Zen -> Cen -> Sen, evolution of a minimalistic IV Converter

[EUVL]

> but I chose to eat a Shabu Shabu and I am very satisfied with my choice in all regards... so I'm an artist !

You are not, but the cook is, because there are infinitely many ways to cook Shabu Shabu.
Even based on the same ingredients and recipe, you can still do it wrong and then it does not taste so nice anymore.

> What I have seen is prejudice against it...

Do what pleases you.
Just don't complain that your noise problem is a circuit design fault of the IV converter.
Because I don't have the buzz problem, and neither does Nic.

> In fact, in my estimate the SEN-board/Buffalo combo has >10 times the length of non-twisted cabling than has a well done stacked design.

If you put the bottom layer of the PCB close to a grounded conductor, you get effective shielding.
And if you place it at a much larger distance to any disturbance, or even better a Ground plane in between, you can suppress any disturbance pick up.
It is a bit more difficult to shield the cable connected to the digital circuit.
That is why twisted cable there (near the digital board) helps.


Patrick

[needsp]

Hi Nic

Is your layout still as shown here?

Zen -> Cen -> Sen, evolution of a minimalistic IV Converter

Mine is here-

Zen -> Cen -> Sen, evolution of a minimalistic IV Converter

Yours now seems much better in retrospect- the SEN boards aren’t directly over the digital board, and the latter is close to the grounded case work. I suspect our layouts were chosen as the easiest to implement from where we started- mine certainly was, but if you were more prescient, well done! And the fact you’re problem free fits with my hypothesis- not prejudice, LazyButt- that stacking the boards directly over one another may increase the changes of rf pickup/oscillation carrying audio noise into the circuit. I’ll test my hypothesis by putting the Sen boards either side of the Buffalo board, close to the casework. If the buzz is absent, and after trying to provoke it in the ways I’ve described, I’ll tentatively conclude that the altered layout has helped, and that the old layout was more problem prone. Only tentatively, because without knowing the exact nature of the interaction between the boards which provokes the hum- it might involve just the layout of the components and their links, and/or through space interactions, I won’t be able to probe the mechanism in detail. But I’ll be a happy listener

Paul N

[EUVL]

> But I’ll be a happy listener

That is the only thing that counts.




Patrick

[Lazybutt]

Originally Posted by EUVL

Just don't complain that your noise problem is a circuit design fault of the IV converter.

I'm not complaining, and never have complained about a design fault in this thread (or show me where, and I'll apologize !)
I think however this particular circuit is more prone to RF pickup than others... I don't call that a design fault.. just one of the drawbacks of that particular arrangement. (sorry for the bad word :P)
Actually I suspect my buzz is coming from the Buffalo DAC (and I have some ideas as to why -something to do with a DC imbalance at the output of the ES9018 channels- ... just need time to do more measurements and tests => for sure if I find the answer I'll keep everyone posted)

Originally Posted by EUVL

Because I don't have the buzz problem, and neither does Nic.

It seems neither you or Nic are using an ES9018 in Single Ended mode..... or at least I have not read reports of it... that's why I was suggesting that no proper scientific evidence or test protocol has been shown so far...
And again: I don't have a buzz issue in Balanced mode either...

Cheers!

Fred

[Lazybutt]

Originally Posted by needsp

I’ll test my hypothesis by putting the Sen boards either side of the Buffalo board, close to the casework..........

Now that's what I call a test protocol !
Looking forward to your findings

Fred

[EUVL]

Fred,

I was just pulling your leg. Don't take it so serious.
It's hobby, and we should have fun.

We (the xen team) have some evidence of where all these buzz problems (might) come from.
But we make it a point not to criticise designs of others.
The fact that you have no buzz in balanced mode tells a lot.


Patrick

[Calvin]

Hi,

I've just noticed, that the silkscreen of the SEN-board reads "September 2011".
So, Happy Birthday then Baby SEN :-)

jauu
Calvin

[EUVL]

Thank you.

Even the parents forgot the birthday.
Bad Papa .....

Never thought we could have gone over 1000 posts.
But disappointed so few people have taken the courage to build and find out.
What a pity. They don't know what they are missing .....


Patrick

[georgehifi]

Hi Patrick, forgive me if it's been asked, but what are you using with the SEN as an output buffer?

Cheers George

[needsp]

Hi LazyButt

By SE output, do you mean taking just one phase and ground? This works OK for-me, no buzz at all! (Though I’ll recheck- presumably also “capricious”.) Ironic, given the issues I’ve had on occasion with a balanced output, and, particularly, the enormous amount of noise and distortion I heard with any other IV stage I’ve tried- Legato, Ivy, etc. See here-

Zen -> Cen -> Sen, evolution of a minimalistic IV Converter

And here-

pink fish media - View Single Post - The art of Sen

Have you compared the two outputs in listing tests? At first I thought them to close to call, but, with more complex material- particularly solo piano- I preferred the balanced out. I run both SE and BAL singles through a Jensen JT-11P-1 line transformer before my single ended line stage- to convert BAL to SE, and to take benefit of the transformer’s common mode signal rejection for the SE single.

Best

Paul N