Naim Uniti Upgrade

NAP 200

Thanks ss. so the uniti would work as a pre amp for the nap 200?

I was in exactly your situation and upgraded to a Superuniti which is absolutely perfect for my needs. I have no neighbours within a quarter of a mile (have had a live band playing in the garden past midnight with no complaints!) so I do like it very loud on occasion. 

You could add a power amp to the Uniti but going to an SU upgrades the pre amp and streamer sections as well as supplying the required welly. You can trade in your Uniti to offset part of the cost. Best of all it's still one box.

Is the Uniti in a cupboard or on a shelf with restricted airflow? If so, this can make it get hot, and if you put it on an open shelf the problem might go away. If not, a 200 would be ideal. You switch off the internal power amp and the 200 takes over. As well as more power, it will sound better. 

What speaker cables are being used? A symptom of a wrong speaker cable is a power amp section overheating.

NAIM tend to be quite sensitive to speaker cables. Best bet is to go with NACA5. 

Yes hungryhalibut it's in an enclosed but ventilated cabinet (and in Australia) so can get quite warm. An open shelf while practical won't go down well with the missus, so instead an upgrade calls. Also I have heard that the dynaudios are power hungry so suspect that is contributing factor. Question with the nap option, the nap replaces the power amp from the naim rather than augments it. So the improvement is from 50w to 70w?

PEV Looks like super uniti doesn't include a cd, and I'm not ready to abandon that option, so looks like a  uniti2 vs nap 200. The nap is the considerably cheaper option so wondering whether the sound quality difference would be that great.

I'd try it on the top first. There is no point buying a 200 and finding that you have the same problem, is there?

Can you give it more ventilation?

As Adam says, make sure you are using a suitable speaker cable...

A 200 (or even a 250) will give you some extra clout as well as an all round improvement. They will also generate even more heat, so in an enclosed rack, they may not solve your problem.

Speaker cables were new with the speakers and not cheap EWI professional 2.5mm. Could they really make that much of a difference?

jm100 posted:

Speaker cables were new with the speakers and not cheap EWI professional 2.5mm. Could they really make that much of a difference?

What is their lenght, capacitance and inductance? All those parameters are vitaly important for your Naim amp to be happy.

ChrisSU posted:

Can you give it more ventilation?

As Adam says, make sure you are using a suitable speaker cable...

A 200 (or even a 250) will give you some extra clout as well as an all round improvement. They will also generate even more heat, so in an enclosed rack, they may not solve your problem.

 

My NAP250DR running into a set of NACA5 resides in a closed cabinet with some ventilation. It barely gets warm.

So with an overheating power amp section my first point of check would be speaker cables.

I'm no engineer, just like listening to music. Speaker cable specs follow.... how would one determine their suitability for my uniti and dynaudio combo from this?

Manufacture: EWI
Model: NNS-1492
No. of inner conductors: 2 x 2.5mm² ( 13AWG )
Copper strand per conductor: 48 x 0.26mm
Conductor insulation: PVC 3.3mm
Capacitance cond. per 1 m: 109pF
Conductor resistance per 1 KM: < 6.7Ω
Electrical rating: 300V
Temperature range: -20°C to +80°C
Jacket diameter: 9.2mm
Jacket color: Black
Weight per 100 m: 13.5Kgs

Length would be about 2.5 - 3 metres

jm100 posted:

Speaker cables were new with the speakers and not cheap EWI professional 2.5mm. Could they really make that much of a difference?

Hi JM100,  where are you in the world,  the only place I've seen EWI speaker cables is South Africa & I have it on my Sony in Hazyview,  it looks a basic & very ordinary round twisted pair similar in construction to my UK home Chord Odyssey.   Odyssey is a popular naim user cable with ordinary middle of the road capacitance - mine measured 63pF/m.    However EWI 2.5mm is a bit higher .........  EWI Model: NNS-1492 = 109pF/m.    This is getting a little high (Naim NACA5 is 16pF/m),   but I don't think it would cause the amp to overheat,  especially with 3m. 

My bet is on the amps ability to drive the Dyno 160's,   they are a nominal 4ohms & not very high sensitivity with 85dB/w/m so will need power to go loud,  I don't think the Uniti has the low impedance grunt in its power supply to do the Dyno's justice.   

Capacitance is very high - the audible effect would be similar to 'someone strangling singers' throat' whilst she/he tries to sing. Or a other way to look at it - think in terms of pipes carrying water. The larger the diameter the easier it is for the water to flow. Lower the capacitance the larger the 'diameter of the pipe' etc etc.

jm100 posted:

I'm no engineer, just like listening to music. Speaker cable specs follow.... how would one determine their suitability for my uniti and dynaudio combo from this?

