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quade777  
#1 Posted : Sunday, February 22, 2015 6:55:02 PM(UTC)
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Hi
I measured 1.8v DC between +/- on the right bal channel. I was able to adjust it down to 1.14v but then I hit the limit of the variable resistor. Any idea what can be wrong?
Russ White  
#2 Posted : Sunday, February 22, 2015 8:58:54 PM(UTC)
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I would start looking for open or shorted solder joints.
quade777  
#3 Posted : Monday, February 23, 2015 6:57:42 AM(UTC)
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Thanks. I bought my buffalo III with legato second hand in 2011 so I guess it has a Legato 1.02 or 1.03. I have redesigned it recently with a controller etc. and have found some disturbing solutions (the AVCC had output caps where the cap on one side was connected with + to NC and - to out, I guess it should be + to out and - to ground??)

Due to this I have two options as I see them
1: Try to fix the legato I have (and search for other possible faults)
2: Order a new legato 3.1

In your opinion. Is the legato 3.1 a soundwise upgrade from the older legatos?

One more quick question
Do you think thix adc module would be a good match with your retro riaa for at fully digital amp/preamp set-up where one would only want to turn the occasional record.

Edited by user Monday, February 23, 2015 5:07:32 PM(UTC)  | Reason: Not specified

quade777  
#4 Posted : Saturday, February 28, 2015 11:11:55 AM(UTC)
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I have checked the pcb and no apparent solderbridges. I then reflowed all rigth channel solderrjoints - still the same.

Then I measured the legs of the transiators and all right t channel transiators read lower resistance compared to the left channel
avr300  
#5 Posted : Saturday, February 28, 2015 5:31:41 PM(UTC)
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Just so we can see which version Legato you're using can you post a picture of the board ?
quade777  
#6 Posted : Saturday, February 28, 2015 5:39:42 PM(UTC)
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It is the v3.1. I thought it was 1.03 but when i dismantled everything to reflow the solder today I saw that it was 3.1.
avr300  
#7 Posted : Saturday, February 28, 2015 5:44:11 PM(UTC)
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Quote:
legs of the transistors


please clarify. Which transistors?
And how did you measure?

Edited by user Saturday, February 28, 2015 5:49:33 PM(UTC)  | Reason: spelling! ;-)

quade777  
#8 Posted : Saturday, February 28, 2015 9:08:47 PM(UTC)
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QP7-12 and the counterparts on the left side. Measured all transistor legs vs each other using the resistance function on a standard digital multimeter.

Edited by user Saturday, February 28, 2015 9:10:11 PM(UTC)  | Reason: Not specified

avr300  
#9 Posted : Sunday, March 1, 2015 9:41:33 AM(UTC)
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Since QP7, QP8 and QP9 all are in parallel when measuring those you are to expect the same reading.

Same goes to QP10, QP11 and QP12.

Can you post a picture ?
quade777  
#10 Posted : Tuesday, March 3, 2015 9:10:27 PM(UTC)
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Legato front

Legato back

Edited by user Tuesday, March 3, 2015 9:14:07 PM(UTC)  | Reason: Not specified

avr300  
#11 Posted : Wednesday, March 4, 2015 5:15:22 PM(UTC)
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I think a lot of the soldering looks less nice.

If I were you, I would use a magnifying glass and look for tiny solder bridges.


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avr300  
#12 Posted : Wednesday, March 4, 2015 5:18:29 PM(UTC)
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Here I have marked examples of what I mean.

A lot of unwanted either flux and/or solder.

Edited by user Wednesday, March 4, 2015 5:19:43 PM(UTC)  | Reason: Not specified

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thanks 1 user thanked avr300 for this useful post.
quade777 on 3/4/2015(UTC)
quade777  
#13 Posted : Wednesday, March 4, 2015 8:53:57 PM(UTC)
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Yes. I did not solder this myself. I think I will just buy a new one. Thanks for the help.
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