The Headcase Stax thread

[GodfatherNiko]

So this is pretty embarrassing:

What I thought to be an imbalance issue with my STAX from maybe potentially arcing the driver one time, turned out to be a clogged Eustachian tube in my left ear, leading me to perceive less bass, and thus driving me mad. All is sorted now.

[Sherwood]

4 hours ago, GodfatherNiko said:

So this is pretty embarrassing:

What I thought to be an imbalance issue with my STAX from maybe potentially arcing the driver one time, turned out to be a clogged Eustachian tube in my left ear, leading me to perceive less bass, and thus driving me mad. All is sorted now.

How'd you diagnose the problem?

[Craig Sawyers]

FWIW I've been through a number of issues with my hearing over the last 6 months, all (thank heavens) sorted out now. Stated with losing bass from my right ear - sounded like a tinny 1960's transistor radio. Doc said fluid behind the eardrum, and it would clear. In the interim it went into low frequency tinnitus - sounded like a perpetual low frequency hum, 24/7.

That progressively cleared up (months), at which point (two or three weeks ago) my left ear suddenly went really pretty deaf. That lasted for a week, and then that has cleared too.

So I have for the first time in 6 months got total hearing back.

The doc reckoned it was the after effects of a head cold back in the Spring.

Fun it has not been.

[guzziguy]

I understand.  It's scary.  As I reported, I had my first (at almost 64) adult ear infection last month.  It started as a head cold and eventually the pressure ruptured the eardrum.  I had all the usual symptoms such as reduced hearing and tinnitus.

I saw my ENT again last Friday.  He says the infection is gone but that there is still a little fluid in the middle ear.  A hearing test revealed slightly reduced hearing in the ear.  I'm to continue treatment (Flonase and hourly clearing of the ear) until the fluid is gone.  My ENT thinks hearing will return to normal.

[Torpedo]

You'll recover your hearing, Ken. Glad the problem is solved, Craig. Did you ever get your cavum inspected? Six months is a long time for an otitis with effusion.

[Craig Sawyers]

in all honesty it cannot have been that long - it just seemed like a long time. Anyhow, complete and stable hearing is back, with no problems in popping my ears.

[Torpedo]

So I assume the answer to my question is no  I'm glad you're OK.

[DefQon]

On 12/3/2016 at 9:04 AM, dsavitsk said:

I wasn't saying it was. I was saying that there is a long and documented history of Lampizator designing poor, dated, and/or inappropriate circuits and trying to pass them off as state of the art.

Unfortunately people buying it/auditioning it don't care about this unless it sounds good nowadays.

[spritzer]

...and the real problem is that this shit doesn't actually sound good.  They just don't have the experience to discern quality from the shitty stuff. 

[wink]

 "See You Tomorrow"

  One sunny day in 2018, an old head-caser entered a Hifi store from across a park, where he'd been sitting on a park bench. He spoke to the salesperson behind the counter.

 "I would like to purchase a Singlepower amp."

 "Sir, Singlepower no longer make amps as they have gone out of business."

 The old man sighed and walked away.

 The following day, the same man entered the same Hifi store and said to the same salesperson,  "I would like to purchase a Singlepower amp."

 "Sir, as I said yesterday, Singlepower no longer make amps as they have gone out of business."

 The man thanked him and again walked away.

 The third day, the same man entered the same Hifi store and said to the same salesperson,  "I would like to purchase a Singlepower amp."

 The salesperson, understandably agitated at this point, looked at the man.

 "Sir, this is the third day in a row you have been here asking to purchase a Singlepower amp. I've told you already several times that Singlepower no longer make amps as they have gone out of business. Don't you understand?"

 "Oh, I understand you fine. I just love hearing your answer!"

 The salesperson grabbed the man and gave him a friendly hug. "Sir, see you tomorrow." 

[ALSO]

For this crowd, and since you've recently put MSB through the ringer, any thoughts, brutal or otherwise on the TotalDAC line?  Have been considering one for some time, and Arnaud's just put his up, but thought I'd check with the evisceration squad first--

[kevin gilmore]

Here is what I have to say for all dac's these days.

Even though this has been going on for 25 years or more, there is still so much to be done for both the hardware and firmware/software.

I'm sure that people 20 years ago that sunk >$25k in to the krell sbx64 stack are kicking themselves for doing so, as today's price on that pile is just about a giveaway.

For R2R discrete dacs, you have your choice of 2's complement dacs (basically 1 ladder per channel per side) with associated issues with switching around virtual 0v and sign magnitude dacs which are twice as many parts, and can generate interesting new distortions when the 2 sides are not perfectly matched.

then there is the firmware and associated iir, fir, closed form etc filters, everyone tries to make theirs proprietary, until someone open sources this, it will continue.

