Integrated Nva clone

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Latteman
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Integrated Nva clone

Unread post by Latteman »

I’ve been busy building an integrated amp- putting a p50, a60 & phono 1 into one box- I have separate transformers for the phono 1 & A60. I’m trying to use similar wiring as original- both psu check out with the multi meter but should or shouldn’t I join the 0 rail and run onto the phono plugs
1 is the split between each 0 rail
2 is on way to phono inputs/ outputs

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Denon DP47f- Ortofon mc20 supreme
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karatestu
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Re: Integrated Nva clone

Unread post by karatestu »

Hello Peter,

Nice project you have going there. I hope you have the phono boards well away from the transformers, rectifiers and caps.

The 0V between the phono amp and power amp must be connected somewhere. In an NVA system (and most others) that is done in the preamp via the 0V wire in the interconnects. The volume control will also need a connection to 0V.

I would say that you have nothing to lose by joining the two 0V wires where you have proposed. It has to be joined somewhere in your integrated amplifier. If you get any hum then you might have to rethink that but you would have to be sure that it is the earthing rather than EMI pick up with the phono stage.

Good luck. Stu
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Latteman
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Re: Integrated Nva clone

Unread post by Latteman »

Cheers 🍻
Working slowly through the connections and layout
Analogue Source -
Denon DP47f- Ortofon mc20 supreme
Ifi Zen Phono
Doug Self balanced Pre amp
Akai 4000DS mk2 R2R
Digital Sources- IfI stream, Ifi Neo idsd Dac; Tidal / Radio Paradise
Amplification Nva 30vdc mono blocks
Speakers Lii Audio F-15 in Open Baffle; Ls6
Weiduka AC8.8- for digital sources
Mini BMU for analog sources

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karatestu
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Re: Integrated Nva clone

Unread post by karatestu »

You done yet Peter ?

:epopc:
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Latteman
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Re: Integrated Nva clone

Unread post by Latteman »

Nearly- not rushing it and gluing/ soldering is a pain

Image
Analogue Source -
Denon DP47f- Ortofon mc20 supreme
Ifi Zen Phono
Doug Self balanced Pre amp
Akai 4000DS mk2 R2R
Digital Sources- IfI stream, Ifi Neo idsd Dac; Tidal / Radio Paradise
Amplification Nva 30vdc mono blocks
Speakers Lii Audio F-15 in Open Baffle; Ls6
Weiduka AC8.8- for digital sources
Mini BMU for analog sources

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southall-1998
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Re: Integrated Nva clone

Unread post by southall-1998 »

That transformer reminds me of a dark chocolate doughnut ;)

S.
Shane Lonergan.

29mile
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Re: Integrated Nva clone

Unread post by 29mile »

Great project.
I have an A60 of the same vintage and was considering separating the power supplies to the input and output stages. There is just one copper arch on the boards ( new boards have 3 I think ) and I was unsure if cutting this would allow you to feed separate rails. Did you ever consider doing this ?

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Re: Integrated Nva clone

Unread post by Lurcher300b »

I would suggest both 1 and 2 are the worst places to call ground. The center point where the transformer secondary joins the rail is better. Both 1 and 2 will have the cap charging current passing through the wire which will generate a voltage that will be induced into your ground reference.

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Re: Integrated Nva clone

Unread post by Latteman »

🤔
I am out of my depth here- I know that- I’ve had a few resistor failures and not sure why- going to strip and check- these boards are older and a little more difficult to work with than the newer ones.
Bridge rectifiers are a mystery when it comes to matching
Analogue Source -
Denon DP47f- Ortofon mc20 supreme
Ifi Zen Phono
Doug Self balanced Pre amp
Akai 4000DS mk2 R2R
Digital Sources- IfI stream, Ifi Neo idsd Dac; Tidal / Radio Paradise
Amplification Nva 30vdc mono blocks
Speakers Lii Audio F-15 in Open Baffle; Ls6
Weiduka AC8.8- for digital sources
Mini BMU for analog sources

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karatestu
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Re: Integrated Nva clone

Unread post by karatestu »

Doesn't sound right Peter. Hope you get it sorted.

I don't understand what you mean about matching bridge rectifiers ?

RD's earthing scheme is nothing like what i was used to before messing about with the nva amp boards.
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