New RSA amp...

[kevin gilmore]

Lets take a standard tube based differential amplifier with a gain of 10 or more.

If you input a SE signal, and the other side is ground, the output is balanced.

The exact level differences are probably no more than 1db. Do the same thing

with a balanced input. The level differences are (or should be) very close to zero.

So what you have is an unbalanced to balanced converter, and a balanced to balanced

buffer all in one tube. Pretty sure this is what ray is doing. The fact that it took him

years to really understand this is not a surprise as mikhail is yet to figure it out.

John Curl is one of the very few that have been doing it correctly for 20 or more years.

Transformers of course make it easy, but no one wants those.

And i agree with justin that there are lots of products out there that take unbalanced

inputs and output balanced. Or take a balanced input that is seriously unbalanced and

turn it into a balanced output. Krell, levinson...Even cheap stuff like outlawaudio.

People forget that the reason balanced exists in the first place is to get rid of the

ground loops. Absolutely necessary for professional audio and cables 100's of feet long.

I would think that most people with half a brain consider ALO a horrible joke, and

its not worth the trouble to bash the hell out of them.

Edited April 2, 2009 by kevin gilmore

[penger]

Ray just posted the 5687 tubes are configured in a SRPP topology.

[justin]

An issue with using a SRPP output stage with an electrostatic amp is that SRPP amps are designed to drive a static impedance, which is why you usually see them as INPUT stages on amplifiers where the next stage will always have the same load, such as the next tube's grid resistor.

An electrostatic headphone is a capacitive load, so you have to do some tricks to properly do SRPP with it (see here: The Tube CAD Journal,SRPP Optimal Rak Value 2)

What this means, if you do not do this properly, is you could have a frequency response that varies greatly depending on the capacitance of the headphone, maybe a bell curve shape. Even setting the "Rak value" for a certain capacitance may not be enough if the capacitance varies widely between the different makes of e-stat headphones. When I looked into this concept I thought of adding a switch to set it for different capacitance headphones, but why bother, just use a resistive plate load on the tube or if you want more gain wire the top tube as a current source

Edited April 2, 2009 by justin

[bhd812]

ohh i see, thanks Justin and KG but i am trained to think balanced from the live shows and pro audio background..

in my mind only one way of balanced is true (or pure like Justin Says)..non of this Magical unicorns or sparkling genies exist!

[Beefy]

Ray just posted the 5687 tubes are configured in a SRPP topology.

It seems to me that perhaps he is watching this thread, trying to head off any criticism that Head Case comes up with......?

*

HEH! Milspec solder

[penger]

HEH! Milspec solder

I wonder what's in it.

[Voltron]

BHSE + GS-X in one box!

[krmathis]A box the size of a Pico![/krmathis]

[Beefy]

I wonder what's in it.

I know...... depleted Uranium solder.

[GPH]

It's pretty funny that this thread has 5x more posts than the official thread on Head-fi, especially considering that neither the price nor any internal pics has surfaced. I'm still enjoying the show though.

[justin]

I know...... depleted Uranium solder.

KG has some of that, and then he thought i stole it from him

[justin]

It's pretty funny that this thread has 5x more posts than the official thread on Head-fi, especially considering that neither the price nor any internal pics has surfaced. I'm still enjoying the show though.

That's because when someone becomes part of Team Electrostats, their days on head-fi are numbered or they've already left. I believe that the biggest impact Ray's amp will have is showing electrostats to new people who just follow the popular trends, now that the issues with their weak bass have been resolved. It won't be long until someone says "My headphone doesn't fit in this big round thing with 5 holes in it!"

[Hopstretch]

Resolved how?

[HeadphoneAddict]

Resolved how?

Moar power.

[GPH]

Resolved how?

The A-10 will make stats go to 11.

[hirsch]

Let's see, we're up to 14 pages bashing an amp that nobody posting (with the possible exception of Billy) has ever seen in person, much less heard. I forget what site I'm on. I thought my sig was making fun of a different site.

