Musical Fidelity A3 CD Player Clock Frequency?

[300_baud]

Hey,

Does anyone know the clock frequency of the musical fidelity A3 cd player? If someone has the service manual for this model, please contact me. I'd like to know because I'm thinking of a clock upgrade.

Thanks,
300_baud

 

[Extreme_Boky]

24.000MHz caned oscilloator for CS8420.
16.9344MHz caned oscillator for mechanism servo

Extreme_Boky

 

[300_baud]

So if i'm buying a tent labs clock, which one should i get? The 16.9344 mhz version? This is going into the reclocking stage in an external dac. I just want the tent labs clock to be synchronous with the one inside the cd player so I won't be dropping bits.

Thanks,
300_baud

 

[Jocko Homo]

Then it has to be the same one.....not just the same frequency.

Yeah, yeah......I know.....guys claim to do it the wrong way all the time.

Jocko

 

[300_baud]

So you're saying that I'm going to be worse off in terms of jitter if I do not use the same clock that is in my player?

 

[Jocko Homo]

No.

But they are going to be syncronised. You will drop bits.

There are ways to feed that clock to both places.........................

Jocko

 

[300_baud]

Hi,

If there is a way to feed the tent labs xo-dac clock to both places, would this be a good way? (without having to buy a second clock for the cd player)

Thanks

 

[rfbrw]

If the CS8420 is functioning as an ASRC, I wouldn't have thought that there would be much point syncing the mechanicals to an external dac.

 

[300_baud]

So even if I put in a tent clock inside the cd player, the advantages will be negated due to the CS8420's async clock?

 

[rfbrw]

So even if I put in a tent clock inside the cd player, the advantages will be negated due to the CS8420's async clock?

Yes, as the output side the ASRC is effectively a new clock domain but it may well have a separate SPDIF Tx that runs off the 16.9Mhz clock.

 

[Jocko Homo]

D'oh!

I forgot that the mother of all digital audio ICs can also do ASRC. Like there isn't enough functions on it already to confuse the hell out of us.

I dunno......if it were mine.......I would still sync them up. Some "experts" claim that ASRCs do not really get rid of jitter: they just shove it to some range that doesn't muck up stuff. But what do I know? I'm only an RF engineer.


OK.............so why 24 MHz??? From what I could decipher, you could go higher. Yes/no?

Over to you, Signoro Bit Head. You understand all this digital codswallop.

Jocko

 

[rfbrw]

This 24MHz and CS8420 stuff just did not make sense to me. So I looked around. The A3CD is based on the MF X-Ray and uses the PCM1716 dac. Master clock is 16.9MHz. GT has a suggestion on his site for sending the master clock back to the transport.

 

[300_baud]

Could you perhaps post a link to "GT's" site?

 

[rfbrw]

The site www.tentlabs.com
The specific article
http://www.tentlabs.com/Info/Articles/Tentlink.html

 

[Extreme_Boky]

Ok,

I was confused as well!!! For this reason (and the fact I had only partial circuit diagram - a bad photocopy) I decided to introduce separate low noise +5V power supplies for each oscillator with my favourite combination for local-close-to-the-oscillator decoupling: 0.1uF/50V NX + ferrite bead(s). One supply for 24 and the other for 16.9MHz. Search for: musical-fidelity-a3.24 mods . The end result was very good!

I will scan what circuit diagram I have at home and post on this thread. Maybe someone could figure out what's going on and make things clearer.

I'm at work (HA!) at the moment, will scan and post in 10 or so hours.

Regards,
Extreme_Boky

 

[rfbrw]

The A3.24 dac is alot more recent than the A3 CD player. The A3CD dates back to around 2000.

 

[Extreme_Boky]

I modified A3.24 upsampling CD player, but have circuit diagram for DAC as well. I'll check again both diagrams but they looked the same - DAC has discrete buffer as the second LPF stage (capable of spitting out 5 or 6 AMPS with a proper power supply!!), where CD player has IC's.


Extreme_Boky

 

[Extreme_Boky]

I can e-mail both diagrams to people who'd like to have a look. They are:
1. A3.24 DAC
2. A3 CD Player

The copies are very bad, but might give some hints to questions in this topic. The units are different not only in analog section, but in digital as well.

I have scanned A3 CD player circuit diagram and will try to post them here as well.

Extreme_Boky

 

[Extreme_Boky]

No2

 

[Extreme_Boky]

and No3