RSE TS508 Saturator: In-Depth Hands-On Review, Controls, Audio Demos & Mixing Insights
Welcome back, everyone! Today, we’re diving deep into a piece of gear that’s got me genuinely excited: the RSE Audio TS508, a stereo tube saturation unit built for the 500 series rack. I’ve been putting it through its paces, mostly on drums so far, and let me tell you—this thing has some serious character.
If you’re a musician, mix engineer, or just a gear nerd looking to bring analog vibe and harmonics into your tracks or mixes, this hands-on review is for you. We’ll dig into exactly what the TS508 does, what the controls mean, how it sounds, and the real-world impact it can have, especially on drums and stereo buses. There’s lots to cover, tons of details, and I’ll walk you through each part step by step—with plenty of audio and visual cues along the way.
Ready? Let’s jump in!
Table of Contents
Intro: What is the RSE TS508 and Why Should You Care?
Let’s set the stage. The RSE TS508 is a dual-slot 500 series stereo saturation unit. What sets it apart? Real tube circuitry, flexible controls, clever EQ placement, and a blend of vintage flavor with modern flexibility. You can use it on drums, busses, stereo mixes—pretty much anywhere you need that “something extra” to make life jump out of dull tracks.
If you’ve ever wanted to:
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Add subtle or aggressive analog harmonics to a sterile digital mix
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Beef up drum transients
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Add glue and vibe to your master bus
...this box is for you.
Background: RSE Audio and Their Approach to Analog Gear
Before we get nerdy, here’s some quick context. RSE Audio is a boutique company based in Ukraine. Everything is hand-built—no mass-produced, cookie-cutter stuff. I first stumbled across their gear with the excellent stereo Vari-Mu compressor (which I still use all the time).
“About six months ago, me and my good buddy David checked out their stereo Vari-Mu unit, which I still have. I use it all the time. It’s a wonderful unit—great piece.”
RSE isn’t some faceless manufacturer; Roman and the team take pride in careful engineering and real sonic results. That’s become obvious as I’ve spent time with their products.
TS508 Overview: Key Features & First Impressions
Let’s break down the TS508 in plain English:
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Type: Tube-driven stereo saturator (500 series, double wide)
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For Use On: Drum busses, stereo busses, full mixes, even individual sources if you want
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Front Panel Goodness: Simple but powerful—toggle switches, big knobs, a unique three-band EQ
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Analog Magic: Harnesses real triode and pentode tube circuits for two distinct flavors of saturation
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Flexible Routing: Pre- and post-EQ options let you shape tone before and after the tubes
Why Drums?
I like to start with drums when testing saturators. Why? Drums are full of heavy transients, which make it easy to hear what a unit is actually doing. If a box can make the drums punchier and fatter without killing the groove, it’ll sing on a mix.
Installation & 500 Series Double Wide Format
The TS508 is a double-wide 500 series unit. That means:
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It’ll take up two slots in your 500 rack. Plan accordingly!
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Super easy to install: just pop it in, power up, and you’re good to go.
There are no weird compatibility issues. I’m running it through my Flock Audio XT patchbay and everything worked first time.
Regardless of your 500 rack, you should have it routed so you can easily patch in and experiment.
The Front Panel: Walking Through Every Knob, Switch & Control
At first glance, the TS508 seems straightforward. Three big knobs, some boutons for EQ, and toggle switches. But some controls are a little counterintuitive—especially when you get into the EQ and the pre/post routing. So let’s walk it through, left to right, step by step.
Custom Knob Labels: A Tip for Usability
I’ll admit—the labeling under the stock knobs is a bit hard to see. My solution? Colored stickers from Amazon! Simple, visible, non-intrusive. If you want to avoid grabbing the wrong knob in a fast mix, I highly suggest you do the same.
"If I keep this unit for myself, I’m actually going to leave the stickers on here!"
Toggle Switches: Pre-EQ, Post-EQ, Metering, and Bypass
There are four toggle switches across the front panel:
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Pre EQ
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Up (off): No EQ before tubes.
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Down (on): Routes the 3-band EQ into the tubes. Awesome for shaping what hits the saturation circuit.
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Function: EQ the sound before it gets colorized, so boosting lows or highs here will push those frequencies harder into the tube circuit.
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Post EQ
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Up (off): Normal output.
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Down (on): This post-processes any boosts you sent to the tubes, attenuating those same frequencies on the output.
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This lets you, for example, push a ton of 200 Hz into the tubes for fat saturation, but keep your final output balanced and not muddy.
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Note: This can sound a bit counterintuitive at first—sometimes it even feels like it’s cutting, not just level-matching. Play and trust your ears.
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Metering Toggle
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Switches the VU meter to monitor input or output.
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Bypass
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Off: Unit is bypassed (no color, no flavor).
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On: Runs signal through the tubes.
