Need help building a proper line level RIAA filter

[DjMikiRia]

Lush on Polycarbonate (Glass Cut No RIAA) http://kiwi6.com/file/d281mhf9ui or direct mp3 link: http://k007.kiwi6.com/hotlink/d281mhf9ui/lush_on_ploycarbonate_glass_cut_no_riaa_.mp3

This is the result I had when cutting without any filter. I am no longer getting static pops due to grounding stylus seat so I embossed at a very low level to not overmodulate the groove, hence the THD. This is where I feel I can ask for some kind of help on frequency control LOL plz.

[markrob]

Hi,

If you are cutting from a digital source I can send you a copy of my VST plugin that does the RIAA curve. Just pm me with you email address and I'll send it along. If you want to go with an analog version, search the forum as there are a few examples (some passive and some active) here. Have you done any EQ to flatten your head response yet? You will need to do this in addtion to the RIAA to get good results. Note that you will need a good deal of reserve power to make the head cut the higher frequencies. The RIAA provides gerenerates +13db of boost at 10Khz and you will probabaly need an addition +30db to make the head flat vs. velocity.

Mark

[DjMikiRia]

Two 4.7 uF non -polarized on each speaker & two 0.5 uF tant. on each line input (Left/Right). For bass cut / high pass. I think I could build a proper phono pre-amp which is what I need for proper playback so I can get a better reference. I am currently using a stereo mic input on my laptop for the emboss to mp3 conversion. All other attempts I've posted here had an approximation of the RIAA curve prior to conversion using Reaper recording software (because it is free LOL). - Stereo phono pre-amp schematics if a simple one could be found.

Thank you for replying Mark

[DjMikiRia]

Two 4.7 uF non -polarized on each speaker & two 0.5 uF tant. on each line input (Left/Right). For bass cut / high pass. I think I could build a proper phono pre-amp which is what I need for proper playback so I can get a better reference. I am currently using a stereo mic input on my laptop for the emboss to mp3 conversion. All other attempts I've posted here had an approximation of the RIAA curve prior to conversion using Reaper recording software (because it is free LOL). - Stereo phono pre-amp schematics if a simple one could be found.

Thank you for replying Mark

[markrob]

Hi,

It looks like Reaper does support VST plugins, so my plugin should work.

Mark

[DjMikiRia]

Is this for pre-emboss (reverse curve) or post playback (forward curve)?

[markrob]

Hi,

I have both. They also allow for the turnover frequenices to be adusted from the standard 50hz, 500hz, and 2122hz. This could be used for half speed mastering or to replicate older pre RIAA curves. The playback version assumes you will connect a magnetic pickup (flat velocity response) to an un equalized preamp with the correct load (typically 47K and 100pf). I also have a version without the 500hz turnover for use with moving iron head like the Presto. This could also be used for a moving coil designs since the open loop response of this type of head is typically rising at +6db oct up until system resonance (compliance control region).

Mark

[scalawag]

Here's another RIAA plugin (Windows and Mac):
http://www.vacuumsound.de/plugins.html