FS: Low Jitter Clock PCBs

[amc184]

I am selling the four leftover PCBs for a low jitter clock I designed and made. I'm wanting NZD35 (that's about USD25) each board, and I have four to sell.

The board is 140 x 50 mm (5.51 x 1.97") in size, and stands about 45 mm (1.77") tall when populated (including PCB standoffs). It is one PCB that has the following things on it:
- Linear 120 or 240VAC to regulated +/- 5VDC power supply
- Common collector Colpitt's oscillator
- High speed comparator buffer

Basically, you plug one end of this into the mains, and one end into the clock input on the CD player's decoder, digital filter or whatever. It has it's own independent power supply, so the rest of the player's supply isn't contaminated by the clock, and vice versa. The Colpitt's oscillator and buffer combo for the clock is a common one, I think that's what both LC Audio's XO3 and Elso Kwak's Kwak Klock (and probably others) use.

I've already assembled and tested three of these, and they work great. They are a significant upgrade over the normal Pierce oscillator in a CD player. I've installed crystal sockets in the one I've assembled, so you can just swap crystals to change the output frequency. I've tested this oscillator with 11.2896, 16.9344 and 33.8688 MHz crystals, and all was fine.

Shown below in the pictures is the bare clock PCB, an assembled clock and the output trace at 16.9344 MHz. Note that the PCBs and assembled board have an extension, I won't be supporting its use and I recommend that portion be removed. Also, the output trace is probably steeper and sharper in reality, a 16.9344 MHz square wave is near the limits of my 'scope.

I will provide the schematic, bill of materials and other relevant information to buyers, and I am happy to help with ordering parts, and maybe even assembly if you're not that handy with a soldering iron.

Each clock PCB costs approximately NZD100 (that's about USD70) to populate if you stick to my bill of materials and order from Farnell. It's probably even cheaper if you shop around.

This has been a long post, and I've tried to fit everything in, but if I've left something out please let me know, feel free to ask any questions.

Anton

[EUVL]

What do the PLLC IC & multi-pin connector do on the LHS of the oscilliscope probe in the middle photo ?

Patrick

[amc184]

It's the separate bit I talked about.

Note that the PCBs and assembled board have an extension, I won't be supporting its use and I recommend that portion be removed.

It's a CPLD and support components. It can (and should) be cut of from the rest of the PCB, and there are mounting holes to allow this. This part is a project that converts the output of the SAA70x0 chipset into I2S, but I haven't finished it and I am not prepared to support it yet.

[QSerraTico_Tico]

PS, crystal and comparator can be bettered....

[amc184]

Maybe there is, but my clock PCB sale thread in the 'Swap Meet' forum isn't really the place to discuss it. You've got me curious though, PM me the type of clock you had in mind, or even better, start a thread about it.

[amc184]

Forgot to mention; postage worldwide will be about NZD10. I accept PayPal as payment. I'm open to offers as well, and maybe trades too.

[amc184]

I've still got three left ...