To clock or not to clock...?

[D.A.R.R.Y.L.]

Hi All,
Still fighting with my denon 2900 in order to get the Tentclock to work.
Guido has been great in supporting me, no faults at all towards the Tentclock.

I have tried to feed the clock with 12volt from within the player, and it worked for 2 listening sessions. I switched the player back on the following day and it started, no display messages at all!! Tray did not open, but there was 12 volt on the clock print input!! Guido has put a led on the clock to reduce it's clock output voltage to 3v3 in order to not fry the Denon clock IC. When all is fine, this led burns brightly. Although 12 volt was present at the clock's input --> no brightly burning led. When I removed the clock output from the denon pcb; the led started to burn brightly again!!!

My guess is that the clock problem has something to do with circuitry load on the clock output side induced from the denon pcb. Why else will the led start to burn brightly again as soon is I disconnect the clock output from the denon pcb?

Any thoughts on the matter would be highly appreciated!!
Thanks and greatings,
Ramon

[georgehifi]

D.A.R.R.Y.L. The power to the clock, is it on all the time or only when you switch the Denon on, the reason I say this is that I've done a few of Guido's clocks now and on a hand full of machines I had your problem.
The way it was fixed was to power the clock first, then turn the machine on, you need a XO-Supply that is powered all the time, that way the clock is getting powered even when the Denon power switch is turned off. Hope this can get you out of trouble.

Cheers George

[D.A.R.R.Y.L.]

Hi George,

I have the XO supply too. Already built XO and XO2 into my Marantz CD-7 with great succes. Unfortionally the XO supply for my denon may be defective; it gives out 28 volt dc unloaded with the clock. I read somewhere that keeping the clock on all of the time, could damage the denon's smxxxx clock divider chip?

I could try to power it with two 9 volt batteries in series, just for testing purposes ;-) I just detest desoldering the tiny smd c's and r's and the clock again from the denon pcb.

Why is the denon 2900 so picky with these clocks?

NB: I also had the problem with the XO supply powered on permanently.

[tubee]

When i putted a clock on a SAA7210, it didn't work proper first either. Checked and everything was allright. But after a few power on/offs it played and kept playing. I think this has something to do with unloading of parasitic capacities somewhere, not sure.

[Elso Kwak]

Originally posted by tubee
When i putted a clock on a SAA7210, it didn't work proper first either. Checked and everything was allright. But after a few power on/offs it played and kept playing. I think this has something to do with unloading of parasitic capacities somewhere, not sure.

Maybe you killed some parasites........
(Not sure though.......)
Wait a minute: must be the wear-out mite.......
You know Philips has these built in!

[D.A.R.R.Y.L.]

Mine is the otherway around Tubee, so I must create parasites from nothing. Antimatter creator!!

[Ruach]

Hi D.A.R.R.Y.L.

Are you sure that your XO Supply measured 28V unloaded? This is a bit high.

The Blackgate capacitor on the XO Supply is rated at 16V and the additional voltage will put lots of strain on the capacitor

[georgehifi]

D.A.R.R.Y.L. this is just a thought you may have been supplied a 110v xo supply, and if your mains is 220-240 this could account for the high output from the xo-suppy.

Cheers George

[D.A.R.R.Y.L.]

Hi all,
I have the version without the black-gate. Mine is Elna 2200µF 35volt. How can I tell if I have the 110volt version? Is this in the transformer? It reads 12volt - 230volt. All components measure correctly when removed from the pcb. I am only missing R2 on the pcb. Don't know if this is standard? On the website www.tentlabs.com I see that this R2 is present on the pcb.

But regardless of a possible faulty XO Supply, the clock stops working after two or three working starts when connected to internal 12volt rail.

When the clock works, it is phenomenal!!! I want that sound all the time. That is why I am so determened to solve this.

Regards,
Ramon

[Ruach]

Mine is rated at 9V and it has a Blackgate 470uF 16V.

R2 should be there. My R2 reads 1.5k ohm.

Your tranny should be the 230V version. You can replace it with something with 9V on the secondaries. Write to Guido for a suitable-sized replacement.

You can also rebuild the XO Supply on a separate PCB using a new 9V tranny.