Register    |    Sign In    |   
electronic MUSICIAN

The Rupert Neve Designs Portico Series 5012

By Tim Green | May 5, 2006

The Rupert Neve Designs Portico? Ahhh . . . a new line of half-rack space units with three things in common: custom designed transformers, minimal crossover distortion, and minimal negative feedback. These are some of the most important ingredients in the recipe for a great mic pre amp and consequently the 5012 received minimal negative feedback from this reviewer.

Please save your laughter for the end of the review.

I have to admit my first impression of this pint-size, plastic-looking, dual pre amp left me a little underwhelmed. But what appeared plastic was actually folded steel and there was nothing pint size about the sounds that came out of this thing. Indeed, the small size lends itself to RND’s mandate of short signal paths, not to mention the fact that it encourages you to buy a second unit so that it can be properly rack mounted.

The usual amenities are also all there: phantom power, phase switching, and a high quality stepped gain attenuator, as well as a continuously variable trim pot, but you’re also treated to a sweepable low-cut filter ranging from 20Hz to 250Hz. I’m a big fan of these types of filters — sometimes I want to start carving into the low mids and sometimes I just wanna eliminate a little rumble. So that won big points with me. In addition to a mute switch for each channel and the ability to buss the channels together to a separate output, there’s also the mysterious “silk” switch, which applies to both channels and which I have yet to fully get my head around. There’s also an LED meter for each channel, and the 5012 also comes with an external power supply that can power two modules simultaneously.

The first round of testing began during a session with San Francisco’s prog kraut rockers, Crime in Choir. In practice this mic pre held up well against the usual mainstays of my studio and in many cases outshone its competitors. While sounding great on snare, I must admit that I still preferred my old, poorly racked UA 1108s. Technically the Portico sounded better, but I like the bit of dirt and overdrive the 1108s impart. The 5012 was just a little too good perhaps.

Nevertheless, it sounded splendid with a pair of Schoeps 221b’s as room mics and the sweepable low cut filter was particularly useful. In fact it sounded great on just about everything. Even with Rupert Neve’s name on it, it seemed a little too good to be true, so . . . another, more intimate round of testing.

Paired with a Klaus Heyne-modified U87, the 5012 excelled at reproducing the sounds of a beat-up acoustic guitar (unlike a neighboring API 512, which sounded murky and boxy). Again the low-cut filter was an essential tool — sure one big, boomy acoustic guitar sounds great, but try layering six with that much bottom end and see what you get? Nothing I would want to listen to, that’s for sure.

But what really stood out in this comparison was the clarity, the sparkle, and the incredibly solid low end — the latter being the most pronounced difference. We’ll chalk that one up to the Neve-designed transformers. Speaking of which, I wonder why this thing is getting so damned hot?

This question, as well as some of the curious terminology used on the RND website, such as “Transformer-Like-Amplifier” and “The RND 5012 uses mainly single-sided amplifier circuitry” led me to start wondering what was going on under the hood. So, against my better judgment, I very carefully opened it up. After the magic elves scrambled into their hiding places, I saw that some serious design went into this thing. There’s not an inch of wasted real estate around the massive output transformers. All switching is relay enabled for quiet and smooth operation. And although, at first glance, the plethora of 5534 op amps was alarming, a subsequent read of an online interview with Mr. Neve regarding the way in which he runs these op amps was reassuring.

Which brings us to the next interesting design point: The 5012 has a frequency range of roughly 10Hz to 160kHz. Yes, that’s right, forget the Nyquist theorem, this is at least eight times the ceiling of average human hearing! I had read an interview with Neve some time ago and tracked it down so I could re-tell the story (or at least give you the gist of it). OK, here goes: The year is 1977, the location is George Martin’s AIR studios, the concerned engineer is Geoff Emerick, the console is a recently delivered Neve and the problem, which only Emerick’s clued in to, is anyone’s guess. Ultimately, testing revealed a 3dB peak at 54kHz on three channels due to some mis-wired transformers.

The point of this story is that while humans may not hear much above 20kHz, there is some sort of perception at work. Anyone familiar with Pauline Oliveros’ work with tones will know that in addition to this perception, one can also hear the interaction of frequencies above the range of human hearing if combined properly. What I’m getting at is this though: The 5012s stated frequency range not only looks good on paper, but makes for good science and even better listening. RND set out to make an affordable, compact, transparent preamp with a minimum of crossover distortion. They have achieved this and our ears will thank them for it. And if anyone cares to check out the interview with Mr. Neve in which he tells the Geoff Emerick story it can be found in greater detail right around here: prosoundweb.com/chat psw/transcripts/ rupert.php.

Also, as a footnote, I wrote to RND asking if the silk feature affects second and third order harmonics. I was rewarded with an immediate response from Rupert Neve himself! And here it is . . . “‘Silk’ reduces negative feedback, which naturally allows increase in second and third harmonics. There are no high order harmonics even without feedback, because the design is effectively single-sided. ‘Silk’ shapes the feedback network to optimize the ratio of second and third to sound musically sweet (for example, too much third would sound muddy at low frequencies).” Genius.

Alert to All Users of the Disqus commenting system:
Because of a recent global security issue, the Disqus website recommends that all users change their Disqus passwords. Here's a URL about the issue: http://engineering.disqus.com/2014/04/10/heartbleed.html
comments powered by Disqus
related articles
Connect with EM
Free eNewsletter
the em poll


most popular