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Old 17th November 2007, 04:24 AM   #1421
jleaman is offline jleaman  Belgium
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Quote:
Originally posted by Peter Daniel


That ground connection is only when C5/C6 are installed, otherwise it's not being used. I explained it here: http://www.diyaudio.com/forums/showt...72#post1324572

ok, Fair enough,

However im still not able to get this amp working ive just checked all the resistors to the schematic, ive checked the pot's and i have checked the psu boards this is so bizzar. My alephs have never been this hard to figure out.

GRR
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Old 17th November 2007, 04:52 AM   #1422
lykkedk is offline lykkedk  Denmark
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What now jleaman, how much voltage on pwr resistors now ? I mean do you only got voltagedrop on left or right side now? As you mentioned before, you figured the GND thing out ?

Jesper.
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Old 17th November 2007, 05:00 AM   #1423
jleaman is offline jleaman  Belgium
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Quote:
Originally posted by lykkedk
What now jleaman, how much voltage on pwr resistors now ? I mean do you only got voltagedrop on left or right side now? As you mentioned before, you figured the GND thing out ?

Jesper.

I haven't figure out the gnd thing yet, im totally lost now. where am i suppose to get the ground from now, i mean you have to have 3 wires from the psu, positive negitive and gnd. where does ground go if its not at the end of the board.
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Old 17th November 2007, 05:05 AM   #1424
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Quote:
Originally posted by Peter Daniel
If you look at F4 amp schematic, you will notice that power ground is not there, only the input signal ground.

The power ground is located on PS board, and this is where speaker ground connects. Signal ground reference is taken from PS board, with a separate wire, and connects to GND point on amp board which is beside SG point (SG is used for ground connection from input RCA).

The GND on the opposite side of the board is only for C5/C6 and if those caps are being used you need another ground wire from PS board.
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Old 17th November 2007, 05:17 AM   #1425
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ok so the psu ground is beside the input ground, the speaker ground is off the psu, now when turning up the variac, i get 5V on the speaker ouput, i can turn the P2 down all the way to 3.5V but then it clicks ( meaning im at the end) but the voltage is still high. I don't have my variac turned up hi because i don't want to blow up this amp and cook these fet's that cost a fortune.
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Old 17th November 2007, 05:21 AM   #1426
lykkedk is offline lykkedk  Denmark
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First thing is to adjust the voltagedrop on pwrresistor's, then DC-offset(P2) adjust when done... Do you still got 1v(P1 ~middle) on pwrresistor's, cause then something else is wrong. Maybee time for closeup picture.

Jesper
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Old 17th November 2007, 05:29 AM   #1427
jleaman is offline jleaman  Belgium
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Quote:
Originally posted by lykkedk
First thing is to adjust the voltagedrop on pwrresistor's, then DC-offset(P2) adjust when done... Do you still got 1v(P1 ~middle) on pwrresistor's, cause then something else is wrong. Maybee time for closeup picture.

Jesper

Here you go, when i power it up and have 5v on the speaker i have about .27v on the output.
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Old 17th November 2007, 05:48 AM   #1428
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Quote:
Here you go, when i power it up and have 5v on the speaker i have about .27v on the output.
You mean 0,27v on resistor's (all 6 ???), and 5vdc between +out/gnd right ???

Jesper.
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Old 17th November 2007, 05:50 AM   #1429
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Quote:
Originally posted by lykkedk


You mean 0,27v on resistor's (all 6 ???), and 5vdc between +out/gnd right ???

Jesper.

correct, and that is not even at full power on the rails. I can hear my 1kva variac humming lots at 60V ac, im not sure of the rail voltage on the amp i can check that if needed also.

Jase
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Old 17th November 2007, 05:57 AM   #1430
lykkedk is offline lykkedk  Denmark
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q6, q7, q10 is irfp9240 on your'e setup right ???

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