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The Pumpkin preamp package(s) for sale

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Zen Mod

Zen Mod

Official Court Jester
Joined 2003
zenmod.in.rs/
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#1
well , as in subject ;

never-ending developing thread (mostly off topic) HERE

freshly started building thread with definitive schematics and other related info HERE


full Pumpkin package is consisted in variant marked as "A" ;

so:

"A" package - two main boards with two reg boards

main pcb - 2 pcs
J310 jfets - 2 matched pairs
J310 jfets - 2 pieces
BC546B - 2 matched pairs
BC546B - 2 pcs

reg pcbs - 2 pcs
BC546B - 4 matched pairs
BC546B - 6 pcs
BC556B - 4 matched pairs
BC556B - 6 pcs
LM336-5Z - 4 pcs
BF245C - 4 pcs

price 95 Euro


"B" package - two main boards with just one reg board; this variant possible with few changes in resistors on reg board and somewhat bigger heatsinks than you can see in mentioned threads

main pcb - 2 pcs
J310 jfets - 2 matched pairs
J310 jfets - 2 pieces
BC546B - 2 matched pairs
BC546B - 2 pcs

reg pcbs - 1 pcs
BC546B - 2 matched pairs
BC546B - 3 pcs
BC556B - 2 matched pairs
BC556B - 3 pcs
LM336-5Z - 2 pcs
BF245C - 2 pcs


price is 80 Euros



"C" package just two main boards- without regs

main pcb - 2 pcs
J310 jfets - 2 matched pairs
J310 jfets - 2 pieces
BC546B - 2 matched pairs
BC546B - 2 pcs

price is 59 Euros

"D" package just two reg boards , if you need them for your own eeny weeny whatever sort of stage ; they're easy scalable for anything between twice 15 to twice 80 - 90 volts at output and - somewhat dependable of output voltage - even to 300 mA of output current

reg pcbs - 2 pcs
BC546B - 4 matched pairs
BC546B - 6 pcs
BC556B - 4 matched pairs
BC556B - 6 pcs
LM336-5Z - 4 pcs
BF245C - 4 pcs

price is 65 Euros

my modest conclusion is that entire package is ,even most expensive, , still best bang for the buck ......


P&P expenses are EXTRA ; count on 6 to 12 Euros ,depending of destination ; Air Mail off course .

Paypal fee is my concern

you can reach me - if you wish , on this e-mail addy :

zenmodiyaudioATgmail.com ; obviously- you need to replace "AT" with "@"

in case that you can make your own pcbs for :Pumpkin: feel free to do this and join us in mentioned building thread 😉

edit: if you want matched IRF outputs , that's 20E more
 
Last edited:
#3
dviswa said:
Hi ZM,

Can you please provide a BOM?
Also is it possible to add a heat sink to the packages for an extra cost?

Regards,
Dinesh
Click to expand...


you can expect generic list of parts this days in new thread ,also as pdf file fr download .
I can't make proper BOM (with digikey or something purchase numbers etc) for you fellas living in US , just because I don't live there and I can't easily check that some part actually exist in vivo,not just in online catalog .

anyway - I think that generic BOM will be enough ,especially if I include adequate simillar types for some positions .

heatsinks ?
off course I can , but you really don't need to buy them from any greedy Eu based boy ; you can easily cut few sheets of AL ....... dissipation is not so big ; heatsinks on piccies are nice and effective , but not more effective than same length ,twice that high - 3mm Al sheet.
 
#4
Hi ZM,

Thanks for the BOM. Please consider adding for extra cost
Q5,Q7 IRF9510 matched pair
Q6,Q8 IRF510 matched pair

This will save the hassle of buying a large number of these devices and matching them, since you are already providing some of the matched devices.

Obviously you know somebody will raise the same question for the shunty once you have published a BOM for it.

Regards,
Dinesh
 
#5
dviswa said:
Hi ZM,

Thanks for the BOM. Please consider adding for extra cost
Q5,Q7 IRF9510 matched pair
Q6,Q8 IRF510 matched pair

This will save the hassle of buying a large number of these devices and matching them, since you are already providing some of the matched devices.
................
Click to expand...


well, I'll do that if someone will be interested 😉

Obviously you know somebody will raise the same question for the shunty once you have published a BOM for it.
Click to expand...

for Shunty - little bjts are just "good to be matched , but not absolutely necessary ; I'm sending them just because they aren't big hassle neither for matching or final cost , and it's really better if they are matched .

regarding IRFs and darlingtons in Shunty , there is absolutely no reason for matching them
 
#7
To save searching through that perfectly organized pumpkin thread -

Regarding the fancy pants shunty, How many volt secondary transformer minimum do we need to get +-36v?

