HomeBrew Electronics Power Screamer

The HomeBrew Electronics Power Screamer is an overdrive pedal built on the JRC4558 op amp, the same chip made famous by the Ibanez Tube Screamer and used in many classic and boutique pedals¹. On top of the usual overdrive controls it adds a three-position diode select switch and a footswitchable boost, which sets it apart from a stock Tube Screamer-style circuit. MusicRadar placed its overall sound somewhere between a classic Tube Screamer-style overdrive and a more grainy-sounding fuzz¹.

Homebrew Electronics built the Power Screamer as an overdrive pedal based on the JRC4558 op amp, a chip used in many classic and boutique pedals¹. Its sound sits somewhere between a classic Tube Screamer-style overdrive and a more grainy-sounding fuzzbox¹.

The controls

The front panel carries the customary overdrive controls: adjustable gain, level and tone¹²³. Vintage Guitar described these as the standard set for the type, so a player moving from any Tube Screamer-style pedal will find the layout familiar². The tone control is a single knob rather than a separate bass and treble pair.

Alongside the knobs sit the two features that define the pedal: the three-way diode switch and the boost footswitch¹³.

The three-way diode switch

A three-position toggle switch lets you change the diode used in the circuit, which changes the clipping character¹. The two reviews describe the three positions differently in detail but consistently in spirit:

• Left: the "classic overdrive" setting, producing a tight, mid-rangey sound not unlike a Tube Screamer¹. Vintage Guitar heard a vintage 808-style sound with midrange bark in this position, with tone at 12 o'clock².
• Middle: MusicRadar found the compression less obvious here, with more gain, bass and treble, calling it the most full-throated sound of the three¹. Vintage Guitar's reviewer called this position much more flat and true, and it was that reviewer's favorite setting².
• Right: a little brighter but heavily compressed, designed to emulate the "sag" produced by running a small valve amp flat out¹.

Because the diodes sit in the clipping stage, swapping between them changes how hard the signal is clipped and how compressed the result feels, which is why the three positions range from a familiar midrange overdrive to something closer to a sagging amp¹.

The boost footswitch and the fat boost option

A second footswitch adds around 10dB of extra boost¹. Vintage Guitar measured the effect differently, finding the boost switch added 6 dB of gain, increasing both volume and gain without really changing the tone, though with a slight loss of low-end that the reviewer did not consider a big concern for a solo boost².

One of the HBE custom shop options adds an extra toggle switch affecting how the boost works: normal or "fat boost"¹. The DIY circuit analysis explains what is happening electrically: the boost switch changes between two sets of components from the op amp's inverting input to ground, so it functions like a fat switch, altering the low-frequency content of the boosted signal rather than simply adding volume³.

How the circuit works

The Power Screamer is based on the JRC4558D³, and its lineage is explicit: Vintage Guitar noted the chip was "made famous by a certain bright green stompbox that also had the word 'screamer' in its name"². The Tube Screamer family it descends from is itself built on a well-worn gain-stage arrangement, a pot in the op amp loop adjusting gain, a schematic Coda Effects points out appears across many overdrives⁴.

The broader Tube Screamer topology, as traced by runoffgroove's analysis of a TS-808 workalike, runs: an input buffer, the audio split into a distortion path and a clean path, two series gain amps in the distortion path, a tone section, and an output buffer and mixer that recombines the paths with extra gain so the circuit has plenty of output signal⁵. The same analysis notes the family's frequency response traces back to the old germanium boosters⁶.

What reviewers said

MusicRadar's verdict on the sound was short: "Smooth, transparent overdrive sound."¹ The same review framed the pedal's appeal for players who want old-style stompbox character with true bypass and top quality components¹.

Vintage Guitar, reviewing the pedal in its January 2005 issue through Crate and Fender amps with G&L, Fender and Zemaitis guitars, found that even with the gain dimed it stayed tight and punchy, with great note clarity². That reviewer also praised the build: chassis-mounted pots, switches and jack, and the heavy duty battery clip riveted to the cover². The test unit wore one of HBE's custom finishes, a lacquered tweed covering the magazine described as meticulously executed².

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