Chris, my understanding is Naim power amps are designed to be used with a Naim NAC amp stage. Given the not inconsiderable costs involved, I would get confirmation from Naim themselves that there is no issue in using another amp stage with your NAP. We have learned from Richard that Naim did once create a version of the 250 to be used independently for the BBC… so it seems possible, but Naim might need to do a mod.
Hummmm … if that was the case, how do you explain that the latest DR power amps have been reviewed with a non Naim pre? By the way, my 250DR is singing very nicely with an Allegri pre …
No harm in asking is there… I just seem to remember hearing in the past that the NAPs were designed to be used specifically with the NAC amp stage and grounding arrangements … where as NACs can be used with other amps.
I suspect it’s a similar consideration to using non Naim speaker cable… although not recommended, it’s fine as long as certain conditions are met… or Naim may say their amps are now plug and play and completely modular with other manufacturers.
i am using non naim pre and non naim speakers cables with my nap with great results.
For me it’s ear pre, other prima luna or townsend allegri. Mcintosh pre work good too and probably many other.
“Designed to work together” doesn’t mean can’t work separately, and doesn’t mean won’t perform perfectly separately! I imagine Naim’s answer would be to simply recommend they are used together – after all that is obviously what Naim want to people to do.
I cannot see that anything is needed other that the source itself is capable of feeding l an input impedance of 16k ohm, a third of the more conventional 47-50k, without detriment to the source or the signal, and very possibly requiring frequency bandwidth limiting to avoid instability. But as SiS says, there is no harm asking Naim. However, any question to them may benefit from being specific, such as asking what characteristics of the source are essential for a NAP to perform as it should.
IIRC the BBC version that Naim built had pro type balanced XLR inputs and pro-type speaker cable sockets - the balanced inputs mean it must have had some modification to the input, whether transformers or other, which would make it a different case. I guess the changes would primarily have been for connectivity reasons, other pro equipment commonly having balanced inputs, and I imagine the BBC would’t want to faff around with different cables for different amps,
The considerations might be around frequency stability and minimising / avoiding intermodulation … therefore the NACs might have a low pass filter incorporated for the NAPs… but hence why I would ask Naim… as that might not be the case at all.
Do remember impedance is not a static thing… it’s dynamic and varies with frequency unless a transmission line… therefore impedance matching occurs at different frequencies along with the frequency loading … so how do you manage this? You need a buffer stage to effectively provide a managed frequency load into the amp that matches what the amp is expecting … enter the NAC.
Now you are right others pre amps may do this and may do it in a way that provides a different performance from the Naim amp… I guess there is nothing wrong with that.
But the thing I would personally check with Naim is whether the low pass filter aspect is required … and if so confirming my non Naim preamp has an equivalent low pass filtering effect.
Getting this area wrong can lead to instabilityand in some circumstances damage.
I can’t see why anyone would not ask Naim this especially as it is not a standard configuration … unless perhaps they are afraid of what the answer might be… surely it’s better to be certain than gamble… and if all ok… you can be confident about it.
Naim might not recommend it, but that is different from advising against it for technical considerations. I think you can rely on a reputable company like Naim to give honest advise.
Do Chord spec sheets tell us how it would feed a power amp? For the Dave, I read an “Output Impedance” of 0.055 Ohm (0.042 Ohm for the TT2, and 0.025 Ohm for the Hugo 2). Is this something totally different? [You see that I have no technical knowledge whatsoever…]
FWIW, Chord’s Etude and Toby (presumably designed to work well with Dave and TT2, respectively) are quoted to have an Input Impedance of 100K Ohm – which, to me, “sounds” quite a bit higher than the 16K Ohm Naim NAPs have. Does is matter in the “real world”?
Re Frequency Bandwidth, is this related to “Frequency Response”?
Cheers!!
What the Chord info tells you in effect is that they are quite stable and can give normal performance even into very low impedances - including direct to loudspeakers or headphones with impedance of nominally 8 ohms. The higher the impedance of whatever they feed the less effect there would be, so if perfect with 8 ohms they will be no less perfect into 100k …or 16k.
Bandwidth is frequency range, but not necessarily the same as a quoted frequency response because manufacturers often only state that in relation to their audible range to show the flatness of it.
