The Stax thread (New) - Page 34

Here's something that you don't see very often:
Stax CA-X Preamp

Are they still worth that much these days? o_o

I paid US$76 for a SRD-7 MK2 back in November, really the price rises seem to have occurred sometime this year from what I've seen.

I had some luck adding stages to the voltage multiplier with a little extension PCB attached to the top of the main one. At first I had a single stage on there to prove the concept and it worked as expected. Unfortunately when I tried to go for pro bias I had a small mistake in the circuit and fried the zener diode but I believe the concept is sound. One of these days I'll pick up some spares to fix it and give it another try if no one else beats me to it.

He wouldn't tell me either when I was visiting the other day. I wonder if perhaps he's waiting for the SR-404 to arrive so he can compare. I should chase up PriceJapan, I've not heard anything from them yet.

True!
And in this case the seller made it pretty clear that he have not tested the unit, so there are a risk that it is not working properly.

There's even a Dac X-1T on audiogon for sale and its HERE in Singapore!! But price is.... at least for me.

Late last year, into this year, seems to me. I was following those prices, wondering if I should buy an old Stax as well as a new one, just in case there is sonic or electronic difference I should account for in the design of my amp. At the beginning of the period a mid-nineties tube amp and accompanying top (equivalent to current 404) earspeaker had been sitting unsold for months for STG395, about USD600. The minute I was informed enough to know this is a bargain, I discovered someone pipped my by minutes -- after months in which the seller told me he didn't get any offers. Right after that someone else in Britain turned down an offer of EUR1000 for a 4040 set; this guy was so ****y that he said he wasn't posting, I could fly to London to pick up the kit. That was when I decided PriceJapan is my friend.

Especially significant over this period was the rise in SRD-X prices, the first linestage-capable. amplifier-independent and even semi-portable model energizer

But the really interesting thing is why all these people should so suddenly become interested in Stax. Since every wannabe trendsetter owns an i-Pod (I don't, of course), I wonder if the upsurge in interest implies that most of them heard first of the in-ear Staxes and then discovered the classic over-ear models. The sudden interest in the SRD-X, a portable driver for fullsize Stax, would thereby be explained.

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
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So even this venerable unit is having a comeback.

Low bias Sigmas sounding better than O2's?

I can't say, but I like all the Sigmas, the low bias, pro and the Sigma/404 (a Sigma pro with 404 components). They each have a distinctive spund signature and I guess I just like getting the drivers forward and away from my ears.

I have been running low bias Sigmas off them for years, and quite enjoying them. Well actually one channel of the amp, was going bad so I didn't get much use of the amp for a few years, however, the preamp has remained the center of my speaker-based system.

Rather than repair the headphone amp, I finally located another defective 12S and cannibalized one amp card to get the original going again.

As is noted, this thing runs hot enough to cook a meal on. I partly solved this problem by connecting the interior power line (I believe it is a 700 volts) to a separate switch so that the headphone amp can be turned off when the unit is just being used as a pre-amp.

At this rate I should fix the other unit and just use it to drive low bias phones. I suspect there is just a transistor gone on each channel. Makes me wonder about converting one of the sockets to high bias.

Edit: Part of the appeal of your Sigma may be the low bias sound per se. When I compare the low bias Sigma with the Sigma pro, the low bias phone seems a bit less harsh and it definitely has more ambience. I am familiar with the later effect through having used a dBx compander. When the compander is set to expand the dynamics of a signal, you get more oomph, but the sound becomes drier and there is less ambience, because the dB's of the low level sound are reduced.

Going to high bias seems to act like a compander. I don't think that you actually lose the ambience but because the peaks are louder you have to turn the volume down a bit, thereby reducing the low level sounds and making the overall sound seem less ambient for a phone which is otherwise identical.

I would like to convert mine to have one high-bias jack also. I have been looking at the schematic for the SRD-7 pro. I would like to have the schematic for the SRD-7 mkII because it has both high and low bias outputs.

AudioD

The new production Mullard EL34's are not worth the price of a cup of coffee.

"Servicing is irrelevant on a unit of this caliber."

Bzzzzt! I don't think so. Caps are caps, and they go bad. Don't buy anything from this guy.

Patrick

I just took my Koss 950 apart and the stators appear to be some sort of plastic. Interesting that Koss was doing this before Stax.

Well Quad did it before everybody else in 1956 so...

OTOH I'm not all that surprised, like Carl said, Koss had great ideas but they were badly executed. The ESP6 is a great great idea and the driver are great but they are too big, bulky and heavy. The same goes for the ESP9. They are too complicated for their own good.

It seems PriceJapan were ignoring me because they thought I was from Russia(?!?) but that's now sorted and the SR-404s are shipping tomorrow I'm told.