kevin gilmore

You need to measure the high voltage rails to know more. If they are 20% high, then what you really have is the transformer wired for 200v running on 240v. And then the transformer gets very hot.

see if you can buy 2sk389/2sj109 or the singles versions... i'll bet you get a few hundred quotes.

This sucks bigtime.

done

No time for a while but I do want this done

patents are a hunting licence. In this case a very poor hunting license. i can think of at least 3 different and easy ways around this patent. actually with logitech vs jha, this could turn into another dishnetwork vs tivo. speaking of alo, their latest http://www.studiosixamplifier.com/ looks a little bit like the old marantz 8b but seriously gas tube power supply ??

change the 15 ohm resistors to 5 ohms. But really that is a lot of extra heat in the power supply. or remove the current limit entirely by removing Q9,Q10,Q13,Q14

about 90ma

And birgir's favorite topic too

in the third stage, if you are using the 2sa1968's, to increase the current decrease R8 and R9. Probably the lowest you can go and still get it to balance is 400 ohms. if you are using the ixys parts decrease the values of R12,R19 for the output stage, to increase current decrease the values of R6 and R5 probably not lower than 125 ohms.

http://gilmore.chem.northwestern.edu/kgsshvpsu.asc

please post the ltspice model for all to see. i can host it if necessary.

everything is on the table. in fact there is so much stuff on the table, the table is going to break.

no change in performance. no changes to the amp. strictly for much higher power tube stuff.

For next board production, there is a slight change in the power supply board. Now works with es1/es2 rebuilds, which are much higher current and +/-400v. Same thing with the universal power board.

spice models on tubes are notorious for incorrect output voltage swings. With a B+ of 300v, a plate resistor of 2.5k, the maximum voltage the tube can possibly do is 225VPP. And that maximum is theoretical because the tube is going to be hard saturated at the bottom, and the linearity is going to be crap. with a plate resistor of 1.5k its even worse, under 200VPP. Voltage gain this way will be under 2. Its all about the Rp of the tube, in this case spec is 800 ohms, but will quickly rise to 1k+ as soon as you start putting signal thru it.

The lowest plate resistance of all electrostatic amps out there is the hev90 which has a plate resistor (actually 3 in series) with a total resistance of 18.3K and runs on +550 volts. This is the maximum rating for an ecl86. Most of the stax amps have plate resistors in the range of 47k to 60k. birgir pointed me to this http://www.bartola.co.uk/valves/category/valves/dht-valves/ 6P21S would handle at least 600 volts. The emission lab tubes would fit the bill, but with good sockets are over $250 each and you need 4

2.5K for the plate resistors, what is the B++ No way that is going to work. The B++ has to be a minimum of 600v to be able to get enough linear voltage swing out of the output section. 800v or 1kv much better. I think that the 2a3 is not going to like 600v. But you will have to try it. A plate resistor that is a minimum of 25k is reasonable. 211's or 845's would be much more fun.

28-70 f2.8 the lenses make all the difference.

the headphones cannot possibly know whether they are hooked up to a balanced or unbalanced amplifier. Maybe if you want to get fancy and add some extra weight you can use wire with a shield on it and wire the shield to either xlr ground (4 pin) or the 5th wire (5 pin)

all tube supersymmetry electrostatic amp with dc output servo http://gilmore.chem....du/electra3.pdf and the one cap one transformer cascode version http://gilmore.chem.northwestern.edu/electra4.pdf

i figured i would toss these two out for your entertainment http://gilmore.chem....edu/electra.pdf http://gilmore.chem....du/electra2.pdf obviously you have to add adjustable bias for the output tubes.

andy fresh roasts coffee. Then ships me some. Very yummy. Highly addictive.

But the amplifier part is in fact completely dual mono. Was from the start. 2 completely seperate power supply umbilicals. Just in case someone wanted to make dual power supplies. see... i think ahead.

in and done