Quote:
Originally Posted by TheEKey /img/forum/go_quote.gif
Hello Guys,
It happened that IC2 of my Bantam DAC was fried sometime ago.
Call it DAC 1, using Elna RFS Silmic II as output caps.
There's DAC 2, Wima as output caps.
First I found that there were serious distortion from the music that I play from my PC. So I disconnected it and reconnected it again. It gave much noise to the loudest volume (so even I turned down the winamp vol to 0, noise was not affected at all). So I disconnect it and reconnect it again. It went totally off (reading only 0.7V instead of 4.7V on IC2).
IC2 on DAC1 fried.
But I applied the same sequence to DAC2. No problem so far.
I'm not sure what happened. I suspect that it's how I connect/disconnect the DAC to the amp and computer. Does it make any sense?
Connecting: I usually turn on and warm up the AMP, Millett Hybrid MAXed. Meanwhile, connect the DAC to the computer. After about ten minutes, connect the input of amp to the output of DAC. Then, I plug in the headphone and start enjoy music.
Disconnecting: Stop music -> Turn vol of amp to 0 -> unplug the headphone -> power off the amp -> disconnect it from the DAC and unplug the DAC.
Any of these sequence can potentially cause the IC2 to be fired? Please advise.
Best regards,
Matt
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No.
The only known instance of frying Alien DACs and BantamDACs is with the Starving Student. That amp has a peculiar power arrangement and the MOSFETs are biased through the tube heaters to ground. The best we've been able to determine lately is that a capacitive charge may develop on the RCA jacks that fries the DAC. Even then, it's the DAC that's fried - because it has no inherent protection on the analog outputs. On any other amp, however, the output capacitors are sufficient for protection.
I have connected/disconnected Alien and BantamDACs in almost every way imagineable - everything from prototype boards, MAXes, MOSFET MAXes, and MiniMAXes - prototypes and production models, using PC's, Laptops, Netbooks, USB hubs, USB cable repeaters, etc., etc. and in all environments - home, work, and headphone meets. Never once have I had an incident with any MAX/MiniMAX/MOSFET-MAX.
The fact that you're saying IC2 was fried leads me to suspect it was probably hanging by a thread at the start. I am not aware of any connection/disconnection scenario even with the Starving Student that would fry IC2. While any device such as IC2 is susceptible to ESD, it shouldn't be once attached to the board and properly grounded. It also has output current limiting as a safety feature.
IMHO, your connections/disconnections had nothing to do with it.