Manufacture: EWI
Model: NNS-1492
No. of inner conductors: 2 x 2.5mm² ( 13AWG )
Copper strand per conductor: 48 x 0.26mm
Conductor insulation: PVC 3.3mm
Capacitance cond. per 1 m: 109pF
Conductor resistance per 1 KM: < 6.7Ω
Electrical rating: 300V
Temperature range: -20°C to +80°C
Jacket diameter: 9.2mm
Jacket color: Black
Weight per 100 m: 13.5Kgs

Specs for the NACA5 are

C = 15pF/m

L = 1.0uH/m

R = 10mR/

An alternative cable to NACA5 is Tellurium Q Balack / Ultra Black. Minimum recommended lenght there is 3 meters.

well spotted I'm in Australia. The EWI cables were sold and recommended to me by local naim/ dynaudio retailer. Ive heard the dynos are power hungry hence the initial thought about more amplification.

New cables would be the simplest (& cheapest) option. Appreciate they may have an impact on sound quality but overheating is not something I'd have considered so a little skeptical, but worth a try.

Here is a section from a NAIM power amp manual. Draw your own conclusions...

1.2

Loudspeaker Cables Loudspeaker cables are vitally important. They should each be at least 3.5 metres long and of equal length. The recommended maximum is normally 20 metres although longer cables may be viable with some Naim ampli ers. Some Naim ampli ers are designed only to work with Naim loudspeaker cable and using alternatives may degrade the performance or even damage the ampli er. Other Naim ampli ers can be used with any high quality loudspeaker cable although we recommend that Naim loudspeaker cable is used. Naim loudspeaker cable is directional and should be oriented so that the printed arrow points towards the speakers. The Naim loudspeaker connectors supplied are designed to comply with European safety legislation and must be used.

Adam Zielinski posted:

Capacitance is very high - the audible effect would be similar to 'someone strangling singers' throat' whilst she/he tries to sing. Or a other way to look at it - think in terms of pipes carrying water. The larger the diameter the easier it is for the water to flow. Lower the capacitance the larger the 'diameter of the pipe' etc etc.

Adam,  sorry but the 109pF/m capacitance is not 'very' high,  its typical of a 2 core twisted pair,  yes its higher than ideal but I suspect a lot of Chords, QED's & similar looking cables are much the same.   Too high C causes output stage instability in the form of capacitive reactance (HF ringing up to full oscillations).   Thats what causes amps to overheat.   I've only seen it once when I used Kimber weave PR8 that has 295pF/m,  it caused my little Nait-2 to protest,  but my Supernait was quite happy with it,  seems you can hook up anything to a SN.    

Mike-B posted:

Adam Zielinski posted:

Capacitance is very high - the audible effect would be similar to 'someone strangling singers' throat' whilst she/he tries to sing. Or a other way to look at it - think in terms of pipes carrying water. The larger the diameter the easier it is for the water to flow. Lower the capacitance the larger the 'diameter of the pipe' etc etc.

Adam,  sorry but the 109pF/m capacitance is not 'very' high,  its typical of a 2 core twisted pair,  yes its higher than ideal but I suspect a lot of Chords, QED's & similar looking cables are much the same.   Too high C causes output stage instability in the form of capacitive reactance (HF ringing up to full oscillations).   Thats what causes amps to overheat.   I've only seen it once when I used Kimber weave PR8 that has 295pF/m,  it caused my little Nait-2 to protest,  but my Supernait was quite happy with it,  seems you can hook up anything to a SN.    

I meant high compared to NACA5 

jm100 posted:

 

PEV Looks like super uniti doesn't include a cd, and I'm not ready to abandon that option, so looks like a  uniti2 vs nap 200. The nap is the considerably cheaper option so wondering whether the sound quality difference would be that great.

If you are ready to accommodate 2 boxes then you could still get an SU and feed it with any CD player with a digital output, even a DVD or Blu Ray player. This would make use of the superior DAC in the SU and should still be an upgrade over the Uniti CD player. I never rated the CD player in my Uniti very highly and was glad to see the back of it and its pesky puck so it won't be hard to improve on.

Do you have access to a decent Naim dealer? If so, you could probably borrow some Naim cables and see if they help. Come to think of it, they could maybe lend you a 200 as well, to try in your system. Also, perhaps you could consider some different speakers that are easier to drive and don't have to make your amp work so hard.

Another possibility to consider might be the Uniti Star which is about to hit the market, replacing the Uniti. I believe it has a slightly more powerful amp, and the chunky looking heat sink fins all down the side might help you.

Thanks all for the tips. Some decent naim speaker cable looks to be first port of call

I added a powerline to my superuniti and the impact was very good, probably the on,y upgrade I would do to an all in one.

Gary

I can empathize JM100.

i am in Australia and went from Uniti to SuperUniti (very happy) to drive some Power hungry 4 ohm Vienna acoustics Mozart speakers.

i use my Oppo Bluray player to spin a disc approximately once a year.

Heat can certainly be an issue so the SuperUniti sits on its own shelf while all other equipment is in a ventilated cupboard.