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Windows 10 Bug

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Bob McGraw - K4TAX

Windows 10 Bug

This may be worth investigation pertaining to the K3S USB application.

https://www.youtube.com/watch?v=guH0NMRRTAo&wide&hd=1

It affects audio through USB when running digital modes.

73
Bob, K4TAX

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Joe Subich, W4TV-4

Re: Windows 10 Bug

The individual posting this does not know what he's talking
about. His instruction to set the "microphone" level to 100%
is completely *wrong*.

Right click on the microphone slider and set the display for
*dB*. In Windows 7 the microphone slider scale will range
from -196.0 dB at 0 to +30 dB at 100% while in Windows 8.1
the scale will be -96.0 dB to +30.0 dB.

Negative gain levels represent attenuation in the CODEC while
positive gain levels represent excess gain. Sands is completely
*wrong* when he says any value below 100% represents attenuation.
In fact *any* "dB" value above 0.0 represents *GAIN* in the
CODEC.

The best recommendation for setting USB levels for any "microphone"
input supported by the Windows "USB Audio Class" driver is:

- go to Control Panel | Sound | Recording tab, double click on
Microphone - USB Audio Codec device
- on the Levels tab, right click on the microphone slider and
set the units to *dB*
- adjust the slider for 0.0 dB +/- 0.5 dB - this will typically
be 3% in Windows 7 and 54% in Windows 8.1
- tune to strong carrier (S9+)
- watch VU meter on Recording tab and adjust output level from the
radio (typically the RX pot on the interface - "Line Out" in the
K3/K3S) to 2 bars below full scale. If it not possible to reach
2 bars below full scale (the K3/K3S has plenty of excess drive)
increase the level slider slightly until signal is no more than
2 bars below full scale.

I no longer have working XP or Vista systems and do not recommend
the use of obsolete operating systems. However, the same procedure
(adjust for 0.0 +/- 0.5 dB) should also work with XP and Vista to
prevent overdrive and clipping there.

In any operating system, a 0 dB input gain setting will provide the
best balance of dynamic range and sensitivity in a sound card with
properly designed audio input circuits. Audio from the transceiver
should be set so the no-signal "sky noise" is about 15 dB above the
noise floor of the CODEC and the strongest signals no more than "2
bars" below the top of the "VU Meter" to prevent clipping.

73,

... Joe, W4TV

On 2015-07-29 11:13 PM, Bob McGraw - K4TAX wrote:

>
> This may be worth investigation pertaining to the K3S USB application.
>
> https://www.youtube.com/watch?v=guH0NMRRTAo&wide&hd=1
>
> It affects audio through USB when running digital modes.
>
> 73
> Bob, K4TAX
>
>
>
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TJ Campie

Re: Windows 10 Bug

In reply to this post by Bob McGraw - K4TAX

Joe,
You are correct when the input device has been enumerated as a microphone input, which is the bug. Without "clearing" the bug forcing windows to enumerate it as a line in device, 100 on the slider is indeed adding gain.

However after clearing the bug, it's now enumerated as a line in device and 100 on the slider is 0db, even if it reads +30 (the UI and dialogue box still thinks this is a microphone input device, this is part of the bug). This was verified by feeding a reference signal of a known level into the chip and obtaining a known output level, confirming 100 on the slider is indeed 0db of gain/attenuation AFTER clearing the bug.

This behaviour is confirmed by TI themselves in this whitepaper: http://www.ti.com/lit/an/sbfa020/sbfa020.pdf

If you have a signal generator I highly recommend feeding a reference level signal into a device using the chip and measuring the output yourself AFTER clearing the bug. Remember, you are correct that the slider value will add gain when it's been incorrectly enumerated as a microphone device. Measure a reference input signal AFTER clearing it. Hope that helps the confusion

73
TJ W0EA
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pa0pje

Re: Windows 10 Bug

In reply to this post by Joe Subich, W4TV-4

Op 2015-07-30 06:09 schreef Joe Subich, W4TV:
> The individual posting this does not know what he's talking
> about. His instruction to set the "microphone" level to 100%
> is completely *wrong*.

Joe,
I have the impression he *DOES* know what he's talking about...
This is a bug he's reporting in the Windows operating system in
conjunction with a certain brand of devices.

