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Post by kcatthedog on Jan 1, 2015 8:29:48 GMT -6
if you mount the fender jewel chassis people can substitute whatever lens colour they want .
Looking good !
can you remind what is happening with clock in your design; on board master clock or gets clock in spdif ?
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Post by svart on Jan 1, 2015 9:30:43 GMT -6
if you mount the fender jewel chassis people can substitute whatever lens colour they want . Looking good ! can you remind what is happening with clock in your design; on board master clock or gets clock in spdif ? The ADC has an onboard master clock. The DAC slaves to the incoming spdif. |
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Post by kcatthedog on Jan 1, 2015 10:46:45 GMT -6
So when tracking AD you suggest setting your box as master and for DA it will naturally slave to clock of spdif source, e.g., apollo or whatever interface or master clock ?
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Post by svart on Jan 1, 2015 11:10:31 GMT -6
Yes. The ADC should be the master for all devices after it. An Apollo, or other device, should be set to clock off of the spdif signal in it's settings. The DAC should automatically sync as slave to the spdif that is fed to it.
If a unit is set for internal clock, it will get out of sync with the spdif timing as you'll get strange behavior, with pops, clicks, an odd sound being the symptoms.
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Post by Johnkenn on Jan 4, 2015 20:07:51 GMT -6
You ever decide on a name?
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Post by LesC on Jan 4, 2015 21:06:02 GMT -6
How about the SP-1 (secret project 1)? Then depending on the configuration:
SP-1AD
SP-1DA
SP-1DAD
And the separate ADAT box, connecting up to 4 SP-1's, would be the SP-1ADAT.
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Post by svart on Jan 4, 2015 21:40:42 GMT -6
You ever decide on a name? Not yet. I thought of a couple and then bounced them off my cousin (who's going to help out with the production and shipping for a cut of the company) and he pointed out that a few might not work out and the others just didn't work for one reason or another. I do have a few thoughts though. 1. Must be a short name or easily written and remembered. A lot of companies will fall into the habit of having excessive model numbers or grandiose nomenclature as egotistical wankery. I'd rather just give each box a simple name. 2. Can't include my real name or my online moniker.. Just because. 3. 2 or less syllables. |
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Post by svart on Jan 4, 2015 21:46:16 GMT -6
So when tracking AD you suggest setting your box as master and for DA it will naturally slave to clock of spdif source, e.g., apollo or whatever interface or master clock ? Yes, that's generally the best for any products. The ADC needs the best clock source simply for the acquisition quality. Once the analog signal is acquired and converted that's the best the audio will ever be. With SPDIF/AES the clock for the data is the data itself. The SPDIF/AES receiver buffers the data and recovers the clock from the data itself. This keeps from having to use a separate word clock and it also allows some devices to buffer and work on the data in non-real-time because the clock can be recovered at any point. Your interface should then be set to clock from the recovered clock from the SPDIF/AES. If you don't, since oscillators are close but not exactly the same, the data will slip out of sync with the internal clock of the interface. it's best that the incoming data clock simply be the master here. The DAC also recovers the timing from the data stream. So the data and clock flow is this: ADC/Master clock -> Interface/Slave -> DAC/Slave |
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Post by category5 on Jan 4, 2015 22:13:33 GMT -6
Will WC be an option as well, or are we strictly limited to clocking off the AD?
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Post by svart on Jan 4, 2015 22:26:02 GMT -6
Will WC be an option as well, or are we strictly limited to clocking off the AD? There is no option for WC in or out. Sorry, that was beyond the scope of this design. Maybe in a future version or design I can make that happen if things work out. If you are concerned about clocking the ADC, I can guarantee that the oscillator being used is about 50-100x less jitter than average WC.. |
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Post by category5 on Jan 5, 2015 8:38:59 GMT -6
A bummer but not a deal breaker. I'm not so much concerned with the quality of your clock as I am the ease of keeping multiple devices sync'ed. WC is simply the easiest way to do it.
I suppose one could slave your DA to the system clock through spdif and clock the AD that way. I agree using yours as as a master is the cleanest option IF it is the only ad in use but if we are talking tracking through multiple boxes simultaneously that becomes a decision of necessity rather than quality.
No I never found WC to have better performance than clocking through spdif in practice, but it's so easy to just slave everything to a solid master clock source and forget about it.
