Bargain Gear: The Crest Audio iPro One Preamp

As you probably know, I’ve been doing a bunch of ribbon mic experiments lately. The thing about ribbons is that, in general, their output level is fairly low, and the mics I’m building are no exception. As a result, you have to crank the input gain pretty high on a ribbon, and when I tested the Austin ribbon mic, it was pretty clear that my preamp department was lacking. And until I start making thousands of dollars in the studio, I won’t be able to buy a nice John Hardy M1 preamp like we had at OnLine Audio (list price, $2905 for four channels. It sounded REALLY good…)

So my alternative was to build one myself. A conversation with Les Watts told me he uses THAT chips for the pres that he’s built, and their performance equals or exceeds discrete mic preamps like those used in the M1. So I began looking at designs and collecting parts to build one or two myself.

The input side of the studio. The two interfaces are usually fed from these preamps, though I have direct outs on my mixer if I need more. I bought the Nady years ago. It works, but isn’t the best solution… I only use it when I’m looking for a quick signal input. It’s due for a complete overhaul soon. My other preamps are relatively new additions, a Presonus Bluetube, and on the bottom is the main subject of this review.

That’s when I came across the Crest iPro One. It uses THAT chips and has a very low EIN (Equivalent Input Noise) spec of -129dB. I found one on eBay for $140, including the shipping, so while I probably shouldn’t have, it was too cheap not to try one. They seem to be discontinued, I can only find them from a seller called Audiosavings. But they are brand-new units and arrived via FedEx just a few days after ordering.

It came in the other day, and I’ve set it in my rack and gave it a listen. Here’s my initial impressions.

About the only real beef I could find was that the name starts with an “I,” which has gotten really overused. The rest is pretty darn good… crazy good considering the price that I paid for it. It is indeed a low noise preamp, and my ribbon mic sounds way better when connected to this box.  In fact, it’s made the mic a viable option for a speaking voice signal, where before you really couldn’t use it for anything relatively quiet like spoken voice.

The Crest preamp and mic processor controls

And there are lots of other options available on this unit for coloring the signal to your liking. Going from left to right, first is a low-cut filter, which will be useful in several cases. It has a fairly gentle 12dB/octave slope, so it won’t be like a brickwall filter or anything like that, but it’ll help with low-frequency noises and resonances.

Next is a basic 2-band parametric EQ section that can be switched into or out of the circuit as needed. With the controls set flat and no mic connected, I noticed very little added noise when the section was switched in and out of the circuit, which was a good thing. It’ll probably be most useful as a notch filter to knock out an offending frequency, and has a greater cut range (24dB) than boost range (12dB). A very handy feature is a parametric to sidechain switch. With this, you can set up a de-esser easily by using the parametric to boost the frequencies that cause the compressor to to operate, causing it to clamp down on the highs. Or if the compressor is reacting too much to, say, a bass note or kick drum, the parametric-to-sidechain button can be used to doctor the compressor’s operation.

Next is a dynamic section which includes a basic expander (I prefer the term noise gate, though that isn’t exactly correct. A noise gate acts more like an on/off switch when a signal falls below a certain threshold, while an expander acts more like a fader that activates below a certain threshold). The release time is fixed, so this unit can seem abrupt on a signal like a voice, but you do have a ratio and a threshold control, so it has a pretty broad adjustment range. The compressor section has threshold, ratio, and make-up gain controls. It isn’t as adjustable as a standalone compressor, of course, but it’s easy to use and works well. There’s also a limiter with fixed attack and release times, I’d imagine this would be useful to prevent overloading your DAW input. The dynamics section also has an external sidechain input and an on-off switch, which are pro-level features.

The “SmarTube” feature adds high-frequency harmonics, which can “brighten up” a signal, according to the manual. I haven’t used it much yet. Personally, I believe that if you want “that tube sound,” you should use tubes. But then again, good tube gear can cost a fortune, so this may be an alternative. It could be especially useful when using the unit as an instrument interface, thanks to the inclusion of a line input and level control… another reason I bought the unit, it should work well as a bass direct in. I haven’t tested that yet, though.

The unit also has a headphone out, which is super handy to have. I love it when these options are available, as I can plug in and concentrate on a single function. It saves time since I don’t have to think about the signal flow.

There are two meters, gain reduction and output level. Sure, Crest could have saved a few bucks by using a single meter and a switch, but it’s great to have visual confirmation of the unit’s operation.

What I really appreciate are the little things, though. The fact that this has front panel connections AND rear panel connections, for example. It increases the cost to the manufacturer, and the suits would argue that the unit would still work with connectors on either the front or the back, but I really prefer both. Sometimes I’ll want to keep things clean in the front and use the back connectors, but when I want to plug in a mic or guitar cord, it’s great not to have to crawl around to the back of the rack, then realize I need my glasses, then go find a flashlight so I can see what the heck I’m connecting… you get the idea. And something as simple as putting the power switch on the front… somehow Nady seemed to think that on the PR8, the back was a good place for a switch, so on my other preamp, I have to reach around the backside of the rack to power it on and off… a stupid place to put a switch on a piece of rackmount gear, makes me cuss every time I do it. (Actually, the Nady is being scheduled for a full heart transplant. I’ll keep the connectors and the case, but replace the power supply and all the circuit boards with something that works better… probably a bunch of THAT circuits.)

Now, I haven’t put this unit through an exhaustive battery of tests, and I’ve only used it on a few actual sessions. A proper audio job is always much more telling than just going through the functions. But it really seems to be an affordable, very functional piece of gear. The overall weight seems lighter than you’d expect for a box of this size, and I’d imagine the switches and pots won’t last into the next century. But waddaya want for 140 bucks? For what it can do, I think it’s a terrific buy… if you’ve been wanting to try an external preamp, and you’re on a really tight budget, this would be a good choice.

Full Disclosure: I don’t have any connection to Crest. This unit was purchased at retail on ebay, and was done so for use in my own studio. I don’t receive any sort of benefit from this review. (though I’m not above that sort of thing at all. Feel free to send me your expensive gear, and I’ll publish an equally expensive opinion.) The post above is strictly my personal impressions, accuracy and correctness are not guaranteed, and your mileage will almost certainly vary- BG

4 responses to “Bargain Gear: The Crest Audio iPro One Preamp

  1. Thanks for the review! I also find myself in the camp of wanting a Hardy M1 but not being able to afford one, so this was very relevant.

    Can I ask, have you put the pre through its paces since getting an initial impression of it?

    • bgilbertsound

      I haven’t used it much, only for mic testing. I haven’t done any studio recordings with it yet, since my studio isn’t really “open…” and I’m still waiting on the right clients. Like I said, it isn’t a Neve or an API, but it’s a very useable channel strip. Even more so when you consider how inexpensive it is.

    • I was wondering how the Crest Audio compares to the Presonus Bluetube. I’ve been looking for an inexpensive pre for a ribbon mic. They now have the iPro II for $149. Two inputs. Thanks!

    • bgilbertsound

      Comparing these two is difficult… they’re two totally different bits of kit. Yes, they’re both preamps, but that’s about the only similarity. The Presonus is a basic tube-based preamp, it will be best used where you need some of that tube warmth. The Crest isn’t like that at all… it’s an input stage. It’s best use is going to be on a tricky source… something that needs compression, for example, or a noise gate. For example, a snare drum with a hardware squeak that you need to EQ. The Crest is going to be more flexible, since it has more options than the Presonus, but there will be times when you’ll rather have the tube sound. Both of these units are on the low-priced end of the spectrum, so don’t expect either one to perform like an API or Neve. But they will both have their uses, especially in a project studio environment.

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