TheVinylRipper
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There seems to be a bit of opprobrium directed toward equalization from some people here.
I just got my test record to analyze my system and I have found that it was not as flat as I might have wished.
Almost all phono preamps have the RIAA curve built into them in hardware, op amps, resistors and capacitors. None of these devices is perfect and they all tend to change values as they age, throwing off what might have well been a quite accurate RIAA EQ in the beginning.
My system uses a flat phono preamp, with no EQ built in. The sound goes to my sound card exactly as it came from the stylus, only amplified.
The EQ is all done in software, controlled by mathematical equations and as perfect as 32 bit floating point math can get it.
Once the RIAA EQ is accomplished, then you can adjust for all the imperfections in your system, all the way from the stylus to the A/D converters in your soundcard. You do this by adding another EQ in the processing chain and tweaking pink noise from the test record until it shows a linear drop of 3 dB per octave. That's why they call it pink noise, it has more energy at the low end than at the treble end.
I thought you might be interested in seeing how much EQ it took to get my system flat as nearly as I could after almost 4 hours of tweaking.
Here is the final spectrum analyzer screen after all the tweaking was done playing pink noise from the test record.
Here is the RIAA EQ curve in the paragraphic equalizer of my software, Diamond Cut Productions DC6.
And here is the graphic EQ it took to get my system as flat as I could make it. As you can see, there is considerable deviation from a completely flat EQ, that is the mirror image of the nonlinearities in my system.
There you have it folks, EQ is a necessity if you are going to have a truly flat system, since no analog hardware is perfect.
On edit:
Just for grins I decided to run the same pink noise test on my old preamp, a Yamaha RX500U receiver. I was shocked to find out that the response of the complete system had a slope of more like 7.5 dB per octave, almost twice what it was supposed to.
That means that in the three octaves from 20 Hz to 20 kHz, my original system was down by nearly 9 dB. Since a change of 6 dB sounds like a doubling of volume to the human ear, my system lost over half its treble by 15 kHz.
I just got my test record to analyze my system and I have found that it was not as flat as I might have wished.
Almost all phono preamps have the RIAA curve built into them in hardware, op amps, resistors and capacitors. None of these devices is perfect and they all tend to change values as they age, throwing off what might have well been a quite accurate RIAA EQ in the beginning.
My system uses a flat phono preamp, with no EQ built in. The sound goes to my sound card exactly as it came from the stylus, only amplified.
The EQ is all done in software, controlled by mathematical equations and as perfect as 32 bit floating point math can get it.
Once the RIAA EQ is accomplished, then you can adjust for all the imperfections in your system, all the way from the stylus to the A/D converters in your soundcard. You do this by adding another EQ in the processing chain and tweaking pink noise from the test record until it shows a linear drop of 3 dB per octave. That's why they call it pink noise, it has more energy at the low end than at the treble end.
I thought you might be interested in seeing how much EQ it took to get my system flat as nearly as I could after almost 4 hours of tweaking.
Here is the final spectrum analyzer screen after all the tweaking was done playing pink noise from the test record.
Here is the RIAA EQ curve in the paragraphic equalizer of my software, Diamond Cut Productions DC6.
And here is the graphic EQ it took to get my system as flat as I could make it. As you can see, there is considerable deviation from a completely flat EQ, that is the mirror image of the nonlinearities in my system.
There you have it folks, EQ is a necessity if you are going to have a truly flat system, since no analog hardware is perfect.
On edit:
Just for grins I decided to run the same pink noise test on my old preamp, a Yamaha RX500U receiver. I was shocked to find out that the response of the complete system had a slope of more like 7.5 dB per octave, almost twice what it was supposed to.
That means that in the three octaves from 20 Hz to 20 kHz, my original system was down by nearly 9 dB. Since a change of 6 dB sounds like a doubling of volume to the human ear, my system lost over half its treble by 15 kHz.
