Can a phono stage really do this?


I just acquired a MAGI Phonomenal phono stage, which feeds a very compatible MAGI line stage. I have a Boz Scaggs album of Great American Songbook standards, which previously has displayed some pressig noise, such as crackling sounds that seem to syncrhonize with the rotation of the record.

I got this MAGI Phonomenal phono stage (handwired PTP), sometimes compared to the Manley Steelhead), and played the Boz Scaggs album with the new phono preamp. There was no noise. No mungy crackling to accompany the rotation of the record. Just pure, high resolution extraction of the musical elements of the LP. It was wonderful.

Can phono stages do this, or is it the result of lucky turntable setup with better tracking force, anti-skating adjustment, and azimuth adjustment? The TT is a Technics SL1210 M5G with KAB fluid damper and Oracle Groove Isolator sorbothane mat. But I never heard this record without the pressing noise until I got the Phonomenal. Cartridge is an Audio Technica AT150MLX with microline stylus.
johnnyb53

Showing 1 response by viridian

Well the arm/cartridge interface may be responsible for minimizing tics and pops but the phono stage and the rest of the system can be responsible for emphasizing them. To explain a bit further, tics have a rise time that is much greater than recorded music. They also have a high frequency component that is above the audible band.

Now certainly the arm and cartridge can be excited by the energy created by the tic and emphasize it. This is because the secondary cartridge and tonearm resonances are excited by this energy. But likewise, the high rise time and high frequency component of the tic, when passed to the phono stage can result in high frequency instability of the circuit, what we call "ringing", which will accentuate tics in those phono stages that run into this problem. Even if the phono stage can amplify it cleanly, it can lead to slew rate limiting in the amp, not to mention that tweeters are not happy being hit with high power at ultrasonic freqencies.

Additionally, it is in vogue, in some circles, to delete the final pole of the RIAA curve that was designed to attenuate the ultrasonic frequencies to compensate for the resonances in cutter heads. This presents a frequency response with a rising curve above the audible range that can spell more problems as these signals are passed on to the amps and tweeters.

It's a very complex, and dynamic problem. I am glad that the OP has found a combo that works for him.