First Listen: A Review of the Retro Instruments Revolver

With the release of their latest creation, the Revolver, Retro Instruments has done it once again by reviving a beloved studio staple and updating it for the modern workflow. Just like other Retro Instrument releases in the past, the vintage vibe extends far beyond the Revolver's classic looking exterior.  

Based on the legendary modded Altec 436, the Revolver is a dual-channel, all tube compressor that has been hand-built in the USA with that classic British tone. It’s also loaded with expanded features, making it a compressor that works in any stage from tracking to mastering.

The basic layout is similar to the Retro 176 or any 1176 style compressor, as it features controls for Input, Output, Attack, and Release independently for each channel. In addition, the Revolver includes a SC Filter on each channel with the two selectable frequencies of 90Hz or 250Hz.

New to the Revolver is the Dual Threshold control, which doubles up on a couple different functions. First, it adjusts the compression ratio between 1.5:1 and 5:1, and depending on how hot the input is set, can also provide a very pleasing amplifier saturation that will thicken up the signal in all the right ways. 

In our new demo, Bryan Reilly tests the Retro Instruments Revolver on his mix bus, drum bus, electric bass, electric guitar, vocals and acoustic guitar. Watch below for the full demo and continue reading to learn more about his thoughts on this new compressor.

Mix Bus
Anytime I get to use a stereo tube compressor, I need to hear what it can do on the mix bus. I love the sound of the UnderTone Audio UnFairchild and Shadow Hills Mastering Compressor that we have over at the 45 Factory, so I was curious to see how the Revolver would hold up.

I wanted to use a track that was unmixed and mastered with no trickery, so I used a track I just finished producing for a Detroit artist named Ben Sharkey. Ben and I finished the production of the track just a few days before shooting the demo video, so all the musical elements are there, but it was still unmixed.

The track has a lot of space, layers of different live and sampled drum pieces, electric guitars with a lot of attack, a super smooth bass line and aggressive pumping synthesizers. With all of those different elements, the end goal was to make everything ethereal and smooth, after all, it is a love song.

I had two versions of the track up on our Tree Audio Roots console, the first version was my post-production rough mix, the second was running through the Revolver. Since there’s no true bypass switch on the Revolver, this setup will allow me to A/B by swapping solo buttons.

It didn’t take long to get everything dialed in to where I could hear a significant improvement. I started with the compressor linked, lowest threshold possible, slowest attack and fastest release, side chain filter at 250Hz, then adjusted the input and output levels for proper gain staging.

The first thing I noticed was how much wider the overall mix appeared. There’s a filter-gated synth that’s slowly panning when the drums kick in, through the Revolver, it popped right out and had the 3D effect it was originally intended to have.

The guitar lick also moved farther into the right speaker, making more room for the kick and pumping synth in the center channel, which then brought out the low guitar harmony in the left channel.

I think the biggest improvement though was in the low end of the mix. Without the Revolver, the electric bass is kind of in the background. When the Revolver is engaged, the bass becomes much more present and focused in the center channel. In the production, I made a parallel stereo chorus bass track to give it a little sparkle and stereo spread, the Revolver also pulled that up just enough to help excite the bass.

The same thing happened to the kick drum, as the Revolver helped add more volume, punch and stereo width. It made the kick nice and pillowy, slightly reducing the attack and extending the length.

The Revolver didn’t make the snare jump out of the track like some compressors tend to do. It actually sits in the exact same spot whether it’s in or out, the only difference I can hear is a slightly smoother attack and just a tad bit of extended decay.

Drum Bus
As far as drum mics go, I used a pretty bare bones setup in this example. For each mic, I used a Shadow Hills GAMA preamp on the nickel setting followed by an API 550a EQ. I used a U47 FET on the kick, SM57 on the snare and two Mesanovic Series II ribbon mics in a Blumlein pattern for the overheads.

Just those four mics sounded great to me, that tone would totally pass on a stripped down record. The live room at the 45 Factory isn’t that big, but has some state of the art acoustic treatment. It's one of my favorite rooms for a tight, natural sound.

The Revolver worked some magic in this example, it expanded the overall tone of the drum kit by making it sound more natural, but not more exciting. Some compressors that are hit with this much gain reduction will turn a tight room into arena rock.

