KSR Ceres - User Manual

Ceres 3-ch Preamp Instruction Manual
March 2019, Rev A. – Kyle Rhodes
Initial Setup Quick-Start
Power / Connections
1. Connect a suitable DC power adapter – center negative, 9V, and capable of at least 200 mA (0.2A) of
current. This jack is between the input and output jacks.
2. Connect your guitar to the input jack (right jack when looking down at the face of the pedal).
3. Connect a power amp to the output jack. Alternatively, connect to an audio interface, cabinet
simulation box, etc.
Controls
4. Set all knobs to 12:00 (noon, straight up), except the Level controls, keep at minimum for now.
5. On Rhythm channel (middle row of knobs), set Bright Up, Fat Down, Mode Up.
6. On Lead channel (bottom row of knobs), set Bright Up, Fat Up, Mode Down.
7. Set Bypass Mode (switch in upper left corner) to Clean (Up).
Buttons
8. After the power-on sequence, the KSR logo should be glowing green (Clean channel active).
9. The Bypass (left) button will toggle the pedal between Clean and distortion.
10. The Rhythm/Lead (right) button will toggle between the Rhythm (blue KSR) and Lead (white KSR)
channels.
11. Note – hold the Left button for a few seconds to mute. This is useful for tuning and changing guitars.
Play
12. Slowly bring up the Level controls until you’re happy with the volume. Depending on the power amp
sensitivity these controls can yield a high volume even with low settings, so use caution for your
hearing’s sake. Feel free to tweak the controls, and see the Control Description below for more
details.
Control Description
Overview
Both distortion channels have the same switches and controls, and work in the same manner. However,
Rhythm is inherently tighter and more aggressive than the Lead channel. Lead is more compressed and
smoother and fatter overall.
The Clean channel is not designed to get the “pushed” sound with the Level increased. It is designed to stay
clean. If you notice any distortion on this channel it will likely be unpleasant, and it is best to lower the Level
control. Note that due to the design of the audio circuit, clipping this channel can also adversely affect the
Rhythm and Lead channels.

Summary

Initial Setup Quick-Start

Power and Connections

Connect power adapter, guitar to input, and output to power amp or interface.

Initial Control Settings

Set knobs to 12:00, specific Rhythm/Lead channel settings, and Bypass to Clean.

Play and Button Functions

Power-on sequence, bypass/channel toggling, and mute function.

Control Description and Overview

Switches and Their Functions

Bypass Mode Selection

Selects True Bypass, Buffered Bypass, or Clean Bypass for signal routing.

Knob Controls

Knob Overview and Gain

Description of Gain, Bass, Middle, Treble knobs for distortion channels.

Overview

1. Function Description
2. Important Technical Specifications
3. Usage Features
4. Maintenance Features

The KSR Ceres 3-ch Preamp is a versatile guitar pedal designed to provide a range of clean and distortion tones, functioning as a preamp, a distortion pedal, or a buffered bypass unit. It features three distinct channels: Clean, Rhythm, and Lead, each with its own set of controls and characteristics.

Function Description

The Ceres preamp offers a comprehensive solution for guitarists seeking diverse tonal options. It can be used to drive a power amp directly, connect to an audio interface, or integrate into a pedalboard setup.

• Clean Channel: This channel is designed to remain pristine and uncolored, providing a clean foundation for your sound. It features a single Tone knob, which acts as a variable frequency notch filter, and a Level control for volume adjustment. Unlike the distortion channels, the Clean channel is not intended to produce a "pushed" or overdriven sound.
• Rhythm Channel: Characterized as tighter and more aggressive, the Rhythm channel is ideal for powerful riffs and articulate playing. It offers extensive tonal shaping with Gain, Bass, Middle, Treble, and Level controls, along with Bright, Feel, and Mode switches.
• Lead Channel: This channel is designed to be more compressed, smoother, and fatter overall, making it suitable for solos and sustained notes. It shares the same comprehensive set of controls as the Rhythm channel: Gain, Bass, Middle, Treble, and Level knobs, and Bright, Feel, and Mode switches.

Important Technical Specifications

• Power Input: 9Vdc @ 200 mA max. The pedal uses a center-negative 2mm pin, 6mm barrel style connector. It's crucial not to exceed ~9.7V, as this will trigger a shutdown to prevent internal circuitry damage.
• Input Impedance: 1MΩ
• Output Impedance: ~25KΩ
• External Control Input: 1/8" (3.5mm) TRS (tip/ring/sleeve) jack. This input is designed for dry (relay) contact only, allowing for remote channel switching and bypass control.
• Toggle Switches: 7 total (5x 3-way and 2x 2-way)
• Potentiometers: 12 total (Gain/Bass/Middle/Treble/Level for Rhythm/Lead channels, plus Clean Tone/Level)
• Buttons: 2 total (Bypass (left) and Rhythm/Lead (right))
• Indicator Lights: KSR logo backlit via 2x RGB LEDs, providing visual feedback on the pedal's status.
• Dimensions Overall: 5.75" wide x 4.75" deep x 2.375" tall (146 mm x 121 mm x 60mm)
• Weight: 1.3 lbs. (0.59 kg)

Usage Features

The Ceres preamp is designed for intuitive operation with a range of features that enhance its usability and versatility.

