Naim 250PRO - inside look at an ultra rare Naim product

[ChrisW]

For the curious, this is a rare Naim product developed with collaboration between Naim and the BBC. It’s one of three delivered to the BBC. It’s based on a NAP 250-2 amp, and for studio purposes it has a balanced XLR input for each channel, and “Speak-On” output connectors instead of Banana sockets. Having recently restored one, here are some pics I took:

Amp boards removed and chassis cleaned

Two pairs of power supply reservoir caps removed

Amp Board ready for rebuild

Rebuilt Amp boards & balanced circuitry

Reassembly of Chassis

Completed Chassis

Front Panel

Rear panel (with new XLR and Speak-On sockets)

Definitely a unique project!

Chris - AV Options

[Eoink]

Thanks a lot Chris, that’s fascinating.

[frenchrooster]

I would like to have it . My preamp is balanced and have xlr outputs. Sad that Naim doesn’t produce it anymore.

[NAC72]

I spy with my little eye output inductors! Presumably the BBC wanted to be able use any standard speaker cable without restriction.

[feeling_zen]

except it seems it be a US voltage version.

[ChrisW]

Yes it’s 120V … the owner moved to the US and had it converted

[Richard.Dane]

The amp had to be stable no matter what kind of speaker cabling was attached to it.

Thanks for the pics Chris!

[Gazza]

Thanks Chris that was really interesting. I would be interested in in other pics of some of the older amps, players etc if you have the time.

[anon93526344]

@ChrisW

Which power cable is that ?

[Murmur]

Hope this isn’t a daft question since I know nothing about studios, but what would its role have been exactly?

[MrUnderhill]

Hi Chris,

Thanks for the pictures.

Out of interest …how does it sound?

M

[frenchrooster]

Out of interest

[el_soldado]

Most likely for driving monitors in a control room or editing suite. LS3/5 possibly?

[Naim_The_Dragon]

@MrUnderhill

Out of interest …how does it sound?

I wonder as to how it sounds compared to a “regular” 250…

[Richard.Dane]

I once asked this of Roy. IIRC he answered that it sounded really good. Just not quite as good as the regular NAP250…