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API TranZformer LX Review

A pair of top-shelf studio weapons are transformed into one DI pedal that gives bassists formidable tone-sculpting power.

Recorded with active Music Man StingRay direct using a PreSonus FireStudio and PreSonus Studio One 3 software.
Clip 1 - Settings: Compression setting #4 and gain at 50 percent. EQ settings at 1 o’clock for bass (100 Hz), 2 o’clock for mids (400 Hz), and 2 o'clock for highs (2 kHz). The clip runs from no effects engaged, then to EQ and compression engaged, then remove compression, and then remove EQ.

Do you listen to music? Of course you do. And if you’ve listened to anything from the past, oh, four decades, you have probably heard what a piece of gear from API (Automated Processes, Inc.) can do. An unavoidable and often overused term in our business is “industry standard,” but API’s gear has become downright standard in pretty much any studio worth its salt. For just one example, the company’s 525 compressor is arguably one of the must-have 500 series modules in the studio world. Fun fact: The concept of a “lunchbox system” to house and mount studio modules in a compact rack was first developed by API.

So, what does this mean for us bassists? We sort of show up to a session with our pedalboard and basses, and let the engineers work their magic from behind the glass. But it seems more and more that the power has been transferred to us, and we’re seeing loads of DI pedals hitting the market with varying tones and mixed results.

One problem is that bassists are not always engineers, so the tone being sent to the control room may not be what the recording needs. Another rub is the constant release of new plug-ins, which can hurt recordings if overused as well. What are we supposed to do? Enter API’s TranZformer LX pedal.

TranZformative Engineering
The folks at API have combined two of their most coveted 500 series modules into a stage- and studio-ready pedal. And it contains the two things bassists really need—compression and EQ—but sometimes overlook. Sure, there are plenty of other companies manufacturing these effects, but not many with the pedigree API can claim.

And because the LX takes the guesswork out of compression with its six presets, it allows a player to dial in a great tone rather quickly.

To put it simply, the TranZformer LX is a beast. The pedal clocks in at 4 pounds and is about 4" tall, so you’ll want to plan your pedalboard and case accordingly. The controls are simple enough, so those with a fear of compressors can rest easy. No ratios or math to conquer here: Just dial up one of six available compression settings—ranging from 2:1 to 20:1—and go. The EQ section is just as simple, with its three knobs that provide a wide range of sonic possibilities by offering +/-16 dB at 100 Hz, 400 Hz, and 2 kHz.

I tested the TranZformer LX with both a passive Fender Jazz and a vintage Music Man StingRay. I ran the basses and pedal through an Eden CXC210 combo and through Presonus Studio One 3 to get the studio vibe as well.

Whatever It Takes
To start, I plugged in my trusty Fender ’75 Jazz reissue that’s equipped with passive Seymour Duncan Antiquity pickups. This bass has carried me through quite a few gigs and I love everything about the instrument. I have found, however, that a hint of EQ can make or break this instrument’s acceptance on tape or live. Incorporating only the EQ section of the TranZformer LX, I added a little bump on the low end, scooped the mid, and retained just a hair of the top. My Jazz came alive and simply sang with authority and shimmer. By boosting the mids a little, to around 2 o’clock on the dial, the bass really entered its zone: pointed yet refined with just enough edge to cut through the mix and not be overbearing. And that’s where the rubber meets the road for API in a studio setting.

The active Music Man also paired wonderfully with the EQ section of the LX. I found myself rolling off the low end just a touch and actually boosting the top end a bit to give the active side of the spectrum a perfect mix position. The pedal’s EQ is based on the API 550A and optimized for bass, so my ears were rewarded with huge tones in the headphones. I could see using this pedal as the pre in conjunction with a power amp and don’t think one would need much else.



Dynamic and refined tones from a world-class studio-gear manufacturer.

Really big footprint for a pedalboard.


Ease of Use:




API TranZformer LX

The Press Test
The compressor side of the TranZformer LX is based on the aforementioned 525 feedback compressor that’s used on, well, seemingly just about everything in the studio. And because the LX takes the guesswork out of compression with its six presets, it allows a player to dial in a great tone rather quickly. A side note: More gain (up to +30 dB) will create more compression, so using these two controls together can create some quite solid results.

With the gain dialed down around the 9 o’clock position, I really liked the second setting on the compressor when paired with the Music Man. It had air and life without sounding pinched, let me hit the bass harder than normal, and kept it all in line. And with the Jazz plugged in, the results were the same. The sixth compression setting kind of sounded like putting the bass under a mattress, but at the same time, it was indeed still usable and distinct.

And Now the Bonus
After playing on the compressor side of the pedal for a while, I had things dialed in and rocking. But wait! It was then that I realized I had the EQ section disengaged while getting a feel for the compression section on its own. And well, wow! Getting the two sides of the pedal working together is where the TranZformer LX is meant to be. This is truly a studio-quality setup, so there aren’t extremes here. Even with the controls dimed, you won’t find yourself out in left field. The overall feel from all the tones I dialed in was sophisticated, without being overbearing.

The Verdict
Think about this: We’re talking studio-quality compression and EQ in a line-level DI that can fit on a pedalboard and provide rich, refined tone, and comes in at around $500? I realize it’s quite a bit more spendy than a “standard” DI, but you are essentially getting two 500 series modules (albeit lighter versions) in one package, which will allow your tone to soar for a price that would normally almost get you just a single piece of API’s gear. Yep, the DI pool is deep with offerings, so navigating the market can be tricky. Your ears need to be the ultimate deciding factor. With that said, if you are looking to bridge the gap between hobbyist and pro session player, or you simply want a delightfully rich and robust sonic palette for your bass that won’t completely destroy your bank account, the TranZformer LX might be a good place to call home.

Watch the Review Demo: