I have a USB-I2S board which uses two Sunny SCO-020 oscillators. These are mounted in DIP 14 sockets, so trying something else would be really easy. The oscillators are 3.3 V models, and I cannot find any phase noise plots for them, or RMS jitter spec. I am wondering if anyone is familiar with the performance of these oscillators, and if there is anything else in DIP 14 which might improve performance. Maybe go to an smd oscillator with an adapter...Crystek CCHD?
Hi,
You don't say what the frequency is but I assume it is 12.000Mhz ? Why are you set on 3.3V ? It really limits your choice.
There is quite a wide range available from cheapo smd to rubidium if your willing to do some diy. What's your budget ?
For me, best bang for the buck so far has been this :
¡¾×êʯÐÅÓþÍƼö¡¿100£¥ºÃÆÀÍÂѪÍƼöºãξ§ÕñOCXO 0.01PPM-ÌÔ±¦Íø
Dunno if you can get this where you are.
FWIW
You don't say what the frequency is but I assume it is 12.000Mhz ? Why are you set on 3.3V ? It really limits your choice.
There is quite a wide range available from cheapo smd to rubidium if your willing to do some diy. What's your budget ?
For me, best bang for the buck so far has been this :
¡¾×êʯÐÅÓþÍƼö¡¿100£¥ºÃÆÀÍÂѪÍƼöºãξ§ÕñOCXO 0.01PPM-ÌÔ±¦Íø
Dunno if you can get this where you are.
FWIW
These are...
for upgrading an existing USB-I2S board. Two fixed oscillators:
22.5792 and 24.576, running on 3.3 VDC supply. I am not looking for ovenized clocks at $100s of dollars each, but low phase noise types like the new Crystek CCHD-957 (available ~8 weeks) seem like a good option. I was just wondering if anyone knows of any DIP 14 types with really high performance which would just plug right in. I am pretty sure I can adapt the CCHD-957s to the board, with some careful mods.
for upgrading an existing USB-I2S board. Two fixed oscillators:
22.5792 and 24.576, running on 3.3 VDC supply. I am not looking for ovenized clocks at $100s of dollars each, but low phase noise types like the new Crystek CCHD-957 (available ~8 weeks) seem like a good option. I was just wondering if anyone knows of any DIP 14 types with really high performance which would just plug right in. I am pretty sure I can adapt the CCHD-957s to the board, with some careful mods.
Vanguard Ultra precision Golden TCXO, 0.3ppm 24.576MHz | eBay
I have used these and they are as good as it gets in dip14 and 3.3V. Very similar to tent lab xo. The 0.3ppm work with 3.3V and 5V, the 1ppm only work with 5V.
TBH, if you're upgrading the xo, you really should think about giving it clean power too.
If you really want a budget option then Euroquartz xo91 are low jitter smd parts.
I have used these and they are as good as it gets in dip14 and 3.3V. Very similar to tent lab xo. The 0.3ppm work with 3.3V and 5V, the 1ppm only work with 5V.
TBH, if you're upgrading the xo, you really should think about giving it clean power too.
If you really want a budget option then Euroquartz xo91 are low jitter smd parts.
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When dealing with Chinese vendors - proceed with caution!
The specification sheet looks fancy but not worth the paper it's written on.
Google Translate
GOLDYÂÛ¾§ÏµÁÐ(5)------ ¾§ÒæSC-CUT OCXOÆÀ²â»ð±¬³ö¯£¡ - ÒôÏìDIYÂÛ̳ - HIFIDIYÂÛ̳ - Powered by Discuz!
Certainly not SC-cut, probably not as good as Tent / Crystek
T
I am
going to go witht he Crystek CCHD-957s when they become available (still 6-8 weeks out). The digital guys I believe in most all seem to talk about phase noise at low frequencies as the most important criteria, and the CCHDs shine in this area-purpose built oscillators for audio.
Of course, totally good call on power supply, no clock will perform its best with a bad supply. Right now the board gets its 5 VDC overall supply from a LiFePO4 battery pack, with a dexa pre-regulator followed by 4x1000 uF of Elna Cerafines. I am trying to decipher which board level regs supply the 3.3VDC clocks, but board level detective work on this tiny smd populated board is tricky. I have a nice mini shunt to use to power the clocks if I can figure it out...
going to go witht he Crystek CCHD-957s when they become available (still 6-8 weeks out). The digital guys I believe in most all seem to talk about phase noise at low frequencies as the most important criteria, and the CCHDs shine in this area-purpose built oscillators for audio.
Of course, totally good call on power supply, no clock will perform its best with a bad supply. Right now the board gets its 5 VDC overall supply from a LiFePO4 battery pack, with a dexa pre-regulator followed by 4x1000 uF of Elna Cerafines. I am trying to decipher which board level regs supply the 3.3VDC clocks, but board level detective work on this tiny smd populated board is tricky. I have a nice mini shunt to use to power the clocks if I can figure it out...
Yep, I completely agree - lots of fakes, lots of caution. For me, it really helps to be a local but I have a western face so I still get more than my fair share of people trying to rip me off.
The items I recommended are from personal experience not second hand third party posts on the internet. I'm sure we're all aware that many people who post stuff on the internet are not reliable so you have to test everything and decide yourself.
I have a Tent Labs too, and I found the Vanguard 0.3ppm to be very similar to the Tent Lab xo module in terms of the definition it gave. I've tried them both in 5V and 3.3V systems and I've actually left the Vanguard in the upsampling cd player rather than the Tent because the Tent seems to be able to do better when it is given a really clean supply and the supply in the cd player is ordinary 3 pin reg. The Vanguard suits this better.
The ocxo has pipped them both so regardless of whether it meets the seller's specs, it is still a very good clock. There's more depth and space and vocals come forward more and seem smoother. However, it takes time to warm up and that's something I'm not so keen on. I don't want to turn on the hifi and then come back 30 minutes later to listen, but despite this, it has stayed because it does sound good. It also needs a cleaner regulated supply because the board it comes with doesn't have enough ripple rejection etc to get the best from the clock. I'm still experimenting with this but so far a 12V sla battery is working very well.
There are still a few more clocks out there for me to try. I'd be very interested to hear from anyone who has compared the Tent to the Audiocom superclock as that is next on my list.
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The Crystek phase noise does look very impressive but I can't see any info about jitter or stability. http://www.crystek.com/crystal/spec-sheets/clock/CCHD-957.pdf
When you get the clock, please post your impressions and any clock you can compare it to please.
I'm also interested in how you regulate the battery to remove battery noise.
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Hi,
I'm no expert but I would say it is unlikely that a system designed around a 10Mhz clock will work with any other frequency.
I upgraded a clock on a soundcard a while back and bodged it, and the darn thing played back at the wrong speed until I fixed it. So who knows, maybe it'd be like playing a 33rpm record at 45rpm for the chipmunk effect.
Cheers,
Tom
I'm no expert but I would say it is unlikely that a system designed around a 10Mhz clock will work with any other frequency.
I upgraded a clock on a soundcard a while back and bodged it, and the darn thing played back at the wrong speed until I fixed it. So who knows, maybe it'd be like playing a 33rpm record at 45rpm for the chipmunk effect.
Cheers,
Tom
Thanks, although it's not exactly what I was hoping for ;-) I'm wondering about the stability in terms of frequency accuracy. It seems conspicuous by its absence ?
I'm also curious to know what power supply was used to achieve a clock with such low phase noise/jitter.
One of the things I found curious about the online test of the ocxo is that no-one asked the tester about the psu he used. The first thing I did when I got mine was to check out the psu and then hook it up to measure current draw and noise/ripple under load. Mine met the seller's specs or it would have been returned (330mA start up, 140mA stable after 15 minutes) but the one they tested didn't, which makes me wonder about that other made-in-china problem, quality control. But don't get me started on that ....
Anyway, the most pertinent Crystek question, who will stock them ? Any luck barrows ?
BTW oshifis - will you post how you modded the clock ? I'm really curious....
I'm also curious to know what power supply was used to achieve a clock with such low phase noise/jitter.
One of the things I found curious about the online test of the ocxo is that no-one asked the tester about the psu he used. The first thing I did when I got mine was to check out the psu and then hook it up to measure current draw and noise/ripple under load. Mine met the seller's specs or it would have been returned (330mA start up, 140mA stable after 15 minutes) but the one they tested didn't, which makes me wonder about that other made-in-china problem, quality control. But don't get me started on that ....
Anyway, the most pertinent Crystek question, who will stock them ? Any luck barrows ?
BTW oshifis - will you post how you modded the clock ? I'm really curious....
The original is a Motorola 1 MHz TCXO, built with discrete components. I attach a picture. The internal crystal is 4 MHz, the output is attenuated by a 74HC73 divide-by-four IC. I simply removed the 4 MHz crystal, replaced it with a 4.2336 MHz from a Marantz CD-84, bypassed the 74HC73, and built the TCXO in the CD-player. I took +12V from the internal regulator, and fed the output to the SAA7000 pin 8.
