Volume Control True Off Position

On Jun 8, 2008, at 12:33 AM, xxxxx@msn.com wrote:

Name : David Yee

Message :
Can you tell me if the phoenix gold VSL125-RB volume control has a true OFF setting? If not is there one with a true OFF setting? I had heard that w/o this then there is a small amount of sound coming from the speakers even with the volume setting at the lowest?



Nope. None of the impedance matching versions out there will have a true off setting, where it totally disconnects from the circuit.

This is because the function of the impedance matching is that the whole circuit needs to remain constant. Meaning that the amp sees 8 ohms of impedance all the time. If one were to be taken out of the circuit, the impedance would change, going up in value, thereby all the other speakers would get more quiet. Which would be undesirable.

But I haven’t experienced that bleed thru with any of the volume controls at all. If you have your system properly initialized with most all of your volume controls set correctly, you shouldn’t hear anything when you turn one off.

Another option to avoid it completely would be to use a speaker selector as your impedance device and when you need to confidently turn off an area, use the button on the speaker selector. Speaker selectors take the leg completely out of the circuit. In this case, you’d use just regular volume controls with no impedance matching.



Impedance Matching Volume Controls vs. Speaker Selector Question

Everything I read indicates I need to connect my receiver to an impedance matching speaker selector, from there to each room’s volume control and speaker pair. If I have impedance matching volume controls in each room, why do I need a speaker selector? What does the speaker selector actually do? Can I run parallel to each room’s volume control directly from the receiver without a speaker selector? Thanks.

Typically, in a home situation we suggest a speaker selector with standard volume controls because you can turn off areas that you wouldn’t normally use and those areas truly get taken out of the circuit. Then the other areas get more power and better sound.

In an application that you would have all the areas on most all the time, you could (and should) use just impedance matching volume controls only. When you turn down an impedance matching volume control to it’s “off” position, it’s not truly off on the back side of the circuit. It has to remain in the circuit or else the circuit would always be changing the load to the amp, therefor causing volume fluctuations everywhere anytime someone even makes one click of an adjustment.

So you can do it both ways. The downside to using the speaker selector method is that it costs a few more bucks.