kevin gilmore

surprisingly on something like a 727, the peaks are already clipped at moderate volumes. so this will let all the wonderful dynamics thru. and damaging you hearing, definitely.

max voltage swing is 4 x bias. so 580 x 4. the amp does loose about 20 volts of voltage swing, so 600 is a nice number. same voltage the koss uses. also the rating on the pnp transistor. could cut the voltage to 550v for a bit more margin.

power supply schematic updated. amp board updated. circlotronpsupdated.pdf kgsshvcarbonv6.1c3cs - CADCAM.ZIP

q12 is the current limit. so if the amp board shorts, at least the power supply will not explode. what do you want me to replace the pzta part with? remember 20+ma

definitely has enough power for that. 2400 volts peak to peak stator to stator at 25ma bias. only otl dc coupled solid state amplifier design that can do this.

and the power supply that goes with it. standard off the shelf antek transformers are $44. need 2 schematic fixed. kgsshv600vpower - CADCAM.ZIP circlotronpsupdated.pdf

i know that birgir has a new batch of megatrons, do not know if they are all sold or not has to deal with eu rules. soren is also making megatrons also has to deal with eu rules. headamp has amplifiers, dont think there is an export tariff so this might be a bargain. there is a guy in california that i cant remember who is doing custom megatrons.

So there is this manufacturer out there that puts a solid state otl electrostatic amplifier in the same box as a high output dynamic amplifier. For a whole host of reasons this just seems stupid. Instead of 1 thing well, lets do 2 things poorly. The first version of the woo audio did indeed use a single tube as a cathode follower into the same apex high voltage opamps. and boy did woo audio turn colors when this information surfaced. So they tripled down on the stupid this time. options include 1) all tube 6sn7 -- 300b -- transformer -- headphones 2) solid state -- headphones 3) 6sn7 -- solid state -- headphones at least that is what i think their advertising goo says. and whether they are lying this time. There are 4 different versions of an all tube megatron that you might want to consider instead.

so here is the latest version of the kgsshv-carbon with the c3m series parts including the current source. Good for up to +/-600v power supplies. board file updated. kgsshvcarbon600v.PDF kgsshvcarbonv6.1c3cs - CADCAM.ZIP

never expected thermal runaway because birgir has been selling the much higher power version and its completely stable. those particular resistors due to the heat really drift. like 10%. and in the wrong direction. with the resistors replaced by current sources its stable. so much easier to make really higher power things.

moar better. by a fair bit. i'm sure i can find a better cascade part. the battery is a dc to dc converter (4kv isolation rated) and is < $10. with suitable heatsinks bias should be about 25ma. the 30uf things are film caps. nothing i know of is smaller and rated at 1kv. mosfetout.PDF

it should be noted that with the 1700 volt output stage parts, its real easy to upgrade to +/-600 volt power supplies. going to need a much bigger box with heatsinks on both sides.

viva does the same shit wrapping various capacitors with wool of some kind.

better put a 300v zener across the output of the h11d

highly similar to hev70 sennheiser amp. and by that i mean n-channel fet as current source into another n-channel fet with grounded gate drive. sennheiser amp single high voltage + 600v. this amp +/-400v (initial guess on current way off) output device is infineon imw120r350m1 which has input capacitance of 3460pf. kind of high. there are better parts to use. like this one. C3M0900170D which has input capacitance of 202 pf. calculated output current is about 12.5ma and about 5 watts per heatsink. going to get fairly hot. mc33078 opamps perform very differently inverting and non-inverting. koss esp950 uses the same part in a very different way. much better ways of doing the unbalanced to balanced conversion. power supply about as basic and cheap as possible. the chinese will do this for less than $500. which means that this is infinitely better than the topping eha5. likely sounds better too.