Field Test: Inward Connections VacRac TSL-3 Limiter

Oct 1, 2007 12:00 PM, By Michael Cooper

OPTO-DYNAMIC CONTROL WITH WARM, TRANSPARENT TONE

Polls


Mix Regional

The Mix Regional section for Mix's July 2014 issue focuses on Atlanta. Send us your studio news: updates, sessions, new rooms, club performances and installations. Let the Mix audience know what is going on! Send photos and descriptions to mixeditorial@nbmedia.com.

Inward Connections VacRac

In 1995, Steve Firlotte and Steve Barker designed the Inward Connections all-tube VacRac, a modular system that integrated the company's TMP mic preamp, TLM-1 limiter and TEQ equalizer, both with external power supplies, in a 19-inch, rackmountable Lunchbox-type chassis. The TLM-1 mono opto-limiter proved to be the biggest hit of the three modules, and many pros were disappointed when the VacRac was discontinued around the year 2000. Hopes were renewed a couple years ago, however, when Inward Connections resurrected its favored limiter in a stand-alone, dual-channel design made for Vintage King Audio, the company's current distributor. And so the VacRac TSL-3 tube stereo limiter was on the market.

Housed in a well-ventilated, gorgeous, 3U steel chassis sporting large knobs and VU meters, it's the TSL-3's onboard power supply that actually deserves the headline. The high-power (300-volt), tube-regulated supply immaculately preserves audio transients, which factors largely into the TSL-3's beautiful, signature sound.

NO-BRAINER OPERATION

Like vintage dynamics processors built around opto-electronic gain-control elements, the TSL-3's front panel sports few controls, making the unit's operation exceedingly straightforward and lightning-fast. Each of the two channels have continuously variable reduction controls that feed light-dependent resistors (LDRs) to adjust the depth of compression up to 40 dB. A continuously variable, rotary gain makeup control for each channel supplies up to 14 dB of gain and is active even when its associated channel-bypass button is engaged; this lets you run audio through the unit's all-tube audio path without any dynamics processing. The gain makeup control serves a 12BH7A tube in the output stage and does not feed back into the gain-reduction circuitry. Each channel's input stage features fixed gain from a 6072A tube.

Two large (3×3-inch), backlit VU meters — one for each channel — can be independently switched to show either gain reduction or output level (the latter setting referenced to +4 dBm and zero'ed using recessed trims). A stereo-link button and rocker-style power switch finish off the spacious front panel. All switches are backlit with LEDs when active.

The rear panel features XLR I/O connectors, an IEC receptacle for the detachable AC cord and a voltage selector accommodating either 120- or 240VAC operation. Inputs are transformer balanced and rated to handle levels up to +20 dBm. Outputs are unbalanced (pin 2 is hot, and pins 1 and 3 are ground) and specified to handle up to +20 dBm at 600 ohms or +34 dBm at 10 kilohms. Output transformers are optional, although not a single customer has ordered them. Frequency response is stated to be 20 to 20k Hz, ±0.5 dB.

IT'S CRUNCH TIME

The TSL-3's action at its “knee” is noticeably firmer than that offered by my Universal Audio LA-2A tube compressor, another opto-compressor. On some sources, such as vocals, compression depth swung from 0 to 10 or 20 dB with fairly small adjustments of the TSL-3's reduction knob and only moderate swings in input level above threshold. Even with such deep compression, however, the unit's sound remained remarkably transparent. The TSL-3 put a firm yet clear lid on triple-tracked, two-part background vocals recorded with a Lawson L251 mic and Millennia HV-3D preamp, preventing a submix pileup and delivering a rich and present tone for the group.

The TSL-3 sounded incredible on strummed acoustic guitar. With swings in gain reduction between 1- and 7 dB, the unit dramatically tightened up the instrument's bottom end while treating the top with kid gloves, creating a leaner and more sparkly track that needed less EQ cut to reduce boominess. Similarly, applying a moderate amount of gain reduction to a kick drum track reduced the amplitude of shell decay to produce a sound that popped more.

Next up was a Strat playing palm-mute diads through a Roland Micro Cube amp miked with a Royer R-122. The TSL-3 transparently controlled the track's level so that it neither dominated nor disappeared into a dense Southern-rock arrangement. Placed on the stereo tracks for overhead drum mics, the TSL-3 gently moderated peaks and shaved off some low end on bleed from the traps. Even with 20 dB of gain reduction on peaks, I couldn't get the TSL-3 to pump; for the bombastic sound of John Bonham-style drums, another limiter would be a better choice. Results on electric bass guitar were also fairly pedestrian, although perfectly usable.

Despite its conservative headroom specs, the TSL-3 handled the 26.5dBu output of my Yamaha 02R mixer's stereo bus outputs without distorting. In a 2-bus application, the TSL-3 lent the mix a more velvety sound and tighter bottom end (not necessarily appropriate for this thumping R&B production). The unit's attack time proved to be too slow to dramatically reduce peaks, leading me to conclude that the TSL-3 is not the best choice for increasing the loudness of a mix.

TAKE IT TO THE LIMITER

My only criticism of the TSL-3's build is that the XLR input connectors don't latch. The $4,500 list price is high, but premium-quality tube gear doesn't come cheap. What matters is the sound. The unit's sonic character tends toward modern and pristine rather than vintage and highly colored. Yet the all-tube audio path certainly adds a warm, velvety touch to digital tracks. If you're looking for an ultratransparent tube limiter with a sweet tone, the TSL-3 is worth considering.

Inward Connections, dist. by Vintage King Audio, 248/591-9276, www.vintageking.com.






Acceptable Use Policy
blog comments powered by Disqus

Mix Books

Modern Recording and Mixing

This 2-DVD set will show you how the best in the music industry set up a studio to make world-class records. Regardless of what gear you are using, the information you'll find here will allow you to take advantage of decades of expert knowledge. Order now $39.95

Mastering Cubase 4

Electronic Musician magazine and Thomson Course Technology PTR have joined forces again to create the second volume in their Personal Studio Series, Mastering Steinberg's Cubase(tm). Edited and produced by the staff of Electronic Musician, this special issue is not only a must-read for users of Cubase(tm) software, but it also delivers essential information for anyone recording/producing music in a personal-studio. Order now $12.95

Newsletters

MixLine

Delivered straight to your inbox every other week, MixLine takes you straight into the studio, with new product announcements, industry news, upcoming events, recent recording/post projects and much more. Click here to read the latest edition; sign up here.

MixLine Live

Delivered straight to your inbox every other week, MixLine Live takes you on the road with today's hottest tours, new sound reinforcement professional products, recent installs, industry news and much more. Click here to read the latest edition; sign up here.

[an error occurred while processing this directive]

The Wire, a virtual press conference offering postings of the latest gear and music news, direct from the source. Visit the The Wire for the latest press postings.