dougi
Addicted to Fun and Learning
In another thread I said I was waiting for the Elipson test record and would post some comparisons with the HFN record when I received it. I have now got it, so here we go!
I am measuring my 10 year old VPI scout (acrylic platter) and a Dynavector DV20X low, into a Project DS2 preamp and recorded using a RME ADI-2 PRO ADC/DAC.
The cartridge frequency response should be something like the below. A gentle 3dB drop from bass to treble and then a 2dB lift at the very top. (50dB scale).
Using the HFN pink noise tracks you get something like the below, with rolloff at the bass and high channel deviations in the upper treble. This has been reported on other forums.
Using the Elipson pink noise mono track I get something which is a lot closer to the paper plot but with more slope and added arm resonance, indicating this pink noise goes lower than 20 Hz so good to use for picking the arm resonance too!
Lets take a look at the Elipson 1kHz tones and use for distortion and rumble. The cart measures <-40dBc 2nd harmonic so not bad. (repeating using the 100 Hz and 10kHz tones gives -52dBc and -25dBc). Power supply worse into right channel. Rumble spectrum can be seen.
What about that silent groove on the HFN record for rumble? Elipson doesn't have that but lets compare with the 1kHz tone. HFN is not very silent at all!
I also used the 3150 Hz track for wow and flutter and used that WFGUI program that you can find. Not very good with ~0.1% rms so work to do there. There is a lot of observed movement in the belt under use. Below is the difference spectrum using Audacity of the flutter measurement. If anyone knows how to interpret these well to identify specific problem sources please impart some knowledge!
Finally, I used the PEQ in the RME and turned on the subsonic filter in the preamp to flatten the frequency response somewhat. Still not perfect but OK.
In conclusion, stay away from the HFN pink noise tracks but the Elipson seems better, but maybe still not perfect. Note that my xtalk, using HFN PN and Elipson 1kHz was the same (21dB one way and 18dB the other so the HFN PN is OK for that. I have not managed to improve cross talk at all despite a lot of azimuth fiddling.
Next I will try the frequency sweeps but this is more difficult to record as I am using REW and that does not have a maximum peak hold in the real time analyser. I will have to use the biqad 30 band analyser that is in the software that comes with the RME.
I am measuring my 10 year old VPI scout (acrylic platter) and a Dynavector DV20X low, into a Project DS2 preamp and recorded using a RME ADI-2 PRO ADC/DAC.
The cartridge frequency response should be something like the below. A gentle 3dB drop from bass to treble and then a 2dB lift at the very top. (50dB scale).
Using the HFN pink noise tracks you get something like the below, with rolloff at the bass and high channel deviations in the upper treble. This has been reported on other forums.
Using the Elipson pink noise mono track I get something which is a lot closer to the paper plot but with more slope and added arm resonance, indicating this pink noise goes lower than 20 Hz so good to use for picking the arm resonance too!
Lets take a look at the Elipson 1kHz tones and use for distortion and rumble. The cart measures <-40dBc 2nd harmonic so not bad. (repeating using the 100 Hz and 10kHz tones gives -52dBc and -25dBc). Power supply worse into right channel. Rumble spectrum can be seen.
What about that silent groove on the HFN record for rumble? Elipson doesn't have that but lets compare with the 1kHz tone. HFN is not very silent at all!
I also used the 3150 Hz track for wow and flutter and used that WFGUI program that you can find. Not very good with ~0.1% rms so work to do there. There is a lot of observed movement in the belt under use. Below is the difference spectrum using Audacity of the flutter measurement. If anyone knows how to interpret these well to identify specific problem sources please impart some knowledge!
Finally, I used the PEQ in the RME and turned on the subsonic filter in the preamp to flatten the frequency response somewhat. Still not perfect but OK.
In conclusion, stay away from the HFN pink noise tracks but the Elipson seems better, but maybe still not perfect. Note that my xtalk, using HFN PN and Elipson 1kHz was the same (21dB one way and 18dB the other so the HFN PN is OK for that. I have not managed to improve cross talk at all despite a lot of azimuth fiddling.
Next I will try the frequency sweeps but this is more difficult to record as I am using REW and that does not have a maximum peak hold in the real time analyser. I will have to use the biqad 30 band analyser that is in the software that comes with the RME.