Attachments
Thanks - now I get it ! A nice bit of diyaudio eh ? I assume that the crystal was something like an hc49 ? How do you rate the performance after the change ? Do you think there are any particularly critical parts that should be upgraded ?
BTW, yep, it seems I'm going blind - just seen on the datasheet that the ppm is in the part number - 25ppm is the example given - and it looks like 20ppm is the best they'll do ?
BTW, yep, it seems I'm going blind - just seen on the datasheet that the ppm is in the part number - 25ppm is the example given - and it looks like 20ppm is the best they'll do ?
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Kid,
It is a curious omission, but based on the other specs, you can reasonably conclude that the nominal room temp frequency is significantly within the over-temp tolerance. I'm sure you could get a prompt reply if you called or emailed them.
BTW, their press release (under new products) says that typical jitter is 82fs.
It is a curious omission, but based on the other specs, you can reasonably conclude that the nominal room temp frequency is significantly within the over-temp tolerance. I'm sure you could get a prompt reply if you called or emailed them.
BTW, their press release (under new products) says that typical jitter is 82fs.
In Japanese DIY digital audio community, SMD type oscillator made by NDK is becoming very popular. Though this component does not directly meet your requirement, DIP 14pin type, two people in Japan made their efforts as these two pictures show;
"Ken" on his blog page;
"atsukita" is an expert of replacing parts;
The second problem is its long lead time, 1.5 - 3 month.
--------------------------------------------------------
CMOS output Crystal Clock Oscillator NZ2520SD
manufactured by a Japanese leading crystal maker, Nihon Dempa Kogyo Co., Ltd.
NZ2520SD(OA / AV)/Crystal Clock Oscillators/NDK
Part number for +3.3V power version are;
NZ2520SD-22.579200M-NSA3449B
NZ2520SD-24.576000M-NSA3449B
The model has a remarkable low phase noise profile. According to their measurement result sheet, Phase Noise [dBc/Hz] 26MHz 3.3V for 5 samples
1Hz: max -76, min -81
10Hz: max -108, min -111
100Hz: max -136, min -138
1kHz: max -151, min -152
10kHz: max -156, min -157
The component is available for personal users by way of a Japanese online web store, chip1stop.
?????????????? - ????????? | ???? (In Japanese, You can switch to English and Dollar currency page.)
The price I bought was 1,500 JPY / piece ( 20 USD/ piece ) and 1,000 JPY/10 piece.
"Ken" on his blog page;
"atsukita" is an expert of replacing parts;
The second problem is its long lead time, 1.5 - 3 month.
--------------------------------------------------------
CMOS output Crystal Clock Oscillator NZ2520SD
manufactured by a Japanese leading crystal maker, Nihon Dempa Kogyo Co., Ltd.
NZ2520SD(OA / AV)/Crystal Clock Oscillators/NDK
Part number for +3.3V power version are;
NZ2520SD-22.579200M-NSA3449B
NZ2520SD-24.576000M-NSA3449B
The model has a remarkable low phase noise profile. According to their measurement result sheet, Phase Noise [dBc/Hz] 26MHz 3.3V for 5 samples
1Hz: max -76, min -81
10Hz: max -108, min -111
100Hz: max -136, min -138
1kHz: max -151, min -152
10kHz: max -156, min -157
The component is available for personal users by way of a Japanese online web store, chip1stop.
?????????????? - ????????? | ???? (In Japanese, You can switch to English and Dollar currency page.)
The price I bought was 1,500 JPY / piece ( 20 USD/ piece ) and 1,000 JPY/10 piece.
Thanks...
Bunpei! That part looks really great, and the phase noise specs are very similar to the Crystek CCHD-957 oscillators: quite impressive that they can do this in such a small footprint. I am sure I could adapt these to my board, just as woudl have to adapt the (9mm x 14 mm) SMD Crysteks.
Bunpei! That part looks really great, and the phase noise specs are very similar to the Crystek CCHD-957 oscillators: quite impressive that they can do this in such a small footprint. I am sure I could adapt these to my board, just as woudl have to adapt the (9mm x 14 mm) SMD Crysteks.
NDK NZ2520SD________________________ Crystek CCHD-957
1Hz: max -76, min -81 ______________ N/A
10Hz: max -108, min -111 ___________ -98
100Hz: max -136, min -138 __________ -126
1kHz: max -151, min -152 ___________ -149
10kHz: max -156, min -157 __________ -162
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