Hafler DH-200

Name: Hafler DH-200
Brand: Hafler

A black box with no meters, no level controls, and no apologies - the amplifier that made MOSFETs affordable.

Overview

The DH-200 is what you get when a legend sets out to design the simplest thing that works. It is rated at 100 watts continuous average power per channel into 8 ohms, 20 Hz to 20 kHz, both channels driven. It comes in a plain metal case with no output meters, no LED indicators, and no level controls. Modern Recording (December 1979, p.69) said this was a deliberate design goal - "a sort of 'no nonsense' approach to audio products" - and that the amplifier "looks like a 'black box.'" The same review said lab testing was mostly a matter of confirming Hafler's published specs.

This was the second product from the new Hafler company bearing David Hafler's own name, after the DH-101 preamp. High Fidelity (March 1980, p.44) described the DH-200 as differing from any other American amplifier in its use of power MOSFETs. That technology choice would define the Hafler power amp line for years afterward.

Into 4-ohm loads, the DH-200 is rated at 150 watts per channel. That makes it a fit for speakers that dip low. For 2-ohm loads the power rating climbs further, though Modern Recording (December 1979, p.68) noted that the 2-amp fuses should be swapped for 5-amp fuses (supplied with the amplifier) when driving severe low-impedance loads. The magazine tested this and confirmed it: the 2-amp fuses did pop under severe overloading into low-ohm loads. The amp tries to deliver more current than the stock fuse wants to pass, and Hafler supplied the parts to deal with it.

The standard transformer is for 120-volt, 60-Hz operation only. For $25 additional, Hafler offered a multitap power transformer for 100-120-volt and 200-240-volt, 50/60-Hz overseas power sources. HiFi-Stereo (January 1980, p.42) noted this as a practical consideration for international buyers.

The DH-200 also runs hot. HiFi-Stereo (January 1980, p.42) observed that the FTC-mandated preconditioning period left the top cover "fairly hot directly above the output transistors." That's normal for a Class-AB design of this era, but it matters if you're stacking components. The metal case does its job, but it needs ventilation.

The lack of level controls means you need a preamp with a decent output stage. That's true of most serious power amps from this period.

But the DH-200 is where the story started, and for anyone interested in the Hafler lineage — or in MOSFET amplifiers generally — it remains a worthwhile piece of gear. It's not the last word in transparency or dynamics, but it's honest, repairable, and capable of surprising performance when paired with the right speakers. And at current prices, it's one of the cheapest ways to hear what all the fuss was about.