So spending $5k or more on something that may have been close to $20k seems like money dumped into the trash can. Especially stay away from lampizator, in my opinion, the new singlepower.

Buy a holo spring and sit on it for 2 years when all sorts of new everything should show up. or if you are pcm only and going to stay that way, buy a yggy.

part 2

more and more people are doing upconversion from pcm to dsd128 and dsd256 and like me seem to like the sound a bunch better. Its so much easier to design one switch per channel (and match the rise and fall times and exactly control the off and on voltages) than it is to design 24 or 28 (2's comp) or 48 or 56 switches (sign magnitude) per channel, then double that for balanced.

Edited December 11, 2016 by kevin gilmore

[Dusty Chalk]

I didn't think hardly anyone implemented PCM DACs that way anymore.  Has there been a resurgence?

[kevin gilmore]

the flavor of the month is clearly r2r discrete dacs

MSB,dCS,Soekris,Lampizator, T+A, Totaldac, DSC1 (an interesting variant),new audio-gd, Holo Spring and probably a bunch of others coming.

the 20 bit multibit that schiit uses is the highest resolution monolithic integrated circuit part available. (no dsd)

everything else is delta/sigma stuff

 

Edited December 11, 2016 by kevin gilmore

[Craig Sawyers]

Designing support circuits, voltage references, precision clocking, and above all board layout is critical to get true 20-bit performance from such a DAC ( AD5791, according to Schiit's site). Given that, the Yggdrasil seems to be something of a bargain.

But on R2R (a technology I haven't looked at for a looong time) I might spring for a Soekris just to find out what the fuss is all about.

[MLA]

On 2016-12-11 at 3:04 PM, kevin gilmore said:

more and more people are doing upconversion from pcm to dsd128 and dsd256 and like me seem to like the sound a bunch better.

+1

Would a Stax Mafia DSD only dac be an option?

[kevin gilmore]

its one of the things i'm thinking about

 

[spritzer]

...and it will have a 211/845 based output stage using the new anode follower.   

[nopants]

what are the technical merits of converting pcm to these high dsd formats? i'm pretty set on pcm at this point but still curious

[Dusty Chalk]

I'm going to guess:  there's a form of "upsampling" going on. 

[skullguise]

39 minutes ago, Dusty Chalk said:

I'm going to guess:  there's a form of "upsampling" going on. 

Yup.  Some folks are going gaga over up-sampling (cross-sampling?) even PCM to multi-times DSD, up to DSD512 if the DAC can handle it.  I myself am thinking of going to try that via HQPlayer software, one of the best supposedly.

Does indeed look quite interesting.....

[kevin gilmore]

yep, upsampling. plus if you are going to keep the original samples you need higher resolution to extrapolate the pieces in between. so at least 20 bits.

one of the main reasons is filtering.  for 16/44, you really need a multi pole output filter to prevent aliasing, and all the analog filters that have been used in the past have significant phase shift among other issues.

so you bump it up to some very high frequency, then a simple single pole filter way outside the audio band, say 100khz.  then no phase shift at all in the audio band.

and you make perfect discrete high power pure class A switches.

[nopants]

some of the more obscure audio forum discussions suggest that the clocks necessary for this kind of upsampling aren't up to snuff, with respect to jitter etc. I can see the utility in being able to handle all these different formats though, I just never really got into DSD formats

Seems like all the switching would wreak havoc on this kind of system too but that's just my conjecture

[mypasswordis]

Andreas Koch apparently does everything with FPGAs, including the 1 bit DACs. To play devil's advocate, the argument against true 1 bit DSD seems to be evident based on what the manufacturers are churning out these days. The ubiquitous ES9018 DS chip tries to improve upon true 1 bit using 64 (6-bit) equal-weighted 1-bit converters, so it ends up kind of being a hybrid. Read this for more info: https://benchmarkmedia.com/blogs/application_notes/inside-the-dac2-part-2-digital-processing

Moral of the story is it's very hard to get 20+ bit accuracy even with the most state-of-the-art manufacturing processes available, so there is not much hope for these discrete designs coming out of the woodworks. The discrete R-2R stuff no doubt measures worse, but for whatever reason some people like the R2R sound more than DS. The fact that there's all these crock pot Lampizator goons out there doesn't really give a ringing endorsement to these DACs, though. 

[Pars]

I thought that most preferred the sound of PCM to DSD? I guess I haven't followed this (obviously) over the last few years, but what is the fuss over high rate DSD?