John Peluso | TapeOp

John Peluso has been quietly providing classic-styled mics to some of the biggest names in music for over ten years. Peluso's line of vacuum tube condenser, solid-state condenser, and ribbon microphones are hand-assembled and tested, and surprisingly affordable. Peluso has recently introduced their P-84 and P-49 small diaphragm mics.

What's the best thing about Peluso mics?

We style our microphones after the classics, but we use our own engineering to replicate the sound. I don't want to get into a pissing match with Neumann or AKG, so we change some things. We do the physics and figure out what we have to change to get the same resonances and sounds. I was able to get centerline graphs on tons of vintage microphones that a large manufacturer in Chicago did in the '60s and '70s. This stuff was all destined for the dumpster when they moved to a new facility.

How did you first meet the man that taught you about microphones?

I was visiting my friend, Eric Enfield, at Chicago Stereo Mastering in 1969. There was this amazing crash right when I was walking in. I went upstairs and heard screaming; then I saw that they were all at the bottom of the elevator shaft! The mastering studio's owner, Verner Ruvalds, had injured his head. I went down to the basement, pried the doors open, loaded him in my car, and drove him to the hospital. We became fast friends. He was also working at Shure Brothers at that same time, as his day job, designing phono preamps. A few months later I applied and got a job at Chicago Stereo Mastering as a mastering and recording engineer. During my three-year tenure there I mastered most of the original Rounder and Flying Fish records.

Did you study electronics in college?

Yes, I did. During my last few years of high school I spent a half my time in high school and half in community college. I studied electronics and chemical engineering. Then I went on to the University of Boston, as well as a quick little stint at MIT. We studied things like network theorems. We also focused on how to do all the calculations to determine the parameters, if you were using your components within parameters, and how different circuits worked. As far as audio, there didn't seem to be any emphasis on it in electronics classes. You would get the Radio Engineers Handbook [by Frederick Emmons Terman] — that was everybody's bible. It's what all of the transformer manufacturers use to determine their transformer specs and winding formulas. The styles of building gear changes because transformers are expensive and a lot of people cut them out.

Do you find that you favor them sonically?

Yes. We make one product that's transformerless, but it's not my favorite sound. When I worked for Verner Ruvalds, he loved to talk about building microphones. I would stay until two or three in the morning and listen to his stories. I think I was the only one who ever worked for him who would take the time to listen to what he said. When I left, and he was getting ready to retire, he gave me jigs and all his notebooks. I still have an original Neumann capsule engineers' handbook. Luckily I can read German...

Are condenser mic capsules' screws like drum lugs? I'm told the trick is tuning the resonance of the diaphragm and damping it with the head electronics.

Your analogy on the screws tuning the capsule like lugs on a drum is not true. You tune it once, when that diaphragm is mounted on that capsule, then there's no changing the tension on it. Most Neumann capsules are glued to the clamping ring. You set the tension in the jig when you diaphragm the capsule; once you tighten those screws down and put the glue around the edge of the clamping ring it's permanent. Even on an un-glued diaphragm you can't change it; if you take the screws off, the diaphragm will go slack — it's cut to the diameter of the clamping ring, so you can't ever put it back in a jig and re-tension it.

So how do you get the tension right in the first place?

The jigs we use can tune. You know, it's a double process — the weight of the jig is about 90 percent of the tensioning, and then we set a starting tension on the diaphragm. We use AKG-style rings. Neumann pressed the material into a weighted ring and used the weight of the ring to tension the diaphragm. If you want a diaphragm that's resonating more in the high-end than the mid-range, then you raise that resonant frequency. Depending on your back chamber volumes, and the resonance of your back chamber, you can do calculations to tell you what frequency your diaphragm will resonate at. At the resonant point you're generally going to have a [volume] peak. If you're putting that resonant point up at 8 or 9 kHz, then the beginning of that peak is going to start at 8 or 9 kHz. In a lot of the Chinese capsules the resonant point is at 6 or 8 kHz, a little lower, so you've got this really hefty, harsh- sounding midrange. AKG mics tend to have their peak at 12 kHz; it's a single peak, rolling off flat to about 18 or 20 kHz, which gives them that nice ethereal high-end air.

What is gold sputtering?

We don't actually use sputtering, but sputtering uses an electron beam that sprays gold out. The process we use is vacuum deposition, which is what Neumann uses and AKG has used. Sputtering tends to damage the Mylar, because it's hit with a high-velocity electron beam. Vacuum deposition takes place in a vacuum chamber. It's very complex machinery and requires liquid nitrogen cooling to get the pumps to pull an absolute vacuum. You evaporate gold and allow it to settle onto the diaphragms, with targets of the correct diameter of the gold you want to deposit. The target fits tightly over theMylar diaphragm to protect the areas that can't be conductive. We have a vacuum system, but we choose to send that work out to somebody who does that every day. They produce much better diaphragms than we could possibly do in-house. We can get a thousand diaphragms made in Minnesota and only really pay for the set-up and labor once we have our targets and everything. We've been doing that since the beginning.

How many people are employed by Peluso?

It's really a team "behind the gear" here. We collaborate on everything. We have three full-time people, which includes my wife Mary, my stepson — Mary's son — Chris Newitt, and myself,. We have three machinists at Virginia Tech — a couple of engineers that help us part-time. Our next-door neighbor here is the one who runs the machine shop for the Virginia Tech Physics Department. Mary builds microphones and handles all the finances. Mary's an amazing buyer — she has great relationships with our suppliers. Chris builds microphones, and he's starting some design work. He's doing all the layout and aesthetic design on our preamps, which is his first major design project here: the upcoming Peluso vacuum tube and solid-state microphone preamps.

I'm told that you have some software that does the job of an anechoic chamber for testing?

Yes, we use what is known as a time-domain spectrometer. It only reads a certain frequency at the exact moment that it's being picked up by the microphone. We use ours in tenth of a hertz increments. That's 4096 steps from 20 Hz to 20 kHz. It ignores all reflections because the reflections are further back in time. This was developed by the JPL [Jet Propulsion Laboratory] for making anechoic tests on items that were too big to put in an anechoic chamber.

Is this how you do your matched pairs?

Most of our microphones are within 2 dB of each other, per model; we do that by controlling the response of the capsules and by making sure our amps are consistent from one to the other. When we do a matched pair, we try to find microphones that are less than .25 dB apart from each other from 20 Hz to 20 kHz. We graph every microphone we make. If you order a matched pair we'll look at what we have available that's built up, and we'll see if we have a pair that matches within those specs. If our microphones are more than 2 dB apart from each other we go looking for the cause. We know they're going to drift out in the field, so if they start out on the edge of acceptability they're not going to last. They're not going to be sounding correct in five or ten years. Because we're a small manufacturer, and we really control our costs, we can afford to do that. We own all of our facilities, our own parts stock, warehousing, and all of our equipment outright. We're not like a big corporation, where we're paying off a huge debt on the equipment all the time.

Did you ever get starstruck by anyone that was using a Peluso microphone?

I've never been starstruck. I've worked with a lot of so-called recording stars. When I worked at Sonart/DB Studios we had The Rolling Stones through. I worked on a movie, Banjoman, with The Byrds and Nitty Gritty Dirt Band. The closest to starstruck I ever have been was working with Ramblin' Jack Elliott. He wasn't that much of a star; he was just a great performer.