Hi Be, the ground wire of some turn table can be also make a big difference to eliminate the 50 Hz power supply noise.
I am not 100 % sure, but the circuit in front of the op-amps are most likely EMI protection circuits. They should not have a notable impact to the sound. Kind regards, Daniel Am 31.10.2016 um 21:18 schrieb Be: > > 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 ------------------------------------------------------------------------------ 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
