Full Digital / CrossOver / Multi Amplifier integrated

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There are forums and threads for Class D, Cross Over, multi-amplifier, but I thought there are no thread for all combined issue.

I'd like to know anyone playing this way.

At recent, some chips handles digital input and amplification, also Filter for cross over / multi amplifier.

I know TI's TAS5508 and TAS5518, Apogee DDX. Common way of handling is,
(1) Supply I2S PCM signal to chip
(2) Micro Controller handles I2C registers for filter setting, volume control, muting, dB offset for each channels

Attached photo is Apogee DDXi-2161 8way board.
and here is TAS5518 4Way.
http://koon3876.blogspot.com/2006/11/tas5518-and-tas5121-8-channel.html

Keywords
PCM, I2S, SPDIF input to Amplifier
Integrated cross over
Multi Amplifier
BiQuad Filter
Micro Processor, with I2C, C language (for Math)

Resources
http://www.apogeemems.com/ddx/ddx_products.html
http://focus.ti.com/docs/prod/folders/print/tas5518.html
http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
http://www.rabbitsemiconductor.com/products/bl1800/

regards,
 

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No one interested?:(

(you love multi-amplifier) and (you love class-D)
then you will love TAS5518.

TAS5518 can contain cross-over in itself, and can control up to 4 way amplifiers. You only need some micro controller with I2C. PIC, AVR, 8051, MSP430, any can do it.

this piece of code

const unsigned char CH12_Q1[20] = {0x00,0x00,0x13,0x78
,0x00,0x00,0x26,0xEF
,0x00,0x00,0x13,0x78
,0x00,0xF4,0x66,0xEF
,0x0F,0x8B,0x4B,0x33};
:
I2CWrite(TAS5508_ADDRESS, 0x51,CH12_Q1,20);
I2CWrite(TAS5508_ADDRESS, 0x58,CH12_Q1,20);

will set 44.1kHz, 300Hz 24dB/Oct LPF to TAS5518's channel 1 and 2, so it can be woofer driver.
 
Koon,

Of course everyone is interested. You just haven't asked any specific question ;) and the topic is huge. I have TAS5518 on my list (I even got 1 sample chip - Giovanni thanks for this). But this would be quite a project. Without help of people from this forum, I wouldn't be able to design someting like this. Would you be willing to share e.g. your LCD control (including the code for the microprocessor)?
Any more info on Apogee DDX? Where did you buy it?

PS: I liked the Digikey enclosures on your blog.

Marek
 
Thank you I'm not lonely now:)

Yes, Topic is too huge! and still I am working around 5518 and DDX. so I wanted to know what people want and how many people around here.

Now C code for TAS5518 amp is > 2700 lines. (still not perfect and bandaids everywhere) so I think it is better to show what is your question and how to solve it, more than just post dirty 2700 lines.

For Crystalfonts Serial LCD,

BYTE Reply[16];
SendCommand(0x18, 0x00, &Reply);
//calc CRC and TX then RX

checks key input with history. (Reply[2] is now / Reply[3] is history)

BYTE Line[16];
strcpy(Line, "aaaaaa ")
SendData(0x07, 0x10, Line, 16);
//calc CRC and TX

displays text at line 1. (for line2, 0x08 instead of 0x07) easy.
making screen string took > 2000 lines by dirty way. I can't recommend my source.

DDXi chips are sent from Asia, but I think

http://gerberelec.com/

has inventory.
 
This is an interesting topic, but somewhat open-ended. I've been persuing something similar using a PC for the xover filters and separate Class-D units (Panasonic Equibit receivers) for the power. However, the 5518 EVM is very very interesting IMHO. As far as I can tell though, it lacks per-channel delay. I'm not sure whether this is a deal-breaker with my intended application until I do some more work - measurement/simulation/prototyping.
 
There was some missunderstanding. I thought that you are refering to RSDA392P Apogee amp but now I see that you refer to Apogee chips. But why not take into account Texas Instruments chips? I have to check the 5518 EVM. On Apogee Web site the DXX chips are listed as Legacy (whatever it means together with the term "New") and it seems that the production was sold to another American company (and it does not look like that they are selling the chips). I would rather prefer to use TI chips.
Concerning the code for microprocessor, I don't was to use it as it is. I would rather like to see the menu structure and how you perform specific tasks.
I you check Brian's thread about TAS5261, you will see that there were some references to your idea. And I'm sure that on this forum 5 to 10 people are interested in this topic but since it is so huge, they are waiting for a "Leader" :) . I even see a candidate for this position.
Anyway, I'm interested and sooner or later this topic will be on my task list.

Marek
 
Ex-Moderator
Joined 2002
This sort of thing is very interesting, and I would love to give it a go, but, I haven't coded since about 1983, and I'm a bit old to learn now!

