Tentlabs XO3 Clock and a Squeezebox

[Jitterbug]

I've been having some trouble getting an X03 clock to work with a Squeezeboox (2 and then 3). I know this has been done by others, but I cannot narrow down what the problem is in this case.

Here's what I've tried:
-Fed the clock to a squeezebox 2. The SB2 took the clock but would not produce clean output. Mostly it was noise with a faint echo of the music. I got the same result from the digital out, and the analogue out on the SB2 so this is not DAC related, or even SPDIF related because the SB2 DAC uses i2s,

-Twice I got good output but it did not last.
-I tried the cable that came with the XO, I switched to coax. As a trial I used a very short cable. All made no noticeable difference.
-I use a 50R/25R resistor divider to bring the clock voltage to 3.3V. I also used a 100R in parallel. Same result.
-All this time, the music bar progresses so it looks like the clock is taking, but somehow not fully working.
-I thought I might have damaged something in the SB2, so I got a Squeezebox 3 to try. Again, I seemed to get a clock lock but not good output, analogue or digital. Exactly the same as the SB2.


As far as I can see the problem must be the XO3. Appreciate any insight into the problem

[Jitterbug]

The question in short would be:

Any ideas what might be wrong in the clock if the transport locks onto it but will not produce a good digital signal?

[Jitterbug]

For those considering buying a Tentlabs clock, may I caution you with my experience. Of course others may have had vastly different experiences.

I found Guido helpful and responsive before the transaction. He offered to accept a return of the XO3 clock if it did not work in my planned implementation. Of course there is also the quoted 5 year warranty.However, after the transaction my emails were ignored.

This thread explains the problem I encountered with the clock and the troubleshooting I did, including purchasing a new transport in case that was the problem. In all of this, I had zero support from Guido, although it looks almost certain that the problem is with his clock. Two weeks ago, after exhausting everything I could do to solve the problem, I asked what the procedure was to return the clock, as had been offered. Yet again my email was ignored. In all we are talking about an approximately month period of ignored emails.

It is extremely disappointing after all the time (and some expense) I have put into this project to abandon it. I have an XO3 which is no use to me. Unfortunately, I have no recourse as far as I know. Others should know about this, given this vendors status on this and other forums.

[-ecdesigns-]

Hi jitterbug,

Which crystal oscillator did you replace? Y1 (halfway underneath the piggyback board in the squeezebox 2) or Y2, and what frequency crystal oscillator module did you order?

[Jitterbug]

Originally posted by -ecdesigns-

Which crystal oscillator did you replace? Y1 (halfway underneath the piggyback board in the squeezebox 2) or Y2, and what frequency crystal oscillator module did you order?

hi ecdesigns;

It was Y1 on the SB2, and later also on the SB3. I ordered the XO3-11.2896 MHz clock.

[-ecdesigns-]

OK,

Did you remove Y1, C6, R1, and C15? did you inject the 11.2896 MHz clock on the xtal terminal closest to U6 / C6 (squeezebox2)?

How did you route the GND connections between external clock oscillator and squeezebox 2?

The external clock signal needs to have a signal amplitude of 5Vpp!, have you tried leaving-out the attenuator and 100 Ohm load resistor?

[Jitterbug]

Originally posted by -ecdesigns-
Did you remove Y1, C6, R1, and C15? did you inject the 11.2896 MHz clock on the xtal terminal closest to U6 / C6 (squeezebox2)?

Yes, first time. Later I cut the trace between pint 42 of the XILINK and and the HCU and fed the clock into pin 42 directly. This worked for a short time.

How did you route the GND connections between external clock oscillator and squeezebox 2?

I tried the cable that came with the XO3, and took a ground from where R1 used to be. Later I tried a coax cable instead.

The external clock signal needs to have a signal amplitude of 5Vpp!, have you tried leaving-out the attenuator and 100 Ohm load resistor?

No, I don't think I tried that. I understood that the SB2 needed a 3.3V signal, so attentuation or the 1OOR load was necessary. Is this mistake?

[audioengr]

If the Xilinx is a 5V part, then the signal levels should be 5V driving it. Also, you need to know what the output impedance of the Tent clock is. If there is a series resistor, then you must compensate for this or remove it to get a good transmission-line termination. The best thing for a hobbyist to do is mount the clock right next to the Xilinx part and run a short twisted-pair cable from the Tent clock to the Xilinx. Pick a ground pin on the Xilinx that is really close to the clock input pin. Use 24 gauge wire of smaller. A pair from CAT5E or CAT6E should be fine.

The best way for you to terminate the clock is to put nothing at the receiving end, but a series resistor at the driving end, around 90 ohms. Locate it as close to the tent clock output driver as possible.

Steve N.
Empirical Audio

[t.]

Sorry its not much help but I have tried a PFM Flea clock modified for 3.3v to use with my SB3, it worked perfect, I'm almost sure the CPLD is 3.3v

[Ryssen]

Yes,I think it´s 3,3v.
Seen this?Mod Squeeze Box