Connecting a nac52/supercap - naxo

hi, can someone help in advising me of the correct sockets to connect a 52/supercap to a naxo x-over, which in turn is connected to 2 x nap 250’s ?

IF you have a NAX0 then this (with substitutions) gives some of the logic with regard to the power supply linking.

HOWEVER, it would be entirely useful to confirm that you do have a NAXO (and that it hasn’t been altered for “horizontal” (see below) use.

What is powering the NAXO?


In an active system an electronic crossover divides the audio spectrum into two or three separate frequency bands, depending on the loudspeaker employed.

In the Naim NAXO, crossover frequencies are defined by a series of active filters, with particular attention having been paid to their transient handling abilities.

Output levels to each loudspeaker drive unit are adjustable for both frequency and channel balance by means of enclosed cermet potentiometers mounted on the main circuit board. [N.B. - Output Level only. Crossover frequency changes require component changes after calculation.]

Introduced in 1977, the NAXO has undergone continuous development.

Early units were constructed in a sectional aluminium case and consisted of a mother board with four or eight daughter boards fitted according to requirements. [Single 24 volt supply]

In 1980 the NAXO as re-engineered into an extruded case and was refined and improved by changes to the circuit layout in 1984, when the 2-4 and 3-6 suffix came into being. This design has all the components mounted on a single large mother board and provides for each of the two outputs from a HiCap to power a separate part of the NAXO circuit.

In 1995 the active crossover was extensively refined and revised, producing substantial gains in audio performance.

Re-named SNAXO (Super Naim Audio X Over), it features a multi-point (18-pin Burndy) power connection, separating the mother board into twelve sections, each supplied with power independently when used with a SUPERCAP. An additional 5-pin Din socket allows it to be used with a HI-CAP or FLAT-CAP in the same way as the NAXO.

In 2002 the crossovers were redesigned – multiple circuit board layout and detail changes but, significantly, both a change to the use of power amplifiers (‘horizontal’ use – where one stereo amplifier feeds the same frequency band to both left and right loudspeaker units) AND improvements to earthing arrangements.

The older designs can be altered from ‘vertical’ to ‘horizontal’ configuration but the newer units should not be altered as this would compromise the earthing improvements."

At the moment (presuming you’re already using the 52 in a passive system) the 52’s Supercap will have an ouput that feeds the NAP250 (I think this is the closest 4PIN socket to the Burndy and is labelled ‘Socket5’.

You will need to take this output and feed it into the NAXO via the NAXO PowerSupply.

I assume the NAXO is powered by a HiCap ? If so then take the output from the Supercap and connect to socket three of the HiCap and then the HiCAP output (socket 4- the 5 pin socket with two power rails, earth and ch1, ch2 signal) feeds into the NAXO input.
NOTE: I think some early HiCaps may have had a single +24v feed on Socket 3, in this case I would use Socket 2 or 1. NAIM have always been very good in labelling the pinout of the sockets on the back panel so just check Socket 3 doesn’t have a +24v on it.

The NAXO then has its two outputs that go to the NAP250s; it’s worth being certain that you’re feeding the correct connections to the speakers- I always check the bass first with very little volume and the treble not connected to see if it sounds right- less likely to blow a bass driver than a treble.

We really need to know which crossover you’re using to be certain about connections.

Good luck!

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hi, thanks; not using the 52 yet [hasn’t arrived] using a 72/hi cap nap250 x 2 passive crossover not connected . naxo set for hbl’s just checking the right sockets etc on 52/supercap, don’t want to blow it up !!

hi after some time my 52/scap have arrived just waiting on a burndy to connect. the system at the moment is 72/hicap naxo/hicap connected to 2 x 250’s. high frequencies to 1, low frequencies to the other. my query is now which sockets on the 52 or supercap do I connect to ??

You take signal from the NAC52’s Supercap to the Hicap powering the NAXO via a SNAIC4 or active lead.

thankyou but there are quite a few sockets ! which number socket on the supercap ?

Sockets 3, 4 & 5 are all signal IN/OUT DIN4s so any one of them will do, although it’s probably best practice to go for the shortest signal path, in which case go for 5.

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