Technology

Universal Audio 4-710d Preamp/DIs Review

FOUR TUBE/SOLID-STATE UNITS WITH 8-CHANNEL A/D CONVERTER 5/01/2011 5:00 AM Eastern

The 4-710d preamps offer all the features of Universal Audio’s 710 Twin-Finity, plus compressors on each channel.

I first had the opportunity to review Universal Audio’s 710 Twin-Finity in the summer of 2009. I found it to be a versatile, affordable and innovative take on the tube vs. solid-state preamp. The only complaint I had at the time was that it didn’t come in stereo. Well, I got my wish and more in the 4-710d. This 4-channel preamp offers all the features of the 710, but adds compressors on each channel; switchable inserts; an 8-channel, digital A/D converter with ADAT optical and AES/EBU DB-25 outputs; an ultra-low-jitter clock subsystem; word clock I/O; soft limiting; and variable sample rates up to 192 kHz, 24 bits.

The 4-710d has all the bells and whistles of its single-channel predecessor. Each preamp has a DI input and six switches bookending the analog meter for phantom on/off, -15dB pad, mic/line, meter switching (output/GR/drive), low-cut (75 Hz) and polarity. Two switches below the meter engage the insert and compressor with either slow or fast attack/release. As on the 710, there are pots for input and output gain, and blend between solid-state and tube. The back panel carries XLR mic in, line in, line out and balanced insert send/returns on TRS plugs. There are also four extra TRS inputs for the extra line inputs. In my sessions, this offered a handy way to get other line inputs into the digital back end of the unit. The digital side of things has AES/EBU outs on a D-Sub connector, word clock I/O and twin ADAT outs that are mirrored at 44.1 and 48 kHz, 4+4 at 88.2 and 96 kHz, and 2+2 at 176.4 and 192 kHz.

ALL AROUND THE STUDIO
I first used the 4-710d in a surround recording session. As I needed five preamps, I brought a 710 Twin-Finity along and ran its output into one of the first of the four extra line-ins in the back of the 4-710d. My hookup to Pro Tools used the optical output of the 4-710d, which I ran into the optical input of an Avid 96 I/O interface. To lock the system’s clocks, I ran a short 75-ohm BNC cable from the clock output of the 96 I/O to the word clock input of the 4-710d and the “lock” light on the front of the unit immediately confirmed all was good.

Five sE Electronics sE3 microphones were patched into the preamps, and Pro Tools saw all five on a single 5-channel track. Levels were set, and I used the rig to record acoustic guitar, conga and vocals. While I didn’t use the individual compressors (because I only had four), I did use the soft-limiter option with great results. These are set at a threshold of -3 dBFS with an infinite ratio and attack time of 0.075 and release time of 100 ms. The manual states, “Although the limiter will help prevent ‘digital overs’ [A/D clipping] during conversion, it is not a ‘brick wall’ limiter. It is still possible to clip the A/D input.” I’m usually conservative with my DAW levels anyway, but I did find that no matter where my levels went, they never showed red in Pro Tools, even when I tried to overload the input on purpose. All I know is that it sounded great when I set the limiter to “on” and I ran my levels moderately as usual.

What was most telling on this session was that I ran the same song and mic setup without the 4-710d earlier in the day. I used the preamps on the Avid C|24 and 192 I/O converters, and the difference was stark. The 4-710ds offered a much clearer picture of the high-end detail of the vocals and acoustic guitar. The sound of the player’s fingers on the strings sat higher in the track and the overall effect was more musical across all tracks. Vocals had more detail and hit the reverb better, but also had the body in the midrange that was needed to keep it from sounding thin. Whether it was the converters, preamps or a combination of both, it worked. Bravo on all fronts.

The back panel offers XLR mic in, line in and out, and balanced insert sent/returns on TRS plugs, as well as four extra TRS inputs for the extra line inputs.

The back panel offers XLR mic in, line in and out, and balanced insert sent/returns on TRS plugs, as well as four extra TRS inputs for the extra line inputs.

Next, the 4-710d was used to record a Yamaha C3 grand piano using a Royer SF-24 active ribbon microphone with the Trans/Tube adjustment set at 12 o’clock. It offered a sweet top end that cut through the mix with a solid midrange. Another preamp was used as a bass DI with the Tube setting all the way “on.” This offered a nice bottom end—not quite as fat as the SSL 4000 preamps usually used in this room, but it still sounded great.

A Fender Guitar amp recorded with a Voodoo VR1 passive mic into preamp number 4 with Trans/Tube set at 12 o’clock had the strat cutting through the mix nicely, with plenty of body and a nice edge that wasn’t strident.

Next, I used the preamps on different drum sessions. On the first, I used them for kick in and out, and snare top and bottom. In this case, I wasn’t getting the thump and transient presence I’m used to when using SSL 4000 console preamps in this studio. After playing with the settings on the 4-710ds a bit, I quickly swapped them for the SSLs and it was much better. Keep in mind that the price jump here is considerable and an A/B comparison is unfair. The point is to offer a reference to a different preamp.

In the next session, I used the 4-710d on toms 1, 2 and 3 top with Heil PR30, PR40 and a Sennheiser 421, and on tom 3 bottom powering an AKG D112. This was just the ticket, offering plenty of stick-hit detail and bottom end from the low-tom bottom mic when I flipped it out of polarity with the top. I also used the 4-710d to power two Blue Bottle mics placed above the kit with great results. It offered nice detail, no brash cymbal wash and great stick detail. I did kick in the individual compressors in this application with a slow attack/release, and it was good but not what I needed in this application.

ON THE BENCH
The 4-710d preamps showed impressive stats when put to the test with an Audio Precision APx525 test and measurement system. (Download the tests.) When testing analog in to analog out with the Tube option completely bypassed, inputs 1 and 2 showed very low distortion levels (0.001% and 0.005%). This was retested using the digital out at a 96kHz sample rate with the same two channels showing 0.002% and 0.004% (solid-state) and 1.408% and 1.621% (tube). The distortion figures jump considerably with the Tube, but that’s to be expected. In all tests, the frequency response was razor flat from 20 Hz to 80k Hz (analog), while the same was true testing analog in to digital out at 96kHz sampling rate.

FOUR IS MORE
I found the UA 4-710d to be a versatile and worthy go-to set of preamps across a range of applications. The feature set is very good and urges you to experiment. The tube vs. solid-state option is a great way to play with nonlinear distortion in the signal path. The manual is well-written and goes beyond the usual “this and that” to offer deep insights into clocking, digital operations and more.

Although I found them to sound great on almost everything I recorded and loved the converters, they wouldn’t be my first choice for kick and snare drum as I found them to lack the punch of higher-end preamps. However, for detail work like vocals, percussion, acoustic guitar, horns and piano, they stand head and shoulders above anything in their price range.

The bottom line is that the value is incredible. Four solid preamp/DIs with compression and a great-sounding 8-channel digital back end with soft limiters is unheard of below $2k (street). For the project studio owner looking for a versatile, affordable front end for a DAW, this is not only a must-hear, it’s a must-buy.


Kevin Becka is Mix’s technical editor.

Click on the Product Summary box above to view the 4-710d product page.

Click on the Product Summary box above to view the 4-710d product page.

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