω ................................................................................................................ 26
Kaskode One Rev 1.1 6
1.0 Kaskode Connections and Setup
From the factory, the Kaskode One is configured as follows
•Subsonic filter is active
•MC Step up module (if installed) is configured for unbalance operation
•MC Step up module (if installed) ratio is set 1:10
•Input capacitance is set to 150pF
•Rsl Cartridge loading is set to 10KΩ= MC input resistance of 100Ω
Pre-Operation Checklist
•Before first use check that the Kascode One is configured correctly for your phono cartridge.
oTo set the input loading for MM cartridge, see 2.1
oTo set the input loading and step up ratio for MC cartridge, see 0
•If using MC, check input connection type (Balanced or Unbalance) to match your setup,
see 1.5
•If using MM, check input connection, see 1.5.11.6
•For turntable and tonearm wiring best practices, see 1.8
•Set Subsonic filter to your preference, see 1.9
1.1 Phono Preamplifier Placement
For best operation and longest life of components, the preamplifier should be set up and used in a
well-ventilated area with good air circulation. Do not use the amplifier in enclosed furniture as
overheating can damage the amplifier, diminish tube life and cause risk of fire.
Due to the extremely high gain, phono preamplifiers are extremely sensitive to vibration. It is
always recommended to place the phono preamplifier on a sturdy substantial shelf to help
minimize vibrations coupled in from the floor.
Radiating electromagnetic noise (EMI) from sources such as large transformers, cellphones and Wi-
Fi routers can also cause audible noise from the speakers if this equipment if placed too close to
phono circuitry. It is best to have this equipment located far away.
Kaskode One Rev 1.1 7
1.2 Mains AC Grounding
Always share the same AC mains ground circuit with all other audio equipment.
For lowest noise, it is always recommended to share the same AC mains ground circuit between all
audio equipment in a system. The easiest and best way to achieve this is to share a common wall
and use a quality power strip to power all pieces of equipment. This is most desirable to insure the
ground reference of all audio equipment is at the same potential.
Ground is used as a safety voltage reference and should not have any current flowing. However, It
is likely that any 2 ground circuits in buildings wiring will have a small voltage differential across
them. If these grounds are shared by audio equipment, a ground loop is formed and the small
voltage differential can now drive a current through the audio ground, causing noise.
Faulty equipment on the AC line can also be a source of ground noise.
1.3 Powering ON & OFF
The Kaskode One is designed with a time delay start sequence to insure all operating voltages are
stabilized and the preamplifier is ready to play audio before the output is active. This removes the
chance of any pop and noise during power on and off. The Kaskode One can be turned on and off
without any need for power sequencing with other equipment. The “Active” indicator on the front
panel shows the status of the power on sequence. The preamp output will be active approximately
60 seconds after power on.
The power on sequences is as follows:
The Kaskode One “Power” indicator will illuminate. The “Mode” and “Mute” settings will also
illuminate with their status. After a delay of approximately 60 seconds, the “Active” inductor
will illuminate indicating that the phono preamp is ready for use and music can be played.
Kaskode One Rev 1.1 8
1.4 Installing Optional (MC) Moving Coil Module
The Kaskode One features optional plug in transformer modules to also support MC type
cartridges. If your preamp was ordered with the MC option, these transformers have already been
installed at the factory.
To install the MC modules:
Align the MC modules so that the white orientation markers are aligned on both the main preamp
PCB and the PCB of the module.
After the correct orientation has been found, carefully plug the modules into the female header pin
sockets on the main PCB. Be careful not to misalign the pins. Press gently until the MC module is
fully seated.
Figure 1: white markers indicate correct MC orientation
Kaskode One Rev 1.1 9
1.5 Moving Coil Input Connections
For MC input mode, additional gain is provided by optional step-up transformers. With the step-up
module installed, the either the RCA or XLR inputs labeled “MC” on the back of the unit can be
used, provided the input “Mode” switch on the front is set to “Moving Coil”. If no MC module is
present, the MC inputs cannot be used.
1.5.1 Balanced / Unbalanced Input
Jumper J3, located on the optional MC module, is used to select between balanced or unbalanced
input. Balanced input is achieved with jumper J3 removed by isolating the primary and secondary
ground of the MC transformer. In balanced operation, the MC transformer will provide a high
degree of common mode rejection, helping to remove noise picked up in the cabling between the
preamplifier and turntable. Always disconnect the power cord before making any adjustments to
the phono preamp. (See Figure 2: Input Wiring Diagram)
In balanced input mode, either the RCA or XLR input can be used, however, the XLR input is
recommended. When using a high quality 3-conductor XLR cable, the positive (+) and negative (-)
signals are a twisted wire pair covered by a metal shield. The +/- pair connects to the MC
transformer and the shield is connected to the preamp chassis. Not only does the shield provide
hum rejection but the +/- twisted wire pair is naturally balanced such that any noise that
penetrates the shield, is removed by the common mode rejection of the MC transformer.
