NOS Sansui QRX 5500 score... but what is the "Level Set" Control Knob for?

[hnash53]

I landed a NOS Sansui QRX 5500 that is fantastic.

But it has something that I've not seen on the other QRX receivers: The "Level Set" knob.

It is described this way: "Adjust the LEVEL SET control so that the pointers of the VU meters will swing up to, but not beyond the red numeral "2."

I RTFM, but its function is still quite vague.

Can anyone explain what/why/how this function works?

Thanks.

 

[vinylguy4]

I don't have that particular receiver, so I can only guess based on what I think are similar setting on other equipment I have.
Want to set the sensitivity of the meters with that adjustment.
For instance if a tape was recorded at a low level, the meters may not move very much, so would want to adjust the meter sensitivity so the meters move the 'full' swing.
Similar for a "hot" tape, may need to turn down the meter sensitivity a bit.

vinylguy4

 

[hnash53]

Thanks for your explanation. However, this knob also acts like a volume control. The volume increases as you turn it clockwise, and of course vice versa.

It doesn't just increase the meter sensitivity, it also increases the volume. This is the part that is confusing to me. If it just increased the sensitivity of the meters, that would be perfect. But since it increases the volume also, that's the part that is confusing. I still don't get it.

Anyone else?

 

[quadsearcher]

Look at the sentence before the one about setting to hit 2 on peaks (I can't seem to copy/paste from the pdf). I think they are describing an input level trim between the two-channel (matrix-encoded or stereo to synthesize) source, and the QS or SQ decoder. As I understand it, that is a good feature because decoders work best with the input level they are designed for.

In other words, main volume will not change the level going into the decoder (it affects all four channels after the decoder), but this trim level does.

 

[DuncanS]

Could be to increase the signal level above the decoder's noise floor, which might also assist any 'logic' decode function.