Universal Audio Astra Review (modulation pedal)

The Astra Modulation Machine is Universal Audio's take on three different analog/amp-based effects: Bucket brigade (analog) chorus, flanger/doubler, and amp-style tremolo. All of these effects are modeled by digital algorithms, expanding the trend of DSP's accurately emulated tones rooted in analog gear. 

Note: We did not load the additional X90 phaser and Dharma Trem effects, which are available via a USB connection and app download.

As usual, I tested the Astra Modulation Machine in my home office, with my PRS CE 24, and Mesa Boogie Rectoverb amplifier.

"I think we're past the point of having to make a major distinction between analog and DSP effects."

To prove I actually have the pedal, here's a pic of the unit on my dining room table:

First, I would note the aesthetics and construction of the external casing. The thing feels like a solid metal brick in your hand, with the more vulnerable switches protected by the heavier control knobs. And besides strength, it just looks great with the blue logo, shiny silver exterior and glowing red LED indicators. While it doesn't have much to do with tone, the Astra looks great on your pedalboard.

Compare to Similar Modulation Pedals

Before getting into the rest of our review, here's a simple comparison table that allows you to see how the Astra stacks up to other chorus and modulation pedals. Note that we use Sweetwater links to support our site, but at no extra cost to you. You can also visit the UA Astra product page for more details.

Price Guide

Price updated Tue, December 05th, 2023.

Price Alert Tool

Price History

Algorithms and Overall Tone Quality

We need to grade the Astra in three separate modulation categories:

• Chorus (plus phaser modulation)
• Flanger
• Tremolo/vibrato

Bucket Brigade Chorus

The chorus is the most applicable mode purely from a tone and usability perspective. It can sound just detuned, or you can smooth it out for subtle clean tone layering. It almost has a phaser-esque quality (there is a downloadable phaser effect), where you can hear the spins (peaks and troughs) in an almost circular pattern.

Guitar Bonedo's demo does a great job of showcasing all three modes:

You can hear a lot of sharpness and grit if you push up speed and intensity, which is where you get the de-tuned effects. Though it can be smoothed out for those wanting a more nuanced layer.

Flanger Doubler

The flanger is a lot smoother and more full, almost sounding like multiple guitars using the same effect in unison. 

In its simplest form (knobs at 12 o'clock), the flanger's tone is extremely warm and smooth, making it one of the better clean tone layering sounds I've tried. If I remember correctly, it was effects mode A and flanger mode 1 that gave you that sound (you can also hear it in Bonedo's demo).

The second flanger mode is a bit more aggressive and almost sounds like the chorus.

If you flip the switch over to B, you get the "doubler" effect. 

Again, it sounds good, but it just wasn't my favorite sound given how much I liked the minimalist settings on the flanger. For all you can do with this pedal, I honestly thought its out-of-the-box settings provided most of its value. 

Tremolo 65

I'll admit, I'm not a guitar player who utilizes a ton of tremolo. Of the three effects, it was the flanger that I was most biased towards, but I suspect it's tremolo fans that would get the most mileage out of the Astra. 

The Tremolo 65 algorithm just sounds extremely smooth and inviting, like the tremolo sounds I've heard on Fender amps, though with the flexibility of digital controls.

Most of the tones I pulled out of the Trem 65 were on the more subtle side of the spectrum, though it can be rhythmically choppy if that's what you prefer. It was Mode 2 that I found to be a little more usable, which created a much smoother layer that still let my amplifier carry the clean tone. 

There's no tremolo on my Mesa Rectoverb, so I couldn't do a direct amp trem to pedal trem comparison.

But as I alluded to earlier, I think we're past the point of having to make a major distinction between analog and DSP effects. Here, the tremolo sounds so good that I think it's dumb to complain about the lack of an actual analog circuit. If the sound quality is this good, does it really matter whether it's an analog tremolo or not?

I would argue that we're to the point where emulators are rising to the occasion.

