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Old 27th October 2012, 05:24 PM   #501
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One side the schematic I think , the other side a board outline with the parts outlines shown- like the board silkscreen layer, Then the list of parts underneath.



Wonderfuuuul!!!
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Old 27th October 2012, 08:01 PM   #502
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Variac a NP pic on arm ?
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Old 27th October 2012, 08:17 PM   #503
Variac is offline Variac  United States
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with a halo!
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Old 28th October 2012, 05:27 AM   #504
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I got a second channel up and running. On each channel I installed a 1K resistor from base to emitter of Q3 with a jumper so as to increase bias current to about 2.2 amps. For some reason the DC adjustments of the two channels interact even though separate power supplys were used for each channel. The output caps, C1 are still in place.

For this first test I just used the balanced in and out of the Audio Precision System 1. I'll try other ways of connecting a single ended signal source in a day or two.
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Old 28th October 2012, 06:18 AM   #505
Variac is offline Variac  United States
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Maybe they aren't interacting but there's heat drift?
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Old 28th October 2012, 01:34 PM   #506
kikko is offline kikko  Italy
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I completed my ACA: Really good. i like it! It sounds really good and with an adequate level with the cdplayer, with the turntable i need a bit more gain.
but there is a little problem: is biased at 10V but is not heating up.. i can keep my hand on heatsinks indefinitely.
the heatsinks are hifi2000 model 3PD02200 (200mm*40*80) rated at 0,67c/w. one channel is a bit warmer than the other one.
Is that all right? Thank you!

About the t-shirts.. i'll work on the file using forum suggestions tomorrow
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Old 29th October 2012, 01:52 AM   #507
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Maybe they aren't interacting but there's heat drift?
I think it was because I was using balanced floating drive. The time constant of C3 is about 4 seconds if the input doesn't have a path to ground. The problem dissappeared when I changed to balanced grounded drive.
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Old 31st October 2012, 08:32 PM   #508
waam68 is offline waam68  United Kingdom
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Been working on these this week after work and finished wiring one up tonight. Seemed ok on a dummy load so I hooked it up and even on one channel sounds sweet. Still need to adjust the voltage, finish wiring up the second mono bloc, finish the cosmetics etc. I will post more thoughts when completed.
Mike
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Old 31st October 2012, 08:39 PM   #509
waam68 is offline waam68  United Kingdom
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Old 31st October 2012, 09:32 PM   #510
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Been working on these this week after work and finished wiring one up tonight. Seemed ok on a dummy load so I hooked it up and even on one channel sounds sweet. Still need to adjust the voltage, finish wiring up the second mono bloc, finish the cosmetics etc. I will post more thoughts when completed.
Mike
What I am interested in is what is it hooked up to as a power source? A block of iron and a tube rectifier? Look very hardcore power source wise...
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