Description
Key Features
- Genuine pure Class A operation throughout — the output stage is biased to remain in Class A at all power levels, a design approach that demands significantly higher idle power consumption but is associated with a smooth, low-distortion character that Class AB designs do not replicate
- Dual mono internal configuration — left and right channel amplifier modules are completely independent, sharing only the mains wiring. Each channel has its own transformer, diode bridges, and filter capacitors
- Power output doubles with each halving of load impedance from 8Ω down to 1Ω — an indication of the amplifier’s substantial current delivery capability and its ability to drive loudspeakers with low or difficult impedance characteristics
- Active cooling via fan — the MK2 revision positioned the fans beneath the heatsinks, drawing air upwards in line with natural convection. Owners should be aware that the cooling fans on amplifiers of this age may require attention or replacement as part of routine maintenance
- Brushed metal casework with integrated side carry handles and gold hardware — a distinctive and purposeful appearance that reflects the amplifier’s engineering priorities
- Single-ended RCA inputs; loudspeaker binding posts with banana plug and spade lug compatibility
- Bias correctly set and verified by Andrew prior to listing — an important distinction, as the correct quiescent current setting is critical to maintaining the amplifier’s full 100 watt Class A output capability
- A significant and historically important American power amplifier with a strong following among serious analogue listeners
Important Owner’s Note: The Krell KSA100 MK2 is a genuine Class A amplifier with a continuous idle power consumption of approximately 610 watts. It generates considerable heat and must not be installed inside a cabinet or in a position where airflow is restricted. The cooling fans should be monitored for correct operation and serviced periodically.
Technical Specifications (Source: Audio Database — KSA 100 MK2 specifications)
- Type: Stereo Class A power amplifier (dual mono configuration)
- Power Output: 100W + 100W into 8Ω (both channels, 20Hz–20kHz)
- Power Output: 200W + 200W into 4Ω
- Power Output: 400W + 400W into 2Ω
- Power Output: 800W + 800W into 1Ω
- Total Harmonic Distortion: 0.05% or less (20Hz–20kHz, 1W to rated output)
- Frequency Response: 0.5Hz–100kHz (-3dB); 20Hz–20kHz (-0.5dB)
- Signal to Noise Ratio: 110dB (IHF-A weighted)
- Input Sensitivity / Impedance: 1V / 22kΩ
- Damping Factor: 120 (at 1kHz)
- Slew Rate: 80V/μs
- Minimum Load Impedance: 1Ω
- Power Consumption: Approximately 610W (maximum idle — continuous)
- Mains Voltage: 220V / 50Hz (as confirmed on rear panel of this unit)
- Dimensions (W x H x D): 483 x 226 x 612mm
- Weight: Approximately 35kg
- Country of Origin: USA (Krell Industries, Milford, Connecticut)
- Year of Production: 1985 (MK2 version)
- Serial Number: 2277
Why Buy From Us
With over 40 years of experience in the Hi-Fi industry, we are well placed to assess and test equipment of this nature. Every item we list is fully inspected and tested before sale — this unit was checked by Andrew in our workshop, with the bias correctly set and verified prior to listing.
When you buy from us you can expect:
- Full inspection and testing prior to listing — not simply a visual check
- Bias set and verified to manufacturer specification before despatch
- A 3-month guarantee on every item we sell
- Transparent descriptions with no omissions
- Professional packaging to ensure safe delivery — given the weight of this unit, specialist packing arrangements will apply
- After-sales support available by phone or email should you have any questions
Summary
The Krell KSA100 MK2 is a significant and historically important American Class A power amplifier with a well-established reputation among serious Hi-Fi enthusiasts. This example is in good working condition, with the bias correctly set and verified prior to listing — an important consideration when purchasing an amplifier of this type. Prospective buyers should note the substantial weight of approximately 35kg and the continuous high idle power consumption inherent to pure Class A operation. This is a single-unit listing. Please feel free to get in touch with any questions prior to purchase.
