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Mcintosh C48

Yes, running JRivers in WASAPI Media Event mode, 100ms buffer and C48-USB as designated WASAPI device, sounds amazing. I am using this straight up without using any of the JR tools. When I listen to headphones on the laptop or the C48 I do add standard level cross-fade in the JR headphone DSP section. This sounds much more relaxing and real with headphones.

Thanks,
Ron-C
 
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ron-c said:
Yes, running JRivers in WASAPI Media Event mode, 100ms buffer and C48-USB as designated WASAPI device, sounds amazing. I am using this straight up without using any of the JR tools. When I listen to headphones on the laptop or the C48 I do add standard level cross-fade in the JR headphone DSP section. This sounds much more relaxing and real with headphones.

Thanks,
Ron-C
Click to expand...

This is nice, but I'm trying to figure out the issue coming from my Mac mini, and why the 48 presents as USB 1 device on two different computers

I tried on an Intel-based MacBook Air with 2gb of ram, and the drops were a lot less but still occurred (runing the latest version of Snow Leopard and iTunes 10)

I also tried for about 30 minutes booting that same MacBook Air into Windows XP SP3, and I didn't notice a drop playing via iTunes...so could there be some issues with the 48 and OS X stock USB drivers? Fwiw, the 48 also presented as a standard USB devices in Windows, not a USB 2.0 device...

I'm on my third USB 2 cable (an audioquest 2 meter Forest), and as noted earlier, the same two computers playing to an hrt streamer II + dac have no dropouts - so it is plausible there is some issue with the USB firmware in the 48.

At the least, I hope this is reported internally as part of the testing of the new firmware, though chuck said he did not have a Macintosh computer in his offices... My, how can Mc dis its Mac brethren...!


Thanks
 
I would think that a more MAC centric computer audio group like computeraudiophile.com could come up with some suggestions. I am hearing that C48/and C50 both work well with the Apple products. I was playing a Power Book over a Belkin USB 2.0 cable to C50 with no noises or dropouts a few weeks ago. Worked geat actually.

Thanks,
Ron-C
 
ron-c said:
I would think that a more MAC centric computer audio group like computeraudiophile.com could come up with some suggestions. I am hearing that C48/and C50 both work well with the Apple products. I was playing a Power Book over a Belkin USB 2.0 cable to C50 with no noises or dropouts a few weeks ago. Worked geat actually.

Thanks,
Ron-C
Click to expand...

I'll try there also, but nothing glitch-free with the two macs I've tried so far.

How much ram in the PowerBook and what os version was it running?

Thanks
 
thrangster said:
....the 48 also presented as a standard USB devices in Windows, not a USB 2.0 device...
Click to expand...

How did you look this up in Windows? I'm trying to help you troubleshoot, as my C48 is working just fine via USB in Windows. If you tell me, I can look mine up to see if it's C48 or your computer.

I also think adjusting the bufffering per Ron's suggestion could help as well.

Keith
 
kredmore said:
How did you look this up in Windows? I'm trying to help you troubleshoot, as my C48 is working just fine via USB in Windows. If you tell me, I can look mine up to see if it's C48 or your computer.

I also think adjusting the bufffering per Ron's suggestion could help as well.

Keith
Click to expand...

In Device Manager it shows up as a Standard USB Device, which my understanding is a USB 1 device.

There's no buffering adjustment in OS X that I'm aware of...

Now I just went our an bought a brand new Mac Mini from the Apple Store, running the latest updates...it also shows the C48 as a USB 1 device...

This Mac also has 2 GB of RAM, and I have an 8 GB upgrade kit on order.

So far, this has had the fewest drops, but there are still some...so how fast of a processor and how much memory to you really need to just pass bitstream of AIIFF or ALAC if this indeed is the answer? And why the HRT doesn't have an issue is beyond me...

Anyway, I will update once I test with the full 8 GB of RAM.

(BTW, I was being daft before; my original Mac Mini was not 11 years old by 6 years old...)

