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Old 6th January 2013, 09:47 PM   #831
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less bias pr device. or higher total bias.
sonics will change a tiny bit. but for the better or worse, that depends on who's listening
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Old 6th January 2013, 09:58 PM   #832
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Hi Guys,
I got these in the mail yesterday and have been at them mostly since,
Check them over,
I am planing on 32 volt rails,around 15 volts for cascode,
I couldn't find the link about the link,Link to gnd?
Q5 and Q6 are correct with the silk ,are they backwards ?need to be turned around?
N out and P out switched on signal board,
any known issues?
I decide it was best to ask instead of smoking,,,,,,,,,
Thanks alot,
NoSmoking.........
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Old 6th January 2013, 10:01 PM   #833
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Quote:
Originally Posted by N-Brock View Post
R5 has 4.22 volts across it. R6 has 4.55 V.

34 volt rails. No cascade going on.

I really appreciate the effort.
What V across source resistors of mosfets. Also, measure across gate and source of mosfets directly. 34V is pushing the Jfets id they are high Idss, but they are alive.
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Old 6th January 2013, 10:06 PM   #834
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Quote:
Originally Posted by noSmoking View Post
Hi Guys,
I got these in the mail yesterday and have been at them mostly since,
Check them over,
I am planing on 32 volt rails,around 15 volts for cascode,
I couldn't find the link about the link,Link to gnd?
Q5 and Q6 are correct with the silk ,are they backwards ?need to be turned around?
N out and P out switched on signal board,
any known issues?
I decide it was best to ask instead of smoking,,,,,,,,,
Thanks alot,
NoSmoking.........
Power up FE first and set drop across r5,r6 to 3.5V using P1 and P2. THis will allow you to figure out which way to turn the posts in order to adjust them. You will be starting at similar Vgs and will have solid footing for hooking up mosfets and firing them up.
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Old 6th January 2013, 10:06 PM   #835
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Q5/Q6 is correct oriented on those boards. N-ch and P-ch is also correct.

Quote:
Originally Posted by noSmoking View Post
Hi Guys,
I got these in the mail yesterday and have been at them mostly since,
Check them over,
I am planing on 32 volt rails,around 15 volts for cascode,
I couldn't find the link about the link,Link to gnd?
Q5 and Q6 are correct with the silk ,are they backwards ?need to be turned around?
N out and P out switched on signal board,
any known issues?
I decide it was best to ask instead of smoking,,,,,,,,,
Thanks alot,
NoSmoking.........
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Old 6th January 2013, 10:07 PM   #836
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Quote:
Originally Posted by AudioSan View Post
Q5/Q6 is correct oriented on those boards. N-ch and P-ch is also correct.
Oh, that sucks. All ok on your front.
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Old 6th January 2013, 10:08 PM   #837
N Brock is offline N Brock  United States
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Quote:
Originally Posted by buzzforb View Post
What V across source resistors of mosfets. Also, measure across gate and source of mosfets directly. 34V is pushing the Jfets id they are high Idss, but they are alive.
P-ch
Source resistors: 136 mV
G-S: 4.06 V

N-ch
Source res: 139 mV
G-S: -4.38 V
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Old 6th January 2013, 10:11 PM   #838
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Originally Posted by buzzforb View Post
Oh, that sucks. All ok on your front.
what sucks?
well. got my sinks cut tonight. so there will be some drilling and tapping tomorrow and if i'm lucky. there will be a power up
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Old 6th January 2013, 10:19 PM   #839
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Quote:
Originally Posted by N-Brock View Post
P-ch
Source resistors: 136 mV
G-S: 4.06 V

N-ch
Source res: 139 mV
G-S: -4.38 V
If your maxed out on p1 and p2, then simply increase R5 and R6. You hove lower Idss Jfets and you just need higher load resistor, as AudioSan suggested, to bring up VGS for the mosfets. All is perfectly fine.
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Old 6th January 2013, 10:20 PM   #840
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Quote:
Originally Posted by AudioSan View Post
what sucks?
well. got my sinks cut tonight. so there will be some drilling and tapping tomorrow and if i'm lucky. there will be a power up
Thought maybe you were suggesting possible routing error on output fets in beta board.

BTW, you may know this, but power drill with clutch set low, and some WD40 is excellent speedy tapping method.
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