The only chip you have to program is the PIC. The program is vritten by ( the original source is from the froum ) me in mikropascal. It fits in the 2k size demo limit of compiler.
All you have to do is to solder the other ics
The 18 bit comes from the chip ( I don't think it can be modificated ).
The khz can be set with the Master Clock ( 12.288 Mhz = 48 khz ). I only could get this cristal . It can be set 32-49 khz on CS5330, but the cs8406 supporst 256x and 512x fosc settings not 386x. If you read the dataseheet of 5330 you will see that how can you set the Master Clock, and fosc ( also set it on 8406 ).
For those who have a CarPC but no SPDIF output, I found this solution based on similar chips but converting USB to SPDIF, so that's another "no-analog" solution.
Of course, as Foldesa mentioned above, you have to solder these beasts and as they are surface-mount, you'd better have advanced soldering skills - not my case :-)
Just my 2 cents
On a related note, anybody knows which bit/sample rates of SPDIF the head unit accepts ?
According to the datasheet of the head unit's main chip the acceptable sample rates are 32, 44.1, 48, 96 khz, but I'm not sure.
I have made a few changes on my desing. The digital and analog parts are separated. And it is easyer to understand now.
The Digital part contains the power suply and the clock generation. The 3 pin connectors are jumpers, so this way every setting of cs8406 can be easily changed.
The 2 other schematics are the analog-digital converters. The analog-1 is CS5330 or CS5331 ( they are pin compatible ). This is 18 bit.
The analog-2 is better, but more complicated. You can use here CS5361 or CS5381, they are also pin compatible. This conncection can go up to 192 khz, but the head unit may not accept a high resolution like this. This connection is 24 bits instead of 18 bits, so it has better sound quality.
Thank you all guys, but all this info is way too much for a normal non-electro technician user, so here is my question:
Could anybody post an easy to read and understand scheme, so anybody who has a basic electro knowledge could sold it together and connect a MP3 player to the CD IN on the head unit?
I know some newer head units have the AUX IN on them, but some of us don't have that luck.
I know you can find the adapter for it online, but with the price of over 100 Euros is way too expensive - you could rather buy a new head unit for the price
Aside from the jumpers, what changed in the new schematics and why are they better ? Also why do you use two preamps for the Analog-2 design ?
Did you test your design ?
We are very interested in this, but since electronics is not our field, we're a bit afraid of frying the head unit (or the ipod)
Aside from the jumpers, what changed in the new schematics and why are they better ? Also why do you use two preamps for the Analog-2 design ?
Did you test your design ?
We are very interested in this, but since electronics is not our field, we're a bit afraid of frying the head unit (or the ipod)
The changes mostly effect the power suply. It is improved to have better realitility.
The second analog alternative needs 2 op.amps, because the analog input ground also needs to be connected to the op.amp. I don't see the reason why, but the datasheet says so.
I didn't have the time to test them. I'm currently working on that.
It is impossible to fry the the head unit, becsuse if the CS8406 doesen't get the master clock or the data itself the output is connected to the ground. It also has a transformer, witch makes it even safer and reduces ground noises.
Tha analog input ( example Ipod ) also can not be fryed. The capacitor ( 6.8 uF ) gives some protection, and the op. amp shouldn't allow any chargebacks.
I found another desing on the net witch is a wireless audio transmitter. It uses cs5330 for AD and another CS ic to make it back to analog. It doesen't have op amp before the cs5330. I want to test this desing also. Maybe today
But there is a mutch simpler way to connect analog source to hu. I'v tried it and it works, but I don't think anybody should use it. In this case you have to connect the analog input directly to the HU's main chip's analog input pins. If you do this then the analog input will work even in radio or casette mode, and I don't know how it will effect the lifetime of the HU.
OK thanks, that sounds great. Let us know how that works out.
I think I'll stick on the 18bit design, since it seems the connects2 uses that too.
Is there a reason why you use the TLC27L2 on this one instead of the TLC272 on the first design and the Analog-2 ?
Finally after a few month of design and a few unsuccesfull prototipes I have DONE it !!!!
The analog is now in SPDIF format !!!
The prototipe I've build today WORKS !!!
I'm so happy about it.
Aldough it has a few bugs too.
It's quality is like an old casette tape. It is very noisey. And only one channel works. I don't understand the problem yet, but I will solve it. My oppinion is thet the problems are mostly from using ceramic capacitors insted of mylar.
Terrific! Now let's hope you manage to get good sound too.
I see you use the headphone output of the ipod instead of the line output from the dock, perhaps the signal is too high for the preamp ?
I've attached the pcb printout just in case someone wants to experiment also. It is now almost noiseless, but only the left or right channel works. To make it work you have to short circuit the other channel's pin of cs5330 to the ground . The Cs5331 wont work in this connection, because it has different output data format. If you want to use cs5331 you have to disconnect pin 5 of cs8406 from ground and connect it to 5 volt.
This connection doesen't have op amp, but the connector on the bottom makes it possible to connect it. The 4 pads on the upper right represents the transformer, and the wide lines are the spdif output.
I wont be reachable for 1 week, and I can't test during this period.
This is annoying, only one channel... Perhaps with an oscilloscope you can check the data sent by the 5330, at least the docs say what it should look like, whereas I'm not sure what the SPDIF signal should look like. What do you plug the SPDIF output into to test it ? If it's a computer there should be a way of figuring what type of signal is output. In particular I didn't find in the docs of the 8406 where you specify whether the stream is 2 or 4 channels. Perhaps it's outputting in 4 channels ?
I plug the SPDIF output to a home cinema amplifier not a computer.
I will test the circuit with different op.amps to see if they work out.
I'll inform you, but you have to wait at least 1 week for this.
!!!!
. The Cs5331 wont work in this connection, because it has different output data format. If you want to use cs5331 you have to disconnect pin 5 of cs8406 from ground and connect it to 5 volt.
Linear Mode