Thanks
 

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thrangster said:
In Device Manager it shows up as a Standard USB Device, which my understanding is a USB 1 device.

There's no buffering adjustment in OS X that I'm aware of...

Now I just went our an bought a brand new Mac Mini from the Apple Store, running the latest updates...it also shows the C48 as a USB 1 device...

This Mac also has 2 GB of RAM, and I have an 8 GB upgrade kit on order.

So far, this has had the fewest drops, but there are still some...so how fast of a processor and how much memory to you really need to just pass bitstream of AIIFF or ALAC if this indeed is the answer? And why the HRT doesn't have an issue is beyond me...

Anyway, I will update once I test with the full 8 GB of RAM.

(BTW, I was being daft before; my original Mac Mini was not 11 years old by 6 years old...)

Thanks
Click to expand...

ok...so I also confirmed in my Windows system that the C48 is not going through USB 2.0. It lists the Mcintosh USB as "USB - Universal Host Controller", not "USB - Enhanced Host Controller". The Enhanced is USB 2.0. However, again, my system is running just fine.

On changing the buffering, this is done right in the J River Media software, not in Windows. Maybe Pure Magic has the same option. What are you using for a Media Player?
 
thrangster said:
In Device Manager it shows up as a Standard USB Device, which my understanding is a USB 1 device.

There's no buffering adjustment in OS X that I'm aware of...

Now I just went our an bought a brand new Mac Mini from the Apple Store, running the latest updates...it also shows the C48 as a USB 1 device...

This Mac also has 2 GB of RAM, and I have an 8 GB upgrade kit on order.

So far, this has had the fewest drops, but there are still some...so how fast of a processor and how much memory to you really need to just pass bitstream of AIIFF or ALAC if this indeed is the answer? And why the HRT doesn't have an issue is beyond me...

Anyway, I will update once I test with the full 8 GB of RAM.

(BTW, I was being daft before; my original Mac Mini was not 11 years old by 6 years old...)

Thanks
Click to expand...

On your Mac, you might check the system preferences sound output to see if there is a buffer setting for the USB output. You might also run the Audio Midi Setup application (it's in the utilities directory in the applications directory) to see if there is a buffer setting for the USB audio.

I don't know if either of those ideas will work since I don't have a USB DAC hooked up to my Mac to test.

And while you should expect the C48 to work as advertised with the USB input, your new Mini has an optical digital output. It's built into the headphone jack on the computer but you need the correct cable to connect. For example, note the little adapter that comes with this TOSLINK cable at the link below. The adaptor plugs into the headphone jack on the Mini and the TOSLINK cable.

http://store.apple.com/us/product/TL955LL/A?fnode=MTY1NDA3Ng&mco=MTA4NDk5MjQ&s=topSellers

Plenty of sources for these TOSLINK cable adaptors on Amazon.

This should work better than USB. I use this approach to run the DAC input on my MDC 500 including hi-res (up to 96 kHz, 24-bit sample) audio. Sounds great.
 
TSmith8605 said:
On your Mac, you might check the system preferences sound output to see if there is a buffer setting for the USB output. You might also run the Audio Midi Setup application (it's in the utilities directory in the applications directory) to see if there is a buffer setting for the USB audio.

I don't know if either of those ideas will work since I don't have a USB DAC hooked up to my Mac to test.

And while you should expect the C48 to work as advertised with the USB input, your new Mini has an optical digital output. It's built into the headphone jack on the computer but you need the correct cable to connect. For example, note the little adapter that comes with this TOSLINK cable at the link below. The adaptor plugs into the headphone jack on the Mini and the TOSLINK cable.

http://store.apple.com/us/product/TL955LL/A?fnode=MTY1NDA3Ng&mco=MTA4NDk5MjQ&s=topSellers

Plenty of sources for these TOSLINK cable adaptors on Amazon.

This should work better than USB. I use this approach to run the DAC input on my MDC 500 including hi-res (up to 96 kHz, 24-bit sample) audio. Sounds great.
Click to expand...