[postjack]

making predictions based on past experiences with a manufacturer is perfectly valid. if the A10 rocks headcasers will be the first ones to admit it.

[mypasswordis]

That's because when someone becomes part of Team Electrostats, their days on head-fi are numbered or they've already left. I believe that the biggest impact Ray's amp will have is showing electrostats to new people who just follow the popular trends, now that the issues with their weak bass have been resolved. It won't be long until someone says "My headphone doesn't fit in this big round thing with 5 holes in it!"

I'm not sure too many sheeple will follow this since the price of the A-10 is just going to be through the roof. If only electrostat owners weren't also people who want every last bit of sound quality they can eek out (oh wait, that's why they own them in the first place) then we could have more stuff like the poor man's electrostat amp that can be built for less than $300. Not to say that we shouldn't have ultimate statement pieces like your BHSE and sort of the A10 in terms of price, but statement pieces aren't the best way to get the common audiophile to switch to 'stats.

[Beefy]

Let's see, we're up to 14 pages bashing an amp that nobody posting (with the possible exception of Billy) has ever seen in person, much less heard. I forget what site I'm on. I thought my sig was making fun of a different site.

Half the fun of Head-Case is being allowed to talk shit about stuff you've never heard, based on aesthetics, design or reputation alone. A million times better than the circle jerks and reach arounds over stuff you've never heard like at Head-Fi.

Skepticism is a healthy thing. It means you can often be pleasantly surprised.

[mirumu]

Let's see, we're up to 14 pages bashing an amp that nobody posting (with the possible exception of Billy) has ever seen in person, much less heard. I forget what site I'm on. I thought my sig was making fun of a different site.

I think the bashing and support of Ray here has been reasonably balanced. The A-10 will succeed or fail on it's own merit at the end of the day. That doesn't make any concerns about the design and topology any less valid. If his past products have been less than ideal then it's not surprising new ones are viewed with a more cautious eye. Especially when the design is a bit unusual for the application at hand. Goodwill is a perishable commodity.

[GPH]

I'm not sure too many sheeple will follow this since the price of the A-10 is just going to be through the roof. If only electrostat owners weren't also people who want every last bit of sound quality they can eek out (oh wait, that's why they own them in the first place) then we could have more stuff like the poor man's electrostat amp that can be built for less than $300. Not to say that we shouldn't have ultimate statement pieces like your BHSE and sort of the A10 in terms of price, but statement pieces aren't the best way to get the common audiophile to switch to 'stats.

The major "problem" with stats is that you can't just plug them into an iPod. Simple and stupid argument maybe, but they will never become popular for that reason alone. Also when you compare the quality of posts on head-fi before and after the iPod boom, the difference is huge. I have nothing against folks who just want good headphones to go with their mp3 player, but these guys are not "audiophiles" in the true sense of the word and their standards are usually lower than most people who post here.

[Beefy]

The major "problem" with stats is that you can't just plug them into an iPod. Simple and stupid argument maybe, but they will never become popular for that reason alone.

It is not stupid, it is absolutely right. Even compared to having one really good dynamic amp and a whole heap of dynamic headphones, taking that extra step to do electrostatics 'right' is significant.

I have nothing against folks who just want good headphones to go with their mp3 player, but these guys are not "audiophiles" in the true sense of the word and their standards are usually lower than most people who post here.

On the flipside of that, just plugging some ESW9 straight into an iPod sounds pretty bloody amazing.

[mypasswordis]

I'm probably way in the minority but I got most of my 'stats for less than the cost of a new ESW9, a lot of them for much less, and would prefer not to shell out more than the 300 or so it would cost to build runeight's poor man's 'stat amp.

I actually don't think many people are plugging their HD650s and K701s into their iPods, even on Head-Fi, and there's still a slight barrier to be had with dynamic headphones with the 1/4" to 1/8" converter, not being able to be used portably due to size and sound leakage, long cable, etc., not to mention poor sound from being driven insufficiently.

