Channel Islands E•200S Stereo Amplifier

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Channel Islands Audio E-200S Front Panel

The last time I tried out some of Dusty Vawter’s amps I was toting two hefty monoblock amplifiers down the Pacific Coast Hwy. On this journey, my payload was significantly lighter. The E-200S stereo amplifier box fit snugly into the back of my Subaru, and once home, this small unassuming amplifier took center stage powering my 2 way speakers- Green Mountain Audio Eos HX.

Getting it out of the box, was a snap (14.0”W x 2.75”H x 10.0”D). The size and weight of this amplifier made setup and handling a breeze. While the front panel grants access to an on/off button with blue LED surround, the host of usual connections can be found on the amp’s business end. Whether you choose RCA or XLR inputs, the custom differential input stage is used. Then an updated UcD Class D stage drives the output. Speaker binding posts are insulated and accept spades or bananas, and a trigger input is also made available. Power cable plugged in, and we are off.

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200 watts per channel @ 8 ohms/ 400 watts per channel @ 4 ohms

For music, I used a Macbook Pro running iTunes/Pure Music 3. The DAC was my Crane Song Avocet, and the Antelope Audio Zodiac Platinum. With everything connected via balanced cables and several hours of warm up (this amp had already been burned-in) I was ready to start listening to some of my favorite tracks.

I cued up some acoustic music by Kings of ConvenienceThis Norwegian duo offers a great starting point to evaluate the naturalness of the male voice. Listening to “Rule My World” from “Declaration of Dependence” gave me some lovely acoustic guitars with harmonizing male vocals.

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View from above, notice the small footprint

The two part acoustic picking of “Declaration of Dependence” maintained all the midrange richness while allowing the male vocals to almost float above the gentle picking style. The clarity of guitars and male voices were presented in an un-hyped and natural way.

Moving onto more complex works, I began listening to Herbie Hancock’s “Steppin’ in It.” This groove laden funk from Mr. Hancock’s “Man-Child” album features rich synth leads, a tight bass lines from Paul Jackson, and a stellar harmonica solo by Stevie Wonder. Allowing all that musical articulation to shine through requires some control over loudspeaker movement. The E200-S gripped My Eos HX and allowed each and every bass note to come through with precision and depth. While everyone in the band holds down the groove, Herbie takes the Rhodes for a stroll… and before you know it Stevie Wonder is syncopating a harmonica unlike I’ve ever heard. With each breath, a new note even funkier than the last is pumped out. All these counter rhythms and complex instruments can be demanding on an audio amplifier, and the CI Audio E-200S never slowed down. In fact, the intricate stereo soundstage was expansive. To top it off, the tonality of instruments (even the squeaky high harmonica) never sounded dull or harsh.

To verify the neutrality, I relied on several orchestral and vocal ensemble recordings I made for NPR, all at the same performance hall. While less capable amplifiers have shown some distortions or break-up, I’m happy to report that the CI Audio amp had none of those shortcomings. Localizing mic placement, hall width/depth, and reverb decay were all amplified without coloration. This provided a sonic portal to the original recorded events, an immersive experience indeed.

Spending time with the E-200S was revealing in so many ways. From black quiet backgrounds to fully erupting orchestral performances, this little beast was in control. Most of all, this CI Audio amplifier proves that green design and audiophile sound need not be mutually exclusive.

Happy Listening

Sesame Seeds or Desert Sand Windstorm?

Sesame Seeds in Glass Jar

Sesame Seeds in Glass Jar

Here is one method that I can use to evoke the sound of wind, or fine grains of sand being swept around in a storm. By pouring a large jar of sesame seeds into another glass jar, I can create a “desert wind storm” sound effect. This is just a taste of what can be done:

Inspiration for Sound Design: Guadalupe Sand Dunes

Inspiration for Sound Design: Guadalupe Sand Dunes

As always, I can provide higher quality versions, or work with you to customize specific sound effects.

