DIY progress report

[Zen Mod]

So I curved those Sony JFETs.

They are the closest things to SS triodes that I have ever
seen.

Don't tell the tube guys - most of them are into avoidance
of cognitive dissonance and they don't need to hear about it.

luckily - I'll never see them

 

[R-K Rønningstad]

luckily - I'll never see them

Looking forward to NP doing something with these then. Obviously(?) Yamaha, Sony (and JVC!!) did not manage to get the best out of tehse devices.
If Threshold et al had got their hands on these in the 70ties, maybe we've had a different world?

RK

 

[Manu]

... most of them are into avoidance
of cognitive dissonance
and they don't need to hear about it.

This nice haiku I'll savour at breakfast today ...


Manu

 

[R-K Rønningstad]

2sk82

I found the following rudimentary information on the 2SK82 on the Web:
V=-240V, ID=10A, Pd=95W.
Datasheets seems long gone.

The question is really "should I buy some on ebay?"

 

[Michael Rothacher]

cognitive dissonance

I think that's what caused HAL 9000 to flip out, and we wouldn't want that.

Can't wait to see those curves and what you do with 'em.

 

[Nelson Pass]

Given that they are complementary pairs, there are only two
interesting applications.

 

[R-K Rønningstad]

Given that they are complementary pairs, there are only two
interesting applications.

What's that? Complementary push-pull class A must be one. And ditto AB maybe ...

 

[Nelson Pass]

No, push-pull Class A in Common-Source and in Common-Drain.

 

[R-K Rønningstad]

Ahh. Stupid me. Always class A of course. How could I even mention the "B"...

 

[R-K Rønningstad]

Seems the IRF240 for example and the 2SK82 is not that different, the MOSFET can handle more current than the VFET, but Pd is quite similar (VFET at 95W vs MOSFET at 125W).
So that Sony VFET pair ain't wimps either.
Ergo some quite sturdy power amps should be possible with a few VFETs.
But of course the design should be bullet proof with belts and suspenders, as replacements for a wrecked amp might not be available in 2012 or so!
(Or can someone persuade these southern men to make p-channels as well?)

RK

 

[ljfont]

Here's one of the 10 B4 prototypes that went out for industry
evaluation.

Is the Full Range High Pass filter a buffered phase coherent crossover network?

 

[Nelson Pass]

One prototype was. The ten I referred to were simply
adjustable Sallen-Key filters 6 or 12 dB/oct with independently
adjustable poles and unity gain buffer.

 

[vdi_nenna]

Open Baffle Design

Hi Nelson,

Any word on an Open Baffle design? There were some rumors of such a project floating round. Is it true?

Thanks,

Vince

 

[Nelson Pass]

Yes, it's a real project, although it's gotten kind of large.

It has made it to the front burner. I imagine that actual
writing will commence at Sea Ranch later this month.

 

[vdi_nenna]

Nice! Thanks for the update. Enjoy the get-a-way!

 

[vdi_nenna]

Heard an OB for the first time a couple of weekends ago. It was a 12" 100+ db P-Audio driver with 4" concentric tweeter; driven by my F5 and BOSOZ. I was surprised by the low end and how tight it was.

Looking forward to seeing what you have up your sleeve, Mr Pass.

 

[Nelson Pass]

I have neglected this thread for a while, but that will change
shortly, so gird your grids...

 

[jackinnj]

I have neglected this thread for a while, but that will change
shortly, so gird your grids...

or grab your loin, as the case may be...

 

[jameshillj]

... a higher powered F3, perhaps?

 

[kzim229]

b2, -3, -4?