Review: Slate Digital Virtual Tube Collection

Tube-processing plug-ins for the virtual mix rack
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The Virtual Tube Collection offers three distinct sounding modules: London, Hollywood, and New York.

The Virtual Tube Collection offers three distinct sounding modules: London, Hollywood, and New York.

Plug-ins designed to add “warmth” to digital audio have become common; many aim to re-create the saturation characteristics of analog tape, while others go for the sound of tubes. In the latter category is the impressive new Virtual Tube Collection (VTC) from Slate Digital.

Like most of the company’s current plug-ins, they open as simulated 500-series modules in the Virtual Mix Rack (VMR) format. The VTC consists of three separate modules: London, Hollywood, and New York. Despite having the same controls, each module has a distinctive sonic signature.

On the upper left of each VTC module is the Preamp/Console switch that selects between two different tube-modeling algorithms: Preamp mode emulates the characteristics of a tube preamp, and Console mode models the sound of the tube summing circuit of a mixer.

The switch on the upper right is called Normal/Push. The Normal setting is the default for the module. Selecting Push toggles the module into a boosted state with an exaggerated tube effect.

Two key knobs for adjusting the behavior of the modules are Saturation and Mix. The former controls the amount of tube distortion you get. In Preamp mode, you don’t usually start hearing audible distortion until you’ve turned Saturation past about 12 o’clock.

In Console mode, you have to crank up the Saturation a lot higher before hearing any distortion. But whichever mode you’re in, you don’t need to hear obvious distortion to reap VTC’s benefits. I found that it added a richness to the sound, even with the Saturation turned all the way down.

The Mix knob is quite useful, allowing you to dial in as much or as little of the tube effect as you want. Like the mix knob on a compressor, it gives you parallel processing capabilities.

The other two knobs are Output, which controls levels coming out of the module, and HP Freq, which sets the cutoff frequency of a highpass filter, giving you extra control for rolling off unwanted bottom end. It has a pretty subtle roll-off; I compared it with the highpass filter on the FG-N EQ module in the VMR, and its effect was much more gradual.

Just like other VMR modules, a pull-down menu at the top gives you access to a collection of factory presets. You get 16 presets in each VTC module, ranging from mix bus settings to patches for snare, bass, vocals and more. I found them to be very useful, and they made excellent starting points for various situations. One of the features I particularly like is that all three VTC modules have the same presets, which makes it a lot faster to compare their sounds. And like other VMR modules, you can save your own presets.

A large virtual VU meter sits at the top of each of the VTC modules, measuring the level at the output. You can calibrate the meters between -6 dB and -24 dB right from the front panel. Below the meter is a Clipping Bulb, which lights when clipping occurs (which is desirable with VTC if you want the sound of tube distortion) and provides a visual indication of how much you’re overdriving the processor.


The differences between the three modules seem subtle at first, but the more you familiarize yourself, the more you start hearing each one’s distinct sonics. According to Slate Digital, London was modeled from “European Tube Gear.” Although they don’t mention Abbey Road Studios, the module’s name seems to imply that. In any case, it’s the subtlest of the three VTC modules, and it provides a smooth distortion, whether the Saturation is low or off, adding a pleasant sheen to the audio.

The Hollywood module provides plenty of breakup with the Saturation set high and the Push switch on. Of the three, it’s the only one that offers a bit of low-end boost (as well as added high-end).

The New York module is capable of the most crunch of the three, and it also seems to add a little high-end to the signal.

Fig. 1. If you use other Virtual Mix Rack modules, you can easily integrate the VTC into your workflow.

Fig. 1. If you use other Virtual Mix Rack modules, you can easily integrate the VTC into your workflow.


I used the VTC modules on multiple tracks across several mixes and was uniformly happy with the results. A couple of the songs had multitrack drums, and I was able to add beefiness to the kick drum with any of the three modules. With Preamp mode chosen, I found that Saturation settings above about 12 o’clock were as high as I could go and still keep the kick sounding natural.

On snare, as well, all three provided excellent results. I particularly liked the sound of London for this application, which added natural sounding crunch and sustain to the snares I tried it on, giving them a lot more life. I also favored London for fattening up a Rhodes-type electric piano sound that was already a little crunchy. In that application, Console mode seemed to work best.

For electric guitar, New York was my favorite, because of its superior distortion capabilities, but Hollywood and London were also excellent for fattening and livening sounds. Any of the modules worked well on electric or synth bass, making those sources sound either distorted on higher settings or just “bigger” on more subtle settings. In general, I found the Mix knob to be helpful for fine tuning the settings.

All three VTC modules excelled on vocal tracks. To add a little extra energy without audible distortion, I used Console mode and increased the Saturation until it started to sound dirty, and then slowly backed it off until it cleaned up. The result was impressive fatness and warmth.

In fact, VTC processing benefitted every track I tried it on. Even without any Saturation, all three modules had a subtlety pleasant effect.

The other area where the VTC modules excel is on the master bus, especially when set to Console mode. I particularly liked London for this application, because it sounded the most transparent. As with vocals, I’d slowly raise the Saturation, and then back it off when the effect became too apparent.

Over the course of my testing, I didn’t find the VTC modules to be overly CPU intensive, which is good because you’ll end up using a lot of them if you have a big session.


As with other Slate Digital VMR processors I’ve tried, the Virtual Tube Collection is very impressive. Its design allows you to get a lot of mileage out of a relatively small set of controls. The Preamp/Console switch gives you a choice of two distinctly different settings. The Push/Normal switch also changes the character, as do, obviously, the Saturation and Mix knobs. Between all of these controls and the three distinct modules, you have a lot of options.

I’ve been a Virtual Mix Rack user since it came out, employing it for compression, EQ, and console emulation among other things. After my initial tests with VTC, I decided to integrate London into my basic VMR preset, which already had the FG-N EQ, FG-401 compressor, the VCC Channel and the Trimmer (see Figure 1). I used this configuration on each track of my mixes during the review period and swapped London out for Hollywood or New York, depending on what I was going for on specific tracks. Consequently, the VTC modules have now become an indispensable part of my mixing workflow.

When it comes to sound quality, ease of use, and utility, I have only positive things to say about the Virtual Tube Collection. Some may find its purchase price to be a tad high, but considering the quality you get, I think it’s reasonable. Slate Digital also offers VTC as part of its Everything Bundle subscription plan, which lowers the price considerably and lets you access most of the company’s other plug-ins.

Mike Levine is a composer, producer, and multi-instrumentalist from the New York area.


Excellent modeled tube sounds. Each module has its own sound. Well-designed controls. Matching presets in each module helps with sonic comparisons.