Channel Islands Audio PLC-1 MKII Remote Passive Controller Review 
Home Theater Preamplifiers Stereo Preamps
Written by Andre Marc   
Thursday, 26 September 2013

Channel Islands Audio, out of California, has been a favorite of mine since I bought their VDA-2 DAC, and an external power supply for my Squeezebox Touch. They are in the business of making handcrafted digital sources, Class D amplifiers, power supplies, and passive controllers for those who seek affordable components and great sound. CIAudio proves these two goals are not mutually exclusive.

I recently heard CIAudio’s excellent new USB to SPDIF converter and stand alone DAC, the Transient MKII, and was very impressed. After a conversation with Dusty Vawter, the owner and lead designer of CIAudio, in which I discussed my growing appreciation for passive “preamps”, he offered the $899 PLC-1 MKII Passive Controller for review. CIAudio also makes the $299 VPC-3 Passive. They differ dramatically in feature set. The PLC-1 MK II has multiple inputs, can be controlled via remote, and is roughly double the size.

Why Passive?

Traditional “active” linestages, or preamplifiers, provide gain, volume attenuation, and input switching. They also match the impedance of the source and amplifier, and allow for the use of long cable runs. However, purists believe there are downsides. First, you have an additional gain stage that, with today’s standard sources, may be unnecessary. Next, there is an extra power supply on the line. And, finally, all active circuitry has its own sonic signature, regardless of any claims to the contrary.

Decent numbers of audiophiles have been using passive linestages for decades, but certainly, active preamps are the norm. I personally became interested passive units when I could not find any active linestages -- solid state or tube -- that were totally neutral. Many sounded superb, mind you, but were clearly colored in some way or the other. I decided it might be a good idea to let the amplifier provide the majority of the sonic colors, and let the source communicate with the amplifier with the most direct signal path possible.

Set Up & Listening

The PLC-1 Mk II features 4 RCA inputs, two outputs, and tape in/out, and a trigger for powering on or off components attached via a trigger cable. To use the remote control, you must plug the PLC-1 MKII into the supplied wal-wart power supply. This allows you to switch input, mute, power on/off an amplifier, and adjust the volume. Blue LED lights on the front panel indicate what input is selected. There is a solid, precise feeling volume knob on the right side of the front panel, and push buttons to manually select input or mute.

I was very impressed with the PLC-1 MKII’s build quality and appearance. Although not heavy, since it has no active circuitry or power supply, it nonetheless felt solid. As a matter of fact, all the CIAudio products I have had in my system have been well built. Internally, CIAudio says they use premium parts. According to product literature, "audio signals are switched by highest quality relays with gold-plated contacts, then fed to a custom ALPS® Blue Velvet motorized potentiometer. Circuit boards are 3 oz. copper with lead free plating, and assembled with lead-free silver solder for best conductivity."

The PLC-1 MK II was set up with Bryston BDA-1 and John Kenny Ciunas (review forthcoming) DAC sources, with Furutech and Stager interconnects. The PLC-1 MKII really got a workout driving no less than four separate amplifiers at various times. I used the solid state Burson Timekeeper, the EL84M tubed Bob Carver Black Magic, the KT120 tubed Audio Research VS55, and the new KT120 tubed Rogue ST 100 amp (review forthcoming). They were all connected to the PLC-1 MKII with Transparent MM2 Super interconnects.

Right out of the box, the PLC-1 MKII proved to be subjectively neutral, with less sound of its own then any active preamp I have had in my systems. Essentially, what I heard was the sound of the source and the amplifier driving the speakers. How did I determine this? With each of the four amplifiers I used, their unique sonic character was apparent. If the goal of a passive controller is to pass the signal through without editorializing, then that goal was met.   Obviously the only way to determine if the PLC-1 MKII was totally transparent is to connect a source direct to a power amp -- and with no way to attenuate volume, a blown speaker is in your future. With the Carver amp, which does feature a volume pot, I was able to do this on a limited basis. But the Carver sounds its very best with the volume pot completely open, so comparisons were inconclusive. Nonetheless, to my ears, the PLC-1 MKII added little, if anything, sonically.

As per my usual modus operandi, I used a variety of music to evaluate the PLC-1 MKII, including a lot of acoustic jazz, classic rock, and current pop. First up is the high-resolution download of Donald Byrd’s sublime Blue Note recording, A New Perspective. It is a complex suite with parts for voice and a jazz ensemble. The PLC-1 MKII allowed the music to flow beautifully and really drew this listener in. It was possible to hear all the nuances of the arrangements and how well the remastering was done.

