[krmathis]

Quote:

Originally Posted by terance /img/forum/go_quote.gif i feel a little shy coming to the stax thread since i only have the baby stax. . . but they are awesome

No need to be shy!
All Stax owners, and potential owners, are more than welcome to post in this threa. Regardless if they have an entry, vintage or top model...

The baby Stax (S-001mk2/SR-003) are great headphones, so you are not missing out on too much.

 

[terance]

Quote:

Originally Posted by krmathis /img/forum/go_quote.gif No need to be shy! All Stax owners, and potential owners, are more than welcome to post in this threa. Regardless if they have an entry, vintage or top model... The baby Stax (S-001mk2/SR-003) are great headphones, so you are not missing out on too much.

thanks, i REALLY enjoy em, it's a nice change from my e500's

i've already decided that I am not going to buy anymore headphones till I can afford the Omega II's (system) and a nice cd player

the dac will have to wait. . .

 

[ericj]

So, I'm gonna go out on a limb and suppose that the hum heard when using the bias transformer in an E.9 energizer (vs. self bias) is probably due to the bias transformer being 1cm from one of the audio transformers.

Since my E.9 is such a train wreck already, and the power cord is missing it's plug already, how's about i get one of those wall-wart enclosures from Jameco and externally enclose my bias transformer, get it a few feet from the audio stuff?

I have as big a problem with high-voltage power umbilicals as anybody, but in this case it would be a captive cord on both ends.

 

[spritzer]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif So, I'm gonna go out on a limb and suppose that the hum heard when using the bias transformer in an E.9 energizer (vs. self bias) is probably due to the bias transformer being 1cm from one of the audio transformers. Since my E.9 is such a train wreck already, and the power cord is missing it's plug already, how's about i get one of those wall-wart enclosures from Jameco and externally enclose my bias transformer, get it a few feet from the audio stuff? I have as big a problem with high-voltage power umbilicals as anybody, but in this case it would be a captive cord on both ends.

The hum is a well documented problem and it's because the diodes and caps in the bias supply are shot. Replacing them will fix it.

A normal 600v teflon wire is fine for the bias supply. If you want to be extra careful you can always put heatshrink around the wire or encase it in a teflon tube.

The ESP9 use the same plug as Stax but they aren't compatible. If you want to use them with a Stax amp you'll have to remove all of the circuits inside the cups and connect directly to the drivers. You can't have both unless you put a selector switch in each cup. They will no doubt sound better direct but I'm not sure what bias voltage they use but they are fine running off a Normal bias plug.

 

[ericj]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif The hum is a well documented problem and it's because the diodes and caps in the bias supply are shot. Replacing them will fix it.

Good to know. Those caps are of questionable quality anyway. Most of them, at least.

Is there any wisdom passed down through the ages regarding the voltage ratings? 1kv caps are no problem to source - i can get very nice MLCCs at 1kv - but some of them are rated for 2kv, and there is a 220pf 3kv cap in each earcup.

Surely 3kv is way over the actual voltage in the circuit, maybe they just wanted thicker dielectric for better frequency response? At 3kv, the replacements i can get from digikey or mouser look a heck of a lot like the original. At 1kv, I can get silver-mica caps. Surface mount, but large enough that they should be able to straddle the pads on the board.

Quote:

A normal 600v teflon wire is fine for the bias supply. If you want to be extra careful you can always put heatshrink around the wire or encase it in a teflon tube.

I was actually thinking about using the existing captive power cord. It's just the plug on the end that's gone missing.

I have about 14 pounds of misc teflon (PTFE) insulated silver plated stranded wire, mostly 22awg. A lot of it is shielded twisted pair, with a teflon outer jacket. This stuff is mil-spec (NASA surplus, I'm told), and highly abrasion resistant (read: stiff and waxy, not soft and cuddly).