Or should I ask - How many volts does shunty drop before arriving at final regulated voltage?

Will Shunty drive Pumpkin drive F4?
 
#8
mpmarino said:
To save searching through that perfectly organized pumpkin thread -

Regarding the fancy pants shunty, How many volt secondary transformer minimum do we need to get +-36v?

Or should I ask - How many volts does shunty drop before arriving at final regulated voltage?

Will Shunty drive Pumpkin drive F4?
Click to expand...


you'll find that all in dedicated BOM-schmtc-few tips -pdf

ya need dreky 84Vct / 600mA xformer

so - 84/2x1,41~60Vdc ........... so you cheapskate can use even 63V caps on input of Shunty

well - if sissssy series reg almost succeeded at BAF to drive a F4 driving Pumpkin ............ I presume that Shunty will do this :devilr:
 
#9
Zen Mod said:



well, I'll do that if someone will be interested 😉



for Shunty - little bjts are just "good to be matched , but not absolutely necessary ; I'm sending them just because they aren't big hassle neither for matching or final cost , and it's really better if they are matched .

regarding IRFs and darlingtons in Shunty , there is absolutely no reason for matching them
Click to expand...

Great, please make a Package A+ , which include the additional FETs.

Thanks,
Dinesh
 
#12
dviswa said:
Oops, I forgot to ask another question. The forum does not let me edit posts beyond 30 minutes.

ZM,

What is the output of this preamp and at what load impedence?

Thanks,
Dinesh
Click to expand...


in this moment I don't have few things:

1. papers with measured data for output impedance ; they're maybe even in trash 😉

2. working Pumpkin ; mine was just in prototype (ugly mess 😉 ) ; first pair of main boards (populated ,tested ) were on BAF :clown: ; I didn't have time to make another one , yet ;

after finishing BAF main boards , I received few days after Shunty boards and I have time just for assemblage and final testing of just one . so - I'm two main boards and one Shunty away of full Pumpkin :devilr:

but......... I can answer you pretty satisfactory - you can squeeze nearly 65Vpp (46Vrms) from Pumpkin output ;

slightly decrease R13 and R18 ,increase 10x C4 and C5 , and you can probably drive whatever earcans you have ...........

good enough ?

even if I cleverly avoided to give you any number ............. :clown:
 
#13
Zen Mod said:
slightly decrease R13 and R18 ,increase 10x C4 and C5 , and you can probably drive whatever earcans you have ...........

good enough ?
Click to expand...

Even an AKG K1000? :devilr:

😀

You really keep interesting times, ZM. I was totally surprised to see your post at this time. It was after 9 PM Eastren time when I posted it.:smash:
 
#14
dviswa said:


Even an AKG K1000? :devilr:

😀

You really keep interesting times, ZM. I was totally surprised to see your post at this time. It was after 9 PM Eastren time when I posted it.:smash:
Click to expand...


so what ?
now is 0503 in the morning here .......... :clown:

well - I tried my K270 Studio on Pumpkin with their 55 ohms impedance

I heard just slight loss in bass (with output caps of just 2 x 4u7) but I haven't impression that :Pumpkin: is running out of steam ....

maybe because my test proto setup was with 250VA donut and 2x 30.000 uF...

but- AKG 1000 ?

yes- with doubling Iq , at least .

:devilr:
 
#16
well , I'm not related to Steve in any way ( except that I just adore surplus places and junkyards ; even if I don't have any surplus place around me ,and have never enough junkyards around me) , but I think that Apex Jr. is good place for asking

anything what will result in (twice) 58 to 70Vdc will be adequate

AR2's biggie xformer for quickie :Pumpkin: bird nest is from Apex Jr.

dirt cheap even for my cheapskate habits .........

well ........ I don't have link handy - if someone is interested , he can see pics in BAF thread...... and Steve's site is HERE


EDIT:

and , yes - EI xformer is always better for preamps than donut , or anything else
 
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