Pumpkin preamp - ordered by Steen , official making thread - Page 346 - diyAudio
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Old 26th December 2012, 09:56 AM   #3451
Zen Mod is offline Zen Mod  Serbia
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I did replied , but can't do again , because I deleted plenty of messages in my box

write here
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Old 26th December 2012, 10:22 AM   #3452
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I did replied , but can't do again , because I deleted plenty of messages in my box

write here
The question is about C5 1nF Polyester (as project) or 1nF Silver Mica (can it be a upgrade) or without C5 (can the amp be yet stable or not),in this last case how i can check if it is yet in sure zone?
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Old 26th December 2012, 10:43 AM   #3453
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check for oscillations on output with CRO

if you don't have any , don't use these 1nF

if you need them - put whatever you have in drawer - no need for mica
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Old 26th December 2012, 11:13 AM   #3454
tonimxp is offline tonimxp  Italy
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check for oscillations on output with CRO

if you don't have any , don't use these 1nF

if you need them - put whatever you have in drawer - no need for mica
Sorry! What is CRO?

I need to use the oscilloscope and signal generator with 100hz 1khz and 10khz signal input?
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Old 27th December 2012, 09:40 AM   #3455
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COMPARE
the input signal to the output signal using a twin beam or dual trace Cathode Ray Oscilloscope (CRO).
Use a variety of signals, including sine, triangle and square, 10Hz to 50kHz, at a variety of levels.

"Compare" is the really important part of the technique.
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Old 27th December 2012, 09:54 AM   #3456
Zen Mod is offline Zen Mod  Serbia
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Tony

for start - if you're not having enough praxis with CRO , just connect this (attached) across spk terminals,of course - with amp powered on
in silent , then with some light level muzak

if LED's are silent , you're good to go , without those two 1nF caps
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Old 27th December 2012, 01:00 PM   #3457
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Cathode Ray Oscilloscope (CRO) ...Good to know,thanks Andrew!

About CRO use...i can try to find the power switch and after i can try also to do something more...but Alex i have to tell you ..."you know always something more of Devil" What mind had designed this circuit..almost doubt (for its simplicity) that will work!

Thanks Alex and Andrew!
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Old 11th January 2013, 08:15 AM   #3458
tonimxp is offline tonimxp  Italy
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Default About shunty heatsink temperature

Hi at all! Please is normal about 70 measured on heatsink of shunty (no load connected and cover open ) ,or i have to add more alluminium sink?
Thank in advance

Antonio
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Last edited by tonimxp; 11th January 2013 at 08:19 AM.
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Old 11th January 2013, 08:19 AM   #3459
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without load , everything is dissipated on Shunty itself

when you connect load , dissipation will go down ........

so , just relax
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Old 11th January 2013, 08:30 AM   #3460
tonimxp is offline tonimxp  Italy
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without load , everything is dissipated on Shunty itself

when you connect load , dissipation will go down ........

so , just relax
Thanks Alex!
I supposed instead that connecting the load shunty would collapse!

Sorry my mistake
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