Adding a second 250DR

Dear all,
Current system 282/HCDR/250DR.
Question: I’m interested in Bi-Amping, adding a second (pre loved) 250DR to my setup above.
Can I connect the second 250DR to the HiCap and run a speaker off each 250DR? (My current speakers are not bi-wire, (but I am planning on upgrading them to a bi-wire speaker at a near future date). I have the option of getting my hands on the pre loved 250DR now and serial number wise it’s manufactured same month as my current 250DR, hence moving on this first.

For reasons best known to myself, I’m not interested in upgrading the 282 or upgrading the HiCap!
I’m hoping Bi-Amping will bring more oomph to the party? I have a large listening area. I have the option of getting my hands on the 250DR now and serial number wise it’s manufactured same month as my current 250DR, hence moving on this first.

As far as I know, Naim have never promoted bi-amping, using their products.

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I don’t know what speakers you are using, but have you considered moving to a NAP 300?


Your profile is obviously out of date with regard to amplification, but what about your sources? If they are still a CD5si and an ND5XS2, that’s where you should be looking for improvements.

Regarding a second 250, a 300DR would be a much better idea.


Unless going forward, you intend to have an active system, an additional NAP, will not bring any significant benefit.
Your profile may not be up to date.
Rather than an additional amp, a NAC252 + SCap DR, would likely cost the same and bring be more beneficial, although your source may become the weakness.
Source first isn’t the only way, but important to bear in mind.
If none of that appeals, then simply enjoy what you have, rather than device systems which you can plan, but you will only be able to judge when you can audition, so perhaps what you propose is purchasing blind, ymmv.
Without understanding your reasons for being specifically against a more logical upgrade, serious caution would be the best answer to your question, as others have indicated, bi-wire or bi-amp has never been a Naim feature and for good reason.

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Then you will need to do proper bi-amping rather than the way most UK manufacturers set it up. The way Naim bi-amping works with the standard cables available only allows you to use each amp in stereo, one for treble, and one for bass (and a third for midrange if the speakers support it). But this really has limited value except in a small number of use cases and is mainly a stepping stone for going active. But the power drain on low frequencies is still pushed all onto one amp so the power advantage over single amping is small.

I believe what you are referring to is “proper” biamping which each stereo power amp gets two sets of identical signals making one amp effectively left and one right. This delivers significantly more headroom and the feedback is also from the same channel. This is certainly how Japanese hifi and a lot of US hifi does biamping and is a different story altogether.

But you will need to order a non standard cable for this to work unfortunately. You’ll need either a single DIN-4 to two XLR with the Y-split in the cable. Either Chord or Naim can probably do this for you to order if you explain what it is you want to do. They are likely to advise against it though.


yep profile out of date
Source is ND5XS2-Naim Dac + non-Naim PS

I am now ! Thanks for you response, Rgds

Big room and wanting more oomph?

I would look at the loudspeaker choice, and a 300DR. Maybe even a small sub?

You will find few Naim owners in favour of a passively biamped system, and Naim themselves don’t recommend when setting out typical systems and upgrade paths.

The search is your friend. Prepare for lots of reading. Some have had success with specific speakers I think.

What are your current, and intended speakers?


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How much your sound system will benefit from a second 250 will depend heavily on what speakers you choose. B&W, for example, favour biamping with some of their models as they are power hungry and will really benefit from it. Other speakers, not so much, in which case there may be more beneficial ways to spend your money.
A 300DR could be another good option to consider. Whenever I’ve listened to one I found that it totally outclassed and 250DR I’ve heard.

For what it’s worth, Naim do not dismiss the idea of this sort of passive biamping. (On the Supernait they even provide a dedicated biamp output socket for those who want it.) It’s rather that they used to support active biamping, which is a whole different game in terms of box count, expense, careful setup etc. but with the potential to bring bigger gains.


I’m hoping Bi-Amping will bring more oomph to the party?

It depends want you mean by oomph.

