Avalon VT-737SP Channel Strip

Revisiting the infamous and ubiquitous 737

by Glenn Bucci

The Avalon VT-737SP is one of the first stand-alone channel strips that were designed and was released in the late 1990's. After its release it received rave reviews from numerous engineers and artists, and is still in heavy use on major-label sessions. There have since been other new preamps and channel strips that have come out since then with bigger and punchier sounds. Many also have impedance and iron controls for added flexibility. I figured it was time to take a look at the 737 SP, and see how it matches up against the new guys on the block.

When the 737 was first released it had ugly purple plastic knobs which many did not care for. Thankfully Avalon updated the unit by putting higher grade aluminum knobs, and also increased the mic input transformer level with the SP (Special Performance) model. Since this release, Mercenary Audio had worked with Avalon's designer Wynn Morro and came out with a cheaper model called the 737 Mercenary Edition. This version has a cool black face with gold lettering, with plastic black knobs. Thankfully all the internal components are the same as the SP model. It is one of the best looking channels strips out there.

The 737 SP combines a tube pre, optic compressor, and a 4 band EQ in a 2U space. In looking at the front panel starting from the left, there is a preamp gain, instrument input, input control knobs that gives an option of line, instrument, or mic. There are push buttons for high gain, phase, phantom power, and filter. The high pass filter has a knob that starts from 30 Hz and goes to 140 Hz. Avalon also has recall sheets that can be helpful in remembering your settings. DAW's like Nuendo/Cubase have a note section for each channel, where you can write information about the track including your settings on compressors and EQ.

In regards to the mic pre, it utilizes two cascaded dual vacuum tube triodes configured with minimum negative feedback. The pre has a clean but smooth sound that is very pleasant. In comparison with my Neve Portico, the 737 pre is more even sounding and not as big. I also compared it to the Tube Channel on the new Manley TNT which is basically a Slam pre. The Manley had more depth than the 737 and a more articulate sound. The 737 had more of a filtered sound in comparison. While this is all subjective, I still like the sound of the 737 pre, but on its own, it lacks some of the punch or sparkle that many other pre's have. Thankfully the 737 does not stop there.

After the pre is a very nice optic compressor. I found up to -3db it performed wonderfully on vocal tracks and it did not alter the sound of the performer. The compressor was able to control the peaks and help give a very even performance. My Langevin DVC limiter acted pretty much the same way. As you start to use more compression, the smooth character starts to get stronger in a very pleasant way. I found myself liking the attack on the fast side, and ratio on about 4 on vocals. Like most optic limiters, they excel on vocals and acoustic instruments, but many times are not fast enough to handle fast transients. This held to be true with the 737 as well. But that is why studios have more than one compressor as each has their own purpose. Generally it's best not to use too much compression at the tracking stage. This is to allow you alter it more during the mixing stage so you can hear it within a full mix.

After the compressor is the 4 band EQ, that is more on the transparent side. I like using a clean EQ when you have a tube pre. The reason is the pre already has a smooth sound, and this EQ allows you to alter the frequencies without changing the real character of the pre. The EQ allowed much flexibility in giving more sparkle, depth, bass, or a nice cut in the middle on vocals, while at the same time keeping the pre's character. I have to admit if the unit did not have the EQ, I would be more drawn a lot more to the cleaner and punchier Avalon 2022, or M5. However this EQ (which is better than any clean EQ plug in I heard), allows you to sculpt the sound of your source and get that right sound you're looking for.

So how does the 737 SP hold up against the current competition? I'd say very well indeed. Good enough that it made me quite sad to return the unit. A special thanks for the Guitar Center in Commack NY for allowing me to try the unit.