• Bypass Modes: The upper-left 3-way switch allows selection of three bypass modes:
  • True Bypass (Center): The signal passes directly through the pedal from input to output without any buffering. The KSR logo is unlit in this mode. Ideal for use with loop switchers or pedalboards that handle buffering.
  • Buffered Bypass (Down): The signal runs through the pedal's buffer without altering the tone. The KSR logo lights yellow. Useful for driving other pedals on a pedalboard into a clean amp.
  • Clean Bypass (Up): This mode enables the top row Tone and Level knobs, allowing the Clean channel to be used to drive a power amp directly. The KSR logo lights green.
• Bright Switch: A 2-position switch (Up for on, Down for off) that adds brightness to the tone, similar to a bright switch on an amplifier. Its effect is more pronounced at lower Gain settings.
• Feel Switch: A 3-position switch that primarily adjusts the low-end response of the selected channel.
  • Center: Provides the tightest low-end.
  • Up: Adds more low-end and punch.
  • Down: Delivers the most thump and bass/low-mid presence.
• Mode Switch: A 3-position switch that alters the overall gain style of the channel.
  • Up (Crunch): Similar to KSR's Ares/Orthos Crunch 3-gain stage tone.
  • Down (Lead): Similar to KSR's Colossus Lead channel 4-gain stage tone, also found in Orthos and Ares Lead.
  • Center: Adds even more gain, akin to KSR's 5-gain stage Artemis purple/red modes. The Mode switch also influences overall brightness and aggression, with Mode Up (Crunch) being smoother and "rounder" at high gain compared to Mode Down (normal Lead).
• EQ Controls (Bass / Middle / Treble): These controls function like a tube amp's EQ, interacting with each other to shape the tone. Experimentation with various settings is encouraged to discover the full range of sounds.
• Gain Control: Offers a wide usable range, maintaining clarity even when cranked without becoming "mushy" or "flubby."
• Level Control: Each channel has its own Level control to adjust its volume. This allows for balancing volumes between channels or creating solo boosts. Caution is advised when adjusting, as high volumes can be achieved even at low settings, depending on the power amp sensitivity.
• Bypass Button (Left Footswitch): Toggles the pedal between Clean and distortion. Holding this button for a few seconds mutes the pedal, indicated by a blinking logo, useful for tuning or changing guitars.
• Rhythm/Lead Button (Right Footswitch): Toggles between the Rhythm (blue KSR logo) and Lead (white KSR logo) distortion channels. If pressed while bypassed, the logo will blink the color of the selected channel, but the channel won't change until the Bypass button is pressed again.
• Lit Logo: The KSR logo provides visual feedback through various colors and blinking patterns:
  • Off: True-bypass
  • Yellow: Buffered bypass
  • Green: Clean channel
  • Blue: Rhythm channel
  • White: Lead channel
  • Red (blinking X times): Indicates firmware version upon power-up.
  • Purple (flashing): Muted in true-bypass mode, otherwise flashes in the color of the current channel/mode.
• External Control Input: Allows remote control of channel switching and bypass via a control-closure output (e.g., from a loop switcher or effects processor). Connecting Tip to Sleeve activates distortion channels, and Ring to Sleeve activates the Lead channel. These require latching-style relay control. Pedal button presses override external control, but external control takes over again when its state changes.

Maintenance Features

The Ceres preamp includes internal jumpers for advanced customization and offers guidance for safe handling.

• Internal Jumpers: By removing the back cover, users can access internal jumper settings.
  • Logo Brightness: Two settings are available (Normal by default, Bright for outdoor use). The Bright setting consumes more power but remains within the 200 mA max.
  • Ultra-Tight Mode: Two jumpers allow setting the Rhythm and/or Lead channel to Ultra-Tight mode. This is useful for power amps with inherent bass boost, preventing a "boomy" sound. The pedal ships with these jumpers open, enhancing bass output. To enable Ultra-Tight, short the two top pins for the Rhythm channel and the two bottom pins for the Lead channel.
• Static Electricity Precaution: When accessing internal electronics, users are advised to exercise caution, as static electricity can damage sensitive components. Discharging oneself by touching something grounded first is recommended.

KSR Ceres Specifications

General

Brand	KSR
Model	Ceres
Category	Amplifier
Language	English