If you mean more ‘solid’ bass, then:
add a sub
change your speakers
add bass traps
Depending on speakers a 300DR may help

If you mean more dynamic midrange
change your speakers
Change the non-naim PSU for a 555
Possibly add diffusers to the room

If you mean more detail and a generally more solid sound or you listen at low volume
Change to a 300DR
Change the non-naim PSU for a 555


I’d bet two mono amps would work much better, each will serve it’s own speaker


I tried this years ago as a stepping stone to an active system. I couldn’t hear any difference between using one power amp or two.

My advice is to go for it if you are aiming for an active system. If active is not for you then either sell your amp and go for an improvement, or spend the money on an upgrade elsewhere or spend the cash on music.

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Hey @CPL
I run a 282 with 2x HCDR and a NAP300 DR, the SQ is stunning. I tested a 250 and much prefer the 300.
Also the 2nd HC DR was a definite improvement.
Good luck with your upgrades.


This is in fact what “proper” passive biamping does. As explained in my earlier post, each stereo amp gets a double feed of either the left and right channel so that no power amp is driving two low frequency drivers.

The stereo HF/LF method of biamping isn’t well thought of in some regions. So it’s important when expressing views on passive biamping to understand that it isn’t done the same everywhere and some ways provide considerably more benefits than others.

I can’t link to it for forum rules but there is a great You Tube video in Japanese from a senior engineer at Esoteric using a cheap TEAC power amp and a white board to explain the benefits of “proper” biamping. Well worth a view with subtitles turned on. He’s so unpolished and not video ready, it’s quite charming from that perspective alone.

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@CPL You still haven’t told us about your speakers. Might help suggestions from the hive mind to know these, and what exactly you are looking to improve (as per Xanthe’s post above).


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e.g. NAP 135s.

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context is key…

I have used biamping as a boost to audio quality, but as Xanthe already listed - there are other ways forward that might make more sense…

I can imaging scenarios when a builder designs a rig to run, with improved sound quality (/at a lower total pricepoint) and from the ground up is ‘ready’.

reworking a bunch of bits to make this work doesn’t seem like a great pathway forward.

for me: bi amping was for ‘being a uni student’ and having the best audio I could muster.
with entry level and mid tier ‘consumer crap’, it cpuld make a discernable and appreciable difference.
(I think my first rig was a NAD 3020(treble) and Rotel ‘monoblockable’ power amp (bass), later upgraded to two matched rotel monoblockable power amps.
that monoblock switch ruling the waters when cosidering buying ‘more amps’ for only two speakers.

The uplift in sound quality is coming from where?

*less burdened power supplies
*ability to run different speaker cable for different speaker driver and amp pairings
*better lectrical isolation between the channels

etc etc

if your system doesn’t have weaknesses (ie from being the worlds cheapest kit like I was using) then it is hard to imagine the gains to be found.

probably better going down a different pathway


if determined to buy another amp of ‘near identical vintage’; might be great to use them as power amps for a multichannel AV processor/receiver.

My NAD/Rotel setup was wonderful.
for 200$ I had the sweet NAD treble and nuance with the Rotel high damping factor and higher wattage for the more (power) demanding bass drivers.

In fairness the best audio upgrade was some Nordost bi-wireable speaker cable…

I’d seriously reconsider this project, certainly before making my speakers ‘bi-wireable’. (unless that is a personal project and ‘fun’)

might affect resale, and your amps would wear out at a different rate based on one being used lightly and the other being hit harder…

(tweeters are a percent or so of the power/midrange units moght delve around 30% and bass takes the lionshare, being 70%+ of the power needed)

I do confirm at the starting point to hifi budget and sound, using second hand, a match in favour of bi-amping as a pound per sound upgrade might work; but more than likely time and $ spent elsewhere will net seriously more

It seems you’re talking about passive bi-amping. That is of uncertain benefit, and personally I would certainly never buy an amp to do that. (Different if you have a spare amp, when you can have a play at the cost only of some cables.)

Active bi-amping (or tri-amping if a 3-way speaker) is quite a different matter, removing the speaker’s passive crossover circuitry from the signal path, and giving the power amps direct control over each driver. It is usually highly beneficial, though whether or not better than spending the same total money on a single power amp is a different matter, in slme cases maybe yes, in others maybe no.

And choosing a speaker on the basis of it having “biwire” terminals seems crazy - much better would be to seek a speaker that sounds great to you, irrespective of the number of terminals it has.


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