hollow-state voltage doubler.

[DummyLoad]

never have seen one implemented with a guitar amp. until now. odds are, others do exist.

100uF stack seems kind of hefty for a hollow-state - alas, it is lower voltage / higher current - love the 1/2 tap for the screens.

guestimating should be around 250V plates and 125V screens and satisfies supply tension tp the delicate screens of the 25L6.   

--pete

[PRR]

My guess is nearer 75mA 200V DC, 360mA peak in the rectifier (OK)
http://www.mif.pg.gda.pl/homepages/frank/sheets/093/2/25Z6GT.pdf

Even though the B+ floats, they use the 68k in the groundy-side of the input stage to limit the lethal currents to user. (This may be hang-on from a totally transformerless plan banned by UL.)

It is not at all clear why the extra 22Ks or the way-low 39Ks. 400Hz bass-cut seems awful high for a "deluxe" amp at the bottom of the scale. I wonder transcription error or just real darn cheap speakers?

[DummyLoad]

It is not at all clear why the extra 22Ks or the way-low 39Ks.

maybe they are actually 220K and 390K - perhaps they wanted to load 6SJ7 cathodyne and and 390K are well, the grid-leaks? 

--pete

[DummyLoad]

here's another cool implementation with hollow state volt dobler: WE 140A amp with a quad of 25L6 and a pair of 25Z6 duo diodes doubled up in ||. not a guitar amp, but it's neat in that it can take a battery stack or AC supply for power source, however, it makes less power on battery. the PI and 1st pre-amp are a damn brain tease. yet another UNSAFE to use amp with AC or DC power


--pete

[PRR]

> yet another UNSAFE to use amp with AC or DC power

If you don't open the box, this is "safe" at the input and output connections, both transformer isolated.

As soon as you start messing with the insides, beware.

[shooter]

ok, I couldn't help myself surfed "hollow-state" since I'm ignorant on that term, webin didn't help so far, got the Vdoubler down fine.  Did find a somewhat fun article though, like the section on degraded Q from broken strands in multi-strand wire 

http://navy-radio.com/manuals/hsn/hsn-issue%2044.pdf

[DummyLoad]

vacuum rectifier. 😝  but you fingered that one out, right? 🤓


--pete

[shooter]

I was just web'n! did you hack my computer 

so far "hollow state design" seems to be a company selling a book on tubes, BUT the Author posted this;
https://hollowstatedesign.tumblr.com/post/54272117178/why-thermatrons

now I'm gonna hit myself 

and NO, I haven't made it to rectifiers except inferred from the schematics, maybe I'll hit twice   

[silverfox]

vacuum rectifier. 😝  but you fingered that one out, right? 🤓


--pete

Yes I did- A leak.


fox.