sv572-10

[oj]

Has anyone the Svetlana technical bulletin (or the schematics) on a SE amp built around a 6EM7 transformer-coupled to a SV572-10?

[zarniwoop]

? what are you asking? Does anyone have a copy of it, has anyone seen it, has anyone built it...

you know that tube has been out-of-production for years now, right? also, i've heard there were some early-failure issues with some of them. but on paper anyway, it looks great. better than a 211, easily.

you know where to buy some? cheap?

[andyjevans]

I have five of these tubes, new in box and unused. I don't have any immediate projects for them so open to offers - I'm in London. Andy

[oj]

actually, I bought four matched tubes from Antique Electonic Supply a long time ago (probably, in 1999). So, I was just thinking to put them on use!

[kevinkr]

The SV572-10 is currently available from New Sensor and is in stock right at this very moment. (I checked) As far as I know it might still be in production, but in any case it is readily available. IIRC This tube was/is made by Reflector AKA ExpoPul which most of you would know as New Sensor.

It would not be my first choice, they are short lived, hard to drive, and thrive best at pretty high voltages. And they are no longer as inexpensive as they once were. If you've got them I'd run them, they do sound pretty good.

The old Svetlana project database is gone.. Most of these projects were originally published in either Glass Audio or VTV. I'd look at back issues of those as well.

[jrdmedford]

I cant find the tech bulletin for that, but I remember it. Karen
Preeda did it. If you can find/contact her - you might get a copy.
She used an ElectraPrint 3034 Interstage (5K 1:1). The 572-10
was run at its zero bias operating point, so the source side
of IT secondary was grounded and I think the 572-10 was run
at 550-600Vanode or so (find a zero-bias point on the spec sheet).

A 211 behaves roughly the same, so if you buy interstage TXs
for this design and get bored with the 572-10, you can very
nicely move on to the 211/845 at your leisure.

-- Jim

[5u4]

I built one of these amps 7 or 8 years ago. Not really my favorite amp, good bass & highs, but a very colored midrange. Maybe you'll have better luck.

Remember seeing a transformer coupled version somewhere too. Will search for the schematic & post it, if I find it. Also wanted to add, I had the filament burn out on a SV 811-10 & had to replace it.