Pumpkin Preamp - Perfect for F4

twitchie said:





:grouphug: Can I join the OT mob? I don't have a green button and I'm not a transsexual yet, but I do like BBQs and skinny legs :cannotbe:

At the risk of exposing myself as a stoopid newb, is this a power supply? I think sister's are great (especially other people's sisters), and I have a FISH under construction, so will I need a Pumpkin?

I am not sure about joining the mob, but yes its a powersupply AND a preamp:D My guess is that the preamp is the Pumpkin;) The powersupply kinda popped up later to feed the Pumpkin.
You will probably not excactly need a Pumpkin to drive a Fish, but I am sure it will be great at it:)

Steen:)
 
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Re: The Pumpkin - sister of B'fish j

jameshillj said:
Hi Alek,
I would suggest to leave the o/p caps off the pcb - many of them are big and just take up blank pcb space - bipasses can easily be fitted later if desired/required.
I would also suggest the common practice of adding a resistor to parallel the WR2 to reduce the 16 mA current through it or perhaps a "slave" transistor for the job, etc ....
.... and perhaps a small cap across those "green zeners"!

regards ... jh


well .........same opinion as steen's regarding output caps ;I'll leave that issue to Oly Mag- he will decide - without caps or just places for two 10/63 Wimas
resistor in para with WR2.....OK,but just mebbe (it's just 0,01W in worst case) ; transistor as slave - definitely not.
caps across the greens - they aren't needed.

steenoe said:


I think that the layout posted earlier on page 1 is a good one. Its flexible enough to be used for "smallish" filmcaps or BG nonpolar's. If one wants to use big output caps, they can easily be wired offboard using the connection points on the board.

:)


steen my man- on that layout you can't find any output caps ;) . mainly because Oly dreamed about DC coupled version ; I know already then that it's not possible . not if you have just upper part of UGS core.

and that's it - nothing more or less......even if I tried , I just can't move away from bloody UGS, if I want simplicity . what I have as options is to overcascode (as Oly's Papa Curl) or to........ I don't wanna mention.......

so- or just place for Wimas ,or even without..... so even Magura San can place his Russian beer can caps ........
 
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twitchie said:





:grouphug: Can I join the OT mob? I don't have a green button and I'm not a transsexual yet, but I do like BBQs and skinny legs :cannotbe:

At the risk of exposing myself as a stoopid newb, is this a power supply? I think sister's are great (especially other people's sisters), and I have a FISH under construction, so will I need a Pumpkin?


ok - you can join the mob; I presume that I'm enough qualified to say that,as invisible and humiliating man,with all sorts of other qualities,so needed in this place ;)

power supply - not yet tested : http://www.diyaudio.com/forums/showthread.php?postid=1237721#post1237721

working Pumpkin :
http://www.diyaudio.com/forums/showthread.php?postid=1243235#post1243235

steen sez about needing Pumpkin for Fish;

If ya wish to drive it balanced,why not ; Susy is Susy,even if Fish isn't Susy
 
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steenoe said:


That was a long post with few words:D Where is the picture:D
A monster it is, being capable of 70 volts outputswing:eek: The F4 will surrender at last:smash:


picture.........just imagine any of previously posted photographs, but with several parts flying in the air, led bargraph from some dreky cassete deck hangin on two tiny wires and also several missing parts ...... my already known overwhelming style ;)


btw- nobody from mob sez anything for http://www.diyaudio.com/forums/showthread.php?s=&threadid=104296

there is also good place for offfffff topic babbling..........hehe......as any other place ;)
 
Zen Mod said:



picture.........just imagine any of previously posted photographs, but with several parts flying in the air, led bargraph from some dreky cassete deck hangin on two tiny wires and also several missing parts ...... my already known overwhelming style ;)


btw- nobody from mob sez anything for http://www.diyaudio.com/forums/showthread.php?s=&threadid=104296

there is also good place for offfffff topic babbling..........hehe......as any other place ;)
Sorry, just returned to the forum after a busy time;) Ya know, life has an annoying tendency to interfer with our interests:D
 
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steenoe said:

Sorry, just returned to the forum after a busy time;) Ya know, life has an annoying tendency to interfer with our interests:D


yes- I know
I wait more than 24hrs between last instrument test and this sound test of Pumpkin ; in meantime I worked on more things than I even like to think

CRO amplitude test tomorrow ; seems that is final time to implement that dreky square wave converter in my old trusty Iskra gene..........
 
When my -at the time- six year old son was sitting in the barber's chair he noticed the unique wall clock in the mirror- mounted behind him. The clock was completely backwards so it could be read while looking in the mirror. My son quickly asked the barber "Does that clock go tock-tick?"

genius:)
 
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mpmarino said:
When my -at the time- six year old son was sitting in the barber's chair he noticed the unique wall clock in the mirror- mounted behind him. The clock was completely backwards so it could be read while looking in the mirror. My son quickly asked the barber "Does that clock go tock-tick?"

genius:)

It's because his mind hasn't been molded by life and tv and the world around him fully yet, so it is free to see things and ponder in ways we have lost the ability to do

My nephew was asking his dad for (candy) money once when he was about 3 and his father replied he had no money cause he just bought a house. My nephew then comes up to me and asks me if I have any money and I replied I had none either, so he then asked me

"why? did you buy a house too?"

Sometimes so complex, sometimes so simple

Kind of like this place


My F4 is running, so I'll use Pumpkin to drive it - my Fish is not mounted on heatsinks yet ...

mpmarino, did you ever get those F4 boards stuffed? Veteran says the jfet is backwards on one side - I haven't flipped mine around yet
 
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hour or two more ear testing today ;

SE in ,SE out

crummy old Kenwood DP-1100 (weight a ton,drek full with 2SJ and 2SK) cd player,mono-ed just tying both lives - crummy noname stereo log pot-Pumpkin- ( minus input tied to gnd) - old Iskra PP 4u7 jobbies on output (minus output again tied to gnd) - 9' cable- to both channels of ECL82SE (0W5/16E) to my adored RCAs ;

boy- even mono- is it deep .......?.... scary .

edit - PSU is nothing more than 300VA donut via variac ,generic plastic Graetz ,two 33000/63 Spragues . no regs .
 
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semi blurs

setup as in previous post ;
clean sine up to ~ 30Vpp

output loaded with permanent resistors on output ; 10k
 

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