Thanks - there are no buffer settings in the sou d control panel or audio midi - I had already checked. I was googling to see if there was some way to edit a plist but could not come up with anything..

Yes, aware of the optical option, and had the adapter from my original Mac mini, but have not been able to find it (small+unused=lost). I've already ordered a new one overnight to see.

I thought, especially with the forthcoming 48/50 usb firmware update, that the USB option would be the best sonically, so I'm also focused on making sure this works.

Thanks
 
Ok, I received and installed the 8 gb memory upgrade for my Mac mini, and after an hour of listening, I did not hear any drops. So perhaps 2 gb was insufficient -maybe 4 would have been fine, but 8 was cheap enough...

I also received the mini to toslink cable today and tried that (at 88.2) - this sounded appreciably better than the USB input - more prominent low end, better attack, even sounded somehow more spacious, open - so am I just hearing the sonic improvement of the 44 to 88 upsample, or is it how USB is currently handled on the c48 with the generic usb drivers vs the more mature optical/coax implementation? (I will of course test this on my own by playing optical out at 44, but have not had the time for another round of critical listening). Conversely, it makes me itch more for the final usb firmware to hear what the high upsample capability sounds like...

Now, to connect the optical output to my avr instead and truthfully ask myself if I hear the difference with the c48 :sigh:...
 
Thanks for the report back. What you hear when you listen to USB on your computer is all the audio circuitry that is built into the computer such as volume controls, EQs, and other manipulating of the audio signal plus the music. This is why third party computer audio playback programs are popular since they can bypass the unneeded audio sections your computer came with. Bypassing the built in stuff may increase sound quality.
I am not hacking on Microsoft or Apple in any way but they both can benefit from third party audio programs if the very highest sound quality is desired. Many of the popular audio programs come from the pro music side where computers are used in the mastering process.
I suspect using the mini optical out is also bypassing some of the internal audio circuitry. If you can use the computer's built in volume control you will know you are not getting the maximum fidelity, in fact you should turn it all the way up and control the volume in the analog domain with C48.

Thanks again,
Ron-C
 
ron-c said:
Thanks for the report back. What you hear when you listen to USB on your computer is all the audio circuitry that is built into the computer such as volume controls, EQs, and other manipulating of the audio signal plus the music. This is why third party computer audio playback programs are popular since they can bypass the unneeded audio sections your computer came with. Bypassing the built in stuff may increase sound quality.
I am not hacking on Microsoft or Apple in any way but they both can benefit from third party audio programs if the very highest sound quality is desired. Many of the popular audio programs come from the pro music side where computers are used in the mastering process.
I suspect using the mini optical out is also bypassing some of the internal audio circuitry. If you can use the computer's built in volume control you will know you are not getting the maximum fidelity, in fact you should turn it all the way up and control the volume in the analog domain with C48.

Thanks again,
Ron-C
Click to expand...

Hi Ron

On the Mac, if you leave itunes volume at full, turn of eq, sound check, and sound enhancer, you are golden avoiding any degredation of the signal - which is how I am running...the volume slider in the general sound preference panel has no affect, as os x apparently recognizes that a digital interface is the selected output.

I am looking at something like pure music for iTunes, buti cannot figure out what benefit it would give me if I am simply bitstreaming a digital signal - how could it give me better 0's and 1's?

Thanks
 
ron-c said:
For sound quality and feature reviews of the various systems see, www.computeraudiophile.com. From what I have experienced the difference is very noticable with a good program.

Thanks again,
Ron-C
Click to expand...

I agree...using third-party software allows you to bypass the windows/apple sound processing before going out to the DAC, per Ron-C's posts. www.computeraudiphile.com is helpful.

I just went through this too. One thing to try: Play different files at 44, 96, then check on the C48/50 to see what the display says. I could see Windows upsampling and could play with the sound device settings, but when I used J River/exclusive mode, it was just passing along whatever was playing. That is how I found the USB tops at 44.
 
same random clicks/pops issues on newest mac mini

ron-c said:
C48/C50 are USB 2.0. How old is your computer?

