spritzer

Happy Birthday little one.

Well I did save 5mm...

We don't really do BOM's but here is the board as it stands now: I think I've gone as far as I can with shrinking it down but I might be able to scrape some mm's off it at the bottom. Here is the new fet: http://www2.mouser.com/ProductDetail/NXP/PMBFJ620115/?qs=%2fha2pyFadui0jglBrupTXFF4afbDGBI0NwQMb%2fYXeEA%3d Here is the 2SA1486 replacement: http://www2.mouser.com/Search/ProductDetail.aspx?R=STN9360virtualkey51120000virtualkey511-STN9360 There is also the 511-STN9260 which is cheaper but has a lower HfE. Should work just fine though.

My buddy has the sloped Dynaudio's and they are very nice speakers. Software volume control will work just fine but I built him a passive volume control just in case.

We should be good for a few years now. I've updated the board to include the dual fet available at Mouser but they haven't been tested yet. Should be just fine but it's a tiny SMD part so it will take a steady hand to install. They have a huge stock and then there are always the Fairchild N-channel parts. Dirt cheap and about 250,000 in stock of one type... This version also added support for the SMD replacements for the 1486 and they are brand new at Mouser. The output devices are a problem though. Mouser has some slightly unusual parts in stock that I'm going to try and report back. I was also looking around and there are some new parts coming that might work. Ohh and reworking the PSU is an epic pain...

Sony can make some very nice equipment when they go all out. That series was awesome in many ways, ditto the R1 and R10's.

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.