Thanks for the quick answer Svart.
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Post by svart on Jan 5, 2015 9:45:10 GMT -6
A bummer but not a deal breaker. I'm not so much concerned with the quality of your clock as I am the ease of keeping multiple devices sync'ed. WC is simply the easiest way to do it. I suppose one could slave your DA to the system clock through spdif and clock the AD that way. I agree using yours as as a master is the cleanest option IF it is the only ad in use but if we are talking tracking through multiple boxes simultaneously that becomes a decision of necessity rather than quality. No I never found WC to have better performance than clocking through spdif in practice, but it's so easy to just slave everything to a solid master clock source and forget about it. Thanks for the quick answer Svart. I'm not sure what you mean by "I suppose one could slave your DA to the system clock through spdif and clock the AD that way." There is no reason to clock the ADC to anything(and there are no provisions for it), it's the master. You set your interface as a slave and the DA is already set as a slave in hardware and it will follow whatever SPDIF info you send it. You simply plug the ADC into your SPDIF input, set your interface's software as "SPDIF IN" for the clock source and then plug the DAC into the SPDIF output. And enjoy using it. If you are using multiple interfaces, they generally handle their own clocking. Take for instance my use of an Alphalink system AND a soundcard in the same computer. They don't share clocks. Right now the soundcard software is set for SPDIF IN as the clock source. The Alphalink uses it's own internal clock. I simply let them be separate. Once the audio passes into the analog domain, there is no reason to WC them together as the domains are not synchronized, nor need to be. Typically there is no need to lock separate converters together in the time domain when using a DAW as the "tape deck". This only comes into play with things like real tape machines and other devices that have an absolute need to be synchronized in time for start/stop sequences and such.. Or older devices that have very poor/cheap internal clocks. I'm not even sure what you meant, so I hope this helped, or maybe you can clarify what you meant. |
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Post by Martin John Butler on Jan 5, 2015 10:01:12 GMT -6
Svart, I have the UAD Apollo. I've tried the Burl DAC, and liked it, and if memory serves, the Burl clock was the master. I would like to use an improved clock instead of the Apollo's clock. I also tried the BLA Microclock and heard an improvement in resolution. So, I want me some of that. Will your A/D-D/A allow me to use it as the master clock like the Burl did. Forgive me if you've answered this already, it's a bit over my head, but I'm trying to catch on.
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Post by svart on Jan 5, 2015 10:10:10 GMT -6
Svart, I have the UAD Apollo. I've tried the Burl DAC, and liked it, and if memory serves, the Burl clock was the master. I would like to use an improved clock instead of the Apollo's clock. I also tried the BLA Microclock and heard an improvement in resolution. So, I want me some of that. Will your A/D-D/A allow me to use it as the master clock like the Burl did. Forgive me if you've answered this already, it's a bit over my head, but I'm trying to catch on. In this case, you would set your clock source as "SPDIF IN" in the Apollo settings(or whatever nomenclature it uses for that). I've not used an Apollo but most every interface as such usually has this choice in the software settings somewhere. This would allow the Apollo to recover the clock from the ADC SPDIF output and thus make the ADC the clock master. Wait, I found this is the Apollo manual: "When Apollo is set to use an external clock as the master clock source and a valid clock signal is detected at the specified port, the External Clock LED is solid green. Apollo can be configured to use an external clock from the Word Clock, S/PDIF, or ADAT inputs" So you would do exactly as I mentioned above. |
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Post by category5 on Jan 5, 2015 11:26:50 GMT -6
Svart, I have the UAD Apollo. I've tried the Burl DAC, and liked it, and if memory serves, the Burl clock was the master. I would like to use an improved clock instead of the Apollo's clock. I also tried the BLA Microclock and heard an improvement in resolution. So, I want me some of that. Will your A/D-D/A allow me to use it as the master clock like the Burl did. Forgive me if you've answered this already, it's a bit over my head, but I'm trying to catch on. In this case, you would set your clock source as "SPDIF IN" in the Apollo settings(or whatever nomenclature it uses for that). I've not used an Apollo but most every interface as such usually has this choice in the software settings somewhere. This would allow the Apollo to recover the clock from the ADC SPDIF output and thus make the ADC the clock master. Wait, I found this is the Apollo manual: "When Apollo is set to use an external clock as the master clock source and a valid clock signal is detected at the specified port, the External Clock LED is solid green. Apollo can be configured to use an external clock from the Word Clock, S/PDIF, or ADAT inputs" So you would do exactly as I mentioned above. However if you also have a second Apollo and a Symphony or Aurora (and wish to use all available channels) you will need to then clock those from the first Apollo since it's the only device with a valid clock source that has additional clock outputs. The Word clock output of the Apollo should still function as a valid output even when the Apollo is sync'ed to an external source through spdif. |
