'Analog Dinosaur' succumbs to the joys of FBA : enter Raspberry Pi 2/IQ-Audio DAC+!!

[NRG]

Do you have a cct diagram of the IQ Dac+?

Thanks, Richard

No, but it uses a PCM5122 and looks like the data sheet implementation more or less, certainly for the o/p stage IE: a 154Khz low pass filer made up of 470R/2n2 cap..

[Bonky]

Dear Lovejoy, that is a very full and detailed response.

Thanks so much.

I reconnected ethernet to the Pi and was able to ping successfully.

However, when I tried the last bit (ssh....)

I got this:

64 bytes from 192.168.1.110: icmp_seq=28 ttl=64 time=2.803 ms
^C
--- 192.168.1.110 ping statistics ---
29 packets transmitted, 29 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 2.297/2.793/3.911/0.358 ms
applesimacg52:~ apple$ ssh -1 192.168.1.110
Protocol major versions differ: 1 vs. 2
applesimacg52:~ apple$

(see the penultimate line)

Any ideas?

(The IP address has volumio on the router's homepage rather than Pi)

Again,

Many thanks,

Richard

Hi Richard,
The first thing is to ensure that your Mac can see the Pi over the network, so with your terminal open issue a ping command which will send a call to the Pi and if they can see each other, the Pi will respond, so type:
ping <IP address of your pi>
e.g.
ping 192.168.0.10

The Mac will now send ping commands every second or so until you tell it to stop (ctrl + c). A successful response will look something like:

Richard$ ping 192.168.0.10
PING 192.168.0.10 (192.168.0.10): 56 data bytes
64 bytes from 192.168.0.10: icmp_seq=0 ttl=64 time=0.062 ms
64 bytes from 192.168.0.10: icmp_seq=1 ttl=64 time=0.121 ms

Those time measurements at the end tell you how long it took from sending the request to returning the response, and all is good if you can see this.

If you see something like:

Richard$ ping 192.168.0.4
PING 192.168.0.4 (192.168.0.4): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
Request timeout for icmp_seq 2

Then your Mac cannot see the Pi, so you can't go any further until you can get ping responses. If this is the case then the problem will lie somewhere in your network configuration:
1. Check that the IP address of the Pi is what you think it is - If the network configuration is set to DHCP then it may change every time the Pi is rebooted. It is for this reason, I always use static IP addresses so you know where everything is. Volumio has DHCP switched on by default, but you can easily set up a static IP configuration in the Network page of the web interface.
2. Ensure the Mac and the Pi are sharing the same subnet, i.e. if your Mac is on 192.168.0.something, then your Pi will also want to be on 192.168.0.something. If any of the first three numbers (octets) differ, then they occupy different subnets and will have trouble seeing each other, unless you start getting into more complex routing methods (which you don't want to do).
3. Following on from 2. check the netmask value (this usually appears underneath the IP address for each device). Firstly, this value should be the same on every device. If it is different then you may start to get problems. Most commonly this value should be 255.255.255.0. A netmask is a pretty good descriptive term. You are applying a mask over the network to each device - The holes in the mask - i.e. the zero - means that the device can see everything else no matter what the value is in this octet, whereas the 255 values mean that if the octet number for that field differs from the one being used by that device for any other device, it is masked and one won't see the other.

Following these rules should get to a point where you can ping, so once you've got there, you should be able to log into your Pi with the command

ssh -l pi <IP address of your Pi>
upon which you will be asked for your Pi password.

Hope that helps,
Rich

[NRG]

applesimacg52:~ apple$ ssh -1 192.168.1.110 this should read.....

applesimacg52:~ apple$ ssh -l pi 192.168.1.110 Thats a lower case L plus the user name....

or use:

applesimacg52:~ apple$ ssh pi@192.168.1.110

[struth]

there is a discussion about that here
https://www.raspberrypi.org/forums/v...p?f=91&t=33091

[Bonky]

Thanks guys, I have at last managed to get something on the screen that looks like alsamixer I've seen from other threads and sites./Users/apple/Desktop/alsamixer.jpg

But what next?
The F1 to F5 keys are 'apple' ones. F6 lets me choose a sound card. I've explored both the IQ and Alsa. I managed to decrease one volume level to get rid of the red part at the top of the 'histogram'.

Is that all? Are there any suggested tweaks?

I can't surely be the only one confused here. Is there any chance that one of the cognoscenti can write a 'sticky'?

Many thanks,

Richard

[lovejoy]

Hi Richard,
Use the arrow keys on your Mac to navigate the various mixer options. The currently selected one will turn from white to red text in the options at the bottom of the screen.
PCM is your master volume - 86 is the 0dB level, anything into the red is boost. I have mine set to 96 which matches the output of my CD player. If you set this much higher you'll likely start to hear distorion. Most people seem to settle around 92-97 I think, but it's handy if you have another source (apart from vinyl) to compare it with.
Move to the right with the arrow key and you'll select 'DSP Prog'. This allows you to select one of the different filter profiles built into the DAC chip. Use up and down arrow to change the value as you would with the volume levels. I've settled on Low latency IIR with de-emphasis. There are changes in presentation for all profiles. You may find another one works better for you, so it's worth having a listen to them all. This one is definitely worth playing with.
The next one along - Playback - gives you a -6dB attenuation if set to 0 and no attenuation if set to 100 (these are the only two values). I can't really see a reason for setting this to -6dB if you have your PCM level set correctly.
The next one along is Playback Boost, which gives a further 0.8dB of gain. This one is subtle and again is an on/off switch. Mine is on, but I don't think it makes much difference.
The rest of the options are mostly concerned with muting periods and how things are handled if there is a problem. Leave these set as they are.

Once you exit (Escape key), it's best to do a soft reboot of the Pi, either from the Web interface or just type:
sudo reboot
from the terminal. This ensures your settings have been saved. If you remove power rather than do a soft reboot, the previous settings will return after the next reboot.

I was thinking a sticky would be a good idea....

[mikmas]

Here's a pic of what it should look like (or at least it does on my Mac)

[struth]

http://www.maplin.co.uk/p/logic3-140...paign=16P03-11

possible power source for pi

[Bonky]

Thanks to Lovejoy and Mikmas.

Very much appreciated.

I'm busy for next hours/days but will experiment and let you know later...


Thanks.

BW

Richard.

[Gordon@IQ]

Rich, yes!

We designed the Pi-DAC+ to offer great performance at an entry level price. This is only made possible by the latest generation DAC's using integrated line drivers at the output. To keep costs and component count low, the Pi-DAC+ utilises this feature and uses a simple passive filter at the output to remove high frequency noise generated in the conversion process. This CAN make the Pi-DAC+ more sensitive to the interconnecting cables, namely the cable length and quality. The loading effect of the device which the Pi-DAC+ is plugged into can also affect performance.

Simply, we recommend keeping the cable lengths as short as possible, and use the highest quality cables you can afford.

Back to tinkering - time to find the best cables for your system / ears = more time listening and enjoying music.

Here we use a range of cables but I still like my home made (25yrs old) van der hul interconnects.

Gordon@IQaudIO.com