Saturday, July 2nd, 2011 | by matthew mcglynn
Last year I reviewed the original Cloudlifter, which I described as an “inline mic pre-preamp” intended to give passive ribbon microphones a 20dB boost of clean gain. The manufacturer, Cloud Microphones from Tucson, AZ, has since updated the design and dropped the price.
I’ve had the good fortune to play with the new single-channel Cloudlifter CL-1 since January. In fact, I used it extensively in my recent podcast microphone shootout, because it let me run my DAW inputs comfortably in the middle of their gain range, leaving plenty of headroom for matching gain across microphones.
The original Cloudlifter was a 2-channel device. The new version of that model is now called the CL-2. As noted above, there is a new single-channel version too, called the CL-1.
The CL-1 streets at $150, making it a low-cost tool for adding extra gain to your mic pre’s. The two-channel CL-2 streets for $250, a bit less than the original model ($289).
The new Cloudlifters have updated circuitry; the changes improve noise rejection. We’ll get more into this in the review.
What hasn’t changed:
The Cloudlifter is a patent-pending, fully discrete amplifier circuit, using no resistors or capacitors in the audio path, built into a solid steel case with Neutrik XLR connectors, and is designed, assembled, and tested by hand in the USA.
For this review, I focused on two applications of the device, both using moving-coil dynamic microphones. According to Rodger Cloud, the company is selling a lot of units to broadcast and voiceover artists who use low-output dynamics like the Electro-Voice RE20. It just so happens that I have one of those here — thanks to this site’s eagle-eared readers, who voted for it in a blind broadcast mic listening survey.
Test #1: How clean is that gain?
One of the findings from my first review is that the Cloudlifter delivers at least 20dB of gain as clean or cleaner than any of my preamps. I retested this conclusion in a new way with the CL-1: I ran one microphone through a splitter into two inputs in my DAW, with the CL-1 inline in just one of those inputs.
CL-1 -> DAW channel 1 (phantom on) / RE-20 -> Radial JS-2 \ DAW channel 3 (phantom off)
Prior to recording, I gain-matched the two channels to within 0.1dB. Needless to say, the CL-1 channel needed ~20dB less gain.
Then I recorded a short narration, and fine-tuned the RMS levels of the two tracks to ensure identical levels.
The result? I couldn’t hear any difference. I listened closely in headphones, but couldn’t pick either reliably in a blind test.
But then I wondered if I’d inadvertently recorded the same source on both tracks, e.g. two channels of CL-1, next to each other. The acid test for hearing differences between audio tracks is to invert one of the two and play them back together, in mono. If the two tracks were truly identical, the waveforms (equal in amplitude but opposite in direction) would cancel out completely, resulting in silence.
Fortunately for the veracity of my test, I didn’t hear perfect silence. There is some tiny difference between the CL-1 signal path and the direct-to-DAW signal path. The difference is inaudible at comfortable listening levels, though; it measures at about 45dB lower than the level of either track, solo’d.
In Pro Tools, I zoomed in on a moment of ambient sound, between takes. The image at right (made with the RE-20, despite the track names) shows the waveforms at maximum vertical zoom. The CL-1 track is on top; the DAW preamp track is below. It’s clear the CL-1 isn’t adding any noise. In fact, when I measured the RMS level of the selected audio, the CL-1 track was 0.3dB lower.
So, when Cloud promotes the Cloudlifter as creating “ultra-clean gain,” they mean it!
Test #2: The Cable Run from Hell
Rodger Cloud suggested that the Cloudlifter could be used to improve the sound quality of long cable runs and noisy preamps. Imagine you’re running an old Mackie mixer at a club, and the singer’s SM58 is at the other end of a 100′ snake. Or worse, a 100′ chain of 20′ mic cables. (Don’t gasp. I know you’ve done it too.)
So I strung together two identical chains of cables, basically everything in my cable box that I had pairs of — two 122' runs, a mix of brand-name quad-core cable and no-name stuff that I swear still has beer stains from college on it. I ran them out of the studio, around the next room, past a couple electrical outlets, into the hallway, around a 500-watt fluorescent light fixture, and back into the control room.
And then I plugged them both into a Mackie 1604 VLZ Pro. I maxed the gain on one channel, and adjusted the other one down to compensate for the boost from the Cloudlifter. The signal level coming into Pro Tools (via the 1604’s direct outs, into the 002’s 1/4'' inputs) was within 0.2dB across channels.
Back at the mic end of the cable run, I put the Cloudlifter inline on one cable, and wired both through the JS-2 into a low-output dynamic (hello, SM57!). And then I read a short narration (as is my custom, another fabulous excerpt from Zen and the Art of Mixing.)
I’ve heard enough lousy bands in enough lousy nightclubs to expect something dreadful from the pure Mackie channel. Surprisingly, it isn’t that bad. But it is audibly noisier. The Mackie channel has more high-frequency hash, maybe 5dB between 10kHz–20kHz.
Then there’s the tonal difference. The voice on the Cloudlifter track has more weight. The ess sounds don’t bite as much. The Mackie track sounds thin and maybe a bit harsh. In short, the Cloudlifter track sounds better.
I pulled the JS-2 and CL-1 out of the circuit and recorded ambient noise with a single mic, a single 122' cable run, and the Mackie. Then I put the CL-1 back inline, reduced the Mackie’s gain to match the signal level in Pro Tools, and recorded ambient noise again. This is to appease the purists who think the JS-2 or some specific fault in one of the cable runs might have interfered with my test. But I got the same results: the Cloudlifter track had about 0.5dB less noise overall (RMS), most audibly between 10kHz–20kHz. Further, the non-Cloudlifter track had an edgy, gritty quality to it that wasn’t there when I used the CL-1.
(By the way, it is not my intention to disparage the Mackie 1604 in any way. I haven’t kept it around for 10 years because I hate it. On the contrary, if anything I’m more impressed with it because of these tests. )
Test #3: Noise Rejection
If you read my review of the original Cloudlifter, you’ll recall that I was getting some noise from the device when it was at the far end of a long mic cable, next to my DAW. The new CL-1 seems to be immune to this problem — I tried it with Cloud’s beautiful JRS-34 passive ribbon mic, before and after a 30' run of very questionable cable, and heard no RF noise in either configuration. Problem solved!
There’s a lot to love about the Cloudlifter. It turns phantom power into clean, transparent gain. It gets the best out of long cable runs and noisy preamps. In fact, it turns any preamp into a high-gain “ribbon preamp.”
If you have passive ribbon mics, you need the Cloudlifter. If you have dynamic mics and a noisy preamp, you need the Cloudlifter. If you’re using a dynamic mic with a 16-bit USB mic pre, and you want to maximize your gain staging before bus-powered A-to-D conversion, you need the Cloudlifter. It’s an inexpensive tool that you’ll find more uses for than you might expect.
Where to Buy
Support this site by buying from one of the excellent stores listed at the bottom of the JRS-34 page. (Thank you!)
No ribbon microphones were harmed during the course of this test. (That’s actually one of the features of the Cloudlifter.)
The CL-1 under review was provided for evaluation. Thanks to Rodger Cloud and David Bryce for the long-term loan. I’m keeping it, by the way. Send me an invoice.
Now if you’ll excuse me, I have 250' of mic cable to wrap up.