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Need Help Converting STAX SRM-007tA from 100V to 117V - Page 2

post #16 of 20
2/14/09 at 5:01am
I thought you wanted to replace the internal transformer. External step down units are much cheaper and should have little effect on the sound if they are properly made. They can even be beneficial as they remove a lot of noise from the power lines.
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post #17 of 20
2/14/09 at 8:47am
Quote:
Originally Posted by spritzer View Post
I thought you wanted to replace the internal transformer. External step down units are much cheaper and should have little effect on the sound if they are properly made. They can even be beneficial as they remove a lot of noise from the power lines.


Lemme try to get a hang on the surgery part...

Yea, any good transformer from Japan should be fine? 200w ones sufficient? Heard that some transformers have a tendency to hum, dunno if that's true..
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post #18 of 20
2/14/09 at 11:13am
200w is more then enough (the amp draws 45w) and while some transformers are just badly made, hum is most often caused by noise on the AC line (DC mostly) causing the transformer to vibrate.
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post #19 of 20
2/17/09 at 1:23am
Ok, just got out from the operation theatre..

Opened up the SRM-717 with the ellen key, got a friend who's train in electronics and a qualified electrician to help me out.

The unit was configured for 100v. Tried to remove the top green plate, and it's glued with 3 round rubber knobs to access the PCB for the transformer. Didn't want to break anything, we unscrewed the 2 screws that holds the PCB to the chassis...now that's the tricky part, and luckily the wires are LONG enough for us to slowly pull the PCB out.

Metal jumpers were set at position 1, 3 & 6. Moved jumper 6 to position 5, removed jumper 1. (Thanks to spritzer and audiod for sharing).

Placed the PCB back, did some probes with the multi-meter... professional hazard, my friend left no stones unturned tested everything to make sure that there's no shortcircult anywhere (even the screws were not spared).

And moment of truth, plugged it into the 220v main and the power LED lights up, the red LEDs in the 717 lights up beautifully...and most importantly, no kabooms

Now can't wait for the O2 to arrive to test run the unit!
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post #20 of 20
2/17/09 at 4:32am
Good to heat that it didn't have any cut windings.
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