In contrast, an RCA cable is a 2-conductor unbalanced cable. The positive (+) signal flows through
the center of the negative (-) shield. Therefore, the geometry and surface area of the + and –
conductors are not identical and noise will not couple uniformly on both conductors. Therefore, the
transformer’s common mode rejection will not help remove noise.
•When using an RCA cable for the MC input, unbalanced connection is recommended.
•When using an XLR cable for the MC input, either unbalanced or balanced connection
can be used.
•Remember to set J3 on both MC module boards
Kaskode One Rev 1.1 10
1.6 Moving Magnet Input Connections
For MM input, the RCA connectors labeled “MM” on the back of the unit should be used. These
inputs bypass the MC step-up module as well as the resistive loading. Moving Magnet type
cartridges will require setting the capacitive loading.
1.7 Kaskode One Input Wiring Diagram
Figure 2: Input Wiring Diagram
Figure 2, above shows how the inputs for the MM and MC sections are wired. Notice that both the
MC RCA and MC XLR inputs can be wired as unbalanced or balanced by connecting or removing
jumper J3.
Kaskode One Rev 1.1 11
1.8 Tonearm and Turntable Wiring
It is critical that the turntable used with the phono preamplifier that has been properly wired to
insure lowest noise and best performance.
1.8.1 RCA Connection
When using RCA cables to connect the turntable to the Kaskode One, no part of the RCA
connector on the turntable should be connected to the plinth or tonearm. The RCA connector
should only connect to the cartridge. For most cartridges, a pair of RCA connectors is used for Left
(L) and Right (R) stereo channels. The Left and Right signals should also be completely independent
from each other with no shared connection.
With no cable connected to the turntable, use a multimeter set to measure resistance in Ohms (Ω)
to check the continuity between the grounds (outer shell) of the L/R channel RCA connectors. Next
check between the RCA connector and any metal on the turntable plinth or tonearm, repeat for the
other channel. In both cases, the meter should read an extremely high resistance (MΩ) indicating
no connection. If the meter does read a low resistance value, it is suggested to have your turntable
rewired for correct operation.
Note: The plinth and tonearm should be connected to the turntable’s external ground wire
which should also be connected to the “Ground” terminal of the Kaskode One.
Figure 3: Turntable Wiring for RCA Input
Kaskode One Rev 1.1 12
Figure 3: Turntable Wiring for RCA Input above shows the correct wiring for RCA connection to the
Kaskode One. Note that the RCA jacks are completely isolated from each other and from the
tonearm. In this case, the tone arm is connected to the Kaskode One ground connection through a
separate wire. The tonearm now acts as an electric shield around the wires that connect to the
cartridge. This ground may or may not also connect to the plinth of the turntable.
1.8.2 XLR Connection (MC Only)
When using 3-pin XLR cables to connect the turntable to the Kaskode One, the Positive (+) and
Negative (-) connections on the turntable XLR connector should be completely independent from
each other. Also, there should be no shared connection between Left and Right channels. XLR
cables also have an outer shield that is tied to earth ground.
Note: On the Kaskode One XLR input, Pin-1 is always tied to Earth ground. This will shield
the entire length of the cable to suppress noise.
Figure 4: XLR Pinout (Front View)
It is perfectly acceptable to have the Pin-1 shield also connected to the plinth or tonearm at the
turntable side of the cable. In this case, an external ground wire from the turntable plinth and
tonearm to the Kaskode One ground lug is not required.
However, if the Pin-1 shield is not connected to the plinth or tonearm, external ground wire is
required.
Kaskode One Rev 1.1 13
Figure 5: Turntable Wiring for XLR Option 1
Figure 5: Turntable Wiring for XLR Option 1 shows Option 1 of turntable wiring for XLR
input, in this case Pin-1 on the turntable XLR connector is not connected. The XLR cable is still
shielded through Pin-1 on the Kaskode One input XLR ground, so there is still hum rejection.
However, the plinth and tonearm are floating, so a wire to connect these parts to the Kaskode One
“Ground” terminal is required.
Figure 6: Turntable Wiring for XLR Option 2
Figure 6: shows a second option where pin-1 on the turntable XLR connector is connected to the
plinth and tonearm. Therefore, it is also connected to the Kaskode One ground through the shield
of the XLR cable. In this case, no external ground wire is required.
Kaskode One Rev 1.1 14
1.9 Subsonic Filter
The Kaskode One has a selectable subsonic filter to help remove any unwanted subsonic noise or
rumble due to warped records and other low frequency mechanical noise. This is in accordance
with the 1976 IEC Amendment for the RIAA equalization curve during playback. This is a 6dB slope
filter placed at 7950uS or approximately 20Hz.
It is generally a good idea to use this filter so that inaudible low frequency noise is not passed to
components downstream, consuming amplifier headroom and shifting the DC operating point of
both the electronics and the speakers.
The filter is selected by installing or removing jumpers J3 and J4 on the main PCB.
