DIY progress report

[Melon Head]

My bet will be that it will be something entirely different (as usual).
That 1000 Jfet amp has been in the works for a while, or maybe an amp based on 2sk82/2sj28, as a guess.
Or will it be the open baffle speaker project?

 

[carpenter]

...gird your grids...

Grids, as in bottle head amplification?

 

[Nelson Pass]

Well...

I haven't decided what. I am operating simply from the
observation that this thread needs freshening

I have a cool list, maybe something will match your heart's
desire, so let me know. Winner gets a prize. (We're cleaning
out the shop again).



Fine print: contest open to everyone except ZM, who
already got his prize

 

[Nelson Pass]

That 1000 Jfet amp has been
in the works for a while, or maybe an amp based on
2sk82/2sj28, as a guess. Or will it be the open baffle speaker
project?

None of these, which are in process.

The Beast has 5 boards (3000 Jfets) stuffed.

(Whew!)

The Sony Vfets have 24 sinks machined, moving right along.

The OB project keeps getting bigger, outpacing my ability to
write. Some new 12 inch FR's out of China added to the pile
......

 

[Melon Head]

So is the competition is to guess what you are going to do or is it to suggest what you should do?

 

[defect9]

... a higher powered F3, perhaps?

oh god I hope so


I'd love to see a FET amp with a sweetness knob for specifically adjusting 2nd/3rd harmonic balance.

 

[carpenter]

You know what? I'd love to see Nelson teach us something about tubes--something simple, and very sweet.

 

[Melon Head]

There are just so many possibilities.

Maybe an amp using those new semisouth depletion mode Power Jfets SJDP120R085
http://www.semisouth.com/products/uploads/DS_SJDP120R085_rev1.0.pdf

 

[R-K Rønningstad]

There are just so many possibilities.

Maybe an amp using those new semisouth depletion mode Power Jfets SJDP120R085
http://www.semisouth.com/products/uploads/DS_SJDP120R085_rev1.0.pdf

Would love to see a complementary p-channel part! But I guess not in my lifetime.
(The datasheet refers to solar inverters - even though I know what a solar inverter actually is, it sounds like something Darth Vader had commisioned.)

 

[Vix]

Hmm....mmM....Magnetic amp, with lots of iron, papa made

 

[Melon Head]

Nelson has never done a quasi complememntary output stage (to my knowledge), maybe these new jfets might entice him to try

 

[flg]

I like the line level crossover idea. That is what I'm most in need of Maybe a center ch sub below 150Hz, and a mid to high at about 3kHz
Maybe built on the B series? And maybe a lightspeed deal on the output ?
Was there ever really a "High Low Pass"?

 

[Tea-Bag]

There are just so many possibilities.

Maybe an amp using those new semisouth depletion mode Power Jfets SJDP120R085
http://www.semisouth.com/products/uploads/DS_SJDP120R085_rev1.0.pdf

I thought this was going to be the Nemesis, with an output transformer, but have not seen anymore about it.

I also vote for diy jfet crossover, but plans look right now for real B5, which would go against the commerce division.

I've been thinking a lot about digital lately, so maybe some new digital output stage mods would be my vote.

 

[vdi_nenna]

How about an amp with no transitors at all... The sound of nothing clapping.

 

[jacco vermeulen]

Fine by me, just hold the grits.

 

[jameshillj]

The concept design of a higher powered F3 (F6?) would be most helpful, and the B2 also.

 

[Tea-Bag]

The concept design of a higher powered F3 (F6?) would be most helpful, and the B2 also.

The SJDP120R085 is a depletion JFET like the LU1014, and more available, and can take more voltage and current.
I've had a few people ask me about retrofitting them into an Z9, F3 type clone. Of course I am not knowing the best method here. I think removing the cascode mosfet would be in in order.

 

[vdi_nenna]

A higher power version of F5, and maybe balanced too.

A simple, balanced Jfet preamp.

 

[carpenter]

How about an amp with no transitors at all... The sound of nothing clapping.

Yeah! We'll call it the clap...

 

[vdi_nenna]

Yeah! We'll call it the clap...

That might be catchy...

"Avoid the clap, Jimmy Dugan"