Different in-wall impedance matching volume controls

[yeshia]

I currently have 4 in wall Impedance matching volume sliders. I need to replace one of them. The brand and model is no longer made. Can I replace just one of them with a different make as long as the resistance setting is the same? Or do they all need to match? Does the max wattage need to match as well or can it be greater? Thanks

 

[highfigh]

I don't think these have been made by a large number of companies, so you need to look at the control- does it have a bunch of light blue resistors, or does it look like it has two transformers? Buy something that looks like what you have. If you can buy it in person, you'll be able to take the old one with you, so you can make sure the plastic color is close to the same- I have seen some that were called 'white' and they had a slight blue tint, others were a warmer color. Fortunately, it may be possible to remove the plastic parts and snap them onto the new control.

Most are rated for 100W, so get one that matches.

 

[TLS Guy]

I currently have 4 in wall Impedance matching volume sliders. I need to replace one of them. The brand and model is no longer made. Can I replace just one of them with a different make as long as the resistance setting is the same? Or do they all need to match? Does the max wattage need to match as well or can it be greater? Thanks

I have been looking into this, and researching it for you as time permits around the holiday. I guess the b0ttom line is that auto transformers in parallel, which is what your four impedance matching controls will be need to be identical in terms of resistance and inductance. This means they have to be identical auto transformers in terms of the core, turns and wire gauge.

So this means you do actually need to replace all your controls.

 

[yeshia]

I have been looking into this, and researching it for you as time permits around the holiday. I guess the b0ttom line is that auto transformers in parallel, which is what your four impedance matching controls will be need to be identical in terms of resistance and inductance. This means they have to be identical auto transformers in terms of the core, turns and wire gauge.

So this means you do actually need to replace all your controls.

Thank you so much for the info. Appreciate it. What do you think would happen if I did mix and match them? Damage my receiver?

 

[TLS Guy]

Thank you so much for the info. Appreciate it. What do you think would happen if I did mix and match them? Damage my receiver?

That is certainly on the list of possibilities. I would not risk having auto transformers in parallel. The inductance of those transformers will almost certainly be different and the relationship between the voltage phase and current impossible to interact. All I can say is there will be interaction but the effects are not predictable.

Those units are not expensive, so changing them is not a big deal

 

[yeshia]

That is certainly on the list of possibilities. I would not risk having auto transformers in parallel. The inductance of those transformers will almost certainly be different and the relationship between the voltage phase and current impossible to interact. All I can say is there will be interaction but the effects are not predictable.

Those units are not expensive, so changing them is not a big deal

Will change them all. Thanks for the help.