Subway Train in Stereo

slow shutter photo of  D.C. metro subway train

slow shutter photo of D.C. metro subway train by Vahan Baladouni

Location sound can present a variety of challenging obstacles to capturing hi-fidelity sound. The infrasound that a fast moving train creates can become a problem for directional mics positioned nearby. Using the techniques described in my previous microphone isolation post allowed me to maximize the available headroom in my recording. Below, listen to a stereo recording I made of the Washington D.C. Metro train. You will hear the subway train arriving from a far left tunnel, after it stops the doors open in the center, then the train rumbles as it fades away into the far right tunnel. The distinct panning or movement of sound in this stereo recording was captured using the ORTF stereo mic technique. Try a pair of headphones or stereo speakers for a fully immersed experience.

Higher quality versions of this recording are available, as well as custom sound designs/effects. Stay tuned to HiFiQC for previews of quality sound design/SFX.

The HiFiQC Method For Stereo Microphone Isolation

Schoeps UMS 20 Stereo Bar mounted to Rycote Lyre suspension

ORTF with UMS 20 Stereo Bar mounted to Rycote Lyre suspension

Recording music and sound effects with carefully placed stereo microphones can present some challenges. Since directional microphones are more sensitive to infrasonic noise, special attention should be taken when placing them in various environments. Wind, machines, automobile traffic, and footsteps can all cause rumble or noise to build-up and eventually reach your microphones. The low-frequency nature of these sounds can take up precious headroom in your audio recordings. While wind (blowing on the capsules) can be tamed with various foam enclosures (the W5D is my favorite for Schoeps) don’t forget to isolate mechanical vibrations from reaching your mics too. After trying elastic shockmounts alone, I devised 3-part system to better isolate my ORTF stereo array (also works for MS, XY, and Blumlein) from infrasonic disturbances .

A 3/8 inch mic mount threading adapter allows me to eliminate the 20 mm Schoeps mounting adapter, saving 38 grams of weight

A 3/8 inch mic mount threading adapter allows me to eliminate the 20 mm Schoeps mounting adapter, saving 38 grams of weight

To start, Rycote has a non-elastic suspension made of a super-strong thermoplastic called Hytrel. And unlike elastic, it won’t sag and eventually wear-out (so far, so good). After being impressed with a Rycote Invision suspension for a single Schoeps mic, I decided to see if a solution existed for isolating 2 Schoeps mics arranged on the UMS 20 stereo bar.

After some digging, I came across the Rycote portable recorder suspension and wondered if it might work since the weight of the stereo bar and mics was nearly identical to most portable recorders. As you can see from the picture above, this model easily supports and isolates the Schoeps universal stereo bracket with mics attached.

Carbon Fiber Disc and Sorbothane Hemisphere

Carbon Fiber Disc and Sorbothane Hemisphere

Using a microphone suspension is certainly one method to help prevent vibrations from reaching your mics, but what about infrasonic born vibration from foot traffic, cars nearby, or HVAC compressors. These disturbances can travel up your mic stand and into your microphone.

After experiencing issues from foot steps and traffic rumble, I worked on a solution to isolate the microphone tripod from the ground itself. Both Carbon Fiber and Sorbothane are materials known to dissipate mechanical energy. So, I settled on Sorbothane hemispheres attached to an equal diameter carbon fiber disc.  Sorbothane works best when compressed under a range of weight (depending on size and Duro rating of hemisphere). By choosing a durometer rating of 50 in the 1.5″x.75″ Sorbothane hemisphere, 7-14 pounds of weight on each tripod leg could be isolated.  And after adding some 8 lbs sand bags to my tripod, I was able to get the load heavy enough to make the Sorbothane hemishpere’s truly effective.

Sorbothane being displaced by the weight of microphone stand

Sorbothane being compressed by the weight of microphone stand and sandbags

Lastly, but equally important is making sure your microphone cables do not transmit cable-borne noise to the microphone body. Carefully dressing your mic cables around the tripod is essential to preventing vibrations from reaching your mic. With the help of velcro cable wraps, you can neatly run your mic cables, but don’t forget to pay attention to where and how they are laid on the ground. In some cases you may need to isolate the cable on the ground too.

For those looking for an even smaller stereo mic setup with windjammer possibilities…Check out this ORTF setup with Schoeps CCM mics, Rycote Lyre suspension, and even a Rycote connobox to eliminate cable handling noise!

Happy Recording,

-HiFiQC