The Headcase Stax thread

[GodfatherNiko]

I remembered what may have caused my little imbalance issue: A few weeks ago, I was listening with the 207 for a long time. I had an itch on my face under the earspeaker, so I lifted the left earcup from my head to scratch my itch. Then my finger slipped and the left earcup slammed full force against my head and -you guessed it- formed a seal. I heard the ugliest noise coming from it, like putting a strip of bacon in to a hot oily pan. A loud sizzling sound beyond any stax fart I've heard. It only stopped when I turned off my amp after about a second or two. Ever since then, the stax fart is a lot louder and more pronounced on the left side as opposed to the right side. Also, here's what really bugs me about the imbalance: It only happens in the bass frequencies, mids and highs are fine, and so is imaging, detail and overall volume! I'll try discharging them a few more times and tapping the casing in all manners and hope it works out.

If not, I'll send them in and hope they don't question my reasons... Or I'll upgrade to the L700 that's been on my list forever now.

[spritzer]

You could have arc'ed them as the diaphragm slammed into the stator.  We just don't have enough data on the new diaphragm material to know how it behaves but the resistive coating should have been able to protect it and just dissipate the small amount of charge at the contact point. 

[GodfatherNiko]

On 3.11.2016 at 11:41 AM, spritzer said:

You could have arc'ed them as the diaphragm slammed into the stator.  We just don't have enough data on the new diaphragm material to know how it behaves but the resistive coating should have been able to protect it and just dissipate the small amount of charge at the contact point. 

Thanks again for your opinion spritzer, I decided to either sell them or keep them as a secondary set. I also found a hifi-store here in Zurich where I can audition the entire STax lineup with all amps and earspeakers. So far I'm thinking of getting the L700 with a 353X.

[Sechtdamon]

I was reading this topic for getting thoughts on my recent purchase of modified egmont clone from Birgir, and spotted some diggings done into taobao electrostatic amps. I found these on yahoo aleado:

 

This is something like malvalve I guess?

http://yahoo.aleado.com/lot?auctionID=k181199121

And this is T2 clone as seller claims:

http://yahoo.aleado.com/lot?auctionID=m95216502

And there are some used Stax earspeakers and amps, here is the whole listings:

http://yahoo.aleado.com/2084219581-category-leaf.html?j=0&page=1

 

On 15.04.2016 at 4:34 PM, spritzer said:

Are there any other electrostatic amps on TaoBao that I might have fun with?    I can search for Stax but that only brings up the KGSS clones and the tube amp by the same guy

If you still have time.

Edited November 14, 2016 by Sechtdamon

[kevin gilmore]

That is not a T2 clone. It is a massive piece of shit and similar to mikhail's disasters

[Sechtdamon]

Sorry Dr. Gilmore, I should add, "as seller claims"

I pressume they are crap. Just want to share cuz Birgir asked for things like these before on this topic.

Edited November 15, 2016 by Sechtdamon
wrong adressing

[Sechtdamon]

Good thing happened too today, as comfortation. I got this today:

 

 

This is the egmont clone that Birgir bought from China website. I was thinking for a long time for amplifier upgrade but I did not want to take 10 steps at a time, cuz I really want to progress slowly, for it's better and joyful to do. So with Birgir helping me a lot about lots of things, I bought it for the half of the price Birgir spent on it (not a discount, you can see how much he spent on this topic).

Amplifier is extremely good for the money I spent, I've never listened it before modified but I read how bad it was before modified by him. But hey, he has magical hands. I mean, It is better than current top tier amps of Stax, imho.

Thanks again Birgir.

 

ps: I sold the bubble wraps and made some profit.

 

Btw, I started to work about that top closure immediately. For a long time I wanted to work on granite. I'm making a granite cover for top of it. If I can succeed, I'll let you know when I start to work on full granite enclosures.

 

And here is my current humble system:

 

 

Edited November 19, 2016 by Sechtdamon

[spritzer]

http://www.msbtechnology.com/amplifiers/headphone-amp-features/

Anybody want to guess what actually makes this thing tick? 

Look at all the bodges in a 37k$ amp... 

Edited November 23, 2016 by spritzer

[Hopstretch]

I'm waiting for the  Platinum Edition at $75K where they cryo all the bodges for you too.

