kevin gilmore

And did he take a beating price wise. I know who got it, they are spending about $1000 on tube sockets and a power supply rewiring job... (nope, not me, i'm tired of those things) And billy is a man of his word.

You are way off. 6sn7 as a cathode follower is 800 ohms best case.

I know of 2 for sure, and one is dead. They are called "concerto's" Hey billy, time for you to prove what you said earlier today with respect to the kidney cancer foundation...

Well if that picture is what ray did, what is the possibility he got the dual filament supplies thing right... And running a 5687 on 600 volts... Double the specifications... Thinking about it, justin is probably right, and ray is using the above design. However since there is only one tube in the middle, that is a standard cathodyne phase splitter. From ray's description.

done billy. proof in your PM. I doubled it. I expect you to do the same.

OK, so lets look at the 5687 datasheet http://www.drtube.com/datasheets/5687-ge1959.pdf Notice the 90 volt max cathode to filament, and the 300 volts max plate voltage. Now lets look at all possible configurations of 4 x 5687 as electrostatic outputs. 1) Both sections of the tube in parallel with resistor plate load. Max Vcc 300 volts. Max power 8 watts per tube. Same power as BHSE. No voltage violations. And probably not ray's style. Capacitor output, or dual power supplies with filament referenced to ground or V-. 2) Both sections of the tube in series, SRPP. Clearly ray's style from cRaptor and B52. Capacitor output, or dual power supplies. In either case there is the cathode to filament voltage violation, same as ES1, except only double the ratings instead of 4x. At least no one will accuse ray of swiping another's design as this is the only electrostatic amp i know of with 5687's as output tubes. OOPS, justin proves me wrong again... With a couple more switches, ray can use the thing as a real B52 replacement i.e. it could also drive regular headphones. Open loop with absolutely no feedback. If you like the rest of ray's stuff you are gonna love this thing.

I was thinking that it was possible ray was using the 5687's as the output stage to drive the electrostatics. But depending on which tube data sheet you read, its good for either 330 or 350 volts max. And since there are 4 of them, the output stage is srpp. Certainly not something i would want to buy. At least it is going to sound very different from everything else out there. Gotta go.

Searching for maestro insides pictures now... WCF driving high impedance cable load, even internally loaded with 150 ohms ?? got to be nasty. At least if the stealth was used that way it would be pure class A.

Billy, no one hears from you in over a month then you come back and whack your mouth off... Put up or shut up. My guess is that although the chassis is complete, the circuit boards are still prototypes, otherwise pictures would have been supplied. Anyone know billy's paypal address, i'll send the money now. And then billy, take it out of your hide later... Can you still get a cup of coffee at starbucks for $5 ??

See i'm going to have to disagree with you on this one. Every picture of the maestro i can find shows a total of 3 tubes. Which is 1 gain tube, and 2 x WCF output tubes, all 6sn7's. This is virtually identical to the RSA stealth which is claimed to be a preamp also. One gain tube and a volume knob does not a preamp make. Mainly its the huge variation in output impedance over frequency and attenuation range that is at issue here. In my system with 20 feet of cable between the preamp and amp, there is no way this thing would work.

OK billy its worth $5. Which part is wrong. paypal immediately. Hey i might be surprized.

The T2 and the BH and BHSE all use +/-400 volt supplies. So clipping would be 800 volts minus the 30 or so volts for the cathode. In practice its a bit lower than that. So something in the 700-750 range. T1's are +/-350 so max would be 670, in practice 625-650 The 717 does slightly better, 650 to 675. The voltage swing is only part of the equation. The other is the amount of current available to charge and discharge the capacitors. A 6sn7 can probably supply only 60% of the current that a 6s4 can.

The fuses were probably in the 5 volt section which was never used in the first place... There might have been a thermal fuse inside the transformer...

I'm just going to quote some of the things i have actually heard. The small conrad johnson preamp is about half the price of a B52. And that is the NEW price. Used is definitely cheaper. Pass labs has a number of wonderful fet based preamps starting at only $2k or so, and going all the way past $18k. ARC is certainly nice, i don't like the sound signature. And krell, well i have 2 of those, but the cast preamp new is more than a B52. And all of these have a remote control. Each is far more complicated than a single gain tube and a cathode follower which is all a B52 is. I'm going to say something else, as far as i know, mikhail never made a real preamp. Yes he made lots of things with a set of connections that said preamp out, but they are absolutely no different from a RSA STEALTH. That is a single gain tube, and a pot. Not even a cathode follower. And his version of unbalanced/balanced ala the SS1 is just dismal.

