spritzer

The website is very outdated so I'm sure they are using the better ECC99 tube, though I'm not quite sure

They aren't worth that much but the Stax hype knows no bounds. It was also in terrible condition. An Alpha Excellent would be worth that much but only to us crazy collectors.

First off, the SRD-7 isn't a Mk2, just a normal 70's type SRD-7. SB is in no way inferior to the AC biased designs and they could even sound better with no crappy AC inside the unit. They are the same more or less except there is a small transformer that borrows a bit of AC of the Right+ line. The Mk2's are highly sought after and can go for way more then 200$. That's certainly what I just sold one of mine for but it is NOS.

The APL sure looks nice For those that don't know, everything after comes off the drive is upsampled to 211kHz/32bit and fed to the stacked dacs. The output stage is transformer coupled so the signal only sees a single transformer and the ECC99 tube. There is no muting circuit or anything else to damage the sound quality. Nice to know I'm not alone here...

I'm not crazy, I'm just special! The adapters normally present a fairly benign 8ohm load and while they do require a bit of current it's voltage they need and they get that from the first watt or two. You can continue to push them but I've seen way too many burned up diaphragms in my time to ever do it myself. I fully agree about the passives and while a top level system should be active there are simply too many compromises at lower price levels to consider going active unless you are dealing with impedance issues or long cable runs. TVC's are a clever way of controlling the volume as you gain some current as you lower the voltage but there is a whole lot of wire in the signal path.

There are indeed multiple gain stages but the gain in a preamp is pretty low but even some CDP's aren't operating at 2v and many output 6v differential.

That is my understanding though I have never owned a Gamma Pro... I've also made my own pro driver by converting a normal Mk3 driver with some 0.3mm copper. Worked like a charm but was way too much work and the Pro drivers used 1.5um diaphragms compared to the Mk3's 2um.

Carl had another set but I wasn't prepared to pay his kings ransom for them... One will show up and it will be mine. >

Ok, I'd buy four just so Larry couldn't get his hands on them. I did the world a favor when I rescued the second to last remaining set of NOS SR-Omega earpads from his butcher hands...

I'd buy one.

Almost any amp can give the voltage necessary but dynamic drivers need plenty of current for all those nasty curves on the impedance graph. The voltage is about 30v or less so that times 25 (1:25) is the voltage swing on the stators. The adapters are fitted with resistors to dissipate all extra current as heat should the volume level be too extreme. A 350w amp will eventually melt the K1000 but not at low volume level. The amp might only be delivering about 1w at said volume level so it won't hurt the phones. As you know a basic volume control is a variable resistor that drops the voltage of the input signal from the standard 2v. The amp has a gain level that is the multiplier of the input voltage. The current draw depends mostly on impedance and where speakers are said to have a nominal impedance of 8ohm they vary quite a bit and can be quite a bit higher and lower. Electrostatics are terribly bad at this, requiring large amounts of current in the bass and treble.

The cost of a 845 based amp would be horrific and it would dwarf any headphone amp ever made. The amp it self is relatively easy to design and build but the power supply is a huge headache. A simpler amp could be built but I just don't get the point of a compromised design around a world class tube. A 572-10 might be a better tube choice but they aren't produced any more.

Mine are so far from stock as I used them to test different diaphragms but they do sound ok for what they are but I would never pay more then what a SR-5 is going for these days.

Do I have to come over to your houses and beat you over the head??? .... A 350w amp only gives out that much into 8ohm at full output. It gives out much less with a lower input level i.e. at a lower volume. Most amps are running at about 1-10w most of the time. The extra power is more in the form of extra current with the voltage being so low and the SRD-7 needs voltage and a bit of current.

The 6s4 is a good choice especially since I have a nice stash of them. That is one toasty amp. I was considering a 845 driving a 845 in a Stax amp so that would be 8*35w just for the heaters... There is a design already out there in the second edition of Morgan Jones's book. It was conceived for loudspeakers but will push the SR-007 really nicely but he says in the book that it is the scariest amp he's ever built and none of his measuring equipment worked with it. 1200v can do that. I'd like something simpler like a push-pull SET and use a push-pull choke instead on the output transformer like Jones did. An amp like this should also work just fine on the Quad ESL.

It can only take about 10w before the internal resistors self destruct. The older phones with unprotected stators and maximum voltage of 400v will be goners but the new ones should be able to handle it. The Senns would have gone up in smoke a while back.

300$ is a bit on the high side... Maybe I should sell mine... Micro Seiki made their own phones and even made an OEM version for Infinity. They are pretty different from almost any other phone I've seen but they can be a bitch to get working again as they all need new diaphragms.

The HE90 is almost a third heavier but they are also quite a bit bigger. The main problem with them is that they won't have enough range on the headband so I can't make it big enough while the He60 fits like a glove. Can it withstand 350w of power...no but it can be used with any amplifier though the extra power will only sound worse.

It mostly boils down to the fact that the HE60 doesn't annoy me as much as the He90. Less diffused and with better bass and a believable soundstage. The HE90 is smoother and more rounded but I'd still go for the HE60 every time as they fit my head better.

What output tubes are you designing it for? The BH is pretty complicated but it is good as a space heater when it gets cold up here in Iceland...

Transformers= more dynamic sound Amps= more detail It's not really that cut and dry but that would be a good baseline

Depend really on what you are looking for as it is a toss up between the extra dynamic sound or the intimacy and detail retrieval of an OTL amp. I prefer the amps but you could get a used T1 cheap so that might be the better choice.

Lets all just forget out that. There were different speakers in the pilot. I was pretty angry when the second episode was show and thery had swapped out the speakers for something small. Btw. This weeks episode was simply brilliant.

That's part of the cable assembly and the only description I've ever hear is that the contact pins are crimped onto the cable. There could be some solder underneath as that's how Stax normally prepares the cables.

He has Duvelle omnis in the apartment and Thor Audio electronics though they were stolen in one episode. You should really find the original pilot as the speakers in the office were different, Audiostatic electrostatic speakers. Really tall but slim speakers.