I don't have the mil spec number for it, but it should probably be able to do the job. I would have to get a tighter strain relief for the E.9. It's bright white, but i have plenty of pleasing black-with-white-stripe braid sheathing.

Unfortunately the shielded twisted pair is a bit stiff for headphone cable use. The ESP9 stock cable is pretty short, and the extension cord that came with my kit is very stiff. I suppose i should investigate some of this 'star quad' stuff. Or i could just bundle 5 wires together inside some braid sheathing, but Koss seems to have used shielded 4-condutor.

 

[spritzer]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif Good to know. Those caps are of questionable quality anyway. Most of them, at least. Is there any wisdom passed down through the ages regarding the voltage ratings? 1kv caps are no problem to source - i can get very nice MLCCs at 1kv - but some of them are rated for 2kv, and there is a 220pf 3kv cap in each earcup. Surely 3kv is way over the actual voltage in the circuit, maybe they just wanted thicker dielectric for better frequency response? At 3kv, the replacements i can get from digikey or mouser look a heck of a lot like the original. At 1kv, I can get silver-mica caps. Surface mount, but large enough that they should be able to straddle the pads on the board.

Most of the E.9 is questionable but the parts quality wasn't all that great. All those jumper cables drove me nuts so I'm going to scrap the box and convert the phones to the Stax standard. If I ever figure out the correct bias voltage I'll make an adapter for that. Parts quality in the bias supply doesn't matter all that much as long as it can get the required charge. Nice caps can't hurt though but I think that the diodes hold the key. They have come a long way in 30 years and should be replaced with something better.

There shouldn't higher voltage inside the unit then 1kv but there are so many revisions of the E.9 I can't be sure.

Quote:

Originally Posted by ericj /img/forum/go_quote.gif I was actually thinking about using the existing captive power cord. It's just the plug on the end that's gone missing. I have about 14 pounds of misc teflon (PTFE) insulated silver plated stranded wire, mostly 22awg. A lot of it is shielded twisted pair, with a teflon outer jacket. This stuff is mil-spec (NASA surplus, I'm told), and highly abrasion resistant (read: stiff and waxy, not soft and cuddly). I don't have the mil spec number for it, but it should probably be able to do the job. I would have to get a tighter strain relief for the E.9. It's bright white, but i have plenty of pleasing black-with-white-stripe braid sheathing. Unfortunately the shielded twisted pair is a bit stiff for headphone cable use. The ESP9 stock cable is pretty short, and the extension cord that came with my kit is very stiff. I suppose i should investigate some of this 'star quad' stuff. Or i could just bundle 5 wires together inside some braid sheathing, but Koss seems to have used shielded 4-condutor.

The old mains cable should work. It could be a good idea to relocate the bias supply and if you ever figure out the correct voltage please let me know. The adapter has some other problems though, primarily it's over complicated design and endless jumper wires.

My ESP9 have a 5 conductor cable but it is very stiff and unwieldy like yours. I have replaced cables with 6 wire bundles of 28AWG teflon wovers wire I had here and it works great. It's not as good as the Stax ribbon cables but it does the job. The wire can be tiny because there is very little current flowing through them. Sennheiser user very fine (26-28AWG) in their stats' but Stax uses much thicker wires so they must thick thicker is better.

 

[humanflyz]

The fact that Justin (HeadAmp) lately have concentrated on developing limited edition amplifiers in small production numbers (12 for the Aristaeus, and 10 for the Blue Hawaii Special Edition), rather than developing amplifiers for the "masses".

I would love to see a great sounding/looking and feature rich electrostatic tube amplifier from HeadAmp, which would be produced in volumes higher than 12. That way we could wait for some initial listening impressions and pictures before we decide to buy one.
Just take the Aristaeus as an example. When the first listening impressions and pictures showed up it was already to late to buy one (all 12 were sold). I bet he could have sold more of them if they were available...
The same goes for the Blue Hawaii Special Edition. Nobody know what it will sound or look like, and when they do its most probably too late (all 10 might have been sold).