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Post by svart on Jan 5, 2015 12:02:31 GMT -6
In this case, you would set your clock source as "SPDIF IN" in the Apollo settings(or whatever nomenclature it uses for that). I've not used an Apollo but most every interface as such usually has this choice in the software settings somewhere. This would allow the Apollo to recover the clock from the ADC SPDIF output and thus make the ADC the clock master. Wait, I found this is the Apollo manual: "When Apollo is set to use an external clock as the master clock source and a valid clock signal is detected at the specified port, the External Clock LED is solid green. Apollo can be configured to use an external clock from the Word Clock, S/PDIF, or ADAT inputs" So you would do exactly as I mentioned above. However if you also have a second Apollo and a Symphony or Aurora (and wish to use all available channels) you will need to then clock those from the first Apollo since it's the only device with a valid clock source that has additional clock outputs. The Word clock output of the Apollo should still function as a valid output even when the Apollo is sync'ed to an external source through spdif. And if it's designed correctly, making the SPDIF the master, the WC output of the first slave should be derived from the clock recovered from the SPDIF source. You might be able to daisy chain the SPDIF output from the first device out to the input of the second and so forth and just set them all to slave to the SPDIF signal too. You'd put the DAC on the end of the chain. |
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Post by Martin John Butler on Jan 5, 2015 15:36:01 GMT -6
Thanks Svart. I've been hoping to eventually get the Apollo Quad satellite to add to my DUO. I'd prefer them to be run by your clock if possible. I'll check with their rep and see what he says.
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Post by Johnkenn on Jan 5, 2015 19:29:08 GMT -6
There's no conversion in the satellite, so there wouldnt be any issue there.
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Post by svart on Jan 6, 2015 16:41:20 GMT -6
About 90% done now. Have to figure out the best way to route a couple power nets and then I have to do double and triple checking.  |
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Post by svart on Jan 7, 2015 15:57:32 GMT -6
OK, so the DAC board layout is pretty much finished. DRC has been run and no errors found. I've checked footprints on all the parts against the real parts and they all fit. I might tweak one copper polygon under the 15V regulator for better heatsinking but I think it's pretty much ready to send out to be made.
I'm on the fence about going straight to a production number of boards or doing expensive prototypes once again..
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Post by Martin John Butler on Jan 7, 2015 17:15:55 GMT -6
Go for the first gut feeling you have, it's the right choice 99% of the time or more. Read Malcom Gladwell's "Blink" if you can. It's a one day read, and an eye opener.
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Post by kcatthedog on Jan 7, 2015 17:49:16 GMT -6
the benefit of a prototype is an absolutely confirmed build v.s. the possibility of some built not to designed spec ?
if you feel that a prototype is basically good insurance, could we help defray those costs ? why should just you incur them ?
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Post by svart on Jan 7, 2015 18:05:54 GMT -6
the benefit of a prototype is an absolutely confirmed build v.s. the possibility of some built not to designed spec ? if you feel that a prototype is basically good insurance, could we help defray those costs ? why should just you incur them ? It's one of those situations where a few fast prototypes cost as much as a bunch of slow production boards. One costs money, the other time. As far as gut feeling, i think this round will have fewer errors simply because most of the errors on the ADC prototypes were mechanical in nature. This board follows all of the same mechanical constraints and a lot of electrical ones, so i feel that having found them previously, there should be almost none this time. |
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Post by Martin John Butler on Jan 7, 2015 18:22:33 GMT -6
Cool, go for it svart!
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Post by kcatthedog on Jan 7, 2015 18:31:13 GMT -6
"all of the same mechanical constraints" if this is true, then you have answered your own question. You are the one who knows .
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