Manley 16x2 Tube Mixer Review

Thank you to Audio Media magazine for kind permission to reprint this review which ran in the May 2001 edition.

Manley Tube Mixer

KEVIN BECKA auditions the new tube mixer from Manley Laboratories and finds the high-end just got higher.

Manley

Manley has redefined the mixer by introducing a user-definable unit that sounds great. It is simple yet versatile enough to cover a wide variety of tabletop or rackmount applications. The unique design lets you tailor the mixer exactly to your needs by choosing one of six configurations. The basic unit from which all other permutations are derived is the Line Version; it simply has 16 line inputs that feed a stereo bus. If your needs call for mic pre-amps, you can choose the Mic Version, which contains 16 mic pre-amps and a few other extras we'll get into later as we zoom in on the details. The 8+8 version splits itself into eight mic pre-amps and eight line inputs and, as I'll attest to later, is perfect for live recording. The Bus Version adds the ability to send the post-pan signals to two stereo busses and also lets you send the aux amp to two mono busses. The Special Line Version is a mic/line hybrid that adds polarity reversal to the line inputs (polarity reverse is only standard on mic inputs) and is switchable between +4dBu and -10dBv input. The L/C/R Version replaces the pan pot with a three-deck pot so you can use the mixer for simple surround applications. Lastly, there is a 32x8 version that lets you send the post pan signal to a total of four stereo busses. Of course, this completely changes the front and back panels to represent the additional inputs and outputs.

A Class Act

The mixer has the distinctive look and feel that Manley fans have grown to love. From the military-grade knobs, switches and connectors to the oversized, lighted VU meters and hefty quarter-inch front aluminum panel, the mixer looks like it's ready for serious business. Designer ‘Hutch’ Hutchison has borrowed some ideas from their existing product line and added some nice new touches. For instance, the input stage is the same low-noise instrumentation amp that's used in their custom mastering console, and the summing amplifiers are similar to the make-up gain amps used in the Massive Passive. Other nice touches include the slick locking toggles used for the on/off and phantom power switches. These prevent accidental AC power up/down or phantom power up situations, which could be hazardous to speakers not to mention ribbon mics. They’ve also used some very cool looking and sturdy micro toggles, which are used to switch the relays for polarity reversal (no IC's here!) and the insert I/O function.

The inside of the mixer is just as impressive, using gold contact Grayhill rotary pots for the monitor switching and mic pre-amp gain, Tocos toggle switches, Bournes series 91 conductive plastic GT series pots and Siemens and Magnecraft relays. As the title alludes to, the mixer uses a tube stage at the stereo output utilizing two 12AT7WA and two 6414 tubes. This adds a very nice touch to anything you send to the stereo bus, making it perfect for those who want to add a touch of warmth to their mostly-digital signal path. The noise and distortion figures from channel input to channel output are an incredible THD+N of 0.0002 percent (-90dB) at unity gain (+4dBu). The channel input to mix output figures are not as good, but hey, a little tube distortion and noise is what imparts that much-needed love touch to a cold digital world. These figures are THD+N 0.05 percent (-65dBu) at unity gain (+0dBu).

Zooming In

Because you can have the mixer custom built to your specific needs, it's best to describe the 16x2 in modular form. From top to bottom a single mic pre-amp channel consists of a pan knob, a micro insert I/O toggle switch and LED, and a microphone gain knob, which is detented from zero to 60 in 5dB increments. Under that there is a micro polarity toggle switch and LED, the mix gain knob and the channel solo and mute buttons. The line input channel from top to bottom features a pan knob, an aux output gain control, the channel volume control and solo and mute buttons. To the right side of the mixer is the user-friendly master section. It has two large illuminated analog VU meters, the aux master volume control, a locking power on/off toggle switch and separate mix and monitor volume controls with corresponding mute buttons. The monitor select knob is a five-position pot that lets you monitor the stereo bus mix, mono mix, aux master or the separate balanced (TRS) tape and external inputs. In addition, there is a button that allows you to switch between two sets of monitors and a dim switch that kicks down the monitor level -15dB.

