Anyone have a suggestion for an ADC chip to attach analog sources to a dsp/dac for my self powered speakers? Looking for something that will work well so people can connect their analog sources whether that is from a cell phone or whatever has an analog output they may want to connect to my powered speaker system. Looking for information, at the same time I'm not looking for the most expensive or audiophile solution, just something that will work well and sound good without getting silly. Cost will be a consideration.
arnyk,
That certainly depends on what type of material your talking about, high speed steel, cobalt, titanium or carbide, all with use different manufacturing processes.
That certainly depends on what type of material your talking about, high speed steel, cobalt, titanium or carbide, all with use different manufacturing processes.
Steven, have you already implemented the dsp/dac part?
If yes, ignore my answer.
If no, and you are in the planning stage, consider the codecs from Analog Devices that incorporate everything you need in one IC (ADCs, DACs plus DSP core)
Audio CODECs | Analog Devices
I am using the 2x4MiniDSP board that uses the ADAU1701 and I am very satisfied so far
George
George,
Thank you very much. I keep taking one step forward and then two steps back. Now if I was only an EE this would probably all be simple. I looked at the description of the ADAU1701 and it sounds like it does everything all in one modular package. I see there is also a version for USB input. If you say it is a good choice I will take your considerable opinion on that. It sure is a lot less expensive than some of the high end solutions from ESS. How would you do volume control?
Thank you very much. I keep taking one step forward and then two steps back. Now if I was only an EE this would probably all be simple. I looked at the description of the ADAU1701 and it sounds like it does everything all in one modular package. I see there is also a version for USB input. If you say it is a good choice I will take your considerable opinion on that. It sure is a lot less expensive than some of the high end solutions from ESS. How would you do volume control?
You can have direct digital access of the 2 (analog) inputs and 4 (analog) outputs also through I2S but I am not aware of a ADAU1701 version with a USB input.
http://www.analog.com/media/en/technical-documentation/data-sheets/ADAU1701.pdf
Volume control in the digital domain is through a linear potentiometer connected btn 3.3VDC and ground. The wiper is connected to one or all of the # 26,27,28,29 pins. There are four 8bit ADCs behind these pins that can be configured as volume controls (among other things).
If you want to explore uses/flexibility of this chip and test it’s audio qualities yourself (better don't trust my opinion) before investing time and resources for design, programming ect, I would suggest to check the ready made 2x4MiniDSP kit (80$ for the board+10$ for the plug-n software configuration). You don’t have to be an EE to configure it, make use of it, or design for it (*)
https://www.minidsp.com/products/minidspkits/2-x-in-4-x-out
Steven, you may ask anything else you’d like to, either in public or via (P or e) mail
George
(*) it can be also your playing ground/scratchpad into DSP and your springboard to special designs of your own
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My only questions have been what size FIR filter can it implement, also does it do the dishes?
I showed how to dramatically (in some cases) shrink FIR's in my LA article. A dishwasher does my dishes, quietly if not quietly enough for you.
MiniDSP boards have an excellent reputation among the system builders around here. They have driven any number of Behringer DCX 2496's out of people's systems. USB conrol trumps serial port control for most people. I find it weird that Behringer was so slow to respond when USB became the control interface of choice many years back.
The ADAU1701 spec sheet looks pretty good from here.
I'd like to chime in with info about the chip that is the core of my JBL Pro LSR 308's, but its got house branding and markings. What ever it is, it sure works!
I have a 2x4 MiniDSP board with balanced I/O on hand for a subwoofer project.
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Yes Scott I saw that. Still useful to know capability.
As to noise, now that it is cold the hot water system makes enough noise expanding and contracting the plastic tubing that it is the loudest noise source.
As to doing the dishes I wouldn't know if it is noisy as I don't stick around while the dishwasher runs.
But as usual we really don't communicate. The joke was that the chip does everything except the dishes.
I have read far more than most people about this topic and nobody seems to address your contributions beyond “designed the electronics” and of course the differential summing amp gets explained pretty well; and I have read your comments on that here. If you don’t mind I have a few questions, and I promise they won’t extend beyond these. I think others can if someone wouldn’t mind reading this as I would sure like to learn.
Was your differential summing amp within each individual differential microphone unit, or was it a separate box as in the following diagram?
An externally hosted image should be here but it was not working when we last tested it.
If it was the separate box, did each of the 4 or 5 differential mic units get their common signals cancelled first, and then those vocal-only signals were summed to mono output? Or, were the complimentary signals of all 8 or 10 mics cancelled at the same time? That is where I am flummoxed, nobody describes the insides of the Summing Amp box in that diagram.
Now here is where any of you experts can help, page 25-27 of here http://www.americanradiohistory.com/Archive-DB-Magazine/70s/DB-1976-04.pdf are schematics, but as a novice I cannot read them.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
So my key question is did that box act as the mixer; in other words, they were no longer using the MX-10s to mix the vocals, but the Summing Amp box combined all 4 or 5 differential mic signals to mono and so the mix was then controlled by the band members with the sensitivity knob of each mic.
