Ok I was reading and it says the Opus has balanced outputs. Does this mean if I'm going to feed it directly into my chipamp that I'll need the balanced to single ended converter? I guess I'm not really certain whats balanced and whats single ended? Pretty sure that balanced is like an XLR connection and single ended is something like an RCA. If this is true I'm not sure why you put balanced connections on the DAC it self as not very many people actually use XLR's. Or maybe thats all the DAC allows by design. Regardless looks like I may not be able to use my opus for a bit until I order the Ballsie.....
Spartacus said ...
"You yourself are claiming good jitter performance for your design, yet have provided no proof at all. I'm talking from experience and understanding of underlying principals."
Sorry friend, but unless you have empirical evidence that you can share ... "You are the one making random noise and not the circuit.".
Spartacus, what empirical evidence can you offer up to validate your position?
"You yourself are claiming good jitter performance for your design, yet have provided no proof at all. I'm talking from experience and understanding of underlying principals."
Sorry friend, but unless you have empirical evidence that you can share ... "You are the one making random noise and not the circuit.".
Spartacus, what empirical evidence can you offer up to validate your position?
Carl_Huff said:
I'm talking from experience and understanding. Do you have "empirical evidence" for all of your views? Of course not - talk about random noise.
Plus, Russ HAS made an assertion, remember.
I did not say ASRCs are immune from all forms of jitter. You have to keep in mind that the types of jitter that are likely to effect the ASRC are not "random jitter" but harmonic. There is no good reason to believe that the crystek XO has any large degree of harmonic jitter. It is much more likely random. Random jitter is very easy to defeat.
Please explain why the (likely minuscule) random jitter <12khz would be a problem for the SRC4192. I look forward to that. Nothing in the datasheet suggests it would be any issue at all. Neither does anything I have experienced or tested. Now if you had a poor clock with bad jitter at the master clock frequency, then your in bad trouble. that's not the case here.
When I said the Crystek XO was good. I only spoke of the specifications for the XO and its performance for the SRC4192..
I have no reason to believe that just because Crystek did not specify jitter down to < 10hz it is any worse than the Tent clock at the same frequencies. It could actually be better, it certainly is better above 12khz (well at least specs I checked). Tent labs is selling clock to audiophiles who might be swayed by a spec like that.
That said, I never claimed the Crystek part is "better" than any particular clock in any case. I simply said it is very good, and that it certainly is.
You said "No it is not".... Which seems a bit odd thing to say unless you can show why it is not with hard facts... Not just why you "think" its not good, but why it "is" not good. 🙂
Hypothetically (as I would never say such a silly thing) If I said "The Tent XO is not good" then people would expect me to provide some tangible proof that it is not. If I don't show a good reason then nobody has any reason to believe me.
The Crystek XO is not my clock, its Crystek's. They have said its good. I believe them. So I also say its good. If you think its not good, take it up with them, or show a tangible comparison where the factors can be identified and demostrated to be "not good".
Cheers!
Russ
Please explain why the (likely minuscule) random jitter <12khz would be a problem for the SRC4192. I look forward to that. Nothing in the datasheet suggests it would be any issue at all. Neither does anything I have experienced or tested. Now if you had a poor clock with bad jitter at the master clock frequency, then your in bad trouble. that's not the case here.
When I said the Crystek XO was good. I only spoke of the specifications for the XO and its performance for the SRC4192..
I have no reason to believe that just because Crystek did not specify jitter down to < 10hz it is any worse than the Tent clock at the same frequencies. It could actually be better, it certainly is better above 12khz (well at least specs I checked). Tent labs is selling clock to audiophiles who might be swayed by a spec like that.
That said, I never claimed the Crystek part is "better" than any particular clock in any case. I simply said it is very good, and that it certainly is.
You said "No it is not".... Which seems a bit odd thing to say unless you can show why it is not with hard facts... Not just why you "think" its not good, but why it "is" not good. 🙂
Hypothetically (as I would never say such a silly thing) If I said "The Tent XO is not good" then people would expect me to provide some tangible proof that it is not. If I don't show a good reason then nobody has any reason to believe me.
