Build thread for Diyinhk ES9018 DAC on Ebay

[qusp]

i'm trying to remember that Chicken/Egg laying analogy in the ESS modulator video.

[glt]

I thought he meant

"don't bother with reducing anything below 10 nsec jitter since it will be reclocked anyhow..."

[KlipschKid]

Hi,

I've had the Wolfson for quite some time and done quite a lot to it, and tried it with a few DACs. In the process I found changing the clock to have a noticeable benefit and that a better source gives a better output. So I suspect that "immune to source jitter" is a nod to marketing - identify a need and say your product meets that need. And it is better. So buy me, today, and get your free.... pardon my cynicism.

I've also tried quite a few things with this DAC, as you guys know, such as differing power supplies, regulators, resistors, op amps, capacitors, and I2S sources. My first test was with the cm6631 direct into this DAC - there's a pic on the first post, and of course I've tried other stuff. I'm on a journey. Normally that would be fun but posting here at Diyaudio is turning it into something else.

Anyway, for sure, I can say, isolating the USB from the DAC is an absolute must - it reduces some graininess (thd), esp noticeable in vocals.

So, if I want to use synch with the cm, I must isolate the clock feed and I2S, which at present, I don't have the parts/pcb for. So I tried the Wolfson and was pleasantly surprised. Its a keeper. I may add a switch (see first post) at a later date, and then change things again... and then try arduino... but at this stage, I'm getting this current set up as good as it will get. It may be that this will be as good as it gets, and the ES9018 truly is immune to jitter.

So, that brings me back to my question... impedance in spdif circuits .... have I done the maths right ? I think so, but it is based on an assumption, so that's what I'm hoping someone will know about/check. Not Qusp. Sorry.

I should apologise for being rude in my earlier post 266. I did it to try to make a point, that will hopefully hit home. But probably not.

[qusp]

I should apologise for being rude in my earlier post 266. I did it to try to make a point, that will hopefully hit home. But probably not.

nope, just made you look like a paranoid child

anyway back to invisible, the help or perspective isnt wanted, seems its usually invisible to you lot anyway.

[KlipschKid]

Originally Posted by qusp

perhaps you guys should start your own forum if you dont want anyone giving you a reality check now and then?

No need, just ignore any/all of my posts please. Thank you. And yes, I'm paranoid and childish. You have better things to do with your time and people who appreciate you. Don't waste your time helping me. Thank you.

[qusp]

ahead of you, click

but you really should consider it, I wont be the only one

[KlipschKid]

FWIW, I finished op amp rolling. Everyone has their own preferences, but these sound best for my system.

Buffer = LME49990, OPA211, LME49710 (in order of preference from earlier tests).
I/V = ADA4627, OPA627, OPA1641 (in no particular order, from today's tests). OPA134 are probably acceptable too, but I only have 2134.

I haven't tried any cfb ones yet.

cheers

[KlipschKid]

Originally Posted by glt

PS: have you heard the MarkAudio 12p? talk about micro-details...

Hi,

I've never heard any of his speakers... and I live not far from his offices too... but people say they are excellent.

I see on your blog you have a very very nice 12p. Lucky dude. What's the plan for it ? Transmission line ?

I have a pair of Merril full-range drivers that I made into an isobaric 16L speaker as a centre channel, with a passive radiator for the reflex. I love the bass and mids it gives and, as you say, detail is tremendous... but only immediately on axis. Just 10 degrees off and it's very much duller, and it's also far from a flat response above about 2Khz. So I've been meaning to tri-amp it and add a tractrix horn tweeter to give better dispersion... but you know, so many projects, so little time.

cheers

BTW, forgot to mention - OPA1611 will also suit the buffer I think. I forgot to try them ! Aiya... getting old...

[luxury54]

Originally Posted by KlipschKid

Hi,

Not exactly about the ES9018.... but I fitted the CM6631 USB receiver to the Wolfson WM8805 I'm using as my I2S source for the DAC. I'm using this :



I don't know what the impedance of the DS receiver is so I assumed 25R. This would mean, on the output side the trafo sees about 100R and the receiver sees about the same.

Output
Trafo sees (25||240 = 22R) + 36R + 36R = 94R
DS sees (100R+36R+36R)||240R = 100R

All good ?

Input
Do I need to change R1 to ~400R and R2 to ~132R ? 300||100 = 75 ; 400||132 = 100

Thanks for the help.

Hi, what would be the correct component values for this setup to output 75 ohm impedance into a BNC jack to be used as an isolated coaxial output ?

[KlipschKid]

Hi,

Sure you don't wanna stick with 100 ? It works.... even with the BNC...

Are you using the cm6631 ? If so, keep the left side of the trafo the same.

On the right side change the zobel to 75R and 18pF (this is based on PE-65612 but should be about right for most spdif suitable pulse trans, e.g Newava, Murata).

Then you need to change the pad values so it and maintains 75R from both ends. It'd be nice if you could also drop about 3db but that might be easier to do by changing the left side of the trafo. I don't actually know the output of the CM but the datasheet seems to say it 3.3V, and spdif is 0.5V.

Trafo sees

(BNC 75R||R5) + R3 + R4 = 75

BNC sees

(Trafo 75R + R3 + R4)||R5 = 75

Is that possible ? R3=R4 so let's call that Ri. 75||R5 + Ri = 75 and (75+Ri)||R5 = 75. Um. Works if Ri is zero. And R5 is infinite. So, different circuit needed. In practice, I'd just keep the 100R +15pF zobel and use a 100R across the BNC.

SMD have lower inductance, which really matters at these freqs, so really you should try to use them and fit the zobel onto the trans and the other(s) onto the BNC.

Please note that I learned this from reading other people's posts, so if you can, check the output of the bnc on a scope, and always listen to it before you decide it "must be right cos maths says it is". Wires, soldering, etc... so be prepared to tweak the values and listen to the deep bass and soundstaging until it sounds right. Anyway, this is what I do. My scope is an old 12Mhz though so I don't really trust it, much like myself - old and seen better days.