J3/J4 Installed = No Subsonic Filter
J3/J4 Removed = Subsonic Filter Active
The figure below shows the location of jumper J3 and J4. Note that the subsonic filter jumpers
are from the factory, enabling the filter.
Figure 7: Location of J3/J4 subsonic filter jumpers
Kaskode One Rev 1.1 15
2.0 Cartridge Loading
Cartridge loading is one of the most critical aspects to obtaining the best sound from your records.
A good loading will maximize the frequency response from your cartridge without any peaking at
high frequencies.
2.1 MM Cartridge Loading Options
2.1.1. MM Input Resistance
Moving magnet cartridge types are typically designed to operate into a 47KΩresistance. The
MM input of the Kaskode One has been set to 47KΩ.
2.1.2. MM Input Capacitance (S2/S5)
Input capacitance loading for MM cartridge types is extremely important for best performance. The
user will need to set the input capacitive loading for a Moving Magnet cartridge to optimize the
frequency response. It is recommended to start with your cartridge manufactures recommended
settings, then adjust as needed for best sound quality. If the input capacitance is too large, there is
severe peaking in the high frequency response. If the input capacitance is too low, high frequency
response is attenuated.
Figure 8: MM frequency response with input capacitances
Kaskode One Rev 1.1 16
Switches S2 and S5 are used to set the capacitive loading (S2 for the Right channel and S5 for the
Left channel) by moving the switch positions 1-4 indicated to the “ON” position.
Note: Orientation of S2 and S5 are rotated 180ºfrom each other. Be sure to set both S2
and S5 identically.
Figure 9: Location of S2 and S5 switches for setting the input capacitance
Kaskode One Rev 1.1 17
The desired input capacitance is enabled with each switch position. Combinations of capacitance
are also enabled by moving multiple switch positions to “ON”. The table below shows all 15 input
capacitance combinations available on the Kaskode One to dial the best performance with any
cartridge.
Table 1: Input Capacitance for each switch
Table 2: Input Capacitance Combinations
The figure below shows how switches S2/S5 should be set for 150pF of input capacitance.
S2/S5 Capacitance Loading Table
Position ON
Capacitance
1,2,3,4
425pF
1,2,3
375pF
1,2,4
350pF
1,3,4
325pF
1,2
300pF
1,3
275pF
1,4
250pF
2,3,4
225pF
1
200pF
2,3
175pF
2,4
150pF
3,4
125pF
2
100pF
3
75pF
4
50pF
S2/S5 Capacitance Loading Table
Position ON
Capacitance
1
200pF
2
100pF
3
75pF
4
50pF
1 2 3 4
ON
OFF
Figure 10: S2/S5 setting for 150pF
Kaskode One Rev 1.1 18
Total Input Capacitance:
Total input capacitance seen by the phono cartridge includes the set capacitance by S2/S5, any
cable capacitance between the turntable and phono preamp, and the native input capacitance (no
additional selected capacitance) of the phono preamp.
The native input capacitance of the Kaskode One is an extremely low 15pF. This allows the user to
better tune the capacitance for their desired cartridge. To keep tunability at a maximum, it is
suggested to use very low capacitance cables between the turntable and Kaskode One and use
S2/S5 switches to precisely set input capacitance.
Equation 1: Total input capacitance
Kaskode One Rev 1.1 19
2.2 MC Cartridge Loading Options
2.2.1. MC Input Resistance
For Moving Coil cartridges, the critical tuning parameter is the input resistance for loading the
cartridge. Since the Kaskode One uses a step-up transformer for MC cartridges, the loading is
dependent on the step-up ratio used. Based on the desired step-up ratio, the proper
Secondary Loading Resistance (Rsl) must be selected for the desired cartridge load.
From Figure 11 above, the load seen by the MC cartridges is the Rsl impedance, reflected from
secondary to the primary (input side) of the MC transformer. For the same Rsl value, the step-up
ratio will change the reflected impedance on the primary side of the transformer, and thus the MC
loading. Rsl is the parallel combination of the turning resistor R_tuning and the standard 47KΩ
resistance of the MM preamp input.
Figure 11: Input Network for MC Input
Kaskode One Rev 1.1 20
Table 3 below shows the cartridge loading input resistance for the available values of Rsl. The
different step-up ratios are also shown (1:5, 1:10 and 1:20).
1:5
1:10
1:20
S1/S4 Table for Desired Rsl
See Section 2.2.3
Secondary Loading Resistance (Rsl)
Ω
MC Cartridge Load Resistance (Zp) Ω
47000
1910
478
119
39000
1590
398
99
30000
1230
308
77
20000
830
208
52
15000
630
158
39
10000
430
108
27
5586
254
63
16
3170
157
39
10
1000
70
18
4
Rsl value of 3170Ωis not recommended for 1:20 step-up ratio. Rsl value of 1000Ωis not recommended for 1:10 and 1:20 step-up ratios.
These setting can be experimented with but may not achieve desirable results.
Table 3: Cartridge loading based on Rsl
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