73,
Peter
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Andy McMullin

Re: Windows 10 Bug

I respectfully suggest that you watch his video and listen to the explanation before making comments. In particular, when software is not executing correctly you should remember that it is not doing what it is supposed to do.

He does not ask you to "set the microphone level to 100%" — he says to adjust the erroneous interface control to the 100% position. Not the same thing.

Watch the video (and pay attention to the oscilloscope displays), then try it for yourself to see what happens.

I hope this helps

—
Regards
Andy, G8TQH

> On 30 Jul 2015, at 09:36, Peter Eijlander (PA0PJE) <[hidden email]> wrote:
>
>
>
> Op 2015-07-30 06:09 schreef Joe Subich, W4TV:
>> The individual posting this does not know what he's talking
>> about. His instruction to set the "microphone" level to 100%
>> is completely *wrong*.
>
> Joe,
> I have the impression he *DOES* know what he's talking about...
> This is a bug he's reporting in the Windows operating system in conjunction with a certain brand of devices.
>
> 73,
> Peter
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Joe Subich, W4TV-4

Re: Windows 10 Bug

In reply to this post by pa0pje

On 2015-07-30 4:36 AM, Peter Eijlander (PA0PJE) wrote:
> I have the impression he *DOES* know what he's talking about...

Any time someone says to run the "microphone" level of a PCM29xx
series USB CODEC at 100%, he obviously does not know what he is
talking about. 100% represents 30 dB of gain (appropriate for
a microphone) - about a 30 x increase in voltage between the
codec input and ADC - which will most certainly cause clipping.

The Microsoft supplied drivers for Windows 7 (and presumably
Windows XP/Vista) do not make setting the CODEC gain easy as
they are *all gain* from 3% to 100% but it can be done. The
drivers for Windows 8/8.1 have been fixed in that the microphone
setting is gain above about 50% and attenuation below that.

*THERE IS NO PROBLEM IN WINDOWS 8/8.1*. In any Windows version
the easy solution is to *right click* on the microphone slider,
set the units to display in dB, and set the level to 0 dB +/-
1 dB.

In addition to the difficulty in setting levels in Windows 7
and before, there is a bug in the USB Audio Class driver with
regard to any USB Audio device that reports *one* microphone
input - Windows will reset the level to maximum gain each time
that endpoint (input) is opened. Resetting the input level to
100% is the only "bug" here and that has been fixed in Windows
8/8.1 (presumably Windows 10 but I have not updated any of my
systems to confirm the repair is present).

73,

... Joe, W4TV

On 2015-07-30 4:36 AM, Peter Eijlander (PA0PJE) wrote:

>
>
> Op 2015-07-30 06:09 schreef Joe Subich, W4TV:
>> The individual posting this does not know what he's talking
>> about. His instruction to set the "microphone" level to 100%
>> is completely *wrong*.
>
> Joe,
> I have the impression he *DOES* know what he's talking about...
> This is a bug he's reporting in the Windows operating system in
> conjunction with a certain brand of devices.
>
> 73,
> Peter
>

Joe Subich, W4TV-4

Re: Windows 10 Bug

In reply to this post by Andy McMullin

On 2015-07-30 5:11 AM, Andy McMullin wrote:
> I respectfully suggest that you watch his video and listen to the
> explanation before making comments.

I did watch his video.

> He does not ask you to "set the microphone level to 100%" — he says
> to adjust the erroneous interface control to the 100% position.

He says that any setting of the mic slider other than 100% is
attenuation. That is completely incorrect as can be demonstrated
simply by setting the legend to decibels instead of percent.

The only valid "bug" in his report is that Windows 7 and prior
resets the endpoint gain to maximum when the endpoint is opened.
Even that "bug" has been fixed in the Windows 8 driver.

