NVA AP50 restoration project

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Adewitte
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NVA AP50 restoration project

Unread post by Adewitte »

Some time ago i discoverd NVA. I have always been a fan of Brtish HIFI but NVA is something else. Been reading a lot about the brand and mr. Dunn. The design philosophy appeals to me a lot. I have heard some amps and paired with equipment which share the same design principles these amps can sound stellar. I can't imagine something can sound better. After al it's al about circuit design and signal preservation. And thats what NVA is al about.

So a old AP50 came to my path. Molested, "modified" and abused by some hifi guru i think.
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Dismantling:



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Cleaned everything, restored the wood, chassis. Complete recap and even new wood:
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New top and bottom alu plate. The old top plate was missing and the bottom was abused.
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During the project i started to think about the lay-out and recap. I always want to keep things as original as possible. But then i remembered mr. Dunn also did some upgrades sometimes for customers. I did had a 30v transformer lie around. So why not use it. I ended up with a setup for powering the vas parted from the last stage instead of dual mono.
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All in all this was a fantastic project. And the result is the best amplifier I can imagine. On to the next NVA project. :dance:
These users thanked the author Adewitte for the post (total 6):
slinger (Sat May 07, 2022 2:12 pm) • CycleCoach (Sat May 07, 2022 4:51 pm) • SteveTheShadow (Sat May 07, 2022 4:51 pm) • Lindsayt (Sat May 07, 2022 5:25 pm) • antonio66 (Sat May 07, 2022 6:29 pm) • Latteman (Sun May 08, 2022 3:48 pm)

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slinger
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Re: NVA AP50 restoration project

Unread post by slinger »

It looks as if you've done an excellent job. :clap:
Amps - NVA P50, AP30, A40, Stanislav Palo Tube Headphone Amp BB 85
Speakers - Monitor Audio Silver RX2
Cables - NVA LS1+LS3, SSC, Gotham S/PDIF, IBRA Optical
Digital - NAD C516BEE, SONY ST-SDB900 DAB TUNER, TEAC UD-H01 DAC
Analogue - Pro-Ject Debut Carbon Esprit SB, Graham Slee Gram Amp 2 Phono
Cans - Grado SR80, ATH-M50X

Adewitte
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Re: NVA AP50 restoration project

Unread post by Adewitte »

Thanks. The amp deserved it.

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Fretless
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Re: NVA AP50 restoration project

Unread post by Fretless »

Mooi gedaan AdeWitte. :grin: :guiness; :clap:
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Adewitte (Sat May 07, 2022 6:01 pm)

Upstairs:
Vinyl
Pro-Ject 1.2 + Grado Sig Jr + Cambridge Alva Duo
DigiVolumio PC + Kiss DP-500 + Sabaj A20d
NVA: P50sa - Cube2 - SSP - LS6+ Sabaj A10a (x2)
Downstairs:
Vinyl
Logic DM101 + Syrinx LE1 + Grado Sig MCX
DigiDenafrips Ares II + Volumio PC + Cambridge CXC
NVA: P50 - BMU+ Aiyima A07 MAX (x2) + Arcam One
HP: HifiBerry Digi+ PRO + Sabaj A10d
Office:
Allo DigiOne SIG + SMSL M300se + Douk G4 (x2)
Mission 760 + Monolith THX AAA 887
Headphones: German Maestro, Monolith & AQ

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Re: NVA AP50 restoration project

Unread post by antonio66 »

Super job Ade, hope you enjoy the fruits of your labours.
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Adewitte (Sun May 08, 2022 5:57 am)

quickie2
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Re: NVA AP50 restoration project

Unread post by quickie2 »

Nice job.

It's been a long time since I played around with any NVA amps, but fwiw I never found increasing the power supply capacitance over a pair of 4700 or 6800uf caps worth doing, and can actually make the amps sound worse ime.
My noise making stuff :

Modified Arcam Alpha 5 CD Player
Inca Designs ID1P Pre
Prototype EWA A40 Power
Q Acoustics 2010i/Royd Minstrel speakers

Adewitte
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Re: NVA AP50 restoration project

Unread post by Adewitte »

Thanks. That is my experience also. It's make the amp sound more "dead" if you put more in. Thats why i have two caps on the VAS stage. I first had four but that did not sound right to me. Going back to two and two Wima bypass did make it sound better. I could maybe get away with 2200uf on the VAS stage. But the project has to stop somewhere. Next time i want to try DNM slitfoils.

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Latteman
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Re: NVA AP50 restoration project

Unread post by Latteman »

Wow- love the wiring - not seen that before
Those are older boards- I used to have some in a metal A60 a few years ago - they had a different tone to the later boards - liked both👍🏼
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Adewitte (Mon May 09, 2022 11:22 am)
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

Adewitte
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Re: NVA AP50 restoration project

Unread post by Adewitte »

Yes, the older do have a different tone. But is that thanks to the pcb or different parts used on the boards? Stuf on the old boards become obsolete like the styroflex and Wima tropyfoil caps. They are both good, but i realy do like the old boards.

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