NAP 120 buzz

Greetings from New Zealand. I have recently recapped my NAP 120 amp. Before and after completing this task the amp produces a buzz in my speakers for a few seconds after power up. I thought replacing the original electrolytics (amp is nearly 40 years old) would have fixed this annoying but not critical fault. Any ideas anyone?
Also the original specs that came with the NAC22 + NAP120 state the power as 40w continuous into 8 ohms, but this setup seems to have way more grunt than that…can anyone clear up the output for me? Cheers

Do u turn on preamp first followed by the amp?
David

Are you powering the NAC22 directly from the NAP120? Did you have the NAC22 recapped or serviced as well?

The name of the original amplifiers is based on doubling their watts per channel into 4 ohms. So a 120 is 60 watts per channel into 4 ohms, so 40 watts into 8 ohms sounds about right. Naim amps are very good at driving real world speakers and usually sound more powerful than their modest wattages might suggest.

I think the Naim amps in New Zealand from 40 years ago were fitted with New Zealand made transformers. Something to do with local tax regulations, must of been cheaper to import that way. The importer fitted them to the Naim boxes once they arrived here.
Story goes JV visited and had a listen, wasn’t impressed at all, as you can imagine things changed fast.
At a guess and I stress a guess, it could very well be you have one of those inferior transformers and its playing up. Btw I have no idea how electronics work so pls disregard…
If your kit has one of them It should say on the back. I think Chris Murphy worked for them way back then. You can guess how he started out with Naim :hugs: (maybe​:woozy_face:)
Now this is a story I herd years ago so I could have it cocked up but that’s my 2 cents to help.
If it was me I’d send it into Chris and get it sorted. Won’t be too expensive. He’s very reasonable considering the joy one gets from a metal box.

I’ve edited your post to remove the name of a UK company who have told Naim they do not wish their name, principal or their products to be mentioned or discussed on this forum.

I think the NZ company you’re thinking of here is Avalon, who used to assemble Naim pre and power amps from kits of parts sent from the UK. They used locally fabricated casework, but I don’t know about locally sourced transformers. Chris Murphy, would know for sure.

The Avalon-assembled NZ versions of the UK NAC22 and NAP120 were called the NAC225 and the NAP125.

Thanks Richard. Well almost had it. Not.

Thanks for the replies, and great to know the 120 denotes 60W into 4 ohms per cannel. The preamp is powered directly from the power amp and does not have its own on/off switch. The buzz is only for a few seconds after power up, and it is definitely not coming from the preamp as it still occurs without connection (via Naim cable) to the power amp. I’ve only recapped the NAP 120 and have not done anything to the NAC 22. I have a technical back ground and are confident that the recapping was done correctly.

Rather amazingly, I still have the original boxes, and printed on them is indeed “Assembled in NZ by Avalon Radio Corpn Ltd.” The model on the boxes is NAP 120 and NAC 22.
And yes, the transformer is locally manufactured, and likely to be the source of my buzz. So thanks for that, and I do now recall the NZ component being part of sales pitch.
As this stereo is but one of four I have in the house, and the one that gets the main thrashing is a Quad 33/405, I shall ignore the buzz and carry on.
Nevertheless the Naim reputation remains high in my estimation, and I’m more than happy to enjoy its clarity and grunt whenever I wish. Thanks again for everyone’s input.

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Imo best just to keep switched on👍

I’m sure you’re right, but being a struggling pensioner determined to deny the electric company a cent more than necessary, red pilot lights give me nightmares

Ha, yes electricity pricing in NZ is crazy over priced. Particularly when it’s pretty much a necessity of life. I went to flick fixed, a lot cheaper by a long way. Savings around 30% per week. If I had a gold card well that would help too.

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