Whoa, wait a minute... The burned components in the pictures of the SS1 clearly should have popped the fuses, if there were any. That is way more power than the amp should have pulled. With respect to the rest, amb did a very nice circuit which i continue to use that monitors any dc to the speaker/headphones, and dumps them for safety. That kind of circuit should be in all otl amplifiers, tubes or solid state. OK, resume RSA bashing...

The pair of these is about 300 amps peak, 160 amps continuous at 3.3 volts. And weighs no more than 5 lbs. Perfect for backpack quickie battery charges... cryogens ?? anyone say cryogens??? Infinite amounts of liquid N2 available...

Let us not forget that 6cg7's used in virtually every single stax tube amp except for the T2 are rated at 450 volts also, yet stax runs them at 700. Furthermore, some of the modification jobs on dynaco stereo 70's push the B+ to something on the order of 550+. The 6sn7's would last a while at 600 volts. But they would sound pretty nasty at large voltage swings.

I've never been able to find the chassis mount esp-950 connectors, if you know of a place, i would certainly like to know. No and NO. The guess is that the 6sn7 is running at 600 volts, which is only a guess. Could be less. Even rudistor ran theirs at 450. At least the filaments are at ground because it is a capacitve output design. (mikhail's major mistake) Of all the tubes ray could pick as electrostatic output tubes, ray picked the worst one. In the smaller size the 6s4a is absolutely the clear winner. In the bigger size a 6ca7/el34 is absolutely the clear winner. In even bigger sizes well it gets expensive in a hurry. when we see the inside pictures we will know for sure, but ray doing a solid state constant current source as a load for the tubes is beyond his level of understanding. One can only hope... Really sad that ray made yet another amplifier that i have absolutely no desire to own. He could have done much better. And one more thing, ray's latest piece is going to have major trouble driving the increased capacitance of the jade's.

It can still be done. It just ain't cheap. The prototype was 600mw per channel. 1.2 watts total. Output connector can be a flat connector just like the stax portable. Converts to a round connector a foot later. You can get about 6 hours out of a honkin-large Lithium battery. Or do it with miniature transformers, then it is real easy. And cheap.

so on closer inspection i will modify my analysis. Pair of balanced input tubes, 12ax7. Left back. Same place as b52. followed by 4 section volume knob. followed by 4 srpp gain sections, 5687's Used to drive output stage and preamp output. So basically identical to 2 x raptors, or 1 x B52. extra 12ax7 as unbalanced ouputs. 6sn7's as electrostatic outputs. Capacitvely coupled, same as aristaeus. A pair of 300 volt power supplies stacked. Outputs at +300 and +600. Same +600 supply used as bias output. Whether or not it is actually dual, dual supplies (i.e. dual mono) is unknown, unlikely. So its either 4 wires, of possibly 8 wires in the umbilical cable.

Pair of balanced input tubes, likely 12ax7 or similar. Pair of cathode follower output tubes, likely 12ax7 or similar. Balanced outputs. a cathode follower tube for the unbalanced outputs. pair of balanced gain tubes for the output stage, likely 12ax7 or similar. 6sn7's as the output tubes. Likely capacitively coupled. Single filament supply for the whole thing which is ok for this circuit. Speaking of which this circuit has been published many times before. Its possible that the small tubes in the back are single triodes instead of duals which means they could be phase splitters instead... Restricted output voltage swing, max 500 p-p. Low current outputs. 68k or higher plate resistors... Yep, typical ray.

massive spoilers

The L bracket heatsinks are very easy to install, thermally efficient, and make any repairs necessary in the future very easy. I've seen this done literally 100's of times. Way easier than trying to get a screwdriver in sideways.

If you are going to go thru the trouble to put in a 5 pin switching headphone jack, you might as well tie the switched outputs to a proper resistive load instead. Made easy by the neutrik switching jack.

I've seen the pics. At least one was shipping today i think... but not mine. Dammit. I got to find a way to clone the guy...