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-   -   Help!!! My Audioromy FU29 amplifier was fried! (http://www.diyaudio.com/forums/tubes-valves/174938-help-my-audioromy-fu29-amplifier-fried.html)

tdmax 7th October 2010 02:17 AM

Help!!! My Audioromy FU29 amplifier was fried!
 
Hi Guys,

I am from Singapore and I really need help and advice on my fried audioromy Fu29 amp. The amp just got fried on its own last week.
And upon opening up the bottom plate, I saw 2 pieces of badly burned resistors.

Due to the resistors burned condition, I can't figure out the resistors value to get them replace. I really appreciate if some kind souls, having the same amp could open up the bottom casing and advice on the resistors color code and value, could help me out on this mess.

All help is greatly appreciated.

http://i413.photobucket.com/albums/p...8/IMG_1624.jpg


http://i413.photobucket.com/albums/p...8/IMG_1629.jpg


http://i413.photobucket.com/albums/p...8/IMG_1626.jpg


http://i413.photobucket.com/albums/p...8/IMG_1627.jpg

TheGimp 7th October 2010 03:53 AM

If someone does find the value, you still need to determine why it failed in the first place.

That looks like a power supply board. Something pulled too much current downstream.

barretter 7th October 2010 06:06 PM

The resistor which is bigger and higher in the picture is 1K and the lower one is 2K2. I have one of these amps which is also not working because the relay on this circuit board chatters and won't latch on but as The Gimp says you need to find the short-circuit or other cause of too much current.

tdmax 9th October 2010 08:26 AM

Thanks for the info. Will try out and see how it goes.

Globulator 9th October 2010 02:54 PM

The bigger resistor looks like the one that got overloaded, with that size and value it is probably a dropper resistor for the driver tubes.

So I would check the driver tubes (and electro capacitors) for a short.
Something on the amp failed first: and it wasn't those resistors IMO, so fix the fault first, then replace the resistors!

poynton 9th October 2010 05:02 PM

Are the Audioromy amps available in Singapore and if so, where ?

I looked for some last year when I was in Singapore and could not find them.


Andy


..

piero7 9th October 2010 08:28 PM

1 Attachment(s)
here the schematic of the fu29 power supply

barretter 10th October 2010 10:56 AM

Thanks very much for that Piero7. Do you have a diagram for the main amplifier? The only schematic I have seen does not have a negative bias supply. Presumably the -31V is applied to the 828 grids?

piero7 10th October 2010 08:46 PM

2 Attachment(s)
Yes the negative tension is for the GU29 grid

barretter 10th October 2010 10:56 PM

Thank you very much indeed! Your diagram makes more sense than the original. And very nice anode connectors too : are they commercially available? Did you ever try QQV6-40s in place of the 829s? My FU29 sounded very nice with these valves until the amplifier gently stopped working.


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