spritzer

I'll drop you a PM about the 2705's later on. As for the Alpha issues, the PCB is upside down so all the connections are in the wrong place. On a 3 pin pot it would just work backwards but this one is 4 pin...

I have some extra 2SC2705's. They seem to be branching out into more components so that is their new site.

All the transistors except the LSK389 can be had from bdent.com and the LSK from Trendsetter. You need custom transformers for this amp so somebody like SumR could build them for you. They can be ordered with two 117V primaries which are then series connected for 240V. If you can live with +/-400V rails then there is this one from Edcor. A small toroid for the low voltage and the end bells can be removed to mount the transformer inside a chassis. I did just that in my B10 with M4 hardware and I'll use this transformer to make a souped up KGSS soon.

They are backwards or they are fed to much voltage.

Those two amps look brilliant!! As for the offset Wachara, most of that is due to the Ixys part.

Banshee. Holy hell this is a brutal show but I kind of like it.

Me like that one Kerry. In other news I have on my desk now a much smaller and simplified version of the HV supply. It's roughly half the size but with only one input cap it is more voltage limited.

The cap is there for stability so I'd recommend adding it. How hot do those sinks get? Edit: No issues with plugging/unplugging headphones when the amp is on and playing.

Looking good!!! Now where are the internal pics...

Stax have used mesh stators twice, first in the SR-X Mk1 and then the SR-Omega. No doubt the plan was to get the drivers as open as is possible with none of the issues one has with holes thick enough for strong stators. The copper mesh is strong and the resin frame does support it quite well but it will never be quite as flat as the PCB. The mesh is also very fine. It would certainly be fun to copy the design.

There is nothing in the SR-Omega that is "too" complicated so we could do a far superior DIY version. The cost would be astronomical for a one off but having enough parts machined for 20-30 sets would make it far more reasonable. The tricky stuff would be the mesh stators and the actual driver assembly as the tolerances are staggering. Then drivers would have to be assembled, tested and sorted into pairs with quite probably some reject rate. Not easy but possible...

Yeah, I quite like that one as well.

For me the first models are the best.

They are SZ1's and what was actually wrong was never confirmed. Most were bad enough that they were repaired immediately but some slipped through. Some of them just sound "off", not as smooth as the Mk1 should be and with overblown bass and treble issues.

Why am I not surprised it is custom. I'm always up for some trading as well. Well that's where it gets tricky as this varies quite a bit. The spec for Stax states the 100Vrms point but how they get that figure is unknown.

It's not really about listening at insane levels. We were well aware that an amp like the KGSSHV and T2DIY can and will burn up a Stax transducer if it were ever to see the full force of the output. Not likely to happen unless somebody were to feed it from a high gain preamp but it is something to think about. That said the amp is then just idling at normal levels so there are clear benefits to using crazy voltage levels.

Not a whole lot of headroom with 300V.

The 6C4C is at least cheap so the voltage limitation is less of an issue. You know me, I have very little willpower when it comes to buying parts... Do these have a 6db gain tap on the primary?

We are indeed alive and well, just sidetracked by some other projects. I might also add a TVC to it for MOAR transformers...

I don't think there ever was any Germanium sand that could handle 1500V... My plan is for a spud electrostatic amp with just two triodes and DHT's at that. I know ETF.12 had a competition along these lines but I'm going to be far stricter to myself. No push-pull, current sources, parallel tubes etc. Just transformer, triode and transformer...

Ohhh it is a poor idea. Building the B-10 was a poor idea but I did it anyway. The 300B is linear but it is limited in terms of voltage so you need output transformers. Costs are starting to mount to say the least at this point. I'm doing it though as I like to build crazy things and I have some 300B's here. This is my version of spring cleaning... While on the subject, an even crazier amp design crept into my head this morning which will be even more expensive and ludicrous.

More voltage swing is a good idea generally but there are two things to consider, the sensitivity of the drivers and the absolute max voltage the drivers can handle. Now these get plenty loud with just 100Vrms so the idea of more voltage swing is more about clean power than anything else. The second limit is the absolute max voltage the drivers can take which is roughly 1200Vp-p. This is even lower for the Senn HE's but again, this is very, very loud. I don't think Stax ever used graphite on the diaphragms. No way it would have lasted 50 years on my SR-1's...

Where did the EL34 break? This can point to what really went down. Still, a burst of air into a tube running this hot will make it into a very nice lightbulb... Ehhh a quad of 300B's is too rich for my blood. If this one goes well then I might try something like triode strapped pentodes at higher voltage. 7403's would be very interesting due to the high voltage and dissipation properties...

I guess it is possible but I just don't get why you'd want that. Varying the bias voltage isn't a good thing in my book especially with the charging issues that come with high resistance.

Yeah this is a generic part so any manufacturer will do.