I also understand you designed the crossovers; what other elements did you design? Direct boxes, splitters, line drivers (or was your line driver for the Dead only in the early ‘80s)?
For the WOS did they use the stacked MX-10s to mix for the 2-track recordings on the Nagra IV-S, or by then had they adopted the Levinson solid state mixer you mentioned they seemed to be happy with. (I know the story of your ’70 solid state mixer)
Thanks in advance, and as you can see the people writing about this only go so far, and IMO these are some of the key missing components. We all know about the speakers and the McIntosh amps and the out-of-phase mics, and there was no FOH mixing console, but not exactly how it was all wired together.
Are there any photos of your gear laying around? I have never seen one and I have looked everywhere.
I was called in as a mediator in our project because the heating/cooling water loop runs 24/7 through all the buildings and one couple complained about the rushing noise. I had to put my ear up to the wall to hear it but they claimed they couldn't stand it, they moved out.
I also had a friend that insisted his plumber install a traditional cast iron and oakum soil stack because he couldn't stand the sound of toilets flushing down PVC.
George thank you very much for directing me to this solution. And Scott thank you for the offer of connecting me with the right people to help when I inevitably get stuck. Can you tell me which issue of LA has your article on the FIR filter optimization? That would be helpful and I'm sure Jan would appreciate getting another copy out there.
I guess what I saw was the following note which I misconstrued: The DSP is controlled by the SigmaStudio™ software, which interfaces to the board through a USB connection.
Would this N-core processor work with the ADAU1701 to add the USB functionality? Is this a good solution for adding this type of feature?
https://www.xmos.com/download/private/XHRA-2HPA-TQ64-C-Datasheet%281.2%29.pdf
Demian recommended a Libre wireless solution to handle wireless connectivity. Now connecting all these together is another story but if all this is a good solution this would move me in the right direction. I am looking at using a class-D amplifier, actually a pair I believe to produce the power requirement without high distortion for the bass/mid speaker and a class-ab chip amp to drive the tweeter. I originally thought to use a class-ab amp for the bass/mid amplifier but it seems the power supply would take some serious room and power along with all the heat that would produce. I am thinking a smps external brick to power the speaker, that would remove the power supply from inside the unit, something that would be rated and appropriate to drive an audio amplifier and not a computer circuit. Does anyone see a mistake in this thinking? The power differential between the tweeter and the bass/mid looks like a 10:1 ratio of power as I expect about 86db from the cone driver and about 96db from the tweeter.
I guess what I saw was the following note which I misconstrued: The DSP is controlled by the SigmaStudio™ software, which interfaces to the board through a USB connection.
Would this N-core processor work with the ADAU1701 to add the USB functionality? Is this a good solution for adding this type of feature?
https://www.xmos.com/download/private/XHRA-2HPA-TQ64-C-Datasheet%281.2%29.pdf
Demian recommended a Libre wireless solution to handle wireless connectivity. Now connecting all these together is another story but if all this is a good solution this would move me in the right direction. I am looking at using a class-D amplifier, actually a pair I believe to produce the power requirement without high distortion for the bass/mid speaker and a class-ab chip amp to drive the tweeter. I originally thought to use a class-ab amp for the bass/mid amplifier but it seems the power supply would take some serious room and power along with all the heat that would produce. I am thinking a smps external brick to power the speaker, that would remove the power supply from inside the unit, something that would be rated and appropriate to drive an audio amplifier and not a computer circuit. Does anyone see a mistake in this thinking? The power differential between the tweeter and the bass/mid looks like a 10:1 ratio of power as I expect about 86db from the cone driver and about 96db from the tweeter.
Scott
Access to the“SigmaStudio tools”, the software development environment for configuring the ADAU1701 family is part of the package when one purchases the evaluation board “EVAL-ADAU1401AEBZ”.
I was wondering what hinders AD for making it accessible to anyone who is using one of their ADAU chips and would like to try programming them.
Steven
Regarding this USB input you wrote. The USB input is only for directly configuring and programming the ADAU1701. It is not for inputing music to it. You have to use a USB to I2S device for this.
Only IIR filters as far as I know. The dishes I do them with my hands. It’s a good work therapy. (*)
The postman brought the #10 LA copy today. Happy reading in front. I’ll post impressions and questions
George
(*)We had received a dishwasher as a gift for the marriage. Never used it for 25+ years, only taking up space in a shelf. A few months ago I gave it to my sister, her’s was malfunctioning
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A sore point for me for years, I'm 100% for open source but the powers that be can be blockheads. I gave up the fight for an equivalent to LTSPICE years ago.
Yes it would.
Demian is a man to listen to
Read this as a proof of concept
http://www.diyaudio.com/forums/minidsp/238892-my-stack.html#post3558208
When you try one of the many available boards with class D amplifier ICs with a I2S input (eg TAS5704) coming directly from ADAU1701, you will be a bit surprised.
George
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You are welcome Steven.
And when you have time, jump on a plane and come for a listen, we are not far away (a few cm on the map) 😀
George
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