NAIM NAC 42.5 Vintage for my updated NYTECH CPA 602 - 2012

[NRWler04]

Gentlemen,

as I'm actually preparing an update of my good old NYTECH CPA602's (DIY Project - Nytech CPA602 today ...) they need also a good updated source.

By developing the 602's lohk offered me a NAIM NAC 42 PreAmp Board. As this is also a good old piece of British Hifi this will be my new PreAmp.

This is the board:


I will use my new boxes ....


And this is the front for my new PreAmp


And there are a lot of questions to setup a Pre with the NAIM Board:
- How should a good Power Supply looks like?
- How can I improve the Board? Is a recapping neccessary?
- How should a input selector looks like? I need 6 Sources ...
- ....

Hopefully I can get some help here ....

My idea is, to set up a new 42.5 as good as possible ....

Regards from Germany

Ingo

[lohk]

Ok, Ingo, lets roll it!

[NRWler04]

Ok Klaus,

have a look here: pink fish media - View Single Post - NAIM NAC 42 VINTAGE for my updated NYTECH CPA602's ...

[MrWavelet]

Hello,
i am currently developing a smart input selector based on reed relais and
with a modul for iPad/iPhone - remote control.
The main idea is to have the old fashion potentiometer and selector-switch
in parallel with digi-interface so that both can be used.
The analog part will be supported by Burr Brown op-amps.

The final pcb will of course fit into NRWler04's designer boxes.

regards

Originally Posted by NRWler04

Gentlemen,

as I'm actually preparing an update of my good old NYTECH CPA602's (DIY Project - Nytech CPA602 today ...) they need also a good updated source.

By developing the 602's lohk offered me a NAIM NAC 42 PreAmp Board. As this is also a good old piece of British Hifi this will be my new PreAmp.

This is the board:


I will use my new boxes ....


And this is the front for my new PreAmp


And there are a lot of questions to setup a Pre with the NAIM Board:
- How should a good Power Supply looks like?
- How can I improve the Board? Is a recapping neccessary?
- How should a input selector looks like? I need 6 Sources ...
- ....

Hopefully I can get some help here ....

My idea is, to set up a new 42.5 as good as possible ....

Regards from Germany

Ingo

[NRWler04]

No input here for optimizing a NAIM 42 ...?????

[ticknpop]

Unfortunately Naim topology - single ended with tantalum coupling caps is rather limited in what you can do with it. A shunt regulator might be worth persuing and getting rid of the coupling caps for film ones is about all. The topology is too limited ( forget the PRAT - the mystical rythym, timing , and all that nonsense).

[NRWler04]

What is PRAT? Never heard it before ....

[Salas]

Pace Rhythm And Timing magazine slang not sure if it was Martin Colloms that introduced it.

[NRWler04]

Ah ... I'm interested whats possible with the 42 board ... should only be better then my Nytech CP112 ....

[lohk]

If you do not like Tantalums in the signal path, you can very easy substitute with something which suits you more. But film caps usually show more distortion when used permanently DC biased.
What is wrong with the "technology"? The buffer is a diamond transistor-combo with a nice CCS, better that with less parts! The gain amp is equally simple. Those single ended classA circuits are very sensitive to power supplies and parts quality and variation, but thats their only fault in my oppinion. Otherwise many other designers (like Nelson Pass) would be to blame.
PRAT was introduced to find something more musically relevent when describing sound quality, than the more technical descriptions like distortion or power, or the more hifi-ish descriptions like spaciousness.