spritzer

Good news everyone!!! Well there are a few of them actually... Kevin has tested the 01N100D's as output devices and they work just fine after a rebias so they can be used. Ceramic insulators are needed but it is better than nothing. Kevin has also updated the design to use available sand from Mouser so no more 2705 shortages. SMD posts also added to sub the 1486's to the latest layout. We are also working on subs for the LSK389 to make sourcing the parts easier. Last but not least, I finally cleared up the onboard PCB design and shaved 20mm off one axis and 25mm off the other one. Not too shabby so the boards will be cheaper and easier to mount into boxes. I also have a small offboard version ready for checking but it is 450V limited with 2SA1968's and intended for one of my personal projects. Might look at the standard one when I have time though. Edit: I'm also going to shrink the PSU a bit.

Ditto. They are the only ones available here is my petite 16.5 size...

The DY294 is good for checking basic parameters and for high voltage sand it is ideal as nobody would ever rebrand some nice HV stuff. Low voltage is more of a problem though as there are so many similar parts out there.

No need to worry about the PS2 box as we can make a far superior bias supply, hell we could do a fully regulated one.

You could just build your own transformer box. The trafo's are 1:60-80 which is high but there is probably something out there. Edit: I did some checking and Lundahl 9202 would work. It's 23K/8 so 1:53 which is enough. Should easily trump what ever transformer they are using...

Ditto on wanting to try the new Floats but not a chance in hell I'd pay for them. The PS2's are a torture chamber for my head which is why I prefer the PS0 which does fit me better.

No doubt the new transformers help but even off an amp the Jecklin's are lackluster. That's a proper amp and not the steaming pile of crap Jecklin sold back in the day. The PS2's never fit me properly but the PS0 did so fit issues aren't exactly new with this line.

These are the Germans remember... they are an optional extra. Justin is right though, the PS0 had some little bit of style and the PMB versions are nice to look at but this just looks like a Home Depot cluster fuck.

It's certainly a grounding issue or something is radiating an awful amount so the headphones are picking it up. If you have something earthed then run wires to that and see if it fixes the issue.

Well somebody has to keep some in stock for the apocalypse. I also have some BH's to build...

The connector is a multipin job but they just use 5 of them. Not compatible with Stax in any way, 1500V bias and four times the voltage swing... Horrendously expensive too.

Most of the sand for the original BH is either all gone or almost gone.

Happy Birthday Al!!

It's most likely the servo for the output stage was off. Basically the "batteries" need to be adjusted to 740V and then the servo can kick in and null the output. If it isn't at 740V then you can hear noises like that.

Tube input makes no sense as it gives us no benefits. That's the whole issue with most hybrid amps, most of them were designed with a SS front end but then tubes were added after the fact by somebody else.

Graphene is strong but size would be an issue for a large (50mm or larger) driver.

Nice twist on the plasma concept but as with so many of these things, it has limitations. I for one remain skeptical that thinner diaphragms are necessarily better for electrostatics. The weight of the air the diaphragm is asked to excite is an issue as is the stability of the material and its damping properties. Now if we could get a material that is stronger than mylar at any given thickness and provides better damping then we'd have something great.

Yup, I used them on most of my amps. Tracked down the data sheet at some point and they are rated at 500V.

More the unreg voltages but mine have been faultless as well.

Something like this? I use these and they are ok in terms of build quality.

Not on a constant charge basis.

Going by the document they didn't measure distortion at all. That's where constant current ESL's come into their own, something you can't really do with a highly conductive diaphragm. Now if they took the Final Audio root and biased the stators and put the signal on the diaphragm...

Funny thing about the Asian forums, the people selling the Rudistor stuff have a huge presence there. When the SR-009 first came out a guy was claiming the Cirolian was an excellent match... that he just happened to sell said amp was naturally not a factor.

The gain of the HV is a bit on the high side but it can be lowered. Ahh Rudi, as braindead as they come. Remember the "independently tested" specs he posted? Turns out he was in good company with Cavalli on that one...

The servo is limited in its range so if the trimpots can't even get close to 0V then then servo will be useless. Matching is important but I did build a Dynalo with no matching at all (except for grade) as a test and I had no problem getting it down to 0V. I didn't even install the trimpots, just used drop in resistors like I did on my last build.