Next up was the 96 Khz download Rush’s recent album Clockwork Angels. On other systems, the recording sounded slightly veiled and tentative to me. Through the PLC-1 MKII it opened up and the bottom end was floor shaking. With veils lifted, these excellent songs shone through and allowed me to really appreciate Rush’s sublime skills as arrangers, musicians, and songwriters. On the downside, the PLC-1 MKII’s transparency also clearly shone a light on the fact this is a digital recording, and revealed the slight icy sheen inherent in the production.

The PLC-1 MKII really brought out the charm in John Mellencamp’s 2010 release, No Better Than This. The album was recorded with a single microphone to an old tape machine, with songs that cover various American music styles. The album is a success as a concept and it really does have a vintage vibe. The PLC-1 MKII presented the album as an organic whole, and you could practically see the tape reels spinning. Mellencamp’s voice was front and center and the overall sound was very intimate, exactly what Mellencamp and producer T-Bone Burnett intended.

Lastly, Tuareg group Tinariwen’s Amassakoul sounded simply superb through the PLC-1 MKII, with its snake-like exotic polyrhythms, electric guitar lines, and chanted vocals. The Malian group combines African grooves with John Lee Hooker like blues stomps to great effect.  The sound is extremely addicting, and the CIAudio passive provided a much larger soundstage than I remember with this album. Quite impressive.

In operation, the PLC-1 MKII was flawless. There was never a time where I needed more gain with any of the amplifiers I used. As a matter of fact, the volume knob never went beyond the 12 O’Clock setting. The unit was also dead quiet, as one would expect, a definite benefit of a passive design. I also very much appreciated the smooth operation with the supplied remote control. Volume changes were precise and incremental. Overall, one of the most headache free components I have encountered.

Channel Islands Audio PLC-1 MKII Remote Passive Controller


Channel Islands Audio has a history of making darn good sounding gear that is very fairly priced. An even more admirable feat considering the gear is made in the USA. Dusty Vawter, head honcho, uses solid engineering, and a no nonsense approach to design and market his products. I strongly suggest checking out the company and their portfolio.
The PLC-1 MKII passive controller is a winner all the way in my book. It is hassle free, offers a transparent window to the sound of your sources, and will work with virtually any power amp and source with reasonable cable lengths. There are far more expensive and exotic choices for passive linestages, but I am not sure they offer more. At $899, the PLC-1 MKII is very reasonable, and, as a matter of fact, I am purchasing the review sample to integrate it into my main system permanently. Consider that a recommendation!


Channel Islands Audio PLC-1 Mk II passive controller: $899

Audio Inputs: 4 pairs standard (one of which can be configured as HT bypass), 1 pair tape
Audio Outputs: 2 pairs variable,1 pair tape (fixed level)
Accessory Outputs: 12v DC Trigger
Potentiometer: 10k ohm ALPS Blue Velvet (motorized)
Remote Control Range: 30 ft
Power Supply: 14v AC/850mA
Dimensions: 8.50"w x 2.75"h x 6.50"d
Warranty: Year Parts & Labor

Review System 1

CD Transport: Musical Fidelity M1 CDT
Server: Squeezebox Touch w/ CIA VDC-SB power supply
via Ethernet to MAC Mini w/ Western Digital & Seagate
external drives.
DAC: Bryston BDA-1, John Kenny Ciunas
Headphone Amp: Pro-Ject Head Box II
Headphones: Grado SR60
Preamp: Audio Research SP16
Amplifier: Audio Research VS55, Bob Carver Black Magic, Rogue ST 100
Speaker: Thiel CS2.4
Cables:  Complete Furutech cable system, Stager Silver Solids, Darwin Ascension (IC), Transparent  MM2 Super (IC), Transparent Plus (Speaker) Acoustic Zen Tsunami II (AC),Transparent (AC).Shunyata Venom (AC) Element Cable Red Storm (Digital AC), DH Labs TosLink, DH Labs AES/EBU, Audioquest, Forest, WireWorld Ultraviolet, DH Labs USB(USB) DH Labs (USB)
Accessories: Symposium Rollerblocks, Shakti Stone, Audience Adept Response aR6 power conditioner,Salamander rack

Review System 2

CD Player: Onkyo C7000R
Music Server: Squeezebox Touch via Ethernet to
MAC Mini w/ Western Digital & Seagate external drives.
DAC: Musical Fidelity V-DAC II, Burson Conductor
Integrated Amplifier: McIntosh  MA6600,
Tape Deck: Revox A77
Speaker: Harbeth Compact 7ES3, KEF LS50
Cables: Darwin Cables Silver IC, Kimber Hero HB,  DH Labs White Lightning (IC),QED Transparent MusicWave (Speaker),PS Audio (AC), Mojo Audio (AC), DH Labs TosLink, Audioquest Forest USB, Wireworld Ultraviolet USB
Accessories:Cable Pro Noisetrapper, Sound Anchors Stands, Wiremold, KECES XPS

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