From Brian Willoughby Sent Mon, Jun 18th 2018, 02:29
From Brian Willoughby Sent Mon, Jun 18th 2018, 02:29
On Jun 17, 2018, at 4:55 PM, stephen watson via analogue = <xxxxxxxx@xxxxxxxxx.xxx> wrote: > I have a Ross Martin PCM 42222 ADC and a Focusrite 14 Firewire = interface I use for the firewire/thunderbolt. The S/PIDF goes from the = PCM 42222 to the Focusrite. I use one of those thunderbolt adapter = cables to a MacBook. There's high headroom on the PCM 42222 ADC because = the line levels from my gear reads very low on its LED meter. The gain = in Logic is +19 or +30. When I do that there is more noise depending on = the gear but it is a very clean signal. As far as overall sound, all I = can say is it sounds different than the Focusrite or something like an = MBox. I don't have a nice DAC, I can monitor the S/PIDF signal using the = Focusirte headphone out, also on the MacBook. One thing I noticed is = when I record audio rom the PCM 42222, pulg-in effects on the digital = audio do sound better for some reason. [snip] > I discovered Ross Martin and Little One 16 through Gearslutz like five = years ago. It's probably obsolete and archaic. I would say that the PCM4222 is not necessarily obsolete or archaic. = It=E2=80=99s just a little awkward to fit into a larger workflow. The only weak link in your setup is the DAC. Everything is probably = ideal inside the Ross Martin, because it probably has an excellent = sample rate clock and does a better job of ADC. The only problem that = can possibly happen after that is with the digital signal. If you=E2=80=99= re just recording to a digital file in Logic, then the Focusrite 14 = FireWire interface is not going to change the quality. The caveat is that when you listen to a S/PDIF signal, the clocking = situation is far from ideal. The good sound is there in the data from = the Ross Martin, but you need a better DAC to hear it properly = reconstructed. It=E2=80=99s not that the digital data is being = corrupted, but that the clock affect the sound quality. If you=E2=80=99re doing live monitoring, you=E2=80=99d probably need to = spend the money on a quality DAC with Word Clock output so that the Ross = Martin can sync up without relying on S/PDIF clocking (which sucks). The = fact that the Ross Martin even has a Word Clock input is what saves it = from being obsolete. The caveat is that the PCM4222 is not guaranteed to = sound the same from external Word Clock compared to internal clock. If = you=E2=80=99re not worried about live monitoring quality, then you = don=E2=80=99t need to bother with clocking. Brian Willoughby p.s. I always record live channel inputs so that peaks are below -12 = dBFS, and usually only -18 dB or even less. Logic has a global zoom = feature for waveform display which makes it a lot easier to work with = digital signals that have so much headroom. By the time you compress and = otherwise process the channels, you get a great sound. Keep in mind that = analog gear has the same amount of headroom, but the ~20 dB of excess = isn=E2=80=99t actually obvious because the analog VU meters peg long = before that and even the red LED clip indicators fire long before the = real analog full scale is reached. Analog consoles often get fairly = close to +30 dBu even though the inputs are only +4 dB nominal. That=E2=80= =99s almost 26 dB of headroom.