Vinyl -> Digital Reply #25 – 2010-12-15 09:44:22 Quote from: LocrianGroove on 2010-12-15 03:36:29Has anyone done any testing to determine the minimum number of bits required for a digital recording to sound the same as a vinyl recording?I just did a very casual test using small section of a typical vinyl rip that I did some time back. The original rip was made at 16 bits with an M-Audio AP2496 soundcard. (The turntable/arm/cartridge/preamp was Linn LP12/Ittok/Karma/Naim NAC42.5). The LP was a fairly typical album from my collection - not a test record or "audiophile" pressing, but a normal album in good condition. I deliberately chose a section that was fairly quiet (final part of a tune with delicate piano and tinking cymbals).I prepared the reduced bit depth samples by cutting the amplitude by 6dB and then raising it back by 6dB. Each such cut/boost cycle gives a 1 bit reduction (as near as makes no odds). I did all this at 16 bit without dither to provoke approximately the same sort of quantisation noise you'd get with native recording at those bit depths.It was trivially easy to hear the difference between 16 bit and 11 bit - ABX log follows:Code: [Select]foo_abx v1.2 reportfoobar2000 v0.8.32010/12/15 09:23:00File A: file://C:\clive\audio\The Guest Stars\Out At Night\x11.wavFile B: file://C:\clive\audio\The Guest Stars\Out At Night\x16.wav09:23:00 : Test started.09:23:33 : 01/01 50.0%09:23:37 : 02/02 25.0%09:23:40 : 03/03 12.5%09:23:48 : 04/04 6.3%09:23:55 : 05/05 3.1%09:23:59 : 06/06 1.6%09:24:03 : 07/07 0.8%09:24:06 : 08/08 0.4%09:24:12 : 09/09 0.2%09:24:18 : 10/10 0.1%09:24:20 : Test finished. ---------- Total: 10/10 (0.1%)I could not tell the difference in an ABX between the 16 bit and 12 bit versions. Note that I was doing this test on a laptop with a not especially sophisticated audio path, using fairly run of the mill headphones (Sennheiser 435). Therefore I think it is conceivable that it might be possible to distinguish the 12 bit version with better playback equipment and/or other music samples.So: how does this answer the question of the minimum number of bits needed to transparently record an LP? Well, my argument is that if there is no difference between 12 and 16 bits, adding still more isn't going to help. My conclusion is that 13 bits is probably enough to faithfully record typical vinyl sources, although you'd then have to be very careful about recording levels to ensure you actually made use of all 13 bits.