Purpose of variable input on some power amplifiers.

[Dalprad]

I have a WIIM pro plus and was considering connecting it directly to an NAD C268 power amplifier. For safety reasons, I'd use the "variable input" on the back of the amplifier to set a "max" level in case the WIIM volume control goes haywire. Is this a viable solution? I know I can buy a preamp or attenuator to place between the two components, but am wondering if there are any drawbacks to trying this setup. I would then use the volume control on the WIIM for further adjustment. Maybe I am overestimating the risk of the WIIM volume control not working, but the thought of it maxing out unexpectedly scares me. Thanks for any input!

 

[voodooless]

Should work just fine this way.

 

[mhardy6647]

For safety reasons, I'd use the "variable input" on the back of the amplifier to set a "max" level in case the WIIM volume control goes haywire.

I must be missing something...
If the WiiM volume control "goes haywire" full on -- how does this constitute safety?

 

[rationaltime]

I must be missing something...
If the WiiM volume control "goes haywire" full on -- how does this constitute safety?

Suppose, for example, the user decides at "full on" input the maximum output level
should be 100 dB spl then adjusts the input attenuator to achieve that . Would that
be a reasonable measure of safety?

 

[mhardy6647]

Suppose, for example, the user decides at "full on" input the maximum output level
should be 100 dB spl then adjusts the input attenuator to achieve that . Would that
be a reasonable measure of safety?

Of course, but I thought that OP said* they would set the amp input to MAX, which seems like asking for trouble to me.
I guess they could have meant "to a level less than "max", which is plausible, now that you mention it.
______________________
* to wit:

For safety reasons, I'd use the "variable input" on the back of the amplifier to set a "max" level in case the WIIM volume control goes haywire.

 

[stoo23]

As suggested the OP's statement was:

I'd use the "variable input" on the back of the amplifier to set A "max" level in case the WIIM volume control goes haywire

Not TO Max

 

[Dalprad]

Of course, but I thought that OP said* they would set the amp input to MAX, which seems like asking for trouble to me.
I guess they could have meant "to a level less than "max", which is plausible, now that you mention it.
______________________
* to wit:

My wording was poor. I meant to say I would set the attenuator to limit the maximum possible power reaching the speakers.

 

[Chrispy]

Is the gain adjustment/attenuator on the amp sufficient range to prevent damage yet provide a good setting for regular use?

 

[Dalprad]

Is the gain adjustment/attenuator on the amp sufficient range to prevent damage yet provide a good setting for regular use?

The minimum setting is -20db. I'm ot sure if that's enough reduction or not.

 

[mhardy6647]

yup, got it.

My wording was poor. I meant to say I would set the attenuator to limit the maximum possible power reaching the speakers.

Yes, and my apologies for not reading more carefully! Your plan is a good one, as others have said, and should minimize uncomfortable and potentially costly mishaps!

 

[Svet Angelov]

I'm looking to replace my Yammy to a power amp so I can skip the preamp stage and only use my DAC for volume control (as it also feeds a powered sub). Didn't know about this option.. will definitely look into this NAD

 

[restorer-john]

If you have ANY source that may randomly default to some arbitrary full output into your chain, ensure the pre/power combo is set to not be overdriven in that situation.

Not rocket science and not remotely challenging.

Get it right. If you can't organise that, you have no business pretending to be an audiophile.

 

[Dalprad]

If you have ANY source that may randomly default to some arbitrary full output into your chain, ensure the pre/power combo is set to not be overdriven in that situation.

Not rocket science and not remotely challenging.

Get it right. If you can't organise that, you have no business pretending to be an audiophile.

I was only trying to get feedback on the use of the variable input level function on some NAD amplifiers. I think that's a fair question as I've never owned one. Grab a coffee and enjoy the rest of the day!

 

[gnarly]

One important thing to remember about input attenuation with amplifiers...
The attenuation does not provide a limit to the full power output.
It only provides that it takes a hotter input signal to reach full power.

If you have a turn on or off transient in the electronics before the amp for instance, there is no guarantee input attenuation will save the day.
It just increases the probability you'll survive.