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Home / Product Category / Whole House Audio / Volume Controls / In-Wall Volume Controls / OSD Screwless Rotary Knob Volume Control 100W Impedance Matching SLK100 Decra Style Wall Plate Snap On

OSD Screwless Rotary Knob Volume Control 100W Impedance Matching SLK100 Decra Style Wall Plate Snap On

Product code: SLK-100

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OSD Price: $49.99
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Features & Specifications

Decorated style matching light switch without any screw holes for your style home.
. Screwless Decora style impedance-matching volume control for whole house audio systems and dedicated audio zones
. Rated at 100 Watts per channel with minimal bass roll-off
. Impedance-matching feature stabilizes the ohm load so parallel connections of multiple volume controls can be installed without damaging the amplifier
. Front-mounted adjustable jumpers allow easy adjustment when multiple pairs of speakers are connected to a single receiver or amplifier
. Accepts up to 14-gauge wiring and fits in a standard gang box with a depth of 2.9”
. Includes junction box and screws as well as white, ivory and almond trim plates to match any room décor
. Precision electronics provide low distortion and a ruler flat frequency response
. 12-step linear rotary-style knob for a wide range of listening volumes

More about Impedance Matching

Now you can match your decora style light switching with this innovative screwless volume control. All speakers have an impedance rating, typically 8 ohm for a pair of home speakers. To operate in the safest mode, most standard amplifiers and basic two-channel receivers are rated for an 8-ohm incoming load. To operate safely and consistently, the amp needs to see an 8 ohm load, and that’s where speaker selectors and impedance-matching volume controls come into play.

In a basic multi room system, only a Speaker Selector is used to connect the speakers to the amplifier/receiver. Not only does the Speaker Selector allow you to connect multiple speakers to the amplifier but also adds internal Impedance Protection which is enabled by a manual protection switch. Both our ISS and DSM series Speaker Selectors feature internal Resistors that protect the amplifier. The down side is that the power rating normally 140 watts is cut in half when the protection switch is enabled so rated at 70 watts with protection.

In a standard multi-room system (using Impedance Matching VC) you will typically have an amplifier/receiver, a speaker selector with 4 to 8 zones, and volume controls connected to all the speakers. Impedance-matching volume controls provide more precise protection for the amplifier/receiver versus the protection built into the standard speaker selector. Plus with the protection switch in the off position you will have the maximum power handling capability of the respective speaker selector. It is important that the protection switch is turned off when using the Impedance matching Volume Controls.

Most impedance-matching volume controls feature three standard settings: 1/2x, 4x and 8x, while some add a 16-ohm setting like our VMS series. These settings correspond to a chart in the owner’s manual based upon the type of amplifier (4 or 8 ohm) and the number of 4 or 8 ohm speakers that you will be using in the multi-zone/room/speaker system. You can use both 4 and 8 ohm speakers when setting up your system. But you need to count a 4 ohm speaker as two 8 ohm speakers when calculating your Impedance setting.


2 Questions & 2 Answers
from Vancouver, Canada asked:
December 27, 2018
I have a DIY whole house audio system. As part of this, I have one stereo power amp powering 2 sets of speakers. The amp is 100W rated at 8 ohms. Both sets of speakers are 8 ohms. I volume control the full channel via digital control of input signal. However, I would like to add an analog speaker control to ONE set of the speakers and leave the other 8ohm set with no analog control. The reason for this is the set I want the analog control on is generally much lower volume that the input volume. EG: I want to separately control the volume in the pair of speakers to be lower (generally ) than the main set and input. Can I use this device? If so, what setting should I use for the impedance matching?
1 Answer
Hi Gary: I believe you want to control the second pair of speakers with an analog style volume control. Note, all of our volume controls are passive devices that add no gain. In fact, The volume control when setting all the way clockwise (full volume) matches the volume level of your master volume control. Then when you turn the volume knob counterclockwise a click at a time, the sound is attenuated lower. You are turning the sound down by diverting the signal to either the Transformers of the Impedance Matching Volume Control or to the Resistors of the Resistor based Volume Control with no Impedance Matching capability. So as long as you are planning to add a volume control to the speakers you want to play lower, than any one of our many Volume Controls will work for your application. The VKR120 (Resistor based/no Impedance Matching) is our best sounding Volume Control with a Broader Frequency Response with no high or low-end roll-off. The SLK100 is an Impedance Matching Transformer based unit that features a screwless outer plate design. The SVC100 is a more affordable Impedance Matching Volume Contol that you see the two screw heads that hold the plate (only a cosmetic difference). Good luck TL/5344
Submitted by: Tim Leahy on December 27, 2018

from St. Charles, IL asked:
June 16, 2018
I'm considering this switch to control my outdoor speakers. Volume Control 1: I have 2 pairs of Polk Atrium 4 speakers (rated at 8ohms, and 10-60W continuous) I'd like to wire in parallel. I'm thinking parallel, so their volume is controlled by one of these single OSD SLK100 volume controls. In reading the information, it appears I can wire these in parallel - is that correct? They are being driven by a Niles SI-1230, bridging a pair of channels for each of the L and R speakers, with an output of 80W. Does this configuration work with this switch? Volume Control 2: Also driven by a bridged channels for L and R at 80W from the Niles SI-1230, I have 3 pairs of outdoor rock speakers. I'd like to control these with one SLK100 volume control as well, and am thinking wiring these in parallel, again. These speakers are rated at 8ohm, and 5-125W continuous. Will this configuration work? Thanks in advance. I see these switches are available from you on Amazon, and would place an order as soon as I hear back confirming this configuration will work. Cheers, Andrew
1 Answer
Hi Andrew: You will definitely need Impedance matching Volume Controls for both Volume Control #1 and #2. It is critical that your bridged channels see an 8-ohm load. In both cases, I would recommend going to the SLK300 especially for case#2. In the first case, Impedance setting would be 2X (2 pair of 8-ohm speakers) and in the second case, 4X (3 pairs of 8-ohm speakers). Note the impedance setting number refers to the number of 8-ohm connections you will have, in the first case 2 pairs of 8-ohm and the second case 3 pairs. Good luck TL/5058
Submitted by: Tim Leahy on June 18, 2018

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