JCM250 Compact Monoblock
Compact Power with Deep Musicality
The JCM250 is a high-performance monoblock amplifier designed for listeners who want serious power without excessive size. Whether you’re driving demanding full-range speakers or crafting a powerful home theater front-end, it delivers authority and finesse—even when the music gets intense.
Designed by John Curl, the JCM250 runs high‑bias Class A/AB with up to 8 W in pure Class A (High Bias; 4 W in Low Bias) and delivers 250 W into 8 Ω, 450 W into 4 Ω, and 800 W into 2 Ω with 100 A peak current. The circuit is direct‑coupled (no capacitors in the audio path) with a JFET input stage and MOSFET driver stage, plus XLR/RCA inputs and loop‑outs for effortless bi‑amping. Integration is simple with 29 dB / 23 dB gain options, 12 V trigger or audio‑sense auto‑on, and a 2U chassis that’s easy to rack. Parasound also equips the input stage with Bybee Music Rails™ high‑frequency filters.
What reviewers say
Power Output
- 250 watts@8 Ω
- 450 watts@4 Ω
- 800 watts @2 Ω
- Power measurements are with 120 VAC: 0.15% THD, RMS continuous power, full audio band (20 Hz - 20 kHz)
Class A Power Output
- 8 Watts, bias set to high
- 4 Watts, bias set to low
Current Capacity 100 amps, peak
Slew Rate > 130 volts per microsecond
Frequency Response
- 2 Hz - 110 kHz, +0/-2 dB
- 20 Hz - 20 kHz, +0/-0.25 dB
Total Harmonic Distortion (THD)
- < 0.15 % at full power
- < 0.02 % at typical listening levels
IM Distortion < 0.03 %
TIM Unmeasurable
Input Impedance
- Unbalanced: 50 kΩ
- Balanced: 100 kΩ, (50 kΩ per leg)
S/N Ratio,inputs shorted
- >120 dB, IHF A-weighted, bias set to Low
- >118 dB, IHF A-weighted, bias set to High
- >110 dB, Unweighted, bias set to Low
- >108 dB, Unweighted, bias set to High
Total Gain
- 29 dB (Gain switch set to normal)
- 23 dB (Gain switch set to low)
Input Sensitivity for 28.28 V into 8Ω (Gain switch set to normal)
- Unbalanced: 1V
- Balanced: 1V per leg
DC Trigger Requirements +9 Vdc to +12 Vdc, 5 mA
Audio Trigger Requirement 2.5 mV - 10 mV
XLR Pin Identification
- 1 = Ground (Shield)
- 2 = Positive
- 3 = Negative (Return)
Dimensions
- Width: 17.25" (437 mm)
- Height without feet: 3.5" (89 mm), 2U
- Height with feet: 4.125" (105 mm)
- Depth: 20" (508 mm)
- Depth with cables: 21.5" (546 mm)
Net Weight 42 lbs (19.1 kg)
ShippingWeight 50 lbs (22.6 kg)
PowerRequirement
- Standby:<1 Watt
- Idle (bias set to low): 125 Watts
- Idle (bias set to high): 240 Watts
- Typical Listening levels: 300 Watts
- Maximum: 800 Watts
- Circuitry designed by legendary John Curl
- Ultra-high bias Class A/AB operation
- Stable with speaker impedance dips below 1Ω
- Bybee Music Rails™ - active high frequency filters for input stage
- John Curl driver stage employs a cascode circuit for greater open loop bandwidth & superior linearity
- Gain switch to select 29 dB or 23 dB gain for optimum compatibility with high gain preamps or extremely efficient speakers
- CHK Infinium, custom 5-way speaker binding posts for easy bi-wiring
- Neutrik locking XLR balanced input & loop output jacks
- Vampire 24k gold-plated RCA input & loop output jacks
- Direct-coupled signal path, no capacitors or inductors in the audio path
- JFET input stage, MOSFET driver stage
- 16 beta-matched 15 ampere, 230V, 60 MHz bipolar output transistors
- Independent power supplies for input stage & driver stage
- Full power is rated all the way down to 2Hz for unrestricted low-end bass
- Harris hyper-fast soft-recovery bridge diode rectifiers
- REL & Nichicon Muse capacitors
- DC servo & relay protection circuits
- AC turn-on inrush surge protection with relay bypass
- Automatic turn-on by 12 V trigger or audio sensing
- 2 rack space chassis with rear carry handles
- Available in black