kevin gilmore

NOPE. GES on steroids. No reason to ever build a srx circuit with beefed up tubes due to filament to cathode voltage concerns in the top of the first stage, and the output stage. Unless you really want 5 different filament supplies.

You want to move somewhere with a great opera company, wonderful symphony, and a thriving live jazz scene. And the best radio station in the world, and ravinia not to shabby either. But dental floss tychoon definitely works too...

replace with a pair of 1n4007 silicon diodes and be done with

And justin beats me to the answer again. Its the AC signal that is the problem especially since the 2 halves of the tubes are 180 out of phase. So one cathode goes up by 90 volts,and the other goes down by 90 volts. Any more output signal than that and you violate the tube ratings. (for 5687's) You could mix the tubes, using one section for L+ and R+, then as long as the music is mono... There absolutely is a way to do this, has to be single triodes. OR single DHT's. Maybe i should publish my all DHT amp schematic, but really don't want the competition (hack cough) to actually learn how to do it right. Sucks to have a day job, otherwise i could be like billy and be on head-case all day.

Nope try again... One triode of the two in the same tube is the high side, and the other is the low side. If the low side tube cathode is pretty close to ground, as one would expect with a srpp with gain, then the most the top cathode of the other triode in the same glass would be +90. Output voltage swing would be very minimal. Not rays "louder than loud" style. Would limit B+ to less than 200 volts... In fact on the cRaptor, the B+ is 250 volts, and the top cathode is at 150 volts, 60 volts over spec.

Lets everyone send justin various things to test and play with. Lets start with bench power supplys. I'm planning on an entire pallet piled high with supplies in a few weeks. Sure hope justin's apartment has a loading dock..

MAJOR FAIL. The top tube violates the filament to cathode spec. Nothing can be done about this either, as they are dual triode tubes.

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.

All electrostatic transducers (other than the beveridge) are balanced devices and must be driven with a balanced drive system. The A10 in balanced input mode must clearly be balanced thru the 4 channel pot to the output section. Now whether or not the 4 output sections are push pull (i.e. srpp) or single ended (tube with resistor plate load pictured a couple of pages back) is a different discussion. Likely the later and either dc coupled outputs (with dual power supply) or ac coupled outputs (single power supply) ES1 is fully balanced input thru output, capacitively coupled in the middle, dc coupled outputs KGSS, KGST, BH and BHSE are fully balanced input thru output completely dc coupled input to output srm-T1, 007t,srm-717 etc are all fully balanced input thru output completely dc coupled input to output

actually ray would be in a position to do a dual unit if he wanted to. chuck the preamp part, just have a unbalanced/balanced switch then 2 x 12ax7 for the balanced /unbalanced inputs, 4 x 5687 for balanced dynamic and 4 x 5687 for balanced electrostatic. You could even have both at the same time.

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...