Another DIY SS Amplifier with NVA Boards

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SteveTheShadow
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow »

OK!

Another day and I've decided to stop trying to be a clever bastard.
Twin rectifiers are out, dual mono is out, everything is out. Simplicity is the key when you are learning. Run before you can walk and all that?
Yes I know plenty about valve amplifiers, but so what? This is NOT a fecking valve amplifier with a single rail, and I'm having to unlearn valve electronics and start to actually READ UP on power supplies for "normal" amplifiers, APPLY that new knowledge, ACCEPT that for the time being at least, I'm a know-nothing cretin when it comes to SS and take things steady, stage by stage.

Clue - a bridge package has a pos and a neg terminal. Well there's a thing. Wonder what those do eh! Oh! and a centre tapped secondary is fecking ideal for a split rail power supply.

OOH yeah isn't it simple......... FFS. :doh:

Logic was never my strong point. :roll:
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Chopsaw54
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by Chopsaw54 »

It looks OK to me Steve but it needs a 0 volt link across the two caps like Lurcher said and from that link a 0 volt wire taking to each amp board.

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SteveTheShadow
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow »

Cheers,
Yesterday I started doubting myself, after the Doc's comments. Doesn't take much these days.
Maybe I shouldn't have put up a picture of an unfinished PSU.

Best thing is to build the PSU and test the outputs first, before connecting the various gubbins to the boards.
Lets's try that first before tearing it down.
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Dr Bunsen Honeydew
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by Dr Bunsen Honeydew »

I am just unsure what you are trying to achieve, it is simpler than you are making it. Remember the kiss, I just see no point in you doing what you are trying. The photo showed basic misswiring of earths and some missing. I really don't like the idea of separating the transformer windings like that. A bridge has both sides wired to it that is the point and if you want to split the supply at that point then two bridges in parallel is just as valid, then caps wired normally, if you want to feck around and experiment then try different bypass caps. But do what you want and take responsibility for it.

In development ALWAYS test the supply before connecting to boards.

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SteveTheShadow
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow »

Dr Bunsen Honeydew wrote: Sat Mar 10, 2018 1:36 pm I am just unsure what you are trying to achieve, it is simpler than you are making it. Remember the kiss, I just see no point in you doing what you are trying. The photo showed basic misswiring of earths and some missing. I really don't like the idea of separating the transformer windings like that. A bridge has both sides wired to it that is the point and if you want to split the supply at that point then two bridges in parallel is just as valid, then caps wired normally, if you want to feck around and experiment then try different bypass caps. But do what you want and take responsibility for it.

In development ALWAYS test the supply before connecting to boards.
I always have tested things before connecting to the circuit. Not yesterday. My mind was elsewhere, for reasons I'm not going to say. I needed to keep myself busy, but chose the wrong thing to fulfil that need.
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Dr Bunsen Honeydew
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by Dr Bunsen Honeydew »

In the photo you had leads connected to the boards it freaked me.

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SteveTheShadow
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Re: Another DIY SS Amplifier with NVA Boards

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It would have freaked me If I had seen it.
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow »

Power supply lives:
Image
Two identical voltages to ground; one positive, the other negative.

I'll soak it for an hour before doing anything else, then discharge the cap bank before wiring them to the boards.
Just grounds to the boards and the inputs and outputs to do after that.
We may have music before bed-time.
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by Lurcher300b »

I'll soak it for an hour before doing anything else
I wouldn’t bother, there is no current being drawn, so that’s still to test, but generally if SS survives the first 5 minutes its good to go.

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Re: Another DIY SS Amplifier with NVA Boards

Unread post by karatestu »

Hi Steve,

I see you are connecting 0V to mains safety earth. Doesn't one of your sources do that already ?. I used to have only one connection from 0V to mains safety earth and that was done in the cdp. I did disconnect it not so long back the whole thing is floating.
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