Pumpkin preamp - ordered by Steen , official making thread - Page 211 - diyAudio
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Old 1st June 2008, 03:03 PM   #2101
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Don't say that, ZM would be a big hit in the Manhattan garment district.
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Old 1st June 2008, 05:59 PM   #2102
steenoe is offline steenoe  Denmark
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Quote:
Originally posted by Manu

Steen : Are you sure you have to change to metal-case? A pity considering your beautiful wood-work. More air flow inside could mebbe cure the heatproblem? No?
All ya guy's are nut's I know I asked for F4 preamp, and I really like the sound of it.... Well, I will simply build the psu into a seperate case, just like the one my Pumpkin is in right now Surely, two cases dissipates double up on the heat, right? I have ordered the wood for it allready. BTW its Erocco-teak. Just hope I didnt butcher a rainforest

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Old 1st June 2008, 06:10 PM   #2103
steenoe is offline steenoe  Denmark
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Default Re: Cook Book - few more lines

Quote:
Originally posted by Zen Mod


- In case that you are fluffy with setting absolute offset (DC voltage between plus and minus
outputs of Pumpkin ) , you'll have replicated DC on both INPUTS of Pumpkin ........ exactly
divided by ratio of feedback net .
That will result in screechy noise during volume pot turning .....
cure is simple - Papa-like ....... just include 2u2 good cap on each input leg (both + and -)
between pot and inputs ; that will block DC to reach pot .
Hehe - that cure is certainly less evil than using any kind of Servo"


regarding these caps - Holger (HB) already sez long time ago that he even will not try his without input caps .........

as usuall , Cook Book can be found HERE


[/B]
You dont need to be fluffy, to need those input caps! I am sure I have been very very carefull to do the adjustments. With "very" I do mean very, indeed. I thought the woofer cones would fly through the room, when I first started up the Pampkin Horrible experience. If you dont like things like that, install the the input-caps
I didnt find them to hurt the sound in any way, though! Funny enough. I thought it would kill the transparency of the preamp, but it didnt.

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Old 1st June 2008, 06:49 PM   #2104
steenoe is offline steenoe  Denmark
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Quote:
Originally posted by Zen Mod
Steen - I just tried for you that version ( if I'm not wrong - PD's ?) of simple 1543 DAC , feeding 22K input impedance of next stage ;


there is not enough dynamics ; sound is -sorta interesting (different than SSDac with xformers , certainly ) but just with occasional glimpse of life in it ; details are almost there , but everything is somehow flat ;

you'll always know that impedance mismatch is in case , if you have wakoo response of volume control ....... turning it up almost without normal response , and then suddenly you have enough volume ;

purely subjective described ......
Thanks a lot ZM. That pretty much matches my impression. Except that I found on top of that, the sound was Zingy and generally not pleasing at all. I have a few details I want to change. The IV resistors needs to be changed to something totally different. Like RIKEN carbon..... or some really old carbon mass resistors, you know the 1/4 watters the size of a 3-watter....


Quote:
Originally posted by housing
Look.........Look!@@@@

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.
Those are really nice looking pictures Nice and sharp closeup's.
BTW I like your filmcaps, indeed

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Old 1st June 2008, 10:36 PM   #2105
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by steenoe

......


whazzat ?
RIFA , as usual?
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Old 1st June 2008, 10:48 PM   #2106
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Old 1st June 2008, 10:49 PM   #2107
Zen Mod is offline Zen Mod  Serbia
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Quote:
Originally posted by steenoe


All ya guy's are nut's I know I asked for F4 preamp, and I really like the sound of it.... Well, I will simply build the psu into a seperate case, just like the one my Pumpkin is in right now Surely, two cases dissipates double up on the heat, right? I have ordered the wood for it allready. BTW its Erocco-teak. Just hope I didnt butcher a rainforest


you'll be surprised if you make it as I wrote - with slots on both sides , on both bottom and upper plates ;

in that case - everything will stay in one box , with enough ventilation
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Old 1st June 2008, 10:51 PM   #2108
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Quote:
Originally posted by jacco vermeulen
It's a polyester pillow.

what's price for 4pcs of 5309 , ya dirty dozen dutchie member ?
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Old 2nd June 2008, 01:10 AM   #2109
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I'm sticking diodes in a clay puppet while i'm typing this, as it happens the thing looks a remarkable lot like you.
Repeat after me : no one does VooDoo like you do.

Nada from a vegetable grower.
Maybe your lowness can send me a number, plus an adressi that is readable this time, i'll kick them over subito combined with the ma24 junk.
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Old 2nd June 2008, 03:04 AM   #2110
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Quote:
Originally posted by jacco vermeulen
I'm sticking diodes in a clay puppet while i'm typing this, as it happens the thing looks a remarkable lot like you.
Repeat after me : no one does VooDoo like you do.

.........

yeah .....

nobody does VooDoo like me.............

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