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Old 5th July 2004, 09:27 PM   #1
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Default Dynaco FM3 220v-120v

I am trying my Dynaco FM3, I bought it from ebay.com.I am using a transformer to get 120v from 220v.The transformer gets hot,itīs not burning hot I can hold my hand on it,is this okay.But when I hold my hand on the tuner I can feel the 50Hz its shaking.Is this normal?
The soud is fine just a little hum when I turn the volume down.
Will more uf fix the hum?
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Old 5th July 2004, 10:38 PM   #2
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Some North American 115 V. equipment contains power trafos suited only to 60 Hz. power. Apparantly, that's the case with the FM3. Under no circumstances, add capacitance in the PSU immediately after the rectifier. If the filter is CLC, you can add capacitance in the 2nd position (after the choke). BTW, have you already replaced the PSU 'lytics? If not, you should.
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Old 6th July 2004, 04:32 AM   #3
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I have an updated (modded) FM-3 and the tranny vibrates like crazy. It did when stock and does now. I put a VPI magic brick on the case right over the transformer and it settled down. I've used one other sample and it did the same thing.

The VPI brick made a huge sonic difference, btw. Sadly, they're no longer available...

I'd love to find a toroid that would replace that vibrating POS.

Van Alstine has a really good article online about the FM-3:

http://www.avahifi.com/root/audio_ba...ep_working.htm


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Old 6th July 2004, 04:42 AM   #4
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Oh yeah, I forgot. It gets plenty hot, too.

Hope this helps.
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Old 6th July 2004, 08:55 PM   #5
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Quote:
I put a VPI magic brick on the case right over the transformer and it settled down. I've used one other sample and it did the same thing.
How does it look like,the VPI magic brick?
I have a pair of Sovtec 12AX7wxt are they any good to replace the excisting ECC83?
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Old 6th July 2004, 11:33 PM   #6
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Hi,

Quote:
How does it look like,the VPI magic brick?
A wooden case about the size of two brick halves stacked on top of each other.
The case is filled with steel laminates, about 6 kgs worth of them and this is meant to be put on top of OPTs, powerxfmrs etc to soak up stray EMF.
IOW, not the kind of thing you want to drop on someone's foot...

The sheer weight of the thing naturally tends to reduce mechanical vibrations from xfmrs as well although I think that problem is best solved at the source itself.

Quote:
I have a pair of Sovtec 12AX7wxt are they any good to replace the excisting ECC83?
Sure.

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Old 7th July 2004, 05:12 AM   #7
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Actually, I think it affects the magnetic field of the power transformer, becuase it's not directly on the transformer itself, it's on the chassis - and it cuts the vibration of the power transformer even when I'm holding it just *above* the chassis. You can feel the reduction of vibration in the chassis and you can hear it as well.

I agree that the best solution would be to replace the transformer with a better unit, however.
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Old 8th July 2004, 10:20 PM   #8
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Is it any good to change to 4 Diodes in the rectifier and adjust with resistors to get down to the right volt level,and change the e-lyts to new ones?
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