Pumpkin preamp - More Boring Making Thread

[Zen Mod]

MODERATOR'S NOTE

This thread is a subset of is a synopsis of the thread:

"Pumpkin preamp - ordered by Steen , official making thread"

http://www.diyaudio.com/forums/showt...hreadid=118994

I have removed all of the off topic posts so it is less entertaining but possibly more useful to learn about the Pumpkin

Variac

END MODERATOR'S NOTE
__________________________________________________ _______

well ...... seems ages ago ,buried in some obscure DiyA Pass thread , after few quickie (on back of napkin) modifications of XYWZwhatever BOSOZ , my budy Lucky Luke (AKA steen) , demanded one little preamp with balls ....

few posts later , LL have some ideas about topology, perfectly good for me , just because I'm good at paper (napkin) and hand calc almost as he is good in making amps ........

little later - I already have some quickie quickie drawn , but somewhat flipped in regard to LL's idea,with added output stage(s) etc.

main reason why I flipped it is because I feel ( well - I rarely think,anyway) that's smart to use some non-audio-fancy-schmanzy Jfet , which is easy to find in near tobacco store, with all other parts .....

well - result is here (lookie lookie schmtc)

crazy process of delivery is also crazy documented in THIS
thread .........

I can just say tnx to entire OFF TOPIC MOB , just because they make my life miserable with regular questions "will it drive F4 " etc .

anyway ......... for first post is 'nuff


schematic:
(next post -The Shunty)...........

[lykkedk]

setup in my livingroom... Swinging so easily 40v with 1,8 on input !!!

Thank's for all the help ZenMod... Maybee it will be a while before finishing it up...

I made a from scratch, designing my pcb (clumsy i know) myself... but the thing is playing really nice, not to mention very relaxing too. All diy'ers, which life depend's on the F4, really should consider the to drive it wild an mad...

ZenMod nice weekend...

Jesper.

[Zen Mod]

crazy danske was fast almost as his country man LL

lykkedk earned his right to post piccies of his own because he is first who actually made non-prototype version ..........

first official pair of main boards are happily arrived at first BAF in history....... we'll hear more about Smashing and Barking tomorrow......


well- steen ordered , but he didn't count on my everlasting love for shunt regs .
as result of that love there is The Shunty ........ simply - proper reg for any eeny weeny preamp ........

my friend Oly (AKA Vangelis on DiyA) is responsible for stunning pcbs for both and Shunty ; btw. "The Shunty" is his name for that simple reg . you'll see pcb piccies in later posts.

he is also responsible for keeping me in sane boundaries ; well - almost keeping me

when I drew series reg, in front of already drawn and tested shunt part of now existing Shunty, his only (and last ) comment was "that's pure demonstration of force....... why you need that ?"

I also wanna say many tnx to Off Topic Mob , which constantly make my life miserable with repetitive questions as "will it drive F4?" etc ..........

anyway - this was (is) open source project ......... my intention to make decent preamp for regular DiyA members, without braking leg and arm to find obscuremadeofpreputium audio parts (read - toshiba 3 or 7 legged fuses) ...

both schematics are here ; I intend to sell pcbs along with matched crucial parts , in several levels ........ just main boards with parts, just Shunty with few important parts (if they exist at all) , complete package, main boards with just one Shunty ( if you are bean counter) etc.

to cut a story..........

here is The Shunty schematic:

[Zen Mod]

[Zen Mod]

[Zen Mod]

The Pumpkin preamp package(s) for sale...............


HERE

[Zen Mod]

as in subject

if anyone see mistake , let me know

[mpmarino]

Page 3 is most informative.

[RKH]

John,

The Pumpkin is the actual pre-amp

Shunty is the regulated power supply for the Pumpkin pre.

Hope that helps.

Ryan

[Zen Mod]

Originally posted by mpmarino
Page 3 is most informative.

agree ...........
you can't so easy find schematic of INT-150 ........