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 » Sat Mar 10, 2018 10:13 am

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:
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Large sealed cabs, with Fane 12-250-TC 12" full range drivers.

Chopsaw54
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by Chopsaw54 » Sat Mar 10, 2018 10:41 am

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.

SteveTheShadow
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 10:46 am

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.
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Large sealed cabs, with Fane 12-250-TC 12" full range drivers.

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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 » 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.

SteveTheShadow
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 1:59 pm

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.
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Large sealed cabs, with Fane 12-250-TC 12" full range drivers.

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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 » Sat Mar 10, 2018 2:10 pm

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

SteveTheShadow
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 2:12 pm

It would have freaked me If I had seen it.
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Large sealed cabs, with Fane 12-250-TC 12" full range drivers.

SteveTheShadow
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Joined: Thu Sep 12, 2013 5:24 pm
Location: S Yorks
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 2:30 pm

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.
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Large sealed cabs, with Fane 12-250-TC 12" full range drivers.

Lurcher300b
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by Lurcher300b » Sat Mar 10, 2018 3:39 pm

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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karatestu
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Re: Another DIY SS Amplifier with NVA Boards

Unread post by karatestu » Sat Mar 10, 2018 4:00 pm

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.
Naim, Linn & Harbeth fanboy

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