[nopants]

i wonder how much of the budget went towards the casework

[kevin gilmore]

the heatsinks and chassis bottom (and likely the top) are all sand castings.  Pricy for sure.

450uf 300V power supply caps?

 

Edited November 23, 2016 by kevin gilmore

[GeorgeP]

I think those are 450v chem-con caps - no boutique stuff here.

guessing the chassis accounts for about 95% of the cost based on what can be seen here.

[spritzer]

That chassis is sure expensive but max 1k$ as they aren't doing one or two of them. 

As for the amp...the amount of suck on display is truly astounding.  Also the sheer lack of proper engineering... 

[GeorgeP]

in that case 60% then.

also wondering what the heatsinks are for. Doesn't seem like anything is connected to them.

[kevin gilmore]

looking at the picture blown up.

450V, 330uf

and if you look, 10 transistors, all in series, banks of 5. and lots of resistors to balance them all. (sot223-4 transistors)

sure looks to be a bipolar version of the koss esp950.  so its a voltage stacker.

transistors are likely matched pnp and npn, and are rated for 250 to 300v (5 transistors with 900v total power supply)

there are no power output transistors attached to the heatsinks

input transformers are used as the phase splitters

 

IF (more like when) it blows up, its impossible to repair.

 

Edited November 23, 2016 by kevin gilmore

[Dusty Chalk]

[johnwmclean]

2 hours ago, kevin gilmore said:

IF (more like when) it blows up...

I’d expect fireworks at this cost.

[spritzer]

I just can't wait for the review to come on HF from a guy who was stupid enough to get those Woo monoblock piles of shit.  Reminds me of when Ray got Skylab to review the A10 and we drove him into the ground for having zero electrostatic experience and thus...nothing useful to say. 

[JimL]

5 hours ago, kevin gilmore said:

looking at the picture blown up.

450V, 330uf

and if you look, 10 transistors, all in series, banks of 5. and lots of resistors to balance them all. (sot223-4 transistors)

sure looks to be a bipolar version of the koss esp950.  so its a voltage stacker.

transistors are likely matched pnp and npn, and are rated for 250 to 300v (5 transistors with 900v total power supply)

there are no power output transistors attached to the heatsinks

input transformers are used as the phase splitters

 

IF (more like when) it blows up, its impossible to repair.

 

Sure makes this statement 100% credible: "I spoke with MSB, as I expected they confirmed that they did all of the engineering work on the amp themselves, no outside source was used at any stage, contrary to some rumours here."

 

BTW, anyone see any sign of a regulated power supply, or is it just lots of big electrolytic caps?

Edited November 24, 2016 by JimL

[spritzer]

I can't see any signs of regulation but those heatshrink "things" between the caps intrigue me.  Might just be a CRCRC supply or something like that.  Needless to say...pretty shitty in a 2K amp let alone something this expensive. 

[sorenb]

12 hours ago, kevin gilmore said:

looking at the picture blown up.

450V, 330uf

and if you look, 10 transistors, all in series, banks of 5. and lots of resistors to balance them all. (sot223-4 transistors)

sure looks to be a bipolar version of the koss esp950.  so its a voltage stacker.

transistors are likely matched pnp and npn, and are rated for 250 to 300v (5 transistors with 900v total power supply)

there are no power output transistors attached to the heatsinks

input transformers are used as the phase splitters

 

IF (more like when) it blows up, its impossible to repair.

 

What happened to TOGTE btw?

[kevin gilmore]

those transistors are all obsolete, would have to be re-designed with available parts

 

[sorenb]

3 minutes ago, kevin gilmore said:

those transistors are all obsolete, would have to be re-designed with available parts

anything you plan on doing?

[kevin gilmore]

unlikely.

I would never use a transformer to drive a voltage stacker like they are doing, something like 900v inside that transformer and i'm sure its not designed for that.

Edited November 24, 2016 by kevin gilmore

[sorenb]

2 minutes ago, kevin gilmore said:

unlikely.

I would never use a transformer to drive a voltage stacker like they are doing, something like 900v inside that transformer and i'm sure its not designed for that.

I was asking if you are planing on updating the TOGTE with available parts any time?