On 10/31/2016 01:07 PM, Sean M. Pappalardo - D.J. Pegasus wrote: > > > On 10/31/2016 10:50 AM, Be wrote: >> Well, if it works with the Maya44 USB as the link Daniel posted reports, >> I don't know why it wouldn't work with a higher quality sound card. > > Oh then it likely will. (I didn't visit that link. Did it say absolute > mode works?) > >> I suppose inverse RIAA EQ >> could have that effect, but I'm doubtful. > > I believe it does, since it attenuates HF instead of just boosting the > full range.
I looked up some block diagrams of phono preamps, and indeed some of them have the RIAA EQ before the op amp, but others do not. According to one source, it's best to split the high frequency attenuation and low frequency boost into two stages and use two op amps: http://www.learningelectronics.net/circuits/riaa-phono-preamplifier.html That's not because of noise picked up along the cable, it's to minimize high frequency noise from minute scratches on the record. While this may matter for maximum sound quality for passthrough mode or digitally recording vinyl records, if the Maya44 USB works, it doesn't seem necessary for timecode control. I opened up my Rane SL2 (which does not have a Linux driver) and it looks like there is some processing before the op amp. I'm not sure whether that is performing the RIAA EQ. Maybe someone more knowledgeable about electrical engineering could provide some insight. Here's a photo of it: https://s21.postimg.org/mkql7q2o7/sl2_input.jpg On a side note, there's no true analog passthrough on that device. When operating in stand alone mode with an AC adapter and no USB connection, the signal still gets converted to digital and back again. This has been confirmed by Rane (http://dj.rane.com/forums/viewthread/30/ ) >> Ah, okay. That doesn't mean that two microphone inputs couldn't work though. > > Of course but the other thing users would need to be aware of is if > their TTs output line level, that can't be used with a mic-level input > at all. (It is way too high and will massively distort.) Sure, but they need to be aware of that anyway to understand whether to use a phono preamp. > Starting to see why we just point out the best practice in the > documentation? :) It causes the least confusion and is easiest to > support. (Trying out alternatives is always welcome and goes without > saying.) > Yes, documentation should make best practice clear but it shouldn't leave out detail that confuses users trying to use unusual setups. ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi _______________________________________________ Get Mixxx, the #1 Free MP3 DJ Mixing software Today http://mixxx.org Mixxx-devel mailing list Mixxx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mixxx-devel