That wasn’t the case with the Revolver. Right off the bat, same as the mix bus example, the whole kit was wider, expanding the stereo image created by the Blumlein pattern. The drums were mixed down in drummers perspective, and if you listen closely after the Revolver is engaged, you can hear a wider transition between the rack and floor tom from the left to right speaker.

In the raw example, you can hear some nice room tone from the overheads, but the whole kit feels a little distant. When the Revolver is engaged, it truly sounds as if you’re standing in the live room with me. The compression was well balanced across the entire drum kit, tightening up the attack while slightly extended the decay of the kick and snare.

Electric Bass
A quality tube compressor can greatly improve a DI electric bass. The electric bass was recorded with my 1978 American P through a Universal Audio 6176 directly into Pro Tools, so there’s already a little bit of tube color from the 610 preamp and compression from the 1176LN on the raw track.

The biggest difference between the raw and Revolver bass examples is in the lower sub frequencies. The best way I can describe it is the track goes from sounding completely digital to warm fuzzy analog. Even though it was recorded through tubes with some compression, it still had a bland, DI, digital feel to it.

The compression from the Revolver rounded off the attack and higher frequencies from the DI tone. Throughout the lick, the low string of the bass is constantly sustaining. In the raw track, that note is consistently at the same level and always slightly louder than the lead notes.

When the Revolver is engaged, the apparent volume of that note remains the same, but the lower sub frequencies start to have more weight. The lead notes are now on top, and slightly make the low string duck when they’re played.

Electric Guitar
I went with a simple loop on the electric guitar example. Every other example had very transient sources, I was curious to see how the Revolver would respond to a tighter electric track with minimum dynamic range.

The track was recorded with my Les Paul Traditional Pro through a JHS Colour Box into my 1965 Ampeg Gemini One. This rig was miked up with a Sennheiser MD421 through a Focusrite ISA One preamp into a Universal Audio Apollo Twin.

It doesn’t seem like there is too much change in the demo, but I hear a lot of cool stuff happening when the Revolver kicks in. Biggest improvements are once again a wider stereo image and increased low end. You can also hear some more attack from the pick on the strings.

I used the smallest amount of flanger when I recorded the raw track to a point where you can barely hear it. When the Revolver kicks in, you can hear some of that flange effect, but not enough to where it changes the tone.

Vocals
For the vocal example, I used a take of my good friend Olivia Millerschin singing into a Flea 47 SUPERFET through a UK Sound 1173. Using the Revolver on this example brought me back to my days of using Retro Instrument's Sta-Level.

In this example, I can hear the Revolver enhancing just about every part of the frequency range, adding more air to the top end and some weight to the low end. It helps tame the more dynamic parts of the performance, which then brings forward the intimate parts. The original feel and dynamics remain intact, but the overall sound is smoothed and consistent.

I’d say I was compressing this example quite a bit more than I probably would in the mix, but even with that much gain reduction on an intimate vocal, you can barely hear a pumping effect. I was able to get a lot of extra gain from the Revolver and still hit the sweet spot on the Burl B80 Mothership's converters. The Revolver surely passed the test on vocals, and now you can get two channels of compression for the price of one Sta-Level.

Acoustic Guitar
I like when a compressor pulls out all the low end, harmonic overtones and buzz from the strings on the frets. This track was recorded with my Taylor Big Baby through an Audix VX5. I used the Manley Labs VoxBox unison preamp plug-in from Universal Audio followed by a Pultec EQP-1a and LA-2A compressor.

The Revolver did exactly what I was looking for. When it kicks in, the whole performance becomes more exciting. Just like every other example, the low end becomes much richer. The attack is smoothed out just a bit, and the lead notes step up to the forefront. All the buzz and finger noise is enhanced just enough to provide some more performance energy, which might not be the best thing for every acoustic track, but worked great with this aggressive style performance.

In the end, Retro Instrument's Revolver passed the test with flying colors on every source. A tip of the hat to Retro Instruments is well-deserved for this one. The Revolver is priced at $2,995, breaking down to $1,500 per channel of compression.

I think it’s safe to say this is hands down one of the best sounding and most flexible tube compressors in its price range, or in any price range for that matter. The Revolver would be an excellent choice for any smaller studio that needs one flexible compressor to rule them all, or a great addition to the compression flavors in a larger commercial studio.