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#46 Re: Definitive Build

Posted: Mon Jan 31, 2022 11:46 am
by Daniel Quinn
I used 2 bridge rectifiers for a phono amp power supply . The power amps pre date this .

I’ve learnt all I know by copying nva amps hence my limited knowledge and the reason I cocked up the second power supply with 2 bridges.

I’m at the stage in understanding there is more than 1 way to wire the transformers , bridges and caps but I haven’t a clue of the relative merits of each method.

So what do I read?

And nick I note what you say but come on I should get some credit for doing it left handed😉

#47 Re: Definitive Build

Posted: Mon Jan 31, 2022 12:28 pm
by Nick
Yep, you get some credit, but there is always room for improvement :)

As to a link that talks about the ways and means. Not sure, there are lots of books I could suggest but they all assume some knowledge. The Elliott Sound Products pages are good places to start.

https://sound-au.com/power-supplies.htm

#48 Re: Definitive Build

Posted: Mon Jan 31, 2022 2:30 pm
by Paul Barker
Daniel Quinn wrote: Mon Jan 31, 2022 11:46 am I used 2 bridge rectifiers for a phono amp power supply . The power amps pre date this .

I’ve learnt all I know by copying nva amps hence my limited knowledge and the reason I cocked up the second power supply with 2 bridges.

I’m at the stage in understanding there is more than 1 way to wire the transformers , bridges and caps but I haven’t a clue of the relative merits of each method.

So what do I read?

And nick I note what you say but come on I should get some credit for doing it left handed😉
Nick is very straight talking but youd be a fool to not listen to what he says.

#49 Re: Definitive Build

Posted: Mon Jan 31, 2022 3:21 pm
by Daniel Quinn
Thanks nick .

#50 Re: Definitive Build

Posted: Mon Jan 31, 2022 3:27 pm
by Nick
Hey I am happy either way. No skin off my back :-)

#51 Re: Definitive Build

Posted: Mon Jan 31, 2022 6:08 pm
by Daniel Quinn
When I was practising law if a client ignored my advise I would think there were a cretin and loved the schadenfraud when what I advised came to fruition.

I don’t mind people knowing more than me about electronics I’m grateful people are happy to share thier expertise

#52 Re: Definitive Build

Posted: Wed Feb 02, 2022 7:19 pm
by Daniel Quinn
Large caps are expensive .

Is there a theoretical difference between 4 33,000 if cap and 12 10,000uf caps?

Deos anybody have experience of both and prefer one ?

#53 Re: Definitive Build

Posted: Wed Feb 02, 2022 7:53 pm
by Nick
Depends on the caps on question. Compare the Dcr and inductance and the ripple current capacity.

#54 Re: Definitive Build

Posted: Wed Feb 02, 2022 8:16 pm
by ed
Daniel Quinn wrote: Wed Feb 02, 2022 7:19 pm Large caps are expensive .
If you know what you want I can suggest that you check the surplus suppliers...there are real bargains to be had if you don't pay any attention to the boutique peddlars.

#55 Re: Definitive Build

Posted: Wed Feb 02, 2022 8:18 pm
by pre65
Nick wrote: Wed Feb 02, 2022 7:53 pm Depends on the caps on question. Compare the Dcr and inductance and the ripple current capacity.
Dennis, I still have a few of those soup tin size capacitors in my stash, depending on what size uf and voltage you need.

I got most of mine as Ed 's last post.

#56 Re: Definitive Build

Posted: Wed Feb 02, 2022 9:01 pm
by Daniel Quinn
I’ll have a look.

For the moment I’m working out theory. Build will be in may onwards.

So assuming they have the same measurements there be no difference in large or small caps .

#57 Re: Definitive Build

Posted: Sun Feb 06, 2022 7:03 pm
by Daniel Quinn
Right . I’m going to play about . Got some naim clone boards that need 40v .

Got a 500va transformer with 30v secondaries.and 4 33,000uf capacitors. A per mono amp .

To run separate bridges , I use a bridge for the v+ and a bridge for the v- . Do I run the capacitors as two separate runs ? That will be black red and 2 caps and yellow orange and the other two caps. No connections between the caps for + and ~

With naims 2 earths to the board is it okay to run one to each rail power supply?

#58 Re: Definitive Build

Posted: Sun Feb 06, 2022 7:41 pm
by Nick
Sorry, I don't understand what you are saying, and if I did, I may not have the same understand as you do. I know you don't like them and they seem problematic, but a drawing is needed,

#59 Re: Definitive Build

Posted: Sun Feb 06, 2022 8:34 pm
by pre65
Dennis, doing a diagram before you start is good practice.

I always do diagrams to help me understand my thoughts, and I keep a folder for each project so I can refer to things when repairs, or upgrading is necessary.

#60 Re: Definitive Build

Posted: Sun Feb 06, 2022 11:10 pm
by Ray P
Daniel Quinn wrote: Sun Feb 06, 2022 7:03 pm Right . I’m going to play about . Got some naim clone boards that need 40v .
So you need a +/-40VDC power supply?

Is this schematic something like what you have in mind?

Image