[HeadphoneAddict]

The major "problem" with stats is that you can't just plug them into an iPod. Simple and stupid argument maybe, but they will never become popular for that reason alone. Also when you compare the quality of posts on head-fi before and after the iPod boom, the difference is huge. I have nothing against folks who just want good headphones to go with their mp3 player, but these guys are not "audiophiles" in the true sense of the word and their standards are usually lower than most people who post here.

re: iPod boom - it bugged me tonight when a guy was complaining on head-fi that his ipod via LOD into Grahm Slee NOVO didn't sound any different than this HFI-780 plugged directly into his iPod, and said that all the NOVO did was provide gain for his HD600.

I posted that if the goal is to have an amp that is a wire with gain (WWG) then why would he be surprised that is sounds as bad as if listening right out of the iPod? I recommended maybe he consider getting a better source (transport and DAC).

As for stats - I got my first rig from plaidplatypus for $235 SR-Lambda with SRD-X, and plugging that into the headphone out of my DV336i was better than plugging the HD600 into the same amp. That started me on this spiral into moar and moar stats...

[bhd812]

Let's see, we're up to 14 pages bashing an amp that nobody posting (with the possible exception of Billy) has ever seen in person, much less heard. I forget what site I'm on. I thought my sig was making fun of a different site.

yeah I heard it but i don't have mucho experience with HE90's and i was really cranky after the Chi event. overall I know i like the HE60/90 electro over all of the Stax i heard though much better detail and way better bass to me ears. I heard the HE90's with Justin Ariathingy when Justin and a few of the Florida guys sat me down at Flor National and i really liked it and I heard D's HE-60's with the Woo at the First Chi and really fell for it (i got in a long quiet listen!). I listened to Tuberollers Stax setups before and even at both National i was at but i didnt like any of the sound. I probably would like the A-10 cause i really Like the RSA sound and i like the HE-60/90's..

I heard the A10 when it was in proto form as a preamp in Ray's speaker rig. anyone who knows Ray knows he dos some final changes to sound before release and he did have new speakers so i couldn't judge it all the fair.....plus i am bias being a B-52 owner and all...

[spritzer]

The issue of the amp being sensitive to the impedance of the transducers is a huge one IMO. HFN reviewed the ML Spire in the April 2009 issue and they found the speaker to reach 0.4ohm impedance at 20kHz and it would go even lower into ultrasonic frequencies. This is of course a byproduct of the transformers used in the speakers but shows just how much the impedance changes with frequency. The Quad ESL reached down to 1ohm and up to 30ohm so if we give them a modest 1:150-1:200 turns ratio it is a frightening impedances range (multiply the square of the ratio*the impedance to find the speaker impedance).

While ESP's have smaller drivers they are by no means a much easier load. The heavily airdamped stators of the SR-007 and SR-001/003 make things even worse by trapping air next to the diaphragm and thus increasing the impedance of the air. I view the role of high-end to be a straight wire with gain and taking the amp (or any other component) as much out of the equation as is possible. Making sure that the amp can deliver it's full output voltage into any impedance load is a fundamental necessity for electrostatics or the amp will be a limiting factor and alter the sound output. Just listen to a SR-007 or SR-Sigma driven by anything but a Blue Hawaii and you hear how much of a difference maintaining a stable output voltage really makes.

All this power isn't cheap so it's no wonder that Stax (with the exception of the T2), Koss or Sennheiser have never come up with an amp that isn't a compromise. Those that are involved in manufacturing know just how cheap those Stax amps are to make given the retail price. Now with something like the BHSE and A-10 there is no retail network to a take a large slice of the price but also no economy of scale. It is far cheaper to make 2000 amps then 20. The A-10 is a very expensive amp though so we should at least expect performance to far out pace something like the 6S4A based Woo GES let alone the PoorMan which will be less then 500$ built and in what looks like two versions (hybrid and SS). Given the data at hand that is far from certain.

Colin and I talked about the reverse

kgbh with a transformer to add dynamic outs.

I've thought about that as well but you would need multiple taps on the secondary to cope with all the different headphone impedances. I sent Justin some of my spare transformers to test the amps with but I don't know if he had any success with that approach.