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Old 19th January 2013, 11:58 PM   #9051
Salas is offline Salas  Greece
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Yes. You should have half the BC560's emitter to ground voltage on its collector to ground after trimming, ~10V across second stage's Jfet drain to ground, for 35V to ground B+. Also the BF245 looks like drawing much. Either isn't an A type (lower IDSS rank) or its a short.
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Old 20th January 2013, 12:39 AM   #9052
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I have bf245b. I have 4ma of current on Jfet gain stage after 43R degeneration. Both channels exactly the same. In terms of general settings and measurement. Is it the bf245b?
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Old 20th January 2013, 12:54 AM   #9053
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Check its legs in its datasheet, its not like Toshiba pin order in case you did not, also take them down to 5mA with a resistor on their gate to source, feeding the leds from gate. See from there on by measuring again.
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Old 20th January 2013, 01:37 AM   #9054
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Are you saying insert a degeneration resistor into current layout. The led's are just a Vref for the bjt, being fed by bf845 current source, correct.
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Old 20th January 2013, 06:26 AM   #9055
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Correct. Or use a K117GR if there is no space for a resistor. Only be sure about orientation. If its wrong or type is changed, do the Irish dancer leads with a pliers.
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Old 20th January 2013, 09:50 AM   #9056
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when you use obbligato premium gold as a coupling which end Is recommended to be In and which out for signal
do you recommend bypass of obbligato premium gold 4.7 uF - If you do which bypass and value - teflon ft-1 ft-2 ft-3
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Old 20th January 2013, 10:31 AM   #9057
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Quote:
Originally Posted by samoloko View Post
when you use obbligato premium gold as a coupling which end Is recommended to be In and which out for signal
do you recommend bypass of obbligato premium gold 4.7 uF - If you do which bypass and value - teflon ft-1 ft-2 ft-3
I normally use the cap orientated as per its casing lettering.
input -------[Obbligato]-------- output

I would start without any bypass. Let the caps settle and see if you like the sound. I once bypassed one of those with a smaller obbligato (0.47u) with good results.
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Old 20th January 2013, 10:33 AM   #9058
RCruz is offline RCruz  Switzerland
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Hi buzz

Here you have my measurements... appart from output buffer, it is the same as yours.
Attached Images
File Type: png Folded cascode 1st build.png (126.6 KB, 103 views)
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Old 20th January 2013, 10:36 AM   #9059
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thank you for reply
I have listened at least 100 Hrs but still think that Is missing air
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Old 20th January 2013, 10:38 AM   #9060
RCruz is offline RCruz  Switzerland
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Originally Posted by samoloko View Post
thank you for reply
I have listened at least 100 Hrs but still think that Is missing air
In that case a 100n FT-3 will open it wide.
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