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known to be noisy?
I built a regulated HV and filament power supply for my Gary Pimms phono preamp and when the B+ comes up to full voltage the power tranny hums(doesn't know the words). It was actually a full power supply board from one of the stores from Hong Kong.
I know that most of you frown on the use of some of the things that comes from Hong Kong and the regulator board is fine. It is doing it's job as far as the filament and the HV.This was the associated tranny that was recommended by the tech for this power supply board for the voltage I needed.
The current output of the power tranny far exceeds the current draw of the preamp so I guess that couldn't be the problem.
I am just baffled that once I turn the switch on it is silent until the HV comes up.
Thanks!
Paul
Follow Ups:
It is an "R" core tranny. They have two 15VAC filament taps, a 5V tap, and a HV tap. None of the taps are putting out even near their rated outputs for current demand.
You been screwed dude. I got screwed by a real friendly Aussie on ebay selling me his after he got screwed I guess lol mine where filament but I think they all are from the same factory and are garbage.I have seen the ones you are talking about and look identical. They are massively overrated and I think they would vibrate and buzz at any rating. They would just not have enough inductance on the primary even. It never ceases to amaze me how often I can get ripped off on ebay. I just keep believing ppl are honest. But with ebay it doesn't seem to matter. The funny est thing this week again hammered it home. I am a hopeless ebay addict BTW. There was a vintage ""xxxxxx" driver on ebay I wanted. It was 100 and had a far away foto of the front only and stated it was in good condition. I thought no rear photo they must be concealing something. Then I though no I am sure he is honest and just being lazy. Anyway I did a search for this type of driver to do a little more study and I found the same driver being being sold in a local on line trading post. Difference is he had taken close up photos of front and rear. Which showed as I suspected but nothing near as bad as I imagined extreme watter damage rendering it worthless and it was listed for $60 too! lmao I couldn't believe it. Maybe I am missing the fine print on ebay listings. Does it really say"now pick a photo that best conceals the items damage" and don't forget to add 40% on now because your items looks 40% better now!
Needless to say my rcore hit the trash parts bin. Perhaps I should open another ebay account and sell it as " I found this in my grandfathers shed after he died I cant test it but I am sure it's great!!" type account lmao Like I see so many do. I still got done with that scam this week on nos tubes in there boxes. Turned out when they came out of there boxes they where all nice and white inside lol. Her accounts name was Wendy so I felt sorry for her and payed nos tested price for them and she quickly told me once I told her they where done that she had a secret non stated no refund policy lol But that was the clever part for me their no refunds disclaimer is the red flag for me and others too thus the lack of it I guess. So I hope it's some solitude to you that there is way stupider people in this asylum lol. On a more positive note I have found some nice cheap Chinese stuff. Like tube caps chip amp boards and thats about it I guess. I did buy one of those little digital preamps for mum but it wasn't very good at all. It had no gain and about 6 volume steps:|
I don't feel I got screwed at all. I just wanted to know if I was doing something wrong or are they just bad designed transformers. It works just fine. It's just that it hums and loud enough to be heard between recordings. I can silence it a bit with insulation or tightening down on the regulator board a bit more. I just think it's a bad design but wasn't sure.
It's not where I was promised the world and got nothing. It was my choice to buy it and I shouldn't have(it wasn't all that much) but I did because it was suggested as the accompanying transformer to this reg board and the rest would be easy to install. And it was!
Lesson learned. I think I saw someone else post about Hong Kong parts. Funny thing is that the regulator board seems great. The voltages are dead on. I will probably change the tranny but then I will need another tranny along with the HV tranny for the rectifier voltage or put a resistor in and drop the voltage 1 volt AC.
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