Yamaha A-1 refurb recap re-relay and repost (binding)
- Thread starter brutal
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Crumb_Bum
New Member
could be a transistor shorted
The amp was working,only problem was that when the dc button was engaged,there was no sound. so to try to fix this ,I flipped it over and did some resoldering on some bad solder joints on the sa913 and sc1913 transistors and a few more circuits in that area .After that, the 2- 330 resistors started smoking.
The amp was working,only problem was that when the dc button was engaged,there was no sound. so to try to fix this ,I flipped it over and did some resoldering on some bad solder joints on the sa913 and sc1913 transistors and a few more circuits in that area .After that, the 2- 330 resistors started smoking.
Ahh, the old, "it was working before I touched it and I guess I should have asked around first before jacking with it" problem. :scratch2:
The Disc button? That's Phono-output with no tone control in the circuit. It was working the way God and Yamaha intended.
You've probably shorted those power regulator transistors that have nothing to do with the Disc function or soldered a bridge between the legs.
You would do well to heed the big warning silk-screened on the bottom and DISCHARGE the filter caps before working on it. Use a couple 2-3 watt 1K Ohm resistors shunted to ground to drain them until the voltage across either reads less than 500mV.
The Owner's Manual is easy to find. Just look in the Yamaha forum "Yamaha literature" sticky here.
specialidiot
Break Glass, Smoke Lucky
hey guys.
Just a note that I'm using cdfac's A-1 in my living room setup, and loving it.
Yeah, still need to fix that speaker lamp though.....
Just a note that I'm using cdfac's A-1 in my living room setup, and loving it.
Yeah, still need to fix that speaker lamp though.....
must be something with the connection, give it a look. i'm sure i probably did something silly when i did the replacement. it flaked out on me a couple times here but always came back on its own or with a well-placed tap. glad your still enjoying the amp, though! i miss it, especially for the convenience of one power button and the small chassis.
Any chance it was the same one on ebay USA over the last week or so?
Bump.
Original post http://www.audiokarma.org/forums/showthread.php?p=3688683#post3688683 updated with some parts listed.
Original post http://www.audiokarma.org/forums/showthread.php?p=3688683#post3688683 updated with some parts listed.
Thanks Dave.
While the product info lists 5A rated load for the Omron, looking briefly at the datasheets for both, which of course don't necessarily relate, it appears the max switching current for either is 7A - I suppose that's inrush? Other than availability, do you see any significant advantage of one over the other?
While the product info lists 5A rated load for the Omron, looking briefly at the datasheets for both, which of course don't necessarily relate, it appears the max switching current for either is 7A - I suppose that's inrush? Other than availability, do you see any significant advantage of one over the other?
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No..I've used both. Just so happens there both available now. Usually thats not the case. And ya gotta use what ya can get.:thmbsp:
I just got hold of an A1 at a decent price and I've been playing with it for about an hour, checking all the inputs etc and I must say it's an impressive amp. I have repeatedly 'forgotten' about the testing and have just sat there listening to the music.
It's short one tape input - I usually wire up tape 2 for an ipod connection. The speaker bulb is out as well - will need to figure out how to change that. Other than that I see no need to even open it up right now - everything seems to be working as it should
.
It's short one tape input - I usually wire up tape 2 for an ipod connection. The speaker bulb is out as well - will need to figure out how to change that. Other than that I see no need to even open it up right now - everything seems to be working as it should
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