What we need is an easily available chip set that will get people going, a GB of a suitable board, (or at least gerbers), then software development can be undertaken as a group effort, but without a universal setup as above, everyone will constantly be going their own way, and though individuals might be happy with their own system, they will all be totally different.
 
EZ Chip

pinkmouse said:
This sort of thing is very interesting, and I would love to give it a go, but, I haven't coded since about 1983, and I'm a bit old to learn now!

What we need is an easily available chip set that will get people going, a GB of a suitable board, (or at least gerbers), then software development can be undertaken as a group effort, but without a universal setup as above, everyone will constantly be going their own way, and though individuals might be happy with their own system, they will all be totally different.


Is thier such a device?
 
Ex-Moderator
Joined 2005
KOON3876 said:
(you love multi-amplifier) and (you love class-D)
then you will love TAS5518.

I like multi-amp setups and class d :) The TAS5518 is nice, but I wouldn't say I love it. It would open up options for configurable multi-amp active speaker systems or multi channel audio systems, but what's the point if you're into 2 channel audio which (in my opinion) is really all you need for critical/pleasurable listening anyway?

You can get great results with a quality DAC, active crossover, and actively driven speakers.

pinkmouse said:
...I'm a bit old to learn now!

I never thought I'd hear such blasphemy from you ;)
 
dwk123 said:
As far as I can tell though, it lacks per-channel delay.

Yes! TAS5518 has no delay, BiQuad filter is a digital implementation of http://www.linkwitzlab.com/filters.htm .(Linkwitz Riley 24dB/Oct crossover). I loved this design and very natural sound when I made 12 opamp crossover. now it's inside of one chip!

for delay, phase issue, I'm keeping Xilinx XC3S500E FPGA board to build FIR filter future, but almost satisfied now.

Markus2006 said:
I thought that you are refering to RSDA392P Apogee amp but now I see that you refer to Apogee chips. But why not take into account Texas Instruments chips?

I would rather like to see the menu structure and how you perform specific tasks.

Hi now I'm contending with both TAS5518 and DDXi-2161. TAS5518 has ascendant now. RSDA302P is just a introducing of Japanese gadget.

.. you want to see my code? please, please do not think I'm writing such a spaghetti also in business.:ashamed:
not completed, I will add Voltage supply controll functions, and will scrap and rebuild for organized code.
(This is for JackRabbit processor)

BWRX said:

but what's the point if you're into 2 channel audio which (in my opinion) is really all you need for critical/pleasurable listening anyway?
Hi imam,
Of course I'm a piece of DIYer and built many speaker network, huge DAC, crossovers and PGA2311 volume, class-A ,chip, or class-D amps etc etc, then now I found speaker have to be multi-way for my satisfaction but components should be as simple as possible, and analog areas should be as few as possible.
So, full digital & integrated Volume control/LPF/HPF is my current interests.
 

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For Brian's board, to work it,

(1) DAI module (SPDIF In, I2S Out)
(2) TAS5518 (I2S In, PWM Out)(I2C In)
(3) MCU to TAS5518 (Config In, I2C Out, 8Bit out)
(4) Power Supply (8Bit in, 0 - 50 V/10A Out)

4 Functions are required.

(1) is very common issue, many DIY example.
(2) is not so difficult, I can give it.
(3) Difficult! :dead: or, requirement is not defined yet.
Now I'm trying 2 way (powerful MCU+LCD+Key)/(PIC + DIP Switches), but still both merits and demerits. Huge software or Huge hardware, not a KISS(keep it simple and stupid).
(4) will be Linear power supply with parallel DAC input voltage.
It will have 30dB PSVC control, 1.5V to 50V.
There will be some DIY sample of Linear power supply..

I'm still thinking about optimized way of implementation.
 
Hi Koon,

I like your schematic mind:

n. (1) is easy to get: I have this USB=>>I2S from DDDAC, based on PCM2707. DDDAC has also SPDIF=>>I2S

usb-receiver001.jpg


n. (3) still easier to get 27£ board: USB=>>I2C with a PIC microcontroller on board. A lot of libraries are avalaible from FTDI.
http://apple.clickandbuild.com/cnb/shop/ftdichip?op=catalogue-products-null&prodCategoryID=12

ftdichip.jpg


To start with, is enough "bit-banging": good programming will come.

n. (4) TI uses this PS for measurements: Labornetzgerät EA-PS-7065-10A - variable PS 0-60V 10A. It costs 1000€ :( but is a reference and the 4A version costs much less. Or we can find somethig else.

CD436641-02.jpg


What is still needed is n. (2): a simple PCB for TAS5518 with I2C and I2S input, PWM outputs and headphone output.

