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Retro Instruments Powerstrip Tube Recording Channel

Established in 2006, Retro Instruments is a relatively new company, but due to the classic nature of its product line and the fact that everything it has released to date is a true sonic gem, it feels like it has been around for decades.

The Powerstrip is “sonically stunning” — the perfect studio or live production tool for tube fanatics.

Established in 2006, Retro Instruments is a relatively new company, but due to the classic nature of its product line and the fact that everything it has released to date is a true sonic gem, it feels like it has been around for decades. Its initial offering was a remake of the Gates Sta-Level compressor followed by the 176 limiting amplifier, 2A3 dual-program EQ, and most recently, the Doublewide: Retro’s debut 500-series-compatible product. The Powerstrip is an all-tube recording channel that includes a mic pre, equalizer and compressor.


Not unlike the other tools in the Retro Instrument product line, the beautifully designed 2U Powerstrip is built into a steel chassis with the appearance of being able to withstand an airstrike. Manufactured in the United States, the box utilizes only highstability, high-quality components.

I/O is provided on the rear panel with a pair of XLR connectors providing line and microphone input and an XLR for output. In an effort to keep noise at a minimum and to reduce potential interface problems, these inputs and outputs are fully floated transformer-balanced. A quarter-inch Couple jack provides the ability to link two Powerstrips together for stereo operation and two more quarterinch jacks provide Instrument Thru (a mult of the DI input) and Hi-Z output. An IEC connector provides 120/240 VAC 50/60 Hz selectable power input.

The front panel of the Powerstrip is somewhat disjointed, as the input selector is on the left side and the input level control is on the right side. Initially, this felt awkward but once I became used to it, it didn’t bother me (it’s easy to overlook the layout when you hear how great this thing sounds). Along with the input selector (mic, line or instrument) on the left side, there are phantom-power and polarity flip switches and a quarter-inch DI input. The mic pre is transformer-coupled Class-A. On the right side, there’s a big VU meter that shows gain reduction only.

The passive Pultec-style EQ looks, feels and sounds like the hallowed classic. It includes the standard Pultec boost and cut frequency selections (LF Boost/Cut at 20, 30, 60, 100 Hz and HF Boost at 1.5, 3, 4, 5, 6, 8, 10, 12, 14 and 16 kHz.) The high-pass filter is switchable between 40 and 90 Hz, and it also provides peaking LF boosts with alternate tonal characteristics perfectly complementing vocals and acoustic instruments. There is an EQ bypass switch.

The compression circuit is of the classic British variable-mu tube ilk, modeled after the EMI RS24 that I have only used in plug-in form. The original RS124 was created exclusively for Abbey Road Studios and was never sold commercially, making it quite rare. The circuit includes six selectable attack/release time-constants and a four-position selectable side-chain filter switch (Off, 90 Hz, 250 Hz and compressor bypass). Since there is no threshold control, if you want more gain reduction, you simply increase the input. When the compressor is bypassed, the input control is still actively controlling the input gain.

In Use

If you’re looking for a clean, sterile recording channel, you’re in the wrong place. The Powerstrip has sonic character for days. When the input is driven hard, the saturation is wonderful — completely musical without any negative artifacts. This allows the Powerstrip to be used almost like an instrument when recording everything from drums and bass to vocals and acoustic guitars. And when it’s not pushed to excess, the box sounds beautiful, smooth and warm. I do wish the design had included a pad on the mic input as many microphones with higher outputs overload the mic pre too easily, even with the input control fully counterclockwise. I found that inserting an inline pad between high-gain mics and the Powerstrip eliminated the problem, but I prefer flipping a pad switch over, taking the time to physically insert a pad into the signal path any day.

Alternatively, I also had great results running higher-gain microphones directly into the line input, regardless of the mismatched input impedance. I feel that this is a great pad alternative if the mic doesn’t require phantom power and I had great success utilizing this technique when using a Shure SM57 on snare drum, Heil PR 31BW on electric guitar and Sony C-800G on vocals.

While there’s no hint of this on the front panel, the input control is also a pull-switch that engages a vintage mode for the input stage. This results in a slightly darker tone that provides a great solution for overly bright microphones or sound sources.

I didn’t have the opportunity to experiment with any other tubes, but the box provides the ability to use current production and NOS (new old stock) tubes that should prove to be rewarding to tube die-hards. Tube changes don’t require any alignment adjustments drastically simplifying this process.

While recording bass and electric guitar, I fell in love with the Powerstrip’s Hi-Z output. It is a post-processing, instrument-level output that allows the box’s EQ and compressor to be easily inserted between the instrument and the amp in the studio or on stage. While it’s slightly pricier than even the most expensive stompbox, utilizing the Powerstrip’s compressor and EQ between a guitar and amplifier is pure bliss. The Hi-Z output also allows the Powerstrip to be used as a re-amp box with the added bonus of being able to add EQ and compression to a line-level signal routed to a pedal chain or guitar amplifier.

I put the Powerstrip to work recording male vocals with a Shure SM-7, and the results were amazing. I’m a longtime fan of the SM-7, and I have never heard one sound better than through the Powerstirp. Unlike a parametric EQ, the Powerstrip’s Pultec style EQ paints with broad strokes and is very forgiving. I had great results utilizing it on kick drum, snare drum, bass, acoustic guitar and vocals and in the instances when I needed more precision, I added a GML 8200 EQ to the recording chain.

While the EQ doesn’t provide any surgical finesse, it does offer endless variation, and it works amazingly well on virtually any sound source. The only real drawbacks are the lack of an input pad, the lack of output metering and the combined preamp gain/compressor drive knob. None of these are deal breakers. And I wish it were possible to independently patch into each circuit of the Powerstrip. It would be great to use the mic pre on a vocal while simultaneously using the EQ on an acoustic guitar and the compressor on a bass. I guess I just need to buy three.


The Retro Powerstrip is one of the most versatile tube products around and between the mic pre, EQ and compressor, it will beautifully capture virtually any sound source with just the right amount of tube character.

Price: $3,595
Contact: Retro Instruments |