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#1 Posted : Thursday, February 26, 2009 12:28:25 PM(UTC)
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hi everybody.

i just finished my buffalo and it sounds great but no imaging.

i tried a test cd and i found that it plays mono.

both speakers work but they play the same things.

currently i am using the buffalo without output stage straight

to the preamp through a coupling cap and a resistor.

any ideas what can be the problem?

thanks in advance

george.
Russ White  
#2 Posted : Friday, February 27, 2009 7:21:45 AM(UTC)
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It could be that the DAC is not being setup correctly via I2C.

What are you using for input?

Is your PIC (IC4) installed correctly?

I would not recommend you use the DAC directly out. It needs a filter.

Cheers!
Russ
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#3 Posted : Saturday, February 28, 2009 4:26:45 PM(UTC)
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after some experimentation i found out that the dip switches

don`t work properly.

when i put them in the middle the sound is clear but mono

playback continues.

if i put them anywhere except the middle between + or - the sound is

distorted.

maybe a firmware problem?

what is the next step i must do?

maybe sent it back to you or maybe you can sent me another pic?

thanks george.
Russ White  
#4 Posted : Saturday, February 28, 2009 4:55:28 PM(UTC)
Russ White

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George, please don't cross post. DIYAudio members probably do not want to be bothered with your support issue. But we are happy to help. That's why this forum is here.

The switch positions in the middle is the same as being at "+" as the PIC has internal pull ups set by default.

Can you please post close up pictures or send them to us by email.

Thanks,
Russ

Edited by user Saturday, February 28, 2009 5:39:20 PM(UTC)  | Reason: Not specified

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#5 Posted : Saturday, February 28, 2009 11:47:57 PM(UTC)
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ok russ i thought somebody might have the same problem there.

the switches work good only in the middle (except mono playback).

if i put one or more at + the sound is distorted.

i will sent you some pictures later.
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#6 Posted : Sunday, March 1, 2009 2:54:40 AM(UTC)
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picture sent at general questions email.
Russ White  
#7 Posted : Sunday, March 1, 2009 8:17:03 AM(UTC)
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Ok looking at your picture I can see that your are using your own PS. The behavior you are seeing can happen when a power supply ramps up too slowly.

There are two ways you can fix this if that is the problem.

1) Use a relay and a delay circuit to only power the DAC after the power supply has ramped completely.
2) Use a faster power supply like the recommended LCDPS.

The problem lies in the fact that the PIC and DAC will be slightly out of sync when VD supply does not ramp up fast enough.

Cheers!
Russ


Edited by user Sunday, March 1, 2009 2:07:28 PM(UTC)  | Reason: Not specified

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#8 Posted : Sunday, March 1, 2009 9:25:59 AM(UTC)
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ok russ i will test it and if that`s the case i will buy the lcdps.
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#9 Posted : Monday, March 2, 2009 7:57:51 AM(UTC)
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i instaled a switch between the ps and the buffalo and power it up after the psu but i have the same problem.

george.
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#10 Posted : Monday, March 2, 2009 2:41:04 PM(UTC)
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sp502 found the problem.

brian was right.

XLR`s was wired with oposite phase and

the + was grounded in the preamp.

some noise at high frequencies remain but

they might be because of filtering lack?

the strange thing is that they disapear

when i put all the dip switch in the middle.

george.
Russ White  
#11 Posted : Monday, March 2, 2009 3:06:55 PM(UTC)
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Very good.

Yes you need to filter. Can't think of any logical reason why changing the switches have any effect on the noise.

Cheers!
Russ
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#12 Posted : Friday, March 6, 2009 3:25:26 PM(UTC)
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everything works good now.

thanks for the help.

is counterpoint close to it`s release?
Brian Donegan  
#13 Posted : Friday, March 6, 2009 3:57:03 PM(UTC)
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It will be available next week. I am putting kits together now (well, tonight after the kids go to bed). Price for a stereo pair of boards will be $15, price for complete kit is $75. I will be posting the page sometime this weekend, including the BOM.
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