Could you design such a PCB so you can offer it in a group buy? :)
 
Koon,

Few qustions:
Do you have a separate board for TAS5518? It would be nice to have it. But I'm not sure whether the connection between TAS5518 and the output stage shouldn't be kept as short as possible?
Can you give me an example of DAI module (SPDIF In, I2S Out), which was practically tested and is not too expensive?
Can you tell me the requirements for the microprocessor (speed, size of code)? I never heard of the one that you mentioned (Rabbit) and I think of using another microprocessor. BTW, is C compiler (and IDE) included with their boards (it is not clearly stated on their Web site)?

Marek
 
Hi Thomas,
with PC, it is much easier for you. the code is large for MCU but easy on PC. PIC just writes result, also easy.
TAS board, I don't have generic EAGLE or something CAD(I'm using expressPCB) so I'm not eligible for group buy?
and important.. I already have my tiny PSVC so I don't need huge power supply.

Hi Markus,
Now I have all conbined one. connection can be 8 inch length to TAS5121 and no problem on wave form. You can see not-a-beautiful CS8416 sample configuration on my board, or I think there are many examples for CS84xx at DAC forum?
If you download and install expressPCB, I can post actual file.

JackRabbit has C IDE with their DEV board. total $139 is most cheap IDE + runtime debug + board, I think.

Now I'm using 63KB flash space! with code attached yesterday.
So, maybe, even PIC18Fxxxx (max 48k Words) is small to implement all function.
 

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Thanks for the info on JackRabbit. But still few questions:
- LCD module (with mini-keybord) is not included in the kit (BL1800), is it?
- you use code specific to Dynamic C (e.g. costate). Where is the definition of BigLoopTop() procedure?
- is any additional module required for the kit (e.g. for programming or debugging)?
- the menu will be still extended, right? You need Tone, Compression and few others. So the code will be much bigger.

Marek
 
Markus2006 said:

- LCD module (with mini-keybord) is not included in the kit (BL1800), is it?
- you use code specific to Dynamic C (e.g. costate). Where is the definition of BigLoopTop() procedure?
- is any additional module required for the kit (e.g. for programming or debugging)?
- the menu will be still extended, right? You need Tone, Compression and few others. So the code will be much bigger.
Marek

Hi Marek,
(1) LCD Module is here, not included in jackRabbit BL1800 Dev board.
http://www.crystalfontz.com/products/633/index.html
(2) nothing description found for BigTopLoop, just written in COSTATE.lib. It looks just checking timer??
(3) Serial Interface for PC. everything to start (without LCD)
included in BL1800 jackRabbit.
(4) can be.. but for me enough now. Tone is already included and I don't need compression. Maybe should organaize first, then expand;)
 
I add some mentions.

Thomas:
FTDI
If you are familier with Programming on PC, maybe it is easy to make application for filter calculation, EQ parameters. Then FTDI board will just write result data to TAS5518, at without-PC startup.
And FTDI board will have Volume input to control Volume independently. Please imagine some CrossOver without display(only parameter controlled by PC).

Power Supply
you need not only Voltage/Ampere, but voltage control.
Too-high supply voltage forces too-low moduration, results low S/N or dinamic range.

Markus:
MCU
My source using sin() function. If you use PIC, over 2,000 bytes of RAM will be used for this calculation. and Flash area must be > 64kBytes.
If parameters are fixed 32 points, (pre-calculated sin() cos() values) 256Bytes will be used.

TAS5518 module
anyone have EAGLE can write
http://photos1.blogger.com/x/blogger2/6693/4591/1600/739394/TAS5518-04-Digital-5518.jpg ? then I can support.

Or.. Shall I purchase EAGLE?:dead:
 
Koon, please buy EAGLE ;)

Just last question about JackRabbit: is there I2C interface provided on the board?

Koon, I looked at the code; does not look that bad. But I see that it can be much shorter. Some functions (e.g. FreqFromEQSetting) can be written just with few lines of code. Of course this wouldn't change the functionality of the code. It would just make the source shorter. I wonder whether the compiled program would be much smaller in this case or not. I can describe you the idea (maybe off the forum).

Marek
 
This is a very interesting project and I'd love to have a go at it when (if) I ever get my current analog active crossover setup finished.

I'd like to make one little suggestion. Is it possible for you to create your C microcontroller code in away that the important guts of it can be used on different micros with different compilers?

What I have in mind is to use an ATMEL AVR micro (ATMEG8 for example) and have USB connection to PC. This can be done entirely in software as shown here http://www.obdev.at/products/avrusb/index.html

Basically you only need the AVR chip, a 12MHz crystal and a few resistors. with the free software USB driver, to get a USB connection up. This software is free for an "open" diy project and works very easily.

My other motivation for AVR is that they are much easier to program. There is the open source GCC compiler for AVR which can be run on Windows and Linux. I really don't want to spend on a PIC C compiler especially as PIC is not such a good chip for targetting C.

What we could have here is a very simple and cheap micro and dev kit solution.
 
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