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Pro Tip: Always check you’re not fooling yourself with tiny changes by level matching input/output using the main controls.
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Input, Output, and Wet/Dry
Now for the three big white knobs at the core:
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Input:
How hard you hit the tubes. Crank it for more saturation or drive. -
Wet/Dry:
Your mix control (parallel processing made easy!).-
All Wet: 100% processed
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All Dry: Bypass
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Anywhere in between: Blends original and processed—think parallel compression.
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Output:
Simple—this is your master volume/level-matching tool after everything else.
Triode vs Pentode Saturation Circuits
One of the TS508’s party tricks is its two different tube saturation circuits:
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Triode:
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Classic, smooth “round” warmth
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Fatter low end
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Softer, more musical harmonics
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Pentode:
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More aggressive – you’ll hear the crunch
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Tighter, a bit more midrange bite
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You can blend anywhere between the two with the rotary knob
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There’s a blend knob labeled Triode ↔ Pentode in green. You’re not limited to 100% one or the other—dial in your ideal hybrid character.
“As I turn on the triode, we get a little less low-end fatness. As I crank it up, it gets to be a little bit more than that. The midpoint is the sweet spot…”
The Built-In 3-Band EQ
The TS508’s EQ is deceptively simple but packs a punch. Layout:
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Low Shelf
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Frequency: 200 Hz
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Application: Adds thickness to drums, warms up vocals, or fattens bass-heavy elements
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Mid Peak
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Frequency: Centered at 1 kHz
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Application: Add presence or scoop out honk
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High Shelf
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Frequency: 2 kHz and above
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Application: Adds air, brilliance, and snap
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Each EQ band has its own knob for fast adjustment.
Important: EQ can be placed before the tubes (Pre EQ), after the tubes (Post EQ), or both, making this a versatile color box for fine-tuning your sound.
Audio Demos: Drum Bus Processing Walkthrough
Now we get to the fun part—the actual sound. Let’s break down the step-by-step changes as I ran a drum loop through the TS508. I recommend you check out the linked video for direct A/Bs, but here’s a detailed play-by-play for what I’m hearing in the room.
Bypass vs Engaged: What’s the Immediate Difference?
First up, all controls at “high noon” (12 o’clock), 100% wet, with no EQ. Listening to a lively drum loop:
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Bypassed:
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Dynamic, but a little bland
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Engaged:
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Adds subtle compression
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Transients get rounded, especially on the snare
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Slight drop in overall volume—just a hair, but noticeably tighter and more contained
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“Already I could hear… As soon as I engage you hear a little bit of compression, it actually drops just a hair in volume. Because we have some compression happening in the tube circuits…”
This subtle squish is the backbone of what makes saturation so valuable in a mix. It’s not an obvious “effect,” but loses the sterile “digital edge.”
Triode & Pentode in Action
Triode Circuit
Running 100% Triode saturation:
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You get warmth and low-end fatness.
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As you turn up triode, the bottom end fills out.
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If you turn it down, some weight is lost—so you can dial in just enough sub and punch.
Pentode Circuit
Switch over to 100% Pentode:
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Instantly, more crunch.
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The attack feels sharper, more bite on the snare and hats.
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Drums sound like they’d cut through a dense mix more easily.
You can blend anywhere between those flavors, giving tons of flexibility.
“With pentode, it’s a little bit more distorted, a little more crunchy. You can definitely hear what’s happening there…”
Pro Tip: I generally find myself living somewhere between the two—just a little bit of extra grit atop that tube warmth.
Mixing In EQ: Pushing Lows and Highs into the Tubes
This is where the TS508 gets really creative.
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Engage Pre-EQ
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Start boosting lows (200 Hz shelf) and highs (2 kHz shelf)
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Pushes those frequency bands directly into the tube circuit—causing them to break up and get saturated more
What happens?
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Bottom end gets thicker and rounder
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Top end opens up, cymbals and snare snaps come forward
“That EQ is what really makes the difference. It sounds very similar to my GainLab Audio EMP EQ with a tube circuit… but this is a little more flexible in the saturation section.”
With a drum bus, even tiny boosts can totally transform the feel—lifting drums out of the speakers and giving them attitude.
Post-EQ Mode: What the Heck Does This Do?
Here’s where things get a bit non-intuitive.
When you engage Post EQ (with Pre-EQ already on):
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Whatever frequencies you boosted before the tubes get attenuated after
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In theory, this lets you push fatness or brightness into the tubes for color, but keep your end output balanced and not muddy or harsh
But in practice:
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Sometimes it sounds like it inverts your EQ choices, or just makes things duller
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If you cut, it can actually brighten up the output
You need to use your ears here. On drums, engaging Post EQ made everything a bit darker—almost as if it missed the “punch” that Pre-EQ alone added.
