The Headcase Stax thread

[Smeggy]

Ouch!

Well, either Stax had a really great design back then or people are just fooling themselves again. I have no idea which it would be.

Oh, and we're still waiting for this Stax portable you've been hinting at..

[spritzer]

Ahhh so designing is now taking an amp that has elevated every ESP headphone I've connected to it to new heights and "fixing it" so a crap (for the price anyway) headphone sounds good. I can see that the old Quad motto of "the closest approach" is long lost on you or you would see just how much crap that is. The He90 is so good that the best amp design available can't drive it and make it sound good can't be an indication that the headphone just isn't as good as you think it is? The fact that the Stereophile reviews (back when they weren't the crap they are today) rank the He90 as good but the SR-? as the standard against which all are measured and that is with a SRM-T1S as a driver. So I tried the He90 with about 20 different drivers and that includes the 1969 SRA-3S (contemporary to the no.2 Stax design the ES-1 is...ahem... based upon) where it sounded ok but it simply can't touch the Omegas in anything we'd call high end quality. The bass can seem deeper and the treble smoother but that is simply the amp fucking up the signal so the phones appear to be better.

[spritzer]

Here is the design for those interested minus the PSU. I have the original from Stax in an instructions manual for the SR-3 in Japanese and there is has a simple RC PSU with no regulation and dual secondaries.

The Stax portable is stranded due to the commitment to the miniature transformers needed. They need to be bought in bulk and that simply isn't feasible unless someone just takes a hit and buys them or their price is added to the first amps bought.

[luvdunhill]

With appologies to Mikahil...

is it true when Mikhail was thinking about releasing an electrostatic amplifier that he contacted you for advise? This might just be urban legend... but seems like this is a reasonable place to clarify this.

[philodox]

You are not an idiot, and i believe you know how to use a calculator.

f = 1 / (2 * pi * r * c) (3db point)

So for 300 ohm headphones

f = about 11hz with 50uf

want the same thing with 32 ohms headphones, guess how much

About 10 times as much I would expect, 470uF should do it. I still don't think my RS-1's sound terrible on my amp though.

[kevin gilmore]

is it true when Mikhail was thinking about releasing an electrostatic amplifier that he contacted you for advise? This might just be urban legend... but seems like this is a reasonable place to clarify this.

Mikhail and i have talked about a great number of things over a significant period of time, at

least 5 years. Certainly have discussed the all tube dc coupled thing and why he should not

have put the thing into production. I'm sure there was some discussion of the BH in there but

never in relation to anyone wanting a special amplifier to drive he90's. As far as the ES1 mikhail

needs to figure out who he is talking to and when. This is the problem when you throw marketing

BS at someone like hirsch who knows absolutely nothing about what is being discussed, and makes

comments based on that. Same thing with Earl. I don't know why mikhail has to hide behind

all this mystique bullshit.

For example the "EXTREME has no interstage coupling capacitors" thing. Which is true, but then

compared to other amplifiers who also have no interstage coupling capacitors. And the

ES1 which has no output capacitors but does in fact have interstage coupling capacitors.

Or my favorite, "i put 4 capacitors in parallel in a proprietary technique" Or the

"its patent pending"...

I'm not saying ray or peter are any better. In fact peter is probably the biggest liar of the

whole bunch.

I believe the miniature power supply for the portable is solved. I posted about it over at that

"OTHER" site. The supplies are made by bear. http://www.bearpwr.com/products_DC.shtml

I'm messing with a way to do the bias that does not eat up an extra .1 watt. Still the best

idea would be to have someone wind me some custom transformers to my specs.

[kevin gilmore]

The stax SRX circuit is all tubes.

The stax SRA-3S circuit is a solid state/tube hybrid. It was the first fully

dc coupled amp that stax made.

One is not an outgrowth of the other, they are just plain different.

There is also very little that is the same between the SRA3S and the SRM-T1

on which all the current amps are based.