73,

... Joe, W4TV

On 2015-07-30 5:11 AM, Andy McMullin wrote:

> I respectfully suggest that you watch his video and listen to the explanation before making comments. In particular, when software is not executing correctly you should remember that it is not doing what it is supposed to do.
>
> He does not ask you to "set the microphone level to 100%" — he says to adjust the erroneous interface control to the 100% position. Not the same thing.
>
> Watch the video (and pay attention to the oscilloscope displays), then try it for yourself to see what happens.
>
> I hope this helps
>
> —
> Regards
> Andy, G8TQH
>
>
>> On 30 Jul 2015, at 09:36, Peter Eijlander (PA0PJE) <[hidden email]> wrote:
>>
>>
>>
>> Op 2015-07-30 06:09 schreef Joe Subich, W4TV:
>>> The individual posting this does not know what he's talking
>>> about. His instruction to set the "microphone" level to 100%
>>> is completely *wrong*.
>>
>> Joe,
>> I have the impression he *DOES* know what he's talking about...
>> This is a bug he's reporting in the Windows operating system in conjunction with a certain brand of devices.
>>
>> 73,
>> Peter
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>
>
>

Joe Subich, W4TV-4

Re: Windows 10 Bug

In reply to this post by TJ Campie

On 2015-07-30 12:36 AM, TJ Campie wrote:
> Joe, You are correct when the input device has been enumerated as a
> microphone input, which is the bug.

No, enumerating the device as a microphone input is *not a bug* when
the device descriptor specifically identifies the input as microphone.

If the designer is using the PCM290x device in a "line in" deign, he
should be using the PCM290xC (or current equivalent) which identifies
the input terminal as 0x603 (Line connector) instead of the PCM290xB
which identifies as microphone.

73,

... Joe, W4TV

On 2015-07-30 12:36 AM, TJ Campie wrote:

> Joe, You are correct when the input device has been enumerated as a
> microphone input, which is the bug. Without "clearing" the bug
> forcing windows to enumerate it as a line in device, 100 on the
> slider is indeed adding gain.
>
> However after clearing the bug, it's now enumerated as a line in
> device and 100 on the slider is 0db, even if it reads +30 (the UI and
> dialogue box still thinks this is a microphone input device, this is
> part of the bug). This was verified by feeding a reference signal of
> a known level into the chip and obtaining a known output level,
> confirming 100 on the slider is indeed 0db of gain/attenuation AFTER
> clearing the bug.
>
> This behaviour is confirmed by TI themselves in this whitepaper:
> http://www.ti.com/lit/an/sbfa020/sbfa020.pdf
>
> If you have a signal generator I highly recommend feeding a reference
> level signal into a device using the chip and measuring the output
> yourself AFTER clearing the bug. Remember, you are correct that the
> slider value will add gain when it's been incorrectly enumerated as a
> microphone device. Measure a reference input signal AFTER clearing
> it. Hope that helps the confusion
>
> 73 TJ W0EA

TJ Campie

Re: Windows 10 Bug

In reply to this post by Bob McGraw - K4TAX

Joe, what device do you use in the Microham?

73, W0EA
TJ
----
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NAQCC #3768 | Flying Pigs QRP #2254
http://W0EA.us
*Because QRO is too easy (but sometimes required!)*
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Eric Swartz - WA6HHQ

Re: Windows 10 Bug

Administrator

In reply to this post by Joe Subich, W4TV-4

This is a Windows related bug documented by Texas Instruments on their Rev B
versions of the PCM29xx USB Sound CODEC.

TI has fixed this issue in PCM29xxC. and later revisions.

On the K3S we are using PCM2901E revision (newer than C). It does not have this
problem.

TI's Application Note about this:
http://www.ti.com/lit/an/sbfa020/sbfa020.pdf

73,
Eric
/elecraft.com/
===

On 7/30/2015 7:55 AM, Joe Subich, W4TV wrote:
>
> On 2015-07-30 12:36 AM, TJ Campie wrote:
> > Joe, You are correct when the input device has been enumerated as a
> > microphone input, which is the bug.
>
> No, enumerating the device as a microphone input is *not a bug* when
> the device descriptor specifically identifies the input as microphone.

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Bill Steffey NY9H

Re: Windows 10 Bug

I remember when 'the masses' were crying for a USB connection. Our
great sages at Elecraft kept suggesting that compatibility issues
would come along with USB et al.

Guess this would have been one ( or could have been one) if the USB
was a few years ago, and our designers were not as slick as they are.

It appears now MS needs to accommodate some slight missteps.

bill A K3 into a happy Microham , no need for usb

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