FuriousD said:
If you would have bothered to read the prior posts in the thread, I modified the demo board with the best oscillator part that I had on hand. (if that is what you mean by "the other Crystek part")
I didn't buy the part specifically for the purpose of modifying the demo board.
I realise I'm a little late, but I recommend you check out York University for this (you are in the UK, ya?). I'm in my final year of a masters there and the course is really quite good for audio.
Wingfeather said:
It's not late, thanks for this. My future wife is currently doing Computer Games Design & Programming (a woman you can play X-box 360/PS3 with 😀 and lose badly
), so I need wait until she's done, but York is an excellent university. I do have a house and good job down south that will not travel that far north plus all family is down south. I've done my fair share of living far from family (high school in Canada while parents in England, and uni away from home when back in the UK). Does the course offer distance learning? Surrey University is my actual local uni.
Did you do Electronics A-level first, or is the first year foundation in maths and electronics? If not at York, wherever you did a BSc first?
Dude, there are many DACs that cost upwards of a couple of thousand, so I see no reason why even a $200 OCXO might not be used.rossl said:
A typical rule of thumb I've heard from electronics manufacturing folk is that a $1 increase in parts leads to a $5 increase in selling price.
This is very inaccurate for actual incremental increases, especially when an individual part has a significant cost.
Perhaps, but it remains true that it is often not as simple as adding up the costs of individual parts. Unless it is DIY, of course!
Apologies for thread-drift, but I've just found the new 'scope at work we got for USB compliance testing (*) has the jitter analysis package installed - can think of *another* use for this!
Might take a day or so to get it up and running but hopefully I can post some actual phase noise measurements of a few oscillator modules I have here. Hopefully will show the difference between the two buck variety and the $$ txcos being suggested.
I'm still working on schematics for my ESS board so it'll be a while before I can check the performance of the ES9008 myself. Very interested to hear how you guys get on with the eval boards.
Local rep made me sign an NDA before I could order parts - I wonder how long this will go on before the catalog distributors start stocking them?
-Len.
(*) Tek DPO7254 with DPOJET s/ware
Might take a day or so to get it up and running but hopefully I can post some actual phase noise measurements of a few oscillator modules I have here. Hopefully will show the difference between the two buck variety and the $$ txcos being suggested.
I'm still working on schematics for my ESS board so it'll be a while before I can check the performance of the ES9008 myself. Very interested to hear how you guys get on with the eval boards.
Local rep made me sign an NDA before I could order parts - I wonder how long this will go on before the catalog distributors start stocking them?
-Len.
(*) Tek DPO7254 with DPOJET s/ware
len_scanlan said:
That's really cool, Len. I will be happy when you will be able to measure a difference between the 20 cent, two buck, 20 buck, and $100 VCXOs. It will take an significant investment in circuit board design to make a test measurment that I will believe.
The real test is about the hearing of a difference between any or all of the above. Some of you guys make too, too much out of the specification game.
Of course, if money is no object in oscillators for our DACs, we can order an atomic clock from the National Bureau of Standards.
< / sarcasm>rossl said:
That's really cool, Len. I will be happy when you will be able to measure a difference between the 20 cent, two buck, 20 buck, and $100 VCXOs. It will take an significant investment in circuit board design to make a test measurment that I will believe.
The real test is about the hearing of a difference between any or all of the above. Some of you guys make too, too much out of the specification game.
Of course, if money is no object in oscillators for our DACs, we can order an atomic clock from the National Bureau of Standards.
Ha ha that raised a smile!, I can just see some tweaker out there with an oscillator the size of a fridge connected to this teeny weeny little DAC chip!
I think that when it comes to clocks, surely everyone will agree that the less jitter / phase noise, the better. Like you say, the question is whether you can hear any differences between product 'A' and product 'B'. All I'm suggesting here is finding out the point of diminishing returns beyond which you get no useful improvement in sound quality. If this part turns out to be more immune to jitter than competing DACs, then maybe a two buck oscillator can will be enough.
I'm going to start a new thread for my oscillator measurements, this is getting too off topic.
Now back to my schematics. (I'm designing a CD player upgrade using this part - a plug-in module)
cheers,
Len.
len_scanlan said:
It would depend on the jitter rejection characteristics of the SRC.
Dustin - is it possible for you to give any information WRT jitter
rejection corner freq and rate (slope) of attenuation.
As you are probably aware, AD1896 etc have this info on the data
sheet.
cheers
Terry
len_scanlan said:
That sounds like a worthwhile project, Len.
There is another thread here about upgrading the analog output of the Behringer DEQ2496. It occurred to me that it would be a good candidate for a Sabre8 drop in board to replace the AKM DAC and the low-grade op-amps.
The add-in board would take the SPDIF out of the DSP equalizer.
This is something most DIY people could do easily. Here we have a box with the appropriate digital inputs jacks, analog output connectors and power supply.
The Behringer SRC2496 is also a good candidate. It has three digital inputs that are switched before going to the CS8420 resampler chip. The SPDIF could be picked off just before it gets to that horrid old Cirrus Logic chip and it's pitiful noisy clock.
The SRC2496 also has a low grade analog output section that could be replaced with a decent design.
Both of the two Behringer boxes have room inside the case for add-in boards.
I'm sure there is enough power supply current available for the digital parts of the board. We would have to analyze the op-amp supplies to see if there is enough current there. I suppose there would be if we disconnected the juice to the existing op-amps.
😀
Well, the question becomes how you can define "useful improvement in sound quality". If you mean indistinguishable in blind testing, there's always the question whether a difference might not be audible when other parts of the signal chain are improved--most notably speakers/headphones, which even in their modern incarnations have high distortion.len_scanlan said:
abzug said:
In the context of my own work, useful improvement means I feel its worth spending the extra money on a more expensive component - I'm working on my own project, so my own ears are the final judge and jury. If I'm happy with the sound, thats good enough for me!
cheers,
Len.
Hello Dustin,
You mentioned earlier that THD is better in current output mode ... how much does performance deteriorate in if used as voltage output?
Dan
You mentioned earlier that THD is better in current output mode ... how much does performance deteriorate in if used as voltage output?
Dan
Re: SuperDAC
There is no analog PLL inside the chip, The data simply comes into the chip at the bitclock rate, then there is a circuit that takes the date into the XI clock domian and makes sure that jitter is not introduced.
FuriousD said:
There is no analog PLL inside the chip, The data simply comes into the chip at the bitclock rate, then there is a circuit that takes the date into the XI clock domian and makes sure that jitter is not introduced.