[spritzer]

I'm not saying ray or peter are any better. In fact peter is probably the biggest liar of the

whole bunch.

I'm eagerly awaiting what crap Ray will come up with for his "reference" ESP amp. Milspec this and that...

I believe the miniature power supply for the portable is solved. I posted about it over at that

"OTHER" site. The supplies are made by bear. http://www.bearpwr.com/products_DC.shtml

I'm messing with a way to do the bias that does not eat up an extra .1 watt. Still the best

idea would be to have someone wind me some custom transformers to my specs.

Good to that there is a solution to that particular problem. There is a large minimum order on the custom units though so that would make a small production run harder, right?

The stax SRX circuit is all tubes.

The stax SRA-3S circuit is a solid state/tube hybrid. It was the first fully

dc coupled amp that stax made.

One is not an outgrowth of the other, they are just plain different.

There is also very little that is the same between the SRA3S and the SRM-T1

on which all the current amps are based.

The SRA-3S is fully DC-coupled but it uses output caps and it is a great little amp, with the emphasis on little as it is tiny!

The SR-X was never put into production so that is clear but it was presented as a design for DIY use and it is all tubes but comes from the same era as the SRA-3S or the old Stax sound.

[kevin gilmore]

I'm eagerly awaiting what crap Ray will come up with for his "reference" ESP amp. Milspec this and that...

I'm not sure that even ray has decided which schematic to steal. But the one on the tubecad

site that uses 5687's seems to be perfect. Take a B52, make a different circuit board, and

change the output jack mounting plate, and leave everything else the same. Major changes

to the power supply section. Bang Zoom and a ray samuels electrostatic amp. Gotta be $6500

or more.

A better question is which schematic he is going to steal for the solid state version.

[kevin gilmore]

Will scan sra3s schematic later today unless someone else wants to

do it.

[spritzer]

I'm not sure that even ray has decided which schematic to steal. But the one on the tubecad

site that uses 5687's seems to be perfect. Take a B52, make a different circuit board, and

change the output jack mounting plate, and leave everything else the same. Major changes

to the power supply section. Bang Zoom and a ray samuels electrostatic amp. Gotta be $6500

or more.

A better question is which schematic he is going to steal for the solid state version.

The tube Cad would be perfect for him and there is also that National circuit that can be used with both tubes and transistors for output duty. Two amps for the price of one...

Here is the National PDF with the electrostatic amp at the back.

Will scan sra3s schematic later today unless someone else wants to

do it.

I don't have a scanner but I can take a picture of it and the two other Stax schematics. I also have the SRA-12S here somewhere and the Jones designs. We might as well make it easy for Ray to steal some good designs...

[kevin gilmore]

I don't have a scanner but I can take a picture of it and the two other Stax schematics. I also have the SRA-12S here somewhere and the Jones designs. We might as well make it easy for Ray to steal some good designs...

Yes lets post as many schematics for ray as possible. I've never seen the jones designs

(well at least not by that name)

That national design has some significant bugs in it...

[spritzer]

The National design is a bit of a joke so it should be perfect for Ray.

The schematics are uploading now and I've included both the 845 "Beast" design and the lesser "Daughter of the Beast" with a 6BX7 pulling output duty. I'll post them as soon as they are done uploading.

[spritzer]

Here they are. First up is the Stax "A" design from the SR-3 instructions manual:

Next is the SRX schematic from the same manual with the PSU:

Here is the SRA-3S design:

I think this is the SRA-12S or the 10S:

This the rather smaller "Daughter of the Beast":

Last but not least the whole 845 equipped "Beast". The schematic is so massive that the printing is a bit too coarse to fit it on the small page so the pictures are equally bad. If there is anything missing just ask me:

Enjoy!!

[luvdunhill]

[The Monkey]

Thanks for answering my questions a few pages back, all. So it sounds like the Lambdas are a good starting point. What about the 303 and 404?

