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QRX-8001/9001 VU meters

KeithD

KeithD

AK Subscriber
Subscriber
Just curious about what volume levels activate movement of the VU meters on the 8001/9001? On some of the Pioneers I've had/have, the volume needs to be past 9 o'clock for the meters to move much at all. So, wondering about that function on the Sansui QRX-8001/9001 as I contemplate pursuing one of these. The reason is I rarely have the volume above that level. My quad listening room is not very big, and I just can't stand playing music really loud for very long (guess my hearing is not shot from years of playing music loud!) If the VU meters don't really register until 9 or past, they would not be much use for me.
 
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OK, thanks. I do see that section in the service manual where it describes adjusting the power meters.

Agree they are eye candy. :) Though they can have some value for comparing relative signal strengths of the channels.
 
They don't move much because normal listening levels are one or two watts at best.

- Pete
 
So if normal listening levels are one to two watts, why are we all always looking for the 9090db's, G9000's, and Pioneer SX-1250's and SX-1280's??????????
We do it just in case we decide to crank it, and watch the windows blow out of our houses!!!!

tom
 
A. They're not VU meters, they'e power meters ... <G>

B. As mentioned, you look at the dials, and halfway up is only five watts out of 200 full scale, so you wouldn't expect to see much bounce at lower listening levels. They're also calibrated for 8 ohm speakers.

PS ... I forget. Does the 8001 have the dolby adjustment feature? I know the 9001 allows you to send a test tone and adjust the output using the front channel meters ... just center them on the red marks in the center of the scale.
 
sKiZo said:
PS ... I forget. Does the 8001 have the dolby adjustment feature? I know the 9001 allows you to send a test tone and adjust the output using the front channel meters ... just center them on the red marks in the center of the scale.
Click to expand...
I don't believe so. There is no Dolby board in the 8001. Instead you get an additional tape-style in/out with a switch labeled Dolby Adapter.

There is a local guy who repairs stereo equipment as a hobby. He's in his 60s. Plays music pretty loud, but says his hearing is shot from racing motorcycles in his younger days. I, myself, have never understood why people want such high wattage equipment (other than what's been mentioned here :)) The service manual for the 9001/8001 says to turn the volume all the way up, then adjust the meter to 100%! WOW, who's playing music THAT loud?? Even on my lowest powered receiver (about 20 watts), I'm never above about 10 o'clock for any sustained period of time. Rest of the room on the volume control is a waste.
 
They are power meters, not Vu meters, they measure the amount of power the unit is producing, they are not eye candy, they serve a purpose, and will indicate (if you play at concert levels) when you are running out of headroom. At low levels there is no need for them to show much as the unit is in no danger of running out of headroom.
The 8001/9001 meters are pretty basic and don't show much at low level. They are for intents and purposes, "low resolution".
If you move up to say a G9000, the meters start at 0.1Watt and at low level you get some minor deflection.
Move up to the G22000 and the meter again starts at 0.1 watt but the meter is larger and has more travel so you see even more deflection. So these are higher resolution.

McIntosh with their very large meters and using my MC452 as an example. The amplifier produces 450 watts, so at 0dBu, it produces 450watts, so the scale on the meter is a divide by 10 scenario, where every number has 45 in it.
So the meter starts at 4.5mW, then 45mW, then 0.45W, then 4.5W then 45W then 450W....with this you can see its a Log scale, its not linear, so McIntosh have been very clever realising that most people will be working in the Milliwatt to the 4.5watt range, so over this range there is quite a lot of meter movement.
Obviously it comes at a cost, and these meters are very accurate.

I have noticed calibrating these smaller meters on the Sansui's and Pioneers etc, they are accurate at the top of the range, but they often do not track very accurately and evenly in the lower to mid range. BUT, they are a good indicator for a general idea of how hard the amplifier is working.
When I am calibrating them now, I check them through the range and make sure they are tracking as best as I can get them, it is possible to get them better than when you just follow the instructions in the manual.

Why do we need all that power?
Speaker efficiency is one.
And remember power output vs SPL is not linear.
At a given level, to go 3db louder (which is a fairly small amount) you need 2 x the power.
At a given level, to 10db louder, (which is often perceived as "twice as loud") you need 10 x the power. As you get louder the power requirement to achieve the level is exponential.
 
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Oh also, the QRX7500A and I suppose the 5500 actually have proper VU meters, they set the pre-amp level, so depending on the level of the program coming in, you have a preamp level adjustment to set the preamp at the optimum level using the VU meters...
I thought that was quite cool.
 
Thanks for all that info Kev, that was really helpful.

I had thought before the 5500 would be the best for my needs (including the pre-amp level adjustment knob); however, it does not have the last/best version of vario-matrix, which I'd want to have for my main quad setup.
 
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