Paging Richard- Dating Service... NAC12S / NAP120

Posted by: Stephen packer on 12 January 2019

Richard,  you were kind enough to help me establish the date for a few pieces of equipment I had acquired and I wonder if you could cast your eye over these two?

I've just picked up a NAC12S and NAP120.

The 12S is S/N 0507,
- Is marked 'gram' for the phono input (and this is a DIN plug, not phono or BNC). 
- The volume and balance pots are 'open' types- not fully encapsulated.
- The boards on it have the 'knife edge' connectors:
-   2 x NA112 Iss. 3 
-   2 x NA114 Iss. 3
-   2 x NA116 Iss. 3 (I think these are MC Phono, sorry Gram, cards?)

It's got quite a lot of 'recent' looking electrolytic capacitors fitted which look different from some older models I've seen so I do wonder whether it's had some work done on it recentlyish- the solder looked quite shiny which might agree with this.

I've powered it up (I just ran a NDAC through the Tuner input) running into my NAXO2/NAP250s/SBLs and it sounds quite sweet.  The pots could do with cleaning though.

I've put some pictures here:
https://photos.app.goo.gl/MEM55C3QqqowCWfT7

 

The NAP120 is S/N 0629
I think this is quite easy to date to either 1978 or 1979?

One of the electrolytic capacitors has a code 8247 on it which I think means it was produced in week 47 of 1982...  So maybe it had an early recap or repair?  Or someone fitted an older capacitor to it at some point?

I will power this up once I've dragged some old speakers out of storage, I don't really want to put it into my SBLs 'just in case'.  It doesn't look bad inside and doesn't smell as if something's gone off.  None of the electrolytics are leaking and the tants are uncracked so I think it will probably be OK.   It was sold as working, but I don't want to chance my speakers on it...


I've put some pictures here:
https://photos.app.goo.gl/PnpgTrvRAYgiANU67

 

The plan is to get both pieces serviced at some point this year, and probably restore the paintwork- a previous owner 'touched it up' with a brush...  

Thanks in advance (if you have the time)

Posted on: 12 January 2019 by Guinnless

Wow. Looks really interesting.  Keep us posted. ????

Posted on: 12 January 2019 by Richard Dane

Iíll take a look when Iím back on my computer. iPhone is not so good for pictures...

Posted on: 12 January 2019 by Loki

Judging only by the topic header I thought that Naim was trying to rival Tinder 

Posted on: 12 January 2019 by Richard Dane

The NAC12 is a version 2 - which actually means it's an early one as the first version (no daughter boards, all components on one main board) was basically the prototype and any of the production units were likely to have been updated to version 2 anyway. Version 2 units had six daughter boards and knife edge connectors.  Also the "Gram" for phono, DIN for the phono input and the flat panel construction give away that this is an early unit.  As for a date, hard to say, possibly '75 or '76, but certainly must be pre '77.  Can you get a picture of the 116 boards?   I don't have these in mine any more as the phono input was modified to pin connectors to take the later NA3xx phono boards.

The NAP120 is an early one too, likely around '76-'77.  later units changed to a toroidal transformer and looked a bit more like a normal Naim power amp,

Posted on: 12 January 2019 by hungryhalibut
Loki posted:

Judging only by the topic header I thought that Naim was trying to rival Tinder 

That would have been so much more fun than a few old blokes getting excited about amplifiers made when they could still get it up. 

Posted on: 12 January 2019 by SamClaus

@Stephen Packer, my NAP 120 is s/n 1670, I bought it in Nov 1978 from Studio 99, yours must be one or two years younger... I got a NAC 22 (s/n 186) on the same day - both are still working fine (recapped by Class A in 2014 - they really needed some work done by then).

Posted on: 12 January 2019 by Stephen packer
Richard Dane posted:

The NAC12 is a version 2 - which actually means it's an early one as the first version (no daughter boards, all components on one main board) was basically the prototype and any of the production units were likely to have been updated to version 2 anyway. Version 2 units had six daughter boards and knife edge connectors.  Also the "Gram" for phono, DIN for the phono input and the flat panel construction give away that this is an early unit.  As for a date, hard to say, possibly '75 or '76, but certainly must be pre '77.  Can you get a picture of the 116 boards?   I don't have these in mine any more as the phono input was modified to pin connectors to take the later NA3xx phono boards.

The NAP120 is an early one too, likely around '76-'77.  later units changed to a toroidal transformer and looked a bit more like a normal Naim power amp,

Thank you.

Here are some pictures of a 116 card:

https://photos.app.goo.gl/yCf5qbnYeiz7m3vk9 

Posted on: 13 January 2019 by Richard Dane

Thanks Stephen, got to love those "artwork" boards!

Posted on: 13 January 2019 by Stephen packer
Richard Dane posted:

Thanks Stephen, got to love those "artwork" boards!

You are welcome, thank you for all of your advice to date.

Looking at something like the 116 and remembering various projects in my teens, I would guess every hole for a component was probably hand drilled, each component inserted by hand and then soldered by hand (probably, rather than wave soldered back then?) What a lot of work.

Does anyone know if I have this wrong, would Naim have automated much of the construction in the mid 70s?

Posted on: 13 January 2019 by Richard Dane

Yes, it was all hand soldered back then. 

Here's a picture of 11 Salt Lane back in the day;

These days, it's a fish and chip shop.

Posted on: 13 January 2019 by Arthur Lee

Iíll have to check with my son as I bought him a 32 / 120 some15 years ago which we had serviced at the factory a couple of years ago. The 120 is such a sweet amp pur joy for listening.  

Regards,

Martin