The Crystek XO is not my clock, its Crystek's. They have said its good. I believe them. So I also say its good. If you think its not good, take it up with them, or show a tangible comparison where the factors can be identified and demostrated to be "not good".
Cheers!
Russ
Dougie085 said:
The Opus has balanced outputs (XLR), but you can get single-ended (RCA) out of it just as easily. Just use only the L+ and R+ and G outputs of the Opus to your RCA jacks.
Dougie085 said:
That's a good question.
The Ballsie gets you a bit better THD, dynamic range, and SNR, as it combines both the inverting and non-inverting outputs of the DAC. It also has spot for optional capacitors which gives you a low pass filter which is (nearly) the same as the one on the WM8740 datasheet.
Cheers!
Riss
The Ballsie is a buffer. The Opus requires that the load it's working into (say the input impedance of your chip amp) is greater than 1k. The Ballsie is something that goes in between the Opus and the load (your chip amp) to take care of this problem, but most amps have an input impedance of at least 10k which the Opus handles easily. There are some who think that it sounds subjectively to have a buffer even if you don't technically need it (I do), but you know how things in audio are ;p
-edit- in addition to those benefits Russ pointed out ;p I'm still a newb at heart 😉
-edit- in addition to those benefits Russ pointed out ;p I'm still a newb at heart 😉
Ok so using a single ended connection directly on the DAC (rca) doesn't perform as well as using the Balanced (XLR) connection directly on the DAC or using the Ballsie to convert to single ended? Is the difference great enough to actually be audible?
Well let me put it this way. Into a high impedance load even without the ballsie it sounds fine. But it will be 6db down, so you will get 6db less output then you will from the ballsie.
It still sounds great even without the ballsie. But yes I can hear the difference, and it does sound better with it. If I were to guess I would say mostly because of the lower noise floor and better dynamic range.
Balanced output will be better (lower THD because it goes through fewer stages) and has other advantages like better noise rejection.
For that reason some people have put the ballsie in their pre/power amps. So they can run balanced XLR cable from the DAC to the amp.
Cheers!
Russ
It still sounds great even without the ballsie. But yes I can hear the difference, and it does sound better with it. If I were to guess I would say mostly because of the lower noise floor and better dynamic range.
Balanced output will be better (lower THD because it goes through fewer stages) and has other advantages like better noise rejection.
For that reason some people have put the ballsie in their pre/power amps. So they can run balanced XLR cable from the DAC to the amp.
Cheers!
Russ
I doubt output will be a problem for me as the chipamps have a lot of gain. I may look into getting a Ballsie later though. Are the RevC's capable of balanced inputs? I have a pair I really need to get a transformer for them and set them up... I was either planning on getting a second DAC module and a Metronome or getting the Buffalo as the next upgrade though. I have a friend that might buy the opus board off me if I get the Buffalo.
The RevC is a single ended amp, so you would need to do some form of bal -> SE conversion to make it work with balanced input. You can actually use a transformer to do that or the ballsie, or similar circuit. or just do as suggested and take just the +out and GND from each side of the DAC. It will still sound excellent.
Cheers!
Russ
Cheers!
Russ
Russ,
Delta-Sigma DACs are plenty sensitive to jitter, ASRCs less so - depending on the performance of their rate estimators.
The Crystek part is not specified for low jitter in the audio band, and therefore it could perform well, or it could perform badly. It's a crap-shoot. The Tent part is specified to perform well.
Manufacturers generally like to publish specs that show their products in a good light. If the Crystek part did perform well at audio frequencies, I rather think they would declare that. Can you back up your assertion that jitter <12KHz is "likely miniscule"?
The rest of my criticism was aimed at the PSU for the clock. You use an LP2985 to supply the clock plus the rest of the circuitry. You can do much better. The Flea mentioned here has several orders of magnitude better specification - anyone who wants "hard evidence" just needs to look at the relevant data sheets. The fleas ripple rejection is better than 160dB above 200Hz and around 125dB at 10Hz. The LP2985 just doesn't compare.
