Receiver: Input sensitivity/Impedance

[nutella]

Folks,

I did a keyword search in the forums but couldn't find a posting that answered by question. So, please point me in the right direction if you're aware of a relevant posting.

Basically, I'm trying to understand what input sensitivity/impedance numbers should mean to a potential buyer like me who is not an expert in the audio field. I'm talking about the numbers found on the receiver specs sheet, not speakers.

Normally, I wouldn't worry too much about it. However, I came across two receivers that had fairly different numbers.

Pioneer 1020: 300 mV/47 kΩ
Marantz 1601: 130 mV/50 kΩ

Does anybody know if a higher number is necessarily better or does it even have a significant impact on the overall performance of a receiver?

Thank you in advance.

 

[Knucklehead90]

Input sensitivity usually refers to the inputs of an amplifier. Your example are of input specs to an AVR - similar but not numbers many ask about or worry over.
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From the link below:

Input sensitivity is the minimum amount of input signal required to drive a device to its rated output level. Normally, this specification is associated with amplifiers and microphones, but FM tuners, phono cartridges, and most other types of gear have a sensitivity rating as well. In general, higher sensitivity is better (less input signal required for full output), but there are definitely situations where a device can be TOO sensitive (picture a very sensitive microphone in front of a wound-up Marshall guitar amplifier!) resulting in unwanted distortion.

http://www.sweetwater.com/expert-center/glossary/t--sensitivity

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There is little difference between the two examples you've provided - and those are probably input specs for a cd or dvd analog inputs.

Usually input sensitivity is something that someone shopping for an amp to connect to an AVR might be looking at since AVRs often have much lower voltage output on the preamp outputs than dedicated prepros do. My Emotiva UPA-7 is speced at 23.5k ohms. Most AVRs should pretty much drive it close to full power. I know my DHC 40.1 does.

 

[nutella]

Thank you for your input, Knucklehead90. Although I now understand the difference is too insignificant to matter, I still have one more question. Does a lower number in mV's mean higher sensitivity?

 

[TLS Guy]

Folks,

I did a keyword search in the forums but couldn't find a posting that answered by question. So, please point me in the right direction if you're aware of a relevant posting.

Basically, I'm trying to understand what input sensitivity/impedance numbers should mean to a potential buyer like me who is not an expert in the audio field. I'm talking about the numbers found on the receiver specs sheet, not speakers.

Normally, I wouldn't worry too much about it. However, I came across two receivers that had fairly different numbers.

Pioneer 1020: 300 mV/47 kΩ
Marantz 1601: 130 mV/50 kΩ

Does anybody know if a higher number is necessarily better or does it even have a significant impact on the overall performance of a receiver?

Thank you in advance.

It's the number they don't tell you that is significant and that's the head room.

The Pioneer will come to full output at 130 mv, which is probably over sensitive. 300 mv is also more sensitive than it needs to be as line voltage should be around a volt.

The real question is what is the input voltage that causes clipping. That really sorts the men from the boys. I have a strong feeling from personal observation that for a lot of receivers the headroom is inadequate. I would love to have some on the bench.

 

[Knucklehead90]

Thank you for your input, Knucklehead90. Although I now understand the difference is too insignificant to matter, I still have one more question. Does a lower number in mV's mean higher sensitivity?

The lower the resistance on the input is what determines sensitivity. Less resistance = higher sensitivity.