“Personally, I don’t like this switch engaged—I kind of like it hitting it with Pre EQ, boosting a little top and bottom, and that just sounds great.”
Recommendation: Start with Pre-EQ only. If things get too crazy, try adding Post EQ and adjust with subtlety.
Context Example: Saturator on a Drum Bus Inside a Mix
How does the TS508 really perform—not soloed, but in the context of a mix with bass, guitars, and keys?
Patch your drum bus through the TS508, with some low and high shelf boost in Pre EQ. The result:
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Drums leap forward, gaining both weight and clarity
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Low end (especially kick) gets huge but not boomy
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Cymbals and snare have more snap and air
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Mix “glues” together—feels more expensive instantly
“Really brings out the low end. Really, really nice with this 200 Hz shelf…”
Mixing Applications: My Real-World Takeaways
Here are some ways you might use the RSE TS508 in your studio setup:
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On Drum Buses:
Add punch, excitement, glue, and size. -
Master Bus Use:
Subtle harmonic enhancement, softness on transients, final polish before your limiter. -
Individual Tracks:
Try it on vocals for warmth, bass DI tracks for thickening, parallel guitar buses for grit. -
Parallel Processing:
With the wet/dry knob, set up instant “New York” style parallel comp/saturation. -
Sound Design:
For destructive or creative effects, crank everything for crushed, broken-up textures.
What sets it apart:
You control both the amount and character of saturation (Triode vs. Pentode) and when you color your tone (Pre/Post EQ). Small company, big flexibility.
Comparisons: How Does the TS508 Stack Up?
I’ve used many boxes in this flavor zone—here’s a quick “compare and contrast”:
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GainLab Audio EMP EQ:
EMP is a full-featured, tube-based stereo program EQ (think Pultec style); TS508 is more about saturation plus a vibe EQ. If you want ultra-precise tone shaping, EMP is king, but the TS508’s two-tube circuit gives you grit and glue not found in most EQs. -
Pultec Clones (EQP-1A):
More hi-fi, less saturation, no parallel blending (unless modded). -
Thermionic Culture Vulture:
More aggressive, wider range of distortion—TS508 is focused on warm and musical, not audio destruction. -
SSL Fusion Vintage Drive or Rupert Neve Portico Saturation:
Those are also analog saturators aimed at master bus enhancement, but TS508, in my opinion, gives a more “classic tube box” sound rather than transformer or IC distortion.
“This is a very small company out in Ukraine; all hand-built, boutique shop. Really high quality stuff, and Roman’s a really nice guy…”
In summary:
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TS508 = Affordable, flexible, boutique, tube-focused, works great on drums/mixes.
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Others = Sometimes pricier, sometimes less flexible, sometimes more HP or precise but less “alive.”
Build Quality, Company Background, and Final Thoughts
Build Quality:
Solid, weighty. Everything feels hand-assembled but built to endure. Knobs are smooth, the faceplate is heavy, and the sockets are tight. You can tell someone sweated the details at the workbench.
Company & Community:
You get the vibe you’re supporting:
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A small builder (not a faceless behemoth)
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Handmade quality
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Real passion and customer support
If you ever get stuck, Roman is friendly, accessible, and happy to walk you through any quirks.
Where To Buy, Pricing, and Next Steps
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Pricing: As of writing, under $1000 USD. For a real tube stereo 500 series box, that’s fantastic.
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Where To Buy: RSE Audio’s Website, direct order. I don’t get any affiliate commission—just sharing killer gear.
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What’s Next:
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Watch for my next video/blog post, where I run a full mix through the TS508 (drums, bass, guitars, keys—no vocals yet).
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Future Feature: We’ll also check out their “tube/optical compressor” 500 series unit.
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“This is not an affiliate link. I don’t get anything for it. But if you’re looking for a stereo saturator in a 500 series module that’s flexible and sounds really good—a little bit goes a long way—this is a great solution.”
Leave Your Thoughts & Stay Tuned!
Let me know in the comments:
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Ever used the TS508? What’s your take?
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What other saturation boxes should I try?
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What do you want to see demo’d in the next mixing and mastering walkthrough?
If you want to level up your mixes, add some analog vibe, or just geek out about gear—stick around. I’ll be keeping the TS508 in my rack, at least until I give it away in one of our mixing contests (!).
“Until the next video where we check out more cool gear by RSE Audio, I’ve been Dave with Mixing Music Analog and mixingmusicanaanalog.com. Thank you so much for watching and reading. See you in the next one!”
Extra Links & Resources
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MixingMusicAnalog.com — For my mixing/mastering services, tips, and more gear walk-throughs
Drop your questions and experiences below.
Want a 25% discount on your first mixing session? Hit up my website, and let’s set up a Zoom call about your music!
Stay tuned—more analog goodness and in-the-trenches gear reviews coming your way.
Happy mixing!
