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Old 31st January 2006, 05:08 PM   #5511
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Ok guys, I know I made you all wait 'cos I took so long perfecting the boards.

But it's not really fair to make all the other members who paid for parts kits outside the US wait because you can't be bothered to check them. Come on, give Troy a break, after all the effort he's put into this, all it takes is five minutes of your time to check a list, then everyone else can get a chance to enjoy the sound like Mark and I have been doing.
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Old 31st January 2006, 05:30 PM   #5512
troystg is offline troystg  United States
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Andrew-

Thanks for the concern, but I'm in for about 30% of the cost of these kits.

To state a different way, I covered(subsidized) a third of the cost for each channel sold.

The funds for shipping (Not envelopes) have been used on parts quite a while ago.

I ask nothing in return except that all GB'ers be patient with me.



EDIT:

Oh yeah I forgot to mention the contents of the kits went from "main boards only" to "all inclusive EXCEPT output transistors" at no price increase.
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Old 31st January 2006, 09:26 PM   #5513
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Default Hook-Up

I've populated my boards (PinkMouse), assembled most of my hardware, and am ready to begin assembly and wiring the components. I have some very basic questions regarding the assembly. I'm using 'Dual-Mono' with separate transformers, rectifiers, and caps. Keep in mind, I am a structural engineer with limited background in electronics.....so some of this may seem very obvious.....but I want to be safe.

1. I haven't decided whether to use BrianGT power supplies, or separate rectifiers and smoothing caps. The caps I would use are three or four 22000uf 100v caps from K-Amps per transformer/rectifier. My transformers are 28v+28v at 500VA. Any suggestions regarding resistors across the rails for a CCCR, CRCC, or some similar configuration? Is something like 3kR at 5 watts appropriate? I'm also planning to place an LED and RLED across the rails on each channel's power supply.

2. I know there have been some discussions regarding powering the main board separate from the driver board for power saving, and for possible use of a regulated supply at the main board, but is it okay to simply wire them both directly to the output from the power supply....full voltage?

3. I do not see a direct connection to the output boards from the power supply? Is it correct that all of their power comes from the driver boards?

4. Which pads on the output boards are connected to the D+ (or D-) and FB outputs from the driver boards?

5. Which pads on the output boards provide output to the + and - speaker binding posts?

Thanks for any suggestions, Robert
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Old 31st January 2006, 09:49 PM   #5514
K-amps is offline K-amps  United States
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Robert,

I didnt realize you were going to use the 100v caps for the KSA-50 , A little overkill but it will work.

Where did you get that chassis/ sinks? Very NICE.

K-
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Old 31st January 2006, 10:01 PM   #5515
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Hi Robert

This'll come in little bits, as I'm rushing around at the moment!

1) I'd go dual mono, four caps per traffo. Dont worry about CRC for the moment, but bleeder resistors are a good idea.

2) It works fine running from the same supply.
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Old 31st January 2006, 10:03 PM   #5516
lgreen is offline lgreen  United States
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Default Re: Hook-Up

Quote:
Originally posted by rjkdivin


1. I haven't decided whether to use BrianGT power supplies, or separate rectifiers and smoothing caps. The caps I would use are three or four 22000uf 100v caps from K-Amps per transformer/rectifier. My transformers are 28v+28v at 500VA. Any suggestions regarding resistors across the rails for a CCCR, CRCC, or some similar configuration? Is something like 3kR at 5 watts appropriate? I'm also planning to place an LED and RLED across the rails on each channel's power supply.

2. I know there have been some discussions regarding powering the main board separate from the driver board for power saving, and for possible use of a regulated supply at the main board, but is it okay to simply wire them both directly to the output from the power supply....full voltage?
Let me take a crack at #1 and #2-
#1- I would think that 0.2 ohms to 0.5 ohms at 10-25 Watts is what you will want to use for an R with a CRC type filter. The R does not go across a cap but between one cap and the next cap... but you know this.
#2- yes, its ok to wire them all up to the output of the main PS, that is the way I have mine. The purpose of the 27volt zeners is to bring this down on the main board to 27 volts no matter how much higher (within reason) your PS goes.

If you put an LED across the caps to bleed out the voltage when they are turned off, make sure to put a resistor in series with the LED or you led will last about 5 minutes. Edit- is that what you meant by Rled?


Hey, nice pictures. Good luck with this
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Old 31st January 2006, 10:19 PM   #5517
K-amps is offline K-amps  United States
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Also while placing an LED on one side of the supply, try and place one of equal value on the other polarity as well otherwise one LED on one rail will discharge the supply in a lopsided manner and the amp can go into oscillations while powering down (if no relay is used). While it may not damage the amp, it will cause annoying buzzing sounds from the speakers...
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Old 31st January 2006, 11:01 PM   #5518
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3) Run power to the output boards from the PSU directly, and separately from the main and driver boards. It helps cut down distortion.
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Old 31st January 2006, 11:03 PM   #5519
K-amps is offline K-amps  United States
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Al ,What about Drivers? Same as main or separate too?
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Old 31st January 2006, 11:26 PM   #5520
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K, not quite so critical, but it all helps. I certainly will be.

4)D+ Goes to Drive+, and D- goes to Drive -, FB runs back from the positive output post of the speaker terminals, or from the point indicated below
.

5) For the speaker output from the boards, connect a thick wire between the thick top traces on the PCB opposite the devices between the two boards, then from the centre, take off the cable to the positive binding post. The negative post goes directly back to the star ground point.

The pic below shows the principle, but note that I have yet to attach the speaker output cable, the one you can see is the feedback.
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File Type: jpg dscf0016.jpg (59.9 KB, 353 views)
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