The Classictone II "Half Stack": Maximum Headroom, Unmatched Depth

The Muscle: Koch KSC 212 OB 180 Cabinet
Koch AmpsTo properly broadcast 40 watts of pure boutique tube power, you need an enclosure that can breathe. The KSC 212 OB 180 is a professional-grade 2x12 cabinet meticulously voiced to bring out the absolute best in your amplifier.

  • The Open-Back Advantage: The "OB" stands for its open-back architecture, featuring specially tuned oval ports.This design allows sound to project beautifully from both the front and the rear of the cabinet, creating a highly dimensional, airy, and beautifully balanced room sound that avoids any boxy mid-range frequencies.

  • Premium Koch Construction: Built to withstand the rigors of the road, the shell is crafted from 18 mm, 13-ply Baltic Birch plywood utilizing heavy-duty, glued wood-to-wood dado joints. This rigid frame is paired with a single-piece baffle, creating a resonant structure that eliminates unwanted vibrations while tightening low-end response.

  • The Power of VG90 Speakers: This cabinet is loaded with two custom-designed 12″ Koch VG12-90 speakers, pushing a massive 180 watts of power handling. Known for their incredible headroom, smooth highs, and colorful mids, these high-performance speakers translate the complex upper-harmonics of the Classictone II Forty perfectly without breaking up prematurely.
Boutique tone, amplified to its absolute fullest potential.
If you are looking to dominate the stage or capture massive, three-dimensional tones in the studio, the Koch Classictone II Half Stack is the ultimate answer. This uncompromising combination anchors the most powerful head in the lineup—the Classictone II Forty—directly to the meticulously engineered KSC 212 OB 180 Cabinet. It is a tour-ready powerhouse that couples classic British tube crunch with an extraordinarily wide, airy acoustic footprint.

The Engine: Classictone II Forty Head
Koch AmpsAt the heart of this half stack is the 40-watt Classictone II Forty Head. Fueled by a robust EL84 power section, this head provides significantly more clean headroom and dynamic punch than its 20-watt sibling, making it the perfect choice for gigging guitarists who need their clean tones to stay pristine at high volumes. When pushed, it delivers that legendary, bell-like chime and a rich, singing overdrive heavily compressed with organic harmonic warmth.
Equipped with Koch’s innovative 3-way Level Switch (Home, Studio, Stage), you can seamlessly drop the output level to get that sweet, fully saturated power-amp tube saturation at any volume without sacrificing tone. It also includes a built-in dummy load and frequency-corrected recording outputs (XLR and Jack) for hassle-free direct tracking or running straight to the FOH desk.

Take A CLOSER LOOK

CL II / Forty Head

The brain of the operation is a pure, EL84-driven all-tube head that captures the legendary warmth, chime, and singing overdrive of vintage tube amplification

Balanced XLR output

The balanced XLR voiced output of the Classictone II delivers an incredibly authentic, speaker-emulated DI sound straight to the desk. It requires little to no tweaking at the mixer, offering a reliable, high-quality signal that both players and FOH engineers will love working with.

KSC212 OB BR120

The Koch KSC212 OB is a high-performance 2x12 cabinet designed to deliver exceptional sound for a wide range of applications. Its open-back design with oval ports provides optimized tuning for a rich and balanced tone.

SPECIFICATIONS:

Amp configuration 

  • All-tube “Class A” amplifier
  • 4x EL84 Power-tubes (II / Forty)
  • 3 x 12AX7 pre-amp tubes

The TONE

  1. 3 channels (Clean, Overdrive & Overdrive Boost) foot switchable
  • One set of passive bass-mid-treble tone controls

HARDWARE & HANDLING

​Two button footswitch (included)
  • Channel select
  • Gain Boost or Reverb on/off
  • (Selectable on back panel)​

Connectivity and OUTPUT

KSC212 OB BR 180 Cabinet
  • 4, 8, & 16 Ohm speaker outputs plus speaker on/off switch
  • Serial effects loop (10 dBV signal level)
  • Balanced Recording output with speaker simulation
  • Long scale spring reverb tank
  • Three master volume settings:
    Home/Studio/Stage

COMBO DIMENSIONS & Weight

  • 52,5(w) x 31(h) x 26,5(d) cm
  • Weight 14.5 kg
  • 18 mm, 13 ply baltic birch plywood
  • All glued woo-to-wood dado joints
  • 2×12 cabinets, one piece baffle
  • 2x Koch VG12-90 speakers​
  • Heavy Duty corners and handles
  • Koch custom Green vinyl
  • Internal wiring: Koch Dynacon speaker cable
  • Comes with 5ft/1,5m Koch Dynacon speaker cable
  • Powerhandling: 1 x 120W RMS or 2 x 60W RM

Cabinet Dimensions & Weight

  • L 76 x W 36 x H 69 d (cm)
  • Weight: 29 kg