I can't be the only one who actually want to see pictures and read listening impressions of a $4.000 product before I buy one?[/QUOTE]

You do realize that HeadAmp is just a one-man operation right? And Justin is only 20-something years old, so it's kind of unrealistic to expect him to produce things in mass. And on top of the electrostat stuff he has to fulfill his more pedestrian orders like the Gilmore Lite, which probably sells way more.

 

[Veniogenesis]

Quote:

Originally Posted by humanflyz /img/forum/go_quote.gif You do realize that HeadAmp is just a one-man operation right? And Justin is only 20-something years old, so it's kind of unrealistic to expect him to produce things in mass. And on top of the electrostat stuff he has to fulfill his more pedestrian orders like the Gilmore Lite, which probably sells way more.

Indeed. And unlike some of the other amplifier vendors, he neither outsources nor possess large resources in terms of machinery. (Examples can be given for each of those two cases.) Justin, on the other hand, design/orders and build/assembles the amps instead (in a fashion closer to that of professional "d.i.y.").

 

[ericj]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif Most of the E.9 is questionable but the parts quality wasn't all that great. All those jumper cables drove me nuts so I'm going to scrap the box and convert the phones to the Stax standard. If I ever figure out the correct bias voltage I'll make an adapter for that.

Yeah, personally I'm gonna wait until i have 'stats that are worth plugging into a stax amp before i go hooking things up to stax amps. I've got all of $40 in these *after shipping.

Quote:

Parts quality in the bias supply doesn't matter all that much as long as it can get the required charge. Nice caps can't hurt though but I think that the diodes hold the key. They have come a long way in 30 years and should be replaced with something better.

I'm not talking about doing films all the way through, but the newer monolythic ceramic formulations are faster, lower leakage, etc. The cost difference between using run of the mill discs like are in there already and upscale MLCCs should be on the order of about $5.

Yeah, it's chock full of 1n4007's, and i do understand that even the 1n4007 has come a long way in 30 years. I have a bevy of BYV95C controlled-avalanche rectifiers but they have a max repetitive reverse voltage of 600v, may not be enough.

Maybe it'll be enough to use current production 1n4007's.


Quote:

There shouldn't higher voltage inside the unit then 1kv but there are so many revisions of the E.9 I can't be sure.

Thanks. I figured that was more or less the case.

Quote:

The old mains cable should work. It could be a good idea to relocate the bias supply and if you ever figure out the correct voltage please let me know. The adapter has some other problems though, primarily it's over complicated design and endless jumper wires.

I've been pondering the question of self-bias vs. external bias power, and i'm going to have to spend some time tracing out part of that circuit.

At the very least i need to figure out hot vs. neutral vs. earth on the existing cord. That reminds me, I need to stop by home depot on the way home and get a three-prong AC plug.


Quote:

My ESP9 have a 5 conductor cable but it is very stiff and unwieldy like yours. I have replaced cables with 6 wire bundles of 28AWG teflon wovers wire I had here and it works great. It's not as good as the Stax ribbon cables but it does the job. The wire can be tiny because there is very little current flowing through them. Sennheiser user very fine (26-28AWG) in their stats' but Stax uses much thicker wires so they must thick thicker is better.

Ah. Well, perhaps i will cannibalize my existing connector, clean it up with deoxit, and run five loose 22awg teflon insulated wires through a loose jacket. Sounds like it oughta do the job as long as i have appropriate strain relief on both end. This would be the cheap way to do it, I just have to pull stuff out of my own parts piles.

 

[krmathis]

Quote:

Originally Posted by humanflyz /img/forum/go_quote.gif You do realize that HeadAmp is just a one-man operation right? And Justin is only 20-something years old, so it's kind of unrealistic to expect him to produce things in mass. And on top of the electrostat stuff he has to fulfill his more pedestrian orders like the Gilmore Lite, which probably sells way more.

