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Now for something different...


spritzer
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Love stollen. 'specially the gunk in the middle....... I don't have a sweet tooth - I have a mouth full of 'em.

The modded version of the LL is preferable. After all, who wants a clone of expensive rubbish when you can have something that's appreciably better and cheaper.

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So do we do a circuit board that is identical to the LL production version, or do

we do a modified version thats better? Off board or on board heatsinks version.

Really, taking the kgsshv board layout, the last 2 stages are identical, so

changing the front end it pretty trivial. And the kgsshv power supply works

great at +/-400 volts with only 2 resistor changes.

Improved version naturally. Fits well with the Exstata V2... grin.gif Onboard sinks too.

And its not a rummage sale... its a rubbish sale. Especially the rudistor clones.

Hey, I quite like those amps given how small they can be made. :) I'm building one now into a SRD-7 box for the smallest fully balanced amp I can make.

Love stollen. 'specially the gunk in the middle....... I don't have a sweet tooth - I have a mouth full of 'em.

The modded version of the LL is preferable. After all, who wants a clone of expensive rubbish when you can have something that's appreciably better and cheaper.

That would be marzipan or rather persipan in most (not pure almonds but cut with apricot kernels). Lovely stuff we use to make cakes up here mixed with 50% sugar and a bit of eggwhites.

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Yeah, that persipan is good. I still have a quarter of a loaf of stollen in the fridge which is going down tonight.

The apricot kernels with their vitamin K definitely would make it a semi-health food.

Never heard a rudistor, are they tasty?

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http://gilmore.chem....edu/srm323s.jpg

you can use non-isolated mosfets if you want.

you should use the bipolar listed for +/-400V

you can use the 2sc4686a and the 2sa1486 in place of the ksa1156 and then go to +/-500V

+/-15 volt supply not needed.

Will add the LED current source option soon.

Same exact size and hole placement as the kgsshv board

Edited by kevin gilmore
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I am a little confused by the response. First he says that the post schematic is of his prototype, then goes on to say any similarities are coincidental. The second part almost seems to backtrack over the first part.

I don't know much aout circuit design, so when I see the two it mostly looks like squiggly lines. So to those more knowledgable. How similar are the. Possibly using a literature analogy. Would it be like he is paraphrasing the 323, or is it more blatant plagiarism. The more similar it is, the less likely I am to believe his explanation.

I have no intent to buy one anyway, so I suppose this is all just for curiosity.

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The root cause of this are the origins of the Exstata design. I was there in the "super secret design forum" when somebody linked to the High-amp.de site which features a design shockingly close to the SRM-1 Mk2. Things spun off from there but with that basic blueprint there are only a few ways to go to improve the design. Different ways such as using zeners instead of resistors (not a good call IMO due to the noise) but the end result is the same. There is a problem with this though as some of the finer points of the design become lost in the translation which is why for instance the Exstata sounds a lot worse than the SRM-1 Mk2 and the measurements back this up. Same problem with the ES-1 amps. Mikhail was working from a schematic which didn't feature the heater wiring and I'm sure he never spent a moment wondering why Stax used unequal rail voltages (+250V/-350V)...

Now for the LL, why on earth is he using mosfets instead of BJT's? They are far worse but it does take some experience with 'stat amps to know why. I've been having some problems lately sourcing high voltage TO3 BJT's to repair my old Stax amps. I can get some old stock at lofty prices as these haven't been made for at least 20 years since the world moved to to220 but this isn't really an option. Now what I can get in ample supply are mosfets but they all have the problem which makes them unsuitable for this role, high capacitance. Same thing applies to the LL, they may give you a certain sound signature but I for one think amps should be as neutral as possible.

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Very close to done now, stuffable many different ways,

mosfet/bipolar

current source transistor/led

stacked current source/single high voltage current source

resistors/zener

400v/450v/500v

http://gilmore.chem....edu/srm323s.jpg

and .5 inch smaller in vertical direction than kgsshv which is what

birgir wanted.

Deepak, you asked for it, you got it.

and here is the schematic which needs a bit of editing to show the rest of the options

http://gilmore.chem....srm323splus.pdf

And we now have an official name for the thing.

Lj├│strandi leiftur

I like it.

Edited by kevin gilmore
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So the LL boards are pretty much ready for production and I've ordered boxes for my version of the A-10. How about "Pyrite" for a name... grin.gif

You too, Birgir? I have got just far too much "stuff" in your typical compact (by US standards) UK house.

Yup, even my dastardly plan of having my friends take some of this stuff doesn't seem to be working all that well either.... laugh.png I really should start to sell some of this stuff as the pile just keeps on growing as I build more and more "crap". Looking over my desk I have the chassis for a tiny triode Stax amp, Hiraga Le Monstre amp and PSU boards, heater transformer and PCB's for my ultra simple poor man amp, PSU board for a SRA-12S, two amp boards from a SRA-10S, mini ESX output stage, numerous high voltage PSU's (five in total) and two Exstata V2 channels all waiting for some attention and/or parts. This is also after I cleaned up a bit over the weekend... unsure.png

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