08/06/2025-17:36:24
(Modification du message : 08/06/2025-18:20:53 par RM8Kinoshita.)
RE: Technics SL-1210MK7+Audio Technica AT-OC9XSL+AT-LH11H
(08/06/2025-17:28:46)Ragnarsson a écrit : Douglas Self a écrit:
"I have designed many phono preamps
that were powered directly by 78/79 or LM317/337 type IC regulators, with no additional filtering.
In no case did rail noise or ripple make any detectable contribution to the output. To give this
some perspective, professional microphone preamplifiers work with signal down to −80 dBu,
which is 77 uV rms, and I have powered thousands of them directly from supply rails provide by
quite conventional power supplies, with no hint of a problem. They were of course balanced
preamplifiers, and this undoubtedly helps.
This immunity rail noise or ripple is very largely due to the excellent power supply rejection ratio
(PSRR) of opamps such as the 5532 or the LM4562"
Merci Pierre, ...
du point de vue du bruit, cela résume complètement mon expérience avec le circuit. L'étage MC est hybride bipolaires low_Rbb (2SB737 rohm originaux) / AOP (NE5532) et le schéma de production est très proche du schéma 11.5 p.380 de son livre "Electronics for Vinyl"
crdt.
" Liberty is an effort of the mind, rather than the arms."
Édouard René Lefèbvre de Laboulaye, 1876
Édouard René Lefèbvre de Laboulaye, 1876

