McIntosh C47 Firmware V1.00
- Thread starter kingstoneage
- Start date
The music comes from my MacBook > Audirvana 3.5 > USB > C47. I need to do some more testing but I think it only happens with 44.1 files. I could be imagining this. I have a Topping D10 which I can use to convert the Mac USB into Coax. I'd really like to utilize the USB port though.
damacman
Resident Psycho
Ron-C is back!
I've updated to the latest Audirvana and I'm still sporadically getting the first couple of seconds cut off of some tracks. The DAC sounds awesome but this is sort of a bummer. I'd love to solve it without having to buy a C49.
Has the C47 been updated?
When I took it to the shop, they forgot to do that so I just need to find time to drive the 100mi back. But yes, good point that I should attempt that first.
My C47 shows firmware version 1.04.
I normally run it with PCM coax input and it works great but as an experiment, I just hooked up the USB and confirmed that it does miss the 1st half-second or so sometimes. I'm not sure what triggers it but I think it is a change of bit rates in the music source or when the music stops (display shows "SILENT") and then restarts - so maybe affects only the first .5 sec of the first track if you play an album.
I recall Ron-C telling me a couple years ago that McIntosh will not be able to or was not planning to provide a fix for this but might affect every track on a playlist.
I am driving the C47 DAC from an Allo network bridge with Roon and the bridge has PCM coax, optical and USB outputs that I can use. The coax limits the bit rate to 192/24 but the USB can run at much higher rates and DSD. Ron suggested that I use coax normally but if I want to play something at a rate higher than 192/24 to switch over to USB (and live with this minor issue). In the 3 or 4 years since, I've not run into any sources at higher rates to play so have never needed the USB. I steam from Qobuz (up to 192/24 so far) and have a small collection of downloaded files at 96/24 and 44.1/16. So I am fine with the way things are working.
But if your only source for the C47 DAC is USB, say from a computer, then this issue and so the C47 could be a problem.
I normally run it with PCM coax input and it works great but as an experiment, I just hooked up the USB and confirmed that it does miss the 1st half-second or so sometimes. I'm not sure what triggers it but I think it is a change of bit rates in the music source or when the music stops (display shows "SILENT") and then restarts - so maybe affects only the first .5 sec of the first track if you play an album.
I recall Ron-C telling me a couple years ago that McIntosh will not be able to or was not planning to provide a fix for this but might affect every track on a playlist.
I am driving the C47 DAC from an Allo network bridge with Roon and the bridge has PCM coax, optical and USB outputs that I can use. The coax limits the bit rate to 192/24 but the USB can run at much higher rates and DSD. Ron suggested that I use coax normally but if I want to play something at a rate higher than 192/24 to switch over to USB (and live with this minor issue). In the 3 or 4 years since, I've not run into any sources at higher rates to play so have never needed the USB. I steam from Qobuz (up to 192/24 so far) and have a small collection of downloaded files at 96/24 and 44.1/16. So I am fine with the way things are working.
But if your only source for the C47 DAC is USB, say from a computer, then this issue and so the C47 could be a problem.
I thought that v1.07 added the ability to defeat the auto mute in USB. However, I was told it was a beta firmware and not for the c47.
I just have this issue with USB. I run a Mac mini so I have to go USB. It sounds great, I never have connection issues but it’s an annoyance. I’d really love to just do the firmware update at home…. Is anyone willing to send it to me? (My nearest authorized service provider is 100mi away)
I just have this issue with USB. I run a Mac mini so I have to go USB. It sounds great, I never have connection issues but it’s an annoyance. I’d really love to just do the firmware update at home…. Is anyone willing to send it to me? (My nearest authorized service provider is 100mi away)
prrar
Active Member
One possible solution, as you use Roon, is to let it upsample everything to 192/24. That should 'fix' it.
Do you mean down sample?
So far I've not run across anything higher than 192/24 to play and the coax connection plays all rates lower less than or equal to 192/24 without the need to resample and without the glitch.
prrar
Active Member
I was referring to the case when using the USB connection, so you don't 'lose' that first 0.5s or so. If the DAC always receive the same bitrate/sample it will not glitch, even on USB. That's why I was suggesting to upsample everything to a fixed 192/24 when using the USB interface.
Got it. Sounds like a good work around for the USB glitch. Thanks.
But coax is fine, in my case.
I find that it's not just the first song, it will do it on certain albums at the beginning of each track when the bit/sample rate isn't changing. Only on USB. CD via coax works perfectly. I've learned to not let it bother me.... it does but it sounds so good overall and I cant really upgrade again. Im surprised Mcintosh gave up on it when it seems fixable like they did when the DA-1 first came out and they resolved it. If I could find a solid USB > Coax converter, I might go Coax for the computer and optical for CD.