[Smeggy]

Thanks for answering my questions a few pages back, all. So it sounds like the Lambdas are a good starting point. What about the 303 and 404?

Most seem happy with them. I prefer my SR-Lambda to the 404 I had but that's not necessarily a universal opinion, just my personal preference. As to 303 or 404, I'd go 303 because it's the same phone with a different cable which doesn't really make any noticeable difference but costs a lot more.

[Dusty Chalk]

Yeah, I didn't notice a huge difference between the 303 and the 404.

[kpeezy]

Normal bias Lambdas on audiogon for $190. And he's selling the Gamma Pros mentioned in the ad for $325.

[The Monkey]

Yeah, I didn't notice a huge difference between the 303 and the 404.

How do you like them overall?

[deepak]

Just curious if I was looking to move away from a bias box/power amp, would the first Gilmore designed all tube amp be a good match with the SR-Lambda? I decided that I don't really want two bias supplies in the Blue Hawaii, especially if I'd never be using the Lambdas in that setup.

Instead using the Lambdas in an alternative setup (office, bedroom?)

[catscratch]

Thanks for answering my questions a few pages back, all. So it sounds like the Lambdas are a good starting point. What about the 303 and 404?

Seeing how you have a balanced HD650... I think the SR-404 would be a definite step down. Yes, it's better in some respects just by virtue of being an electrostat (faster impulse response, better resolution in the bass) but at least in my rig, the HD650 kills it. Fuller, richer, more natural tone, much more impact and dynamic range, very focused and holographic imaging (the SR-404 tends to be a bit diffuse), and a very nice midrange, which is IMO the SR-404's biggest fault. I'd be willing to forgive the SR-404 nearly all of its faults if it didn't have an enormous spike in the upper mids that completely ruins its tone (everything sounds brittle and electric), but in the end, the mids are what killed it for me. Every headphone I've ever really liked - balanced HD650, K340, ES2, and on audition HE90, has shared one trait - a somewhat forward and generally excellent midrange. I liked the SR-001/003 too specifically because of the mids, though lately I've cooled somewhat on them, so to speak.

I really don't know what the sweet spot in Stax is since there are so many problems with the current generation of Stax products (O2 excluded, which I have yet to experiment with). The SR-001/003 are great for the money but not that great overall, with some serious comfort issues. The 303/404 have great drivers but the housing was obsolete 20 years ago, and they share a midrange coloration that is very much not enjoyable.

I also really miss the planar sound, but I don't see any cheap way of getting seriously good planar sound at all when it comes to what's currently available. No comments on anything vintage since I've got no experience with it.

Maybe the Koss? Maybe the SR-202? It's the only new Stax, other than the O2, that I've never heard.

[Smeggy]

I was quite surprised with the old SR-Lambda. I sounds more natural overall, not as etched or as shrill as the 404 and can be driven nicely through a SRD-6SB. I sold the 404 but I'm keeping the Lambda. The fact that they're low bias does nothing to harm the sound whatsoever.

If you go for the Agon SR-Lambda I'll throw you an SRD-6 SB, as long as you have a power amp of some description it'll be a great Stax entrance.

[Dusty Chalk]

How do you like them overall?

Correction: I have the 202's (I got the SRS-3010 system) -- I actually like them quite a bit, they've got most of the performance of the 404's, but are just a little bit more harsh/less "smoov". Thrice can tell you more, he's borrowed them for an extended audition, and he's more familiar with the whole line than I am.

[spritzer]

Just curious if I was looking to move away from a bias box/power amp, would the first Gilmore designed all tube amp be a good match with the SR-Lambda? I decided that I don't really want two bias supplies in the Blue Hawaii, especially if I'd never be using the Lambdas in that setup.

Instead using the Lambdas in an alternative setup (office, bedroom?)

So you are going to skip a 10$ bias supply and go for a 1k$ amp instead?? I like it!!! It should be a fine match but the SR-Lambda loves the extra power the BH can give them though the GES should be quite nice with some MKP coupling caps.