Timbre TT1 DAC, died today, Please need help !

[zeroairman]

My DAC stop playing today, I know it's from the late 90's but what a shame, bummer. I unplugged the unit and removed it from the shelf immediately.
Opened the unit and I can smell something cooked inside. Upon inspection I can see what it looks like a voltage regulator but cannot identify because It is burnt, only a few letters and numbers show. I tried to find schematics with no luck. I have some pics of the IC in question. I also took pics of the surrounding voltage regulators to see if it helps to Identify the burnt one. My guess that it can be a 7815/ LM340T15 but Im not sure.

 

[zeroairman]

Fixed, working excellent !!

 

[Blue Shadow]

And your initial guess was the culprit? Glad you got it running again. .

 

[BillWojo]

@zeroairman , nothing like posting a problem asking for help, saying that you fixed it and than not offering up what the fix was.
If it was the voltage regulator the big question is why did it fail. Something must be pulling a lot more current than it should. Is the new regulator running hot? Is it on it's way to failing as well?
Could be a capacitor going bad and offering a partial short. Not uncommon on older gear.

BillWojo

 

[zeroairman]

@BillWojo, well man, I assumed no one cared what the fix was since didn't get any feedback or suggestions in how to approach the issue. In desperation into getting this gear back in service, I started studying the circuit and looking at the components mind you, I am no super Tech, but it was a long shot for me. I connected the power cable didn't had anything to loose since it was already broken, started poking around measuring voltages had a 18v ac after the transformer and most of the regulators were missing the input voltage. Looking at the other components in the pics above I realized that my first hunch had a chance, the 7915 was missing its mate 7815 so, I put one in, and tried it, and nothing happened still did not come up. So I took a closer look at the board under a magnifier glass and found few traces coming out from the bridged rectifier area that feeds the input on some of the regulators were gone, so I repaired them, and I took another look and found some bad solder joints, so I re-fluxed and soldered the all caps and that was the fix. I also checked for any components with above normal temperatures and they all run cool, so far so good. I might want to recap the unit in the near future. What capacitors should I be looking into for this project, I want to get high quality caps for the best sound and reliability. Anyone have any recommendations for caps for this unit ?

 

[Blue Shadow]

Part of the problem is this forum is mostly a ghost town. Most are receiver lovers and this better gear forum is not even in the mainstream audio forums section.

I don't know what caps are in the unit now to be able to recommend. We like Nichicon UPW for power supply and film caps for audio if the value is small enough. Otherwise, folks fight over what brand and cap to use. Nichicon has about 10 different audio caps.

 

[zeroairman]

@Blue Shadow, thanks man ! I was so happy that I got it back running again. I heard the difference in my main system with out the Timbre, It sounded dull and too digital in my opinion.