Learning Center: Electronics Modules

The electronics module in each HeadRoom amp is designed first and foremost for exceptionally accurate sound quality. All of our electronics provide dynamic, natural-sounding music reproduction; you’ll find them a wonderfully organic listen, without any harshness or tonal fatigue. Each module is made up of two circuit boards, one each for the left & right channel. All HeadRoom modules are built on 4-layer circuit boards for maximized conductivity and durability; All resistors are metal thin film while all caps in the signal path are high-end polyphenylenesulfide (poly film caps); the output amplifier stage in the modules is a solid-state, discrete-emitter design adapted from Walt Jung’s superb 'Diamond Buffer' topology. In other words, we never skimp on audio parts, even in the lower cost modules. Let's have a closer look!

The Desktop Amp Module

Constant-current sourcing forces the Desktop Amp module into 'Class-A' bias while doubling the output buffers. What's that mean? Too much current draw for our small portables, but, oh my gosh, the amazing sound!

This little Class-A module contains all the electronics basic to a standard HeadRoom Desktop Amp. Versions of the 'Home' electronics module is also found in our little HeadRoom Micro Amp, and our flagship mobile-use design, the HeadRoom Portable Desktop Amp .

In the 'Home' electronics module, there are two 4-layer circuit boards (one each for the left & right channel) that are connected with a series of header pins used to solder the module to the main circuit board. The Home module is designed to sound phenomenal without going up the ridiculously steep part of the diminishing returns curve. The output buffer stage is our own HeadRoom-adapted version of the highly-regarded Diamond Buffer discrete transistor design by Walter Jung. The internal input buffer, crossfeed, summing, and gain stages use the excellent-sounding, tonally accurate, and smoothly detailed soundscape provided by Burr-Brown OPA2134 op-amp. All these active circuits are forced thoroughly into "Class-A” performance bias with constant-current sources. Resistors are 1% metal thin film, and caps in the signal chain are high-end polyphenylenesulfide (poly film). The sound signature of this module is not only extremely well-balanced, richly detailed, and smoothly punchy, but also liquid-clear and fully integrated throughout the entire frequency spectrum. It's simply a sweet & organic audiophile listening experience.

The Ultra Desktop Amp Module

This little gold & black 'Max' electronics module is nothing short of an audiophile work of fine art The HeadRoom Ultra Desktop Amp and Balanced Ultra Desktop Amps. It's the BIG guns: this module board is physically bigger than our other modules to fit the spectacular Burr-Brown hyper-pricey OPA627 op-amps. Deep Class “A” bias, double-output buffers, gold-plated 2 oz. copper four-layer boards, poly caps throughout. Holy Moly!

This 'no-cost-spared' and deeply "Class-A"-biased Max module surface is practically littered with tiny audio chips costing well over $20 bucks a piece, 0.1% metal film resistors, and polyphenylenesulfide (poly film) caps that are silver soldered to 2 oz. gold-coated copper traces which blur into a glittering haze over a black solder masked four-layer circuit board. Speaking of circuit boards, this is the first time we have increased the physical size of our electronics module circuit board. But fear not, since it remains pin-for-pin compatible with our most of our older (post-2002 model year) HeadRoom Home and HeadRoom Max headphone amp units of yore. However, the Ultra Desktop module itself must always be mounted on edge due to heat dissipation issues, an intensely tricky and highly technical maneuver in older amps, thus making it an expensive retro-fit installation when done as an upgrade in our older HeadRoom units.

The Ultra Desktop module uses what many hard-core audiophiles insist is the best and most musical audio op-amp available anywhere -- the rare Burr-Brown OPA627 -- for the internal input buffer, crossfeed, summing, and power amp voltage gain stage; it certainly is about the priciest! The output current buffer is our own HeadRoom-tweaked version of the very highly-regarded Diamond Buffer discrete transistor design originated by Walter Jung. All active stages are forced deep into full 'Class-A' bias with constant-current sources.

Frankly, the advanced topology design, dedicated audio circuitry, and precise build quality of this module is simply out of this world, and when coupled with the finest of reference headphones and the most superb of audio front-ends, the results are pure transcendent sonic bliss as realistic as virtuoso musicians playing a private concert inside your head.