Parasound JCM250 Monoblock Amplifier - Black - Each

Two Hundred and Fifty Watts, Two Rack Units Tall

The JCM250 is a monoblock: one chassis, one channel, one speaker. Each makes 250 watts into 8 ohms, 450 into 4 and 800 into 2 ohms. Those are continuous RMS figures across the full audio band, not a single-frequency headline.

The 2-ohm rating is the one that matters. Plenty of amplifiers quote a big 8-ohm number and then give up when a speaker's impedance drops. This one keeps doubling down, backed by 100 amps of peak current on tap.

It does that from a chassis only 3.5 inches tall. Parasound built the JCM250 to stack, so a pair occupies the height of one ordinary power amplifier while giving each channel its own case, its own supply and its own heatsinking.

Inside the Chassis

Class A Where You Listen

The JCM250 runs high bias, holding the first 8 watts in pure Class A with the bias switch set high, or 4 watts on low. Most domestic listening happens inside those first watts, so the amplifier spends much of its life in its cleanest operating region.

Speed and Bandwidth

Slew rate is better than 130 volts per microsecond and frequency response runs from 2Hz to 110kHz. An amplifier that wide is not straining anywhere inside the audible band, which is the point of measuring far beyond it.

Direct Coupled

There are no capacitors in the signal path. Direct coupling removes a component that colors whatever passes through it, and that absence is a large part of why the JCM250 stays this open at low listening levels.

Who Is This Mono Amplifier Best For?

• Owners of speakers with a difficult impedance curve — 800 watts into 2 ohms and 100 amps of peak current mean the amplifier keeps its grip exactly where lesser designs let go, so the speaker sounds the same at every frequency.
• Listeners who play at civilised volumes — The first 8 watts run in pure Class A on the high bias setting. That covers most real listening, so the quality you paid for is the quality you actually hear.
• Anyone tight on rack height — At 3.5 inches, two JCM250s stack into the space one conventional amplifier would need, so true monoblocks stop being a reason to buy more furniture.
• Systems built around balanced connections — Balanced XLR and unbalanced RCA inputs are both fitted, so you can site each amplifier beside its speaker and run a long balanced cable back without picking up hum.
• Each listing is a single amplifier — This page sells one JCM250, which drives one speaker, so a stereo system takes two. If you would rather have both channels in one box, our Stereo Amplifiers covers the Halo two-channel models.

How Does It Connect to Your System?

Run one interconnect from the left output of your preamp or processor to one amplifier, and the right output to the other. Choose XLR or RCA to match your preamp. Each amplifier then drives the speaker standing beside it through a single run of cable.

Set the bias switch to high if you want the larger Class A window and do not mind the extra heat, or set it low if the amplifiers live somewhere with limited ventilation. Either way the rated power is the same, and the preamp still sets the level.

Pairs Well With

A monoblock pair needs a preamp and two of most things. Here is the list.

• Preamplifiers — a stereo preamp or processor feeds one JCM250 per channel. Browse preamplifiers.
• Balanced interconnects — two XLR runs, one to each amplifier. Browse interconnect cables.
• Speaker cables — short runs, since each amp sits by its speaker. Browse speaker cables.
• Floorstanding speakers — the 2-ohm rating suits large, demanding designs. Browse floorstanding speakers.

Frequently Asked Questions

How much power does one make?

Each JCM250 delivers 250 watts into 8 ohms, 450 watts into 4 ohms and 800 watts into 2 ohms. Parasound measures those as continuous RMS power across 20Hz to 20kHz at 0.15% distortion, on a 120-volt supply.

What does the bias switch do?

It sets how much of the output runs in pure Class A. High bias gives you 8 watts of Class A and runs warmer; low bias gives 4 watts and runs cooler. Both settings deliver the same rated power.

Does it take balanced cables?

Yes. Balanced XLR and unbalanced RCA inputs are both fitted on every JCM250, so it partners with hi-fi preamps and home-theatre processors equally well.

How many do I need?

One per channel. A stereo system uses two, and a multichannel system uses one for each channel you want to drive at this level. Many owners start with the front two and add more later.

How big and heavy is it?

The chassis is 3.5 inches tall, which is two rack units, and weighs 42 pounds. The low height is deliberate so that a pair stacks neatly in a normal rack.

What warranty does it carry?

Parasound covers the JCM250 with a five-year parts and labor warranty for the original owner. Coverage is tied to that first purchase, so call us at 800-942-0220 before ordering a demo unit and we will tell you exactly what comes with it.

See It in Action

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Learn More

Want to learn more about mono amplifiers, Class A bias, or matching an amp to your speakers? Visit our Learning Center for guides, tips, and expert advice.