eXStata DIY Electrostatic Amp for Intermediate DIYers
Sep 30, 2009 at 7:33 PM Post #61 of 2,969

sachu

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Quote:

Originally Posted by runeight /img/forum/go_quote.gif
One of the prototypers used 4k7 instead of 470 in two locations in the PS. And though the PS couldn't come to full voltage nothing blew up. Using the correct values fixed the problem with no other issues.


hmm wonder who that was?
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Sep 30, 2009 at 7:36 PM Post #62 of 2,969

Coreyk78

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Very interested in this amp, happy to see that its almost ready, although my wallet won't be as happy
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This will probably be put in line after I finish my Aleph-J and Millet "Engineer's Amp" speaker amps and my Buffalo DAC.

If I read Pabbi1's post correctly electret stax are compatible with this amp? Would be good news, I could use my SR-30 for testing purposes then to make sure I have a working amp before I invest in some electrostatics.
 
Sep 30, 2009 at 7:59 PM Post #63 of 2,969

ericj

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That is correct.

We suspect that Sony electrets may not be compatible due to their crazy-wide stator spacing needing crazy-high gain. But i haven't actually tried it.

But the SR-40, SR-30 (which is SR-60 in europe), and SR-80 are all compatible with this amp, as are the Audio-Technica electrets (provided they aren't one of the weird models with a TRS plug - but those can be converted to a 5 pin plug no problem)
 
Sep 30, 2009 at 9:36 PM Post #65 of 2,969

00940

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To the designers: I'd need an amp with a voltage swing of 250Vp-p, gain of 80 or so and running from a single 300V supply. Frequencies of interest are 1Khz and above.

Could the ss version be modified for those requirements ? I guess input and output caps will be in order at least.
 
Oct 1, 2009 at 12:03 AM Post #67 of 2,969

pabbi1

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I have to also say this amp really isn't 'low end' at all - how far into the upper tier is yet to be determined, but I have been startled by some of the detail, layering, air and speed. Oh, and PRaT - it just makes listening fun - again.

Marc, we can always put mine on your scope...
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Oh, yeah, and about those jacks... the elves might need to get busy, as I see a wee bit of demand. This amp IS worth it.

Let me further say the amp is NOT the weak point in my chain with the Azur 840c and the he60. It is remarkably up to the task with both of those components.

Now, we just need comparisons, and honest, unbiased observations from outside the team, which will be coming shortly.
 
Oct 1, 2009 at 12:12 AM Post #68 of 2,969

Emooze

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I notice people keep asking for input and output waveforms and it seems very few have the equipment to do so. Do you just need a function generator and scope? My school labs have them and I know they have no qualms about me using them for personal projects. I'd be more than happy to help out once I build an amp.
 
Oct 1, 2009 at 12:30 AM Post #69 of 2,969

mypasswordis

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Hats off to runeight for designing the eXStata SS and hybrid amps, and the prototypers for... prototyping. I eagerly await more impressions on the SS versions and of course the inclusion of the hybrid version soon. Cheers.
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Oct 1, 2009 at 1:08 AM Post #70 of 2,969

wolf18t

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Count me in the seriously interested builders crowd. My only problem is that I don't have any stats. Very handy for the final QC test.
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But that shouldn't be a problem for very long.
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One thing I would need before getting into the project is find info of what are the bias standard and what are the connectors needed/available for what phones. I'm a total stats newbe.

As for the high voltage, I agree this is something to take seriously. You always have to take your time and think twice of what you're doing while working around this voltage. Like manipulating the DMM probes with the circuit offline and caps discharged. That reminds me the old days I was repairing computer tube monitors, working around the flyback and the horizontal amplifier...
 
Oct 1, 2009 at 2:06 AM Post #71 of 2,969

ericj

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Quote:

Originally Posted by wolf18t /img/forum/go_quote.gif
One thing I would need before getting into the project is find info of what are the bias standard and what are the connectors needed/available for what phones. I'm a total stats newbe.


That's all pretty academic stuff. Stax are generally 230v for old stuff and 580v for new stuff. The koss esp/950 (which is about the best deal going for an electrostatic headphone) is 600v.

Staxen use a 6-pin or 5-pin socket available either from Cooper/WPI through Allied Electronics or from various boutique fabricators. The Koss have a unique connector available only from Koss either by gutting the included amp or by chopping the end off a $16 extension cord.
 
Oct 1, 2009 at 5:05 AM Post #73 of 2,969

sergery

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Wow, all of the sudden from quiet to loud in the now exStatA camp! Thanks proto team!
 
Oct 1, 2009 at 5:14 AM Post #74 of 2,969

wiatrob

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Quote:

Originally Posted by pabbi1 /img/forum/go_quote.gif
I have to also say this amp really isn't 'low end' at all - how far into the upper tier is yet to be determined, but I have been startled by some of the detail, layering, air and speed. Oh, and PRaT - it just makes listening fun - again.


I've been building up the first tube board and listening critically to the sand amp for about three hours straight.

The detail and separation of this amp are outstanding. In fact, If I didn't have a soldering Iron in my hand, I'd be dancing around the workshop.

This amp is just plain fun! I would agree with Al it performs well above the demands of the initial requirements.

No bass demands this evening - but FLAC'd Infected Mushroom last week was pounding on both the Lambdas and Lambda Sigs.

I have a scope here (guess I could use my PC as a function generator). I say let YOUR ears be the judge!
 

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