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Retro Powerstrip Channel Strip Review


The Retro Powerstrip brings tube personality-plus through its preamp, EQ and compressor sections.

Some manufacturers produce products that are the best one-trick ponies money can buy, while others attempt to pack a wide range of features into a rackmountable or desktop unit. The Retro Powerstrip channel strip adheres to the latter philosophy with great results and no corners cut. The Powerstrip features a tube preamp with lots of clean gain; a Pultec-style, 2-band passive tube EQ; and variable-mu tube compressor in a two-rackspace unit.

As with other Retro gear, the build is rock solid with a chassis sporting knobs, dials, meters and even the colors looking like they came from military hardware. All mic and line I/O are fully floating and transformer balanced. There are features you’d expect like switchable phantom power, polarity reverse and an adjustable meter, as well as others that tube-heads will love, like the ability to use current production and new-old-stock tubes with no alignment needed after a tube swap. The unit’s I/O is versatility defined: You can use the rear XLR mic input and line-level input for recording and mixing, or the front-mounted instrument DI, which can exit line-level or through the bonus instrument level output to go straight to a guitar or bass amp for live use, or both.

The signal flow on the Powerstrip is not linear like some three-in-one units, meaning gain on the left goes to compressor, to the right goes to EQ, to the right of that, etc. For instance, the mic/line/instrument input selector is on the far-left of the unit, but the gain is set on the far-right—separate input and output knobs let you drive the output with tube goodness, if you desire. I liked how much gain I could get out of it, even when using a passive ribbon, without any hiss, which is remarkable for a tube preamp.

The switchable EQ on the left of the unit offers separate low and high bands. The Pultec passive style means you can boost or cut, or boost and cut, creating unique EQ effects. I found myself loving the 60Hz and 100Hz settings when I was cutting bass guitar or kick drum. Passive EQs always take quite a bit of boost to be apparent, but they are very forgiving and easy to use. The HF section offers a lot more versatility with 10 frequency choices as opposed to only four in the LF section. There is also a HF bandwidth control marked 0-10 (Sharp to Broad) and an extra knob allowing you to cut at 5 kHz, 10 kHz and 20 kHz while you’re boosting at one of the other 10 frequencies. There are a lot of possibilities here, but I found myself drifting back to a couple of key boosts that ended up making the track. For instance, on bass, a boost of 100 Hz and then again at 5 or 6 kHz brought out the big bottom and definition in the higher range of the instrument beautifully.

The compressor is as beautiful-sounding as it is simple. It offers six time constants from slow to fast and is turned on via the sidechain HPF knob, which can be set to Comp Out, 250, 90 or Off, which means the compressor is on but there is no sidechain filter in play. I really liked how the sidechain HPF kept the compressor from choking down on the fundamental of a kick drum while grabbing the transient of the beater hit and putting it right in my face. Next, there’s a separate three-position subsonic filter switch that can be set to Off, 40 Hz or 90 Hz. This takes rumble out of play on any recording. There’s also a push/pull feature on the input knob that cuts down the gain and is described in the manual as a way to add interesting effects during instrument recording. I tried it a few times and it did cut the gain, but I always preferred the results I got with the knob “in” and off.

Being a longtime guitar player, I couldn’t help plugging my 1968 Gibson L5 into the front of the Retro and then out the instrument level TS port to a Fender Pro Reverb amp. This is where the EQ shined. It brought out the beauty of the low end at the 100Hz setting and a variety of great tones when I set the boost to 12 o’clock and switched through the 4, 5, 6 and 8kHz HF bands. The broad bandwidth setting is very broad, and you can use this with the bandwidth to park the midrange frequencies and highs just where you want them at the ends of the boosted HFs.

I next used the Retro to power a Sennheiser e 602 microphone outside a kick drum. After setting the gain, I switched in the EQ, set the low frequency to 60 Hz and brought up the boost. The bottom end bloomed immediately and sounded great. Then I wanted to add more beater “pop,” so I set the high frequency to 3 kHz and brought up the boost until the balance between the boom and pop was perfect. I switched in the compressor at a medium time constant and started playing with the sidechain filter. Just as I expected, as I cut more low end to the sidechain, the compressor left the bottom alone, letting it peek through while grabbing the frequencies above. This gave me a nice, full bottom end that wasn’t crushed while the compressor grabbed the attack of the beater, making it more uniform and sitting it perfectly in the track.

I also used the Retro to record hand percussion through an sE Electronics Voodoo VR1 microphone. The unit had plenty of gain to power this passive mic and sounded great in this application. The compressor’s versatile controls let me tame the transient hits of a cowbell, giving me the ability to quickly audition the effect the squasher had on the signal in the mix as I switched through the settings from slow to fast. On other recordings of moderate to low-level acoustic guitar parts, I had the new AEA KU4 ribbon mic from Wes Dooley during my time with the Retro. Being a passive ribbon with a big engine, it needs a lot of gain, and I was pleasantly surprised that where other preamps needed to be at their limits, the Retro had a lot of clean gain to give with plenty left—also remarkable for a tube unit. Using the combination of the KU4 and Retro to record acoustic guitar was a thing of beauty. I used no compression in this case and added just a bit of sweetness at 8 kHz with the EQ and notched out the very bottom end with the subsonic filter set to 90 Hz. Perfect.

The Retro Powerstrip brings the best of what a new/vintage tube preamp, passive tube EQ and tube compressor has to offer—all in one box. It repeatedly brought a smile to my face as I ranged through the many features and tried different combinations. It has oodles of clean power, more than you’ll need, even when powering a passive ribbon mic. And it’s clean; there’s no nasty hiss when you get to the top of the usable range.

While the EQ is not precise like a parametric, it has tons of personality and sounds very musical on bass, kick drum, vocals, guitars and more. Think of it as a broad-stroke tone-shaping tool and you’ll get it. Even though the compressor seems very simple, it honestly has all of the control you’ll need to tame peaks and make an uneven performance work like glue in the track. Its most usable feature is the sidechain frequency control, which feeds the compressor and avoids pumping. I was able to easily tailor how much crush I was getting with this feature and it’s far more useful than a dedicated threshold control.

The instrument level output is a brilliant addition and begs you to feed a guitar and bass amp with a Powerstrip as the front end. All those cool tube toys beats any stompbox or freeze-dried plug-in combo—hands down.

If you’re looking for that one sweet piece of gear that brings your front end to the next level, the Powerstrip may just be the ticket. Its unique feature set, solid build and great sounds makes it an instant classic.

Kevin Becka is


’s technical editor.

Click on the Product Summary box above to view the Retro Powerstrip product page.

Video Demo of Retro Instruments Powerstrip