spritzer

Better yet, just get some of the Japanese models to begin with. You have probably done a lot of damage doing something wrong so the best bet would be to scrap all the small transistors. Also clean the flux on the output devices. It can short... You mean upper left? That is supposed to be there as the LED is part of the 2SA ccs.

Also crazy expensive. Skeleton is made from carbon fiber, just because they could.

On the 0.4 offboard amp boards the feedback is flipped so either cross the 50K resistors or the 1N914 diodes. I crossed the diodes but it doesn't really matter... Correct on the parts marked with a A but not the 180R being changed for 250R. That's for when you use IXYS parts as output devices plus some other changes. This resistor sets the current through the output stage so you can play with it a bit. Wouldn't really go lower than 120R though... 1K and 1K2 are for the IXYS CCS. You can't mix and match the old Japanese transistors and the new On semi stuff, different pinout. Use the global feedback as the amp was always meant to be used. Larger caps can be used but they also mean far more bang is something goes wrong. The 0.6 psu board works just fine but keep the caps off the board and made sure that all solder joints are very clean and precise. Overhang even close to the ground plane can end very badly. Kevin and I have never done any BOM's so I have no idea what's in them. That said, any major sonic difference will come from changing the output devices. The rest will be more or less the same assuming the parts are all of equal spec.

No problem supplying you with a stable board design Christian. +/-400V means you can use current made parts and BJT's for the output devices, go any higher and you need to find out of production parts. The KGST vs. KGSSHV will be clear soon enough when I get some boards and can get building. So these then? http://www.aavid.com/products/standard/531102b02500g It's Europe, everybody is in a union. Though they not like in the US though...

100 of them take up a bit of space so I imagine 1400 could take up a pallet...

I like that one a lot. Something about the difficult ones...

Hmmm superconducting flooring would make millions!!!

I could always send Justin the highly modified LL1 to measure. It's not like it isn't just gathering dust here but it wouldn't give the right impression as unlike the stock version, it's not a shitstorm of distortion. I have an Exstata too somewhere though it was a highly modified version. One amp I'm truly interested in seeing measured is the SRA-12S as it was their first foray into solid state. The T2 was a crazy project, we haven't done one of those in a while. I've been gearing up to rebuilding the amp section in mine and reworking the PCB design quite a bit in the process.

Both I'd think. There is a picture in the largest national newspaper here today of a high end system (Pass pre and power amps feeding ESL2905's) and it has those idiotic stands too.

Hot off the presses, KSSHV mini THD measurements. I asked Justin to measure my first prototype of the mini and here are the results: Compared to the BHSE measured using the same setup: This is very impressive indeed and I'm sure the second version is a bit better as I switched to 2SC4686A's for that one for lower Cob.

Higher voltage means less current so easier to power using regulated DC. No possible to do on the current boards without cutting some traces.

I'm out of boards but we can supply you with the gerber files needed to have the boards made.

The real curse is to know all the CC details by heart. Well that and Paypal... bloody paypal...

Same Chinese stuff as you can buy on ebay. It's normally pretty nice if the seller can be bothered to package it properly...

That looks good. I still don't know why we made the front end filaments 6.3V though. They really should have been 12.6V or even 25V. Hell a LM7824 with a diode on the ground pin would be perfect for that.

No problems with the mini but for a first build, it will bite you and bite hard. I'd do an onboard as then it can be tested safely and then assembled.

Ditto but sometimes it is just a pain.

This shit happens to me all the time. I keep getting notices from customs about some packages that I don't have a clue about.

Happy Birthday!!!

This one does have to be fixed as there are a number of issues. Heatsinks should be soldered down and grounded, the ground plane in a mess so not working properly and one resistor per side is running right on its limit. There are also some small changes to part values and ideally they should be put right plus the transistor mounting to the heatsinks needs work.

Indeed...

Minor detail...

I forgot about the tiny heatsinks.

Not sure about the low voltage caps but the high voltage supply should have no problem with higher AC input voltage. The PSU is regulated so the output is fixed, the only issue being the prereg DC voltage not being excessively high for the filter caps. Try to ask SumR to use a larger core. That seemed to help when I was working on this with him. As others have said, tubes aren't just tubes in the same sense that not all transistor devices are equal. To think of tubes being different to transistors would be a fallacy as they both do the same job and can often be used in very similar circuits. There are differences in the same sense that bipolar transistors and mosfets aren't the same thing but the key difference is how any component is used. The Stax 007t and the BHSE are both hybrids with similar rail voltages and many parts of the solid state circuit are similar. How the tubes are used couldn't be more different though. The 007t tube stage could just as well have been designed in the 50's and is just about as simple as they come. The later version have added bits here and there but the final design is always the same. The BHSE on the other hand is radically different. Active circuits set the correct operational area for the tubes so they don't rely on the massive drift found in passive devices. The tubes are also wired differently for even lower distortion so this is far from a normal tube amp. Moar expensive doesn't mean better tubes. Shuguang is a good example of that and I for one would never use anything they make, in any of my amps. The old Mullards were simply better made than anything today so that is the biggest factor.

Yup, that's correct and it has been fixed.