Clean Signal Layering

All three of the effects on the Astra do a fantastic job of allowing you to layer over a clean signal. If you've read my content in the past you'll hear me mention this a lot: Good modulation pedals should be primarily used to layer or "dress up" a clean tone that might be otherwise thin or just plain boring.

Whenever you hear a guitar on a recorded track, whether vintage or modern, it's almost always been filled out by some kind of modulation.

Even with an ambient effect like delay or reverb, a subtle layer of modulation is probably still working in the background.

The Astra is a great candidate for handling this type of guitar work, especially in the studio. 

Control and Versatility

With multiple modes for each pedal, and what amounts to a five-band modulation EQ for each effect, there's nothing lacking in the area of control and tweaking ability. For all three effects, I was able to span a wide range of sounds. Even if I didn't love each sound or find them all usable - given my own playing style - it's pedals with this type of versatility that will provide the most options for the widest range of players.

In other words, it's flexible enough that you'll find something for just about any style or occasion.

A five-band EQ in a modulation pedal is pretty exceptional 

On the Astra you have:

• Speed
• Depth
• Intensity
• Shade
• Shape

It's not unusual for most modulation pedals, particularly those with a single effect, to only provide speed and depth. Universal Audio did a good job here giving you as much flexibility as possible. 

How it Compares to Cheaper Chorus Pedals

How does the Astra compare to cheaper chorus, flanger, or tremolo pedals?

The first obvious difference is that the Astra is a combination of the three effects, where most of the time you would have separate pedals devoted to the three sounds.

Instead, Universal Audio takes the effects category and puts in the three most relevant algorithms or effects types. 

Other differences would include what we've already mentioned about control:

• Astra: 5-band EQ
• Most other chorus pedals: 2 or 3-band EQ

The Universal Audio Astra also has presets, tap tempo, and additional flexibility via an app and USB connection. While the digital elements are becoming more common, most comparable chorus pedals do not offer a corresponding app. 

There's also a difference in price that deserves its own discussion.

Overall Value (price)

At $399 retail, the Universal Audio Astra is fairly expensive by most comparisons. However, we should also consider that it's essentially three pedals in one, with what we'd have to consider superior digital emulations.

In other words, divide that $399 by three, giving you $133 for each pedal: Chorus, flanger, and tremolo.

If you're in the market for all three pedals, the Astra does two things:

• Conserves pedalboard space
• Centralizes effects use
• Gives you a bulk discount

It's common to see modulation effects, analog or digital, listed at $199 retail. If you buy the Astra for $399, you're getting a bulk discount for effects of this quality, which leads me to suggest that if you're in the market for all three effects, this is a great solution for you.

Had each effect been released as its own separate pedal, Universal Audio could have easily charged $199 for each one.

Thus, if you're looking for just a chorus or just a tremolo pedal, the Astra is going to be overkill and not your best option. But, if you're trying to snag all three, the Astra is actually a cheaper alternative to buying three separate pedals of similar quality.

On the down side, we're really disappointed that we didn't get a MIDI connection here, especially when there is so much control and variations to work with in the Astra. It would be great to be able to do that externally.

Perhaps this is a feature for consideration in the future?

Ideal Fit and Context

Having said all that, the ideal Universal Audio Astra buyer should:

• Be in the market for all three effects (chorus, flanger, tremolo)
• Be looking to consolidate cost and pedal board space
• Play a lot of clean tones
• Be looking for more of a vintage tone profile

Honorable mentions would include a session or studio guitarist who does a fair amount of recording. We like it less on a live pedalboard because of the MIDI omission, but it can still be a great option if the aforementioned conditions are met.

Review Conclusion

As stated, I've tested the Universal Audio Astra in-house with my own guitar gear. Please note that the views expressed in this review are opinion, and should be taken with a grain of salt.

This is also not meant to be a comprehensive rehash of features or each possible tone. For that, we recommend Bonedo's YouTube video and/or the Universal Audio Astra product page.

If you have questions about the Astra, my review process, or perhaps your own experience with this pedal, feel free to drop them in the comments section below.

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