my flat pre amp from dr bora's design.
picture here
no less than 10 identical posts , posted in 10 different threads ......
![rolllaugh :rofl: :rofl:](https://files.diyaudio.com/forums/images/smilies/rolllaugh.gif)
seems that you are extremely happy , in same time finding most impressive way of social bonding .....
![clown :clown: :clown:](https://files.diyaudio.com/forums/images/smilies/clown.gif)
edit:
to make you completely and nonquestionable happy - -here is your picture
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Gentlemen,
Finally I am going to put the
to work. I am building it into its final case right now. Before closing the thing I have been running some more tests with Shuntys only and 470R as load.
Unfortunately R21,R22 keep "blowing" - they are actually not burned, just R is > 2M. My first attempt was 1R8 1/4W noname according to notes in the cook book, then I used 2R 1W Vishay metal film. They just died 5 minutes ago when I switched of/on the third time (It always happens when I switch it on). Both channels at the same moment. I use low ESR Rubycon caps and a 42V 250VA EI transformer...
What could I do?
Thanks
Sven
Finally I am going to put the
![pumpkin :Pumpkin: :Pumpkin:](https://files.diyaudio.com/forums/images/smilies/pumpkin.gif)
Unfortunately R21,R22 keep "blowing" - they are actually not burned, just R is > 2M. My first attempt was 1R8 1/4W noname according to notes in the cook book, then I used 2R 1W Vishay metal film. They just died 5 minutes ago when I switched of/on the third time (It always happens when I switch it on). Both channels at the same moment. I use low ESR Rubycon caps and a 42V 250VA EI transformer...
What could I do?
Thanks
Sven
An externally hosted image should be here but it was not working when we last tested it.
What could I do?
Thanks
Sven
First, I would have prayed!
Regards zeoN_Rider
I guess I will not be able to fix it "ex post" with this method?![]()
Regards zeoN_Rider
.......I use low ESR Rubycon caps and a 42V 250VA EI transformer...
What could I do?
....
you have two solutions , obviously ;
1. either toss those Ruby's out .........
2. or keep changing resistors ; put some fuse holders in their place , to ease that change ........
or ....... maybe you can decrease them in value , 'till they start to survive powering up
![clown :clown: :clown:](https://files.diyaudio.com/forums/images/smilies/clown.gif)
What could I do?
Sven,
if you still have that Sledge tool from the D-Seite, shoot it !
I have to admit "shooting it" was among my first thoughts, however that is satisfactory only at a very very short term
.
Ex post praying did not work, so I guess will have to actually put other resistors. The fuse socket is not such a bad idea since these PCBs clearly have been designed to solder ONCE and then never again![Roll eyes :rolleyes: :rolleyes:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
.
I don't really know how much current runs through these resistors during startup and why 1W is not enough - I already halved the value. Without much experimenting - bear in mind frequent soldering/desoldering is not the best thing to do to these PCBs
- what should I use? 1/2W Carbon 2R? Generg mentioned MOX?
Regards
Sven
Ex post praying did not work, so I guess will have to actually put other resistors. The fuse socket is not such a bad idea since these PCBs clearly have been designed to solder ONCE and then never again
I don't really know how much current runs through these resistors during startup and why 1W is not enough - I already halved the value. Without much experimenting - bear in mind frequent soldering/desoldering is not the best thing to do to these PCBs
![tongue :tongue: :tongue:](https://files.diyaudio.com/forums/images/smilies/tongue.gif)
Regards
Sven
Hi there.
I have started to check and solder what i have in stock...![Cool :cool: :cool:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
On Pumpkin cook book, i read : R9, R10, R14, R15, R29 : 150E to 240E.
How can i define the good value ? Is 220R OK ?
How to define the correct value for caps ?![Eek! :eek: :eek:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Sorry for these noob questions...
But i am sure i'll have more... ![Stick out tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I have started to check and solder what i have in stock...
On Pumpkin cook book, i read : R9, R10, R14, R15, R29 : 150E to 240E.
How can i define the good value ? Is 220R OK ?
How to define the correct value for caps ?
Sorry for these noob questions...
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