The unit is 5U high and only seven inches deep from the front of the knobs to the back, which makes it great for traveling racks and leaves plenty of room for cables in the back. The mixer comes with a separate robust power supply that allows the main unit to weigh in at a svelte 18 pounds. It comes with a six-foot power cable to carry all the necessary voltage to the main unit. The cable is fixed at the back of the mixer but attaches to the power supply using a sturdy locking multi-pin connector. The back panel is loaded with I/O as you would expect from such a full-featured mixer. I/O for the mic pre-amp modules includes a locking toggle for the phantom power (switched in groups of four channels) a balanced direct output, an unbalanced combination send/return TRS insert jack and a combination XLR/TRS connector for the mic input.

The line modules have a post-fader pre-cut direct output, an unbalanced aux out and a combination XLR/TRS line input. There are three mix outputs, one balanced and two unbalanced. The unbalanced outs are TRS with the ring grounded by a resistor that provides an impedance equal to the tip. This assures common mode rejection and allows these outputs to drive either a balanced or unbalanced input. The extra unbalanced out can also be used to chain other 16x2 mixers together with solo linking via a wired connection from the Solo Link jack. There are separate XLR and TRS monitor outputs that can drive either balanced or unbalanced inputs to power amps or powered speakers. One nice touch is the separate ground terminals for audio and the chassis that are handy if you’ve got some hum problems to solve.

Tech-heads as well as the user who just wants to jump in and start recording will love how the well-written manual is laid out, although you don’t need it, as the mixer is very intuitively built. There is an extensive troubleshooting section that takes every level of user into consideration and some nice templates for those who need to document their work for recall.

The Test Drive

I have been eyeing the new mixer since I saw it displayed at AES 2000 in Los Angeles. Hutch and EveAnna promised that it would be out ‘soon’, which just caused me to put them higher on my list for phone harassment. It's when I got the call to do a truly unique live recording in California that the light bulb went on, and I felt the 16x2 and my project were a match made in Heaven. I mean Heaven literally, because I was going to record the chants of the Camaldoli monks at their hermitage in Big Sur. The story behind that recording is in the works for a future issue, but I literally wrote this review on the plane coming back from the sessions because I wanted to get the word out on the mixer as soon as possible.

The version I had was the 8+8 version, which is evenly split between mic/line inputs and straight line inputs. It was the perfect configuration for the project, because I was doing multiple passes in surround and recording them to an eight-channel multi-track recorder. My microphone set-up was stereo front and rears using Schoeps microphones directly into the mic pre-amps of the Manley. The pre-amps sounded great, and the -90dB noise floor made it the perfect box for recording source material with a wide dynamic range. I then took direct outputs from those channels to my recorder and brought back the eight tape returns to the line inputs of the mixer. By putting the mic input channels into mute, I was able to use just the pre-amps of the mixer and not worry about them getting to the stereo bus. Once the mics and returns were set up, it was easy to route audio as I needed. During the sessions it was necessary to feed separate speaker feeds from the mixer to the recording space as well as the makeshift control room we'd set up in an adjacent room. No problem, I simply ran the aux master out in mono from the Manley to some Hafler TRM8 powered monitors I had set up for the talent and dialed up their own mix from the return channels. I then used the main monitor outputs to send to the speakers in the control room. Because of the proximity of the control room to the mics, we had to monitor on headphones during recording — this is where the mute buttons for the monitor feed came in handy. I simply kicked the speakers on when we were done with a take and needed to monitor what was on tape. The one thing I wish I’d had was a stereo headphone output with a volume control, although I don’t know where they’d fit it.

Conclusions

The mixer is absolutely delicious. As we've all come to expect from Manley, the execution of this product is rock-solid. The layout and all switches, buttons and dials tell the tale of many hours of thoughtful design and construction. Indeed, it looks like no expense was spared in putting this product together. For my live recording application, the 8x8 worked perfectly. The only caveat I’d give would be that the power supply puts out a slight hum. If used in the same room as your mics, this might present a problem, but in a rack behind your gear it should be fine. I used the mixer for three days, leaving it on 24 hours a day under questionable AC conditions (the monks were on their own power grid using diesel generators). We had absolutely no problems of any kind even under these conditions. Anyone who is looking for a custom-built, next-generation professional mixer with the added bonus of a sweet sounding tube stereo bus should consider the Manley 16x2, there’s nothing like it on the planet.

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INFORMATION

Manley 16x2 Tube Mixer Line Version $9000; Mic Version $9500; Line/Mic 8+8 $9900.

Manley Laboratories, Inc., 13880 Magnolia Avenue, Chino, CA 91710.

909 672 4256.

909 628 2482.