Pendulum Audio: Quartet II Recording Channel

The Pendulum Audio Quartet II (Mercenary Audio Edition) sounds outrageously beautiful. The Quartet II is four independent analog processing elements: a tube mic preamp, a tube EQ, a tube compressor, and a solid state limiter. It takes up two rackspaces and has both XLR and 1/4'' I/O's, giving it more flexibility than any other multi- element device I've ever seen. Greg Gualtieri designed the Quartet II with the intent of having one piece that he could bring to a session and knowing that he could get a great sound out of anything he had to record. The Quartet II easily meets that goal.

The mic preamp has what I've come to think of as a modern design-having both a gain control and an output control so that you can drive the input for extra coloration while controlling the output separately, like the gain and master volume controls on a guitar amp. The impedance is switchable between 1500 and 10K ohms. One feature that I haven't seen before is a switch for selecting between two input transformers. The first transformer is labeled Full, and the other is labeled Focused, with the Focused transformer providing a little more gain. While mic'ing a snare drum, I'd describe the difference along the lines of Neve (Full) vs. API (Focused) preamps. Both transformers sounded great on every source I tried them, and it wasn't always easy to choose which was the better option (a nice problem to have). The front panel has all the standard phantom, polarity and high-pass filter (75 or 150 Hz) controls. There are also switches for selecting mic or line level (the single XLR input can be either) and DI inputs. One unusual feature is the inclusion of two 1/4'' DI inputs (front/back); the two are loaded differently so each has its own tone.

The passive, inductor-based EQ has three unique bands and two modes. The low-shelving band can boost and cut simultaneously like a Pultec (at 20, 30, 50, 100, and 120 Hz). The mid dip can only cut and has a continuously variable Q, labeled intuitively Broad to Sharp (at 200, 350, 500, 650, and 800 Hz). The high-peak band can only boost, with a continuously variable Q like the mid band (at 0.8, 1.4, 2, 3, 4, 5, 8, 10, 12, 15, and 18 kHz). The EQ can be positioned before or after the compressor in the signal path, and it can be switched between Passive mode and Aggressive mode. The latter increases the saturation of the EQ and adds harmonic content.

The Delta Mu compressor is basically identical to a single channel from the Pendulum ES-8 compressor. It's an actual tube compressor, which is a rare thing because most compressors calling themselves "tube" don't actually use a tube for gain control (just for the output stage). It has five modes: Fast and Manual like the ES-8; and also Faster, Vintage (program dependent), and Average (RMS) modes. The peak limiter is the only non-tube element in the Quartet II (of course, in order for it to be fast enough), and it can switch between JFET and MOSFET operation.

How does it sound? As I said earlier, beautiful. It's my first choice for a natural sound that's not devoid of character. The Quartet II has a tube vibe (the real tube vibe) with which people aren't always familiar. Tube gear is usually described as sounding warm, which it often is, but that's more often a result of the transformers and other circuitry (see Neve for an example of how circuitry creates warmth without tubes). It's not uncommon for this circuitry to add extra coloration through poor high- end response, a muddy low end, and large quantities of harmonic distortion-all problems that the Quartet II avoids. As a result of the Pendulum approach to tubes, the Quartet II has a beautiful three-dimensional quality that I've never heard from any other piece of recording gear. It was the first thing I noticed when I tried it out by running my Gibson SG into the rear DI. Between driving the preamp a little, some simultaneous low boost and cut from the EQ, and a few dB of compression in the average mode, I was able to get a sound reminiscent of a clean sound from a Fender Deluxe. It was such a nice tone that, had I been in a session, I would have considered tracking it-even though I've always hated direct guitar tones. As I played through my monitors (bone dry), I realized that the guitar sat differently than dry signals usually sit. It's hard to describe, but it was like there was an air around the sound. It wasn't obnoxiously forward like a DI sound usually is. It was kind of like it was hovering in the vacuum of space (vacuum tubes-coincidence?). It was clear that it was going to be great for placing vocals in a mix, especially when going for a dry, in-your-face sound- which was the next thing I tried. That tube quality with a little peak-limiting made it easy to sit the vocals forward in the mix and allowed me the option of leaving them dry without sounding awkward.

I invited John Lardieri of Twin A by for some vocal comparisons. We ran a TLM 103 through three paths: a super-mint, all-original Neve 1073 through an 1176; an Avalon 737; and finally through the Quartet II trying both input transformers. John's first reaction was that the Quartet II sounded "richer" than the Neve, and I definitely agreed. The Avalon sounded tinny and a little brittle next to the Quartet II. Both of these comparisons were made with the Full transformer. We then A/B'd the vocal through the Full and Focused transformers. They both sounded great. John preferred the Focused transformer because he likes his voice when it's less "husky" sounding. The Focused transformer had a slightly tighter low end and a little push in the mids. We also tried it on snare where it sounded full and robust, and with a boost at 8 kHz, I could bring out the snare rattle better than I could with a 1073. I tried duplicating the sound of my Shure Level Loc with the "faster" compression setting and couldn't quite do it, but I was able to get a truly nasty distorted sound by turning everything all the way up. I tried bass DI'd through the front, and it sounded great. I experimented with guitar though a Pod, which the Quartet II made acceptable. I couldn't find a use at which the Quartet II didn't excel.

Another feature that sets the Quartet II apart from every other recording channel I've seen is that you can run all four components independently. The main I/O's are the XLR's, but there are also the 1/4'' I/O's for each device in the path. So, for example, you could use it as a complete signal path while recording; and then when mixing, you could use the EQ on one source, the compressor on another, the preamp for its transformer tone options on a third, and the brickwall limiter on a fourth. It's important to understand that you're getting four separate top-of-the-line pieces in one box, because you'll find that the Quartet II's price is in line with purchasing the four devices separately.

The Quartet II was designed to be a jack of all trades. Often that means mastering none, but the Quartet II mastered every use I came up with. Its inherent Pendulum tube tone will make it a classic piece of gear, and in an era where studios are competing with each other as well as with home studios, the Quartet II is in the caliber of gear that will give people a reason to hire you for a sound they can't get elsewhere. When you compare the Quartet II to other pieces of gear at the same quality and price level (say a new reissue 1073), it's clearly an exceptional value. I'm also very curious how a pair would fare as a mastering signal path. (I'd love to hear some non-L1/L2 limiting.) Congratulations to Greg on another exceptional product, and a nod to Fletcher at Mercenary Audio for his consistently excellent gear collaborations. ($5250 MSRP; www.pendulumaudio.com)