Hmmmm, I seem to be coming across as the bad guy here, which is hardly my intention. TP offers a very fine product. I'm rather trying to encourage people to experiment in order to a) get better sound quality b) increase their understanding (as we are all doing) c) have fun!
Delta-Sigma DACs are plenty sensitive to jitter, ASRCs less so - depending on the performance of their rate estimators.
The Crystek part is not specified for low jitter in the audio band, and therefore it could perform well, or it could perform badly. It's a crap-shoot. The Tent part is specified to perform well.
Manufacturers generally like to publish specs that show their products in a good light. If the Crystek part did perform well at audio frequencies, I rather think they would declare that. Can you back up your assertion that jitter <12KHz is "likely miniscule"?
The rest of my criticism was aimed at the PSU for the clock. You use an LP2985 to supply the clock plus the rest of the circuitry. You can do much better. The Flea mentioned here has several orders of magnitude better specification - anyone who wants "hard evidence" just needs to look at the relevant data sheets. The fleas ripple rejection is better than 160dB above 200Hz and around 125dB at 10Hz. The LP2985 just doesn't compare.
Hmmmm, I seem to be coming across as the bad guy here, which is hardly my intention. TP offers a very fine product. I'm rather trying to encourage people to experiment in order to a) get better sound quality b) increase their understanding (as we are all doing) c) have fun!
http://diyenclosures.com/products/chassis/diy0908/ I was thinking about maybe using this chassis for the DAC do you think its big enough? Or if you know any other aluminum chassis thats pretty nice thats cheaper 🙂 I don't want it to be to big.... but around the size of a commercial DAC would be nice.
Spartacus said:
No worries Spartacus,
I was built to take criticism. 🙂 It is very useful. But much more so when it is concrete and most importantly correct!
You should do whatever pleases you. It is your hobby.
But, regarding me what you should be showing me, if you really want to improve things, is that the design choices I made actually (not theoretically) do adversely effect the final outcome. If they do, they will be changed, and if they don't then we are just wasting time. Which is sorta what a hobby is anyway, so that's not necessarily bad. 🙂
We should not assume that since Crystek does not spec jitter down to Xf it is poor below Xf. Especially since it is excellent at the frequencies which are known to be important for the application. 🙂
Tent is marketing to folks like you. Crystek is not so much. 🙂
The Wolfson and TI parts have excellent jitter rejection. At least so they say 😉 Perhaps you will disagree.
Cheers!
Russ
Russ White said:
The important frequencies are in the audio band, particularly low down.
I read a lot of Guido Tent's early writings (before he started buisness) WRT jitter, and he does know his stuff. Being cynical towards people like him is fine, but at least he fully discloses the performance of what he sells.
Modern delta sigma parts are advertised as being "jitter tough", but this is only in comparison to early generation bitstream parts that were extremely sensitive to jitter in comparison to R2R DACs. My experience: all DACs benefit from a good clock.
Spartacus said:
Spartacus,
I am not cynical toward Guido Tent. I am sure he knows his stuff.
You are simply assuming a deficiency where none has been demonstrated.
You on the other hand seem to be cynical toward Crystek. 😉
I will arrange for a definitive test next time I am able.
Cheers!
Russ
Russ White said:
I'm not cynical toward Crystek, and I didn't mean to imply that the performance of either the Crystek or your circuit is BAD in any way .... rather just that if one is shooting for the stars, there is room for improvement. I was probably too blunt in my early post.
I look forward to the result of your tests! 🙂
Spartacus said:
I actually agree with you. 🙂
Just about anything can be made better. And it is fun to try even if we fail.
I actually enjoy exchanges like these, so I hope I was not too blunt either.
I occasionally make trips to Knoxville and visit the UT physics lab, which has all I need to measure the actual performance of the circuit. I will see what data I can extract from that.
I hope you have a very nice weekend. Now lets go listen to some music and/or have a beer.
Cheers!
Russ