USB422 Latency and Yosemite III - Solved

Today I posted on the USB-422 web page signed low latency drivers for Yosemite.

The certification from Apple arrived when I was on holiday and it took a while before I could update the software. I checked the driver on the Yosemite macbook air that I purchased for testing. I certified the driver on a separate computer so that I could be sure that the driver was certified for all computers.

The hardest part of the installation is to be sure that the Low Latency driver is being used. Please read the MacLow installation notes! You can use the Latency check program that I wrote to be sure.

You can see the two versions installed below.

 Please let me know if you have any problems!

Yosemite and Latency II - More Problems

Last week I had a customer report more problems with Yosemite so I tried to replicate my last results - and failed! I then re-installed Yosemite from scratch and still failed!

To help make tests I wrote a small test program which measures the total time to send and receive a message.
 http://www.colinbroad.com/cbsoft/usb422/latency-mac.zip
Note: It is the maximum time that is of interest.

On investigation I discovered with the help of others that Yosemite requires signed drivers, if you rename the kext files or edit the plist file it disables the signing and the driver will no longer install.

I am now waiting for certification from Apple which will take 7 - 10 days assuming that they approve my application. If I get certification I will build a certified driver.

There is one alternative if you need it now, you can run a uncertified driver by disabling the gatekeeper which will then allow uncertified drivers to run. Wolfgang at SMM has confirmed this works.  Note: this allows any uncertified program to run with out confirmation.

TMC-1 User Interface

You may have noticed the change in the description below the title. I have worked on the TMC-1-Penta design since the beginning of the year and I am now happy to release it on our customers. In the process I have updated the User Interface for both versions of the TMC-1 (XMon and Penta) a number of times.

I have to thank Owen Curtin at the Bridge Soundstage for his feedback, Owen was the first person to order a TMC-1-Xmon about 6 months ago. Although I have not always implemented his suggestions they made me look at his problems and come up with my own solutions. Owen also came up with solutions to two of the limitations of the X-Mon - Monitoring the Studio Loudspeakers in the control room and playing back into the Studio from a different source to the Control Room.

I hope that my existing users will find the time and patience to upgrade to the new user interface and will like the changes that I have made.  If there is anything that I have removed that you want back or anything else that you need, let me know and I will try and work out a way.

Unless I have an urgent request or bug fix I hope that this will be the last User Interface upgrade for a while.

The picture below shows the new Meters Page with the Sum source indication, user defined names and Meter layout, you can also see one of the new user key functions [SLS A/B].
Note: I disconnected XMon to stop the Meters.

Yosemite and USB-422 Latency

Having updated Mavericks for USB Latency I was still getting a few emails from customers about Yosemite.  Because I use my macbook as my main machine running Mac, Windows and DOS and do all my work on this computer I was reluctant to upgrade just in case of problems.

Whilst in the USA for NAB I bought a new macbook with Yosemite pre-installed I can now use this machine for trying out new programs. I followed the posted instructions and disabled the Apple driver. You can use the 'ls' command to check that the driver has been disabled (Renamed). I then went to the FTDI web site where I discovered that FTDI had posted a new driver for the Mac that very same week! Version 2.3 2015-04-15. I installed the new FTDI driver, used KextDrop to add the low latency driver and restarted the computer. Everything worked OK and the port was discovered correctly.

I had to wait until I got back to my office to measure the latency, as you can see below it measures at 1mSec s expected. The Yellow trace is the command from the Mac via the USB422 and the Blue trace is the reply from our RM-6 synchroniser. They are both set up to send a message immediately after receiving a message. The USB runs a 1mSec poll so that there is approximately a 1mSec delay on the Mac. The embedded software reacts a lot faster as it is not limited by the USB Poll.

TMC-1 Mechanical Switch Noise in Talkback

I received a report that the mechanical switch noise on the TMC-1 when switching was annoying. Initially I assumed that the problem was switch On (easy to fix with a short delay) but the problem was that the noise from the switch release was too loud.

 I have tried to reduce the mechanical coupling on the panel by using a grommet and thin wires. The pictures show how to cut the grommet and glue to the front panel. The grommet Internal Diameter is 10mm and fixing hole is 12mm . We are supplying future units with this modification.

This reduces the noise but does not completely remove it. There are two alternative approaches you can try.

1) Use an external microphone and connect directly to the X-Mon or Digital system. You can then use the switches on the TMC-1.

2) Use external switches to Enable/Disable the internal talkback on the TMC-1. I have just added Int T/B 1 and Int T/B 2 as options to all the User GP inputs on the TMC-1.

Note this is not a problem with the External talkback microphone and switches.

Let me know how you get on, I am always available and welcome ideas to improve products. 

TMC-1-Penta and Dolby Atmos 7.1.4 and 9.1.2

Today I revised the specification of the TMC-1-Penta to cope with 12 channel Stems. To increase the channel count from 10 to 12 it was necessary to remove one of the stereo cue outputs. The revised specification for the mixer is as follows.

Stem/Input Summing - 12
Four Stereo Cues  - 8
Mono/Stereo main mix - 2
7.1/5.1 Downmix - 8
Stereo Downmix - 2
Total = 32

Here is a revised block diagram of the monitor system

TMC-1-Penta Details

The TMC-1-Penta monitoring is based on a enhanced  TMC-1-Xmon, the changes have involved an increased channel count and removing some limitations of the Digidesign XMon hardware. The block diagram below shows the current design of the system. I expect that this will be modified to respond to users requirements.The main features at present are as follows

• Up to 64 channels on the main monitor path
• Alternate Output (8 Channel)
• Mini Output (8 Channel)
• Five 10 channel wide alternate inputs/stems
• Input and output trims
• Two Listen back Inputs
• Two Talkback Inputs
• Two Talkback output feeds
• Five Cue Outputs
• Three stereo cue inputs
• Stereo Downmix Output
• 8 Channel Downmix - 7.1, 5.1
• Meter Outputs