Because a power amplifier might become unstable if fed with frequencies way above the audible range, there may be frequency limiting in a preamp, whether that be 40KHz, 60, 80 or whatever. Those Chord DACs do include a filter - with Dave it is at 60KHz, and can be selected to be on or off. I don’t recall if the others are at the same frequency or if they are switchable. It is also possible that a preamp may have low frequency limiting to block subsonic frequencies that could cause overloading of the power amp or speakers, though I have come across that most often in relation to phono inputs (to reject the effect of record warp). I’m not aware of the Chord DACs having that.
Well, I’ve checked the NAP user manual. There are some warnings about the speaker cable length but nothing about using a non Naim pre. Given how litigious the world is, if there was just a remote risk of damaging a NAP, the user manual would include plenty of disclaimers and warning notice …
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Is it my imagination, or is that eyebrow raised just a little higher than it used to be?!
Anyway, I have called Naim support, and they say it’s not a problem to connect Dave directly to my 250. Still, it would be interesting to know if Naim preamps do limit bandwidth, and if so, by how much. I guess the Dave HF filter goes some way towards doing this, albeit digitally, by cutting off at 60kHz, although my uneducated guess would be that a Naim pre might have a lower cutoff frequency than that.
Regarding the signal ground arrangement, I have no idea if this is still optimal for a Naim system with Dave pre. @Analogmusic mentioned that it has a signal ground unlike other Chord DACs.
There are some good points being made on running alternative pre’s or running straight into a Naim power amp and in certain situations I think it’s a viable alternative. However, I do think there is a point where the systems capabilities start to become compromised.
My experience is as follows; I managed to obtain a 500 power amp several months before I found a good 552 and primarily used it with my (POTS-8/Serviced) 52. A few months later I sent my 552 to be serviced and had to resort to an old 72 (having just sold the 52) for temporary use with the 500. This was about the same time that there was some positive chatter around the Townsend Allegri passive pre-amp, and as I pass Townsend on my way to work I thought I’d borrowed one to try. They were very obliging, so it went into the system.
My initial thoughts were very positive as it was definitely an improvement on the 72/Hi-Cap but it didn’t seem quite as good as I remember the 52 sounding. Then the 552 came back from servicing and proved to me just how significant the pre-amp can be in an all Naim system. The performance lift over the Allegri was substantial.
My conclusion is that passive pre-amps or non pre-amp alternatives can sound good up to a point, better than perhaps a 72/272/82/282 but not as good as a 52/252/552.
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Except it is rather stretching things to suggest that just because one brand - or even multiple brands - of passive preamp are not as good as something else, the same will apply to Dave’s own volume control, which is not a passive preamp in the same sense.
Of course, if what you like is something the non-passive preamp is doing changing the signal in some way, then very possibly you would find it better to your ears compared to without it.
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Yep, I accept that someone may well find a particular pre or non-pre doing something they like. And I entirely agree that on some of the smaller systems it might work quite well. My point is that when you get to a certain levels of transparency the limitations become much more obvious particularly with Naim.
Ultimately, for me, I run a radio, record player and DVD player through my system and having no pre-amp would become a bit of a pain and a limiting factor no matter how good it sounded.
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Indeed, preamps usually have tei core functions aside from controlling volume: to switch inputs, and to raise low level signals to that needed for the power amp, and to control volume. When you have just one digital source, or several all going through just the one DAC, then these two functions aren’t needed - but they are if you have analogue sources!
Hi, what cables have you used with the Allegri or Dave? I have a few different options to try, but so far I haven’t had great results with the Allegri, so I’m curious to know if any particular cables would work well here.
Hi Chris, I’m using cables from Townshend - rca rca, chord signature - din rca, atlas mavros - rca to xlr for my 300DR. I was just listening to the allegri/250dr system connected via flashback cable, sounded great and these cables are great value.
Chris, FWIW, I tried both Naim Hiline, and DNM DIN to phono leads.
Thanks, I’ve tried some Flashback Premier cables, also a Hiline between Hugo and Allegri, and some Fractals I had on loan. So far, none of them have been good enough to persuade me to keep the Allegri.
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Simon, I recall that you mentioned using DNM cables with their HFTNs fitted. Any reason why you would choose HFTNs with Dave? I’m not sure I understand exactly what they do.
I tried both with DAVE into my 552.
The HFTN filter the RF that may be being conducted in the lead. Filtering the RF then helps prevent intermodulation effects in the connected equipment.