I am perfectly aware that HeadAmp is a one-man operation (Justin).
I also understand that $3-4.000 electrostatic amplifiers never will be any vendors best seller. Their lowest priced unit will most probably take that place. With "masses" I mean a bit more than 10/12 units, but certainly not mass-production in 100's of units.

But I just think it would be more time efficient to construct and fine tune one really good amplifier, then spend more time building that amplifier. Than to constantly construct new amplifiers (one after another), and spend less time building them...

Edit:
Guess I will never be happy with the higher-end electrostatic amplifiers.

They are either not balanced (HeadAmp Aristaeus), using a ugly off-the-shelf chassis (HeadAmp Blue Hawaii),or ugly (imo) and with potential quality issues (Singlepower ES-1).

The HeadAmp Blue Hawaii Special Edition sounds very promising though.
It just remains to be seen if its too late to order one when we know what it will sound and look like.

 

[humanflyz]

Quote:

Originally Posted by krmathis /img/forum/go_quote.gif I am perfectly aware that HeadAmp is a one-man operation (Justin). I also understand that $3-4.000 electrostatic amplifiers never will be any vendors best seller. Their lowest priced unit will most probably take that place. With "masses" I mean a bit more than 10/12 units, but certainly not mass-production in 100's of units. But I just think it would be more time efficient to construct and fine tune one really good amplifier, then spend more time building that amplifier. Than to constantly construct new amplifiers (one after another), and spend less time building them...

But you have to realize that the Aristaeus was never really planned as a commercial product: Justin only agreed to build it because there was a demand for a limited edition e-stat amp for those people who got in in the limited HE90 re-issue. I guess from Justin's point of view, there isn't enough demand for a mass-market (relatively speaking) e-stat amp to justify designing another one than the KGSS he currently offers.

 

[Veniogenesis]

Quote:

Originally Posted by humanflyz /img/forum/go_quote.gif But you have to realize that the Aristaeus was never really planned as a commercial product: Justin only agreed to build it because there was a demand for a limited edition e-stat amp for those people who got in in the limited HE90 re-issue. I guess from Justin's point of view, there isn't enough demand for a mass-market (relatively speaking) e-stat amp to justify designing another one than the KGSS he currently offers.

Right, it was more of a custom demand build. Blue Hawaii and KGSS are both Gilmore designs. My view is that Justin just builds them and then released a heavily maxed out version of each as limited runs (most probably based on custom demand as well).

 

[humanflyz]

Quote:

Originally Posted by Veniogenesis /img/forum/go_quote.gif Right, it was more of a custom demand build. Blue Hawaii and KGSS are both Gilmore designs. My viiew is that Justin just builds them and then released a heavily maxed out version of each as limited runs (most probably based on custom demand as well).

Yup, Justin doesn't release limited edition amps for the sake of releasing limited edition products; he does it because there is enough demand to make it worth his while. For example, a while back Akwok and I were trying to persuade Justin to custom build us a FirstWatt F1 for the K1000s, but we couldn't get enough people to make this possible.

 

[patrickamory]

Quote:

Originally Posted by krmathis /img/forum/go_quote.gif Guess I will never be happy with the higher-end electrostatic amplifiers. They are either not balanced (HeadAmp Aristaeus), using a ugly off-the-shelf chassis (HeadAmp Blue Hawaii),or ugly (imo) and with potential quality issues (Singlepower ES-1).

I agree the Blue Hawaii and the KGSS aren't very nice looking. But the bigger turnoff for me is dual-mono volume controls. I can't stand that!

Patrick

 

[milkpowder]

I quite like the looks! It's a no-frills, elegant design that looks like they mean business. I've never used one but I expect dual mono volume controls to be a pain in the butt to use. I'm sure you could ask Justin to use a single stereo stepped attenuator instead of the dual-mono... Are there any benefits for using a dual-mono volume control setup?