Thanks,
Ron-C
Click to expand...

Ron,
I just bumped into this forum and I'm glad I did. I've been having the same exact problems with the USB input, and I have the latest Mac Mini, with 8 Gb of RAM and latest OS 10.6. My C48 shows up as a USB 1 (12Mb/Sec) device and i hear the same random clicks/pops (all my music is stored in a USB 2 external drive, in AIFF format).
Hopefully the new firmware will fix that.
 
iTunes should just fine into C48, C50 USB. You have something wrong in your computer's settings.

Thanks,
Ron-C
 
thrangster said:
Hi Ron

On the Mac, if you leave itunes volume at full, turn of eq, sound check, and sound enhancer, you are golden avoiding any degredation of the signal - which is how I am running...the volume slider in the general sound preference panel has no affect, as os x apparently recognizes that a digital interface is the selected output.

I am looking at something like pure music for iTunes, buti cannot figure out what benefit it would give me if I am simply bitstreaming a digital signal - how could it give me better 0's and 1's?

Thanks
Click to expand...

I am also pondering the same theory and have same question.

In addition to the steps you mention above, I also run the Audio MIDI Setup utility and make sure the audio output sample rates and bit-depth match the audio file being played so that the computer does not have to convert sample rates / or bit resolution. I let my MCD500 DAC, rather than the computer, do any needed conversions.

If your doing bit rate conversions in the computer in real time, I believe the software Ron mentions helps a lot by doing faster, more precise conversions including using 64-bit calculations to convert from 16-bit to 24-bit samples to make sure nothing is lost due to round-off.

Also, this software allows the file to run from RAM rather than the hard drive providing a more constant bit stream. This were using the optical output helps as it provides a continuous data stream dedicated solely to the audio. The USB is more bursty and must also support other connections and data and the date protocol needed to support multiple connections and data flows.

I'm not sure if Apple publishes a technical description of the Quicktime player software that would further answer the question of what processing is done by the computer and why quicktime falls short of the specialty software.
 
childlost said:
Ron,
I just bumped into this forum and I'm glad I did. I've been having the same exact problems with the USB input, and I have the latest Mac Mini, with 8 Gb of RAM and latest OS 10.6. My C48 shows up as a USB 1 (12Mb/Sec) device and i hear the same random clicks/pops (all my music is stored in a USB 2 external drive, in AIFF format).
Hopefully the new firmware will fix that.
Click to expand...

I wish I could help you - I did get to the point of no clicks or pops after purchasing a new Mac mini and adding 8 gb of ram - this was for about an hour of listening...I ended up returning the C48 after a lot of a/b testing vs the HRT dac going into my Denon 4311 analog in Pure Direct mode - unfortunately, there was no difference in the quality of the sound, so I could not justify keeping the C48. Same soundstage, same frequency exension, same attack and decay...

I ended up selecting a Prima Luna Dialogue 3 tube preamp, which, for me, is offering a world of improvement, especially in terms of detail, soundstage, bass, and smoothness - currently using the HRT dac to feed it analog.

Now I'm no McIintosh bashing - I don't own Mc gear, was itching to buy a stereo preamp, and was really thinking this would be the ideal entry for me...

I hope to try some other McIntosh gear in the future, perhaps amplification.

Ron, thanks for your help, but as a note, be aware that there are very few setting on the Mac to successfully avoid d/a/d conversion and pass bitstream - afaik, iTunes volume at full, eq off, sound check off, gapless playback off, and sample rate left at 44.1 in audio midi (presuming one is playing cd rips at 44.1) passes the bitstream.

There are no special USB settings - the c48 is not showing up as a high speed USB device, but to be fair, I noticed that the HRT dac is not either - but the HRT never had dropouts, even with my original 512k PowerPC Mac Mini.
 
Terry,

You pretty much hit the nail on the head with your explanation. One of the advantages of the McIntosh USB solution is that it will be upgraded by software downloads in the near future. This built in flexibility will be valuable in the future as USB audio becomes more popular.

Thanks again,
Ron-C
 
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