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Old 18th June 2008, 02:18 AM   #2491
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it is the bleeder resistor-those two jumpers hook the two ground rails together and the wire at the end of the board is the ground wire to the star ground.i didn't know i was doing anything new--do you guys just use 1 board and 4-- 30,000 uf caps??? two boards for 8 --15,000uf caps is what i did-just like the ps diagram showed that i have. no cold joints that i know of, was very careful with that.
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Old 18th June 2008, 02:27 AM   #2492
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well this amp has been on for 12 hours, believe it or not the hum is less and in my main system the F4 just drives the lowthers and ribbons in my basszilla's which is 150 hz and up so the hum is even less- i can just hear it from my listening seat. been listening to patricia barber-taste of honey-black magic woman... and just about slid out of my chair!!!!! detail- nuance-detail-lack of any coloration(compared to what i had before) and a soundstage that was 10ft by 16ft in a 8x12 room!!!!!!!!!!
thankspapa thankspapa thankspapa
i'm spending my stimulus check on an F5!!!!!!!!!!!!!!!!!
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Old 18th June 2008, 02:28 AM   #2493
tms0425 is offline tms0425  United States
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Quote:
Originally posted by bubba177
it is the bleeder resistor-those two jumpers hook the two ground rails together and the wire at the end of the board is the ground wire to the star ground.i didn't know i was doing anything new--do you guys just use 1 board and 4-- 30,000 uf caps??? two boards for 8 --15,000uf caps is what i did-just like the ps diagram showed that i have. no cold joints that i know of, was very careful with that.
Take a look at my picture on post #2128. I agree with Carpenter and would stick to the Peter Daniels plan for the PS. +/- rails per board. The caps don't need to be exact. I think I used 15,000 x 4 for mine. I tested it with one trafo and PS board first, then just decided to overkill it with two later. Mine is absolutely dead quiet into 100db drivers, such that it's hard to tell it is even on.
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Old 18th June 2008, 08:12 AM   #2494
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@bubba

xformer's secondaries are wired in phase?
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Old 18th June 2008, 08:46 AM   #2495
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See, the boy does have a sense of humor.
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Old 18th June 2008, 09:13 AM   #2496
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Default hum

Bubba,

Check PSU caps polarization, there is something wrong for me, look at the attached picture.
Also check PSU caps temperature.
a.
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Old 18th June 2008, 11:11 AM   #2497
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Andrzej,

Bubba is using one secondary of the transformer to generate the minus voltage, the other for positive.
The PS board on the right side of the picture feeds the positive rails of both channels, 2 red wires.
The one of the left handles the minus rails, 2 Grey wires going left and right.

(setting them up as dual rail CRC boards, what the layout of the boards was intended for, would have been more rational. Symmetrical looks nicer, imio, only requires different resistor values in the CRC's. Rotating the PS boards 90 degrees and moving the rectifiers closer to eachother also would have saved a few feet of wiring.)
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Old 18th June 2008, 01:45 PM   #2498
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Quote:
Originally posted by jacco vermeulen
Or disconnect the labyrinth boards and try a simple lytic bank with a few wires to see if the CRC mumbo-jumbo is causing the hardships.

(might have been wiser to jumper the CRC boards at the front and the back instead of playing crossroads. Tom Waits in the Fisher King : Whoop, Whoop, now boarding for the Ground Loop Express)
like dis, master jacco?
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Old 18th June 2008, 01:47 PM   #2499
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and another angle....
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Old 18th June 2008, 01:53 PM   #2500
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Quote:
Originally posted by luvdunhill
and another angle....

Very pretty.....fear not the deep water, this fellow knows how to swim! Where can we read the post on it's evolution?
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