NAD amps for warming up RTi10's?

SoundSolution

I thought I'd ask on this forum after combing through old threads here swayed me away from going the Emotiva route. I want to get my first external amp to power my RTi10's via a 5.1 receiver (NAD T758 V3) for stereo & multichannel music.

I see Parasound & B&K are recommended most around here, but how about NAD for taming the RTi's brightness & for music? I'm seeing a lot more NAD options in my area & price range. This is what I'm looking at:

- NAD C272 (2x150 watts)

- NAD S250 (2x200 watts)

Anyone have experience with the NAD "silverline series"? Supposedly it was designed & built by 'Gryphon' & some old discussions online describe this line as "bright" which is something I'm trying to avoid with RTi's, but then this looks to be the highest end amp I could score in my price range. Of course an old NAD catalog claims it's warm, so I don't know what to believe:

"A differential Pure Class A input stage using precisely matched FETs (Field Effect Transistors) imparts a wonderfully warm sound with a grain-free upper midrange and treble response"

I'm also looking at a Rotel RB-1582 & an Adcom GFA-555SE (the new ones).

Any thoughts on these choices?

Kex

No familiarity with the S series, but the C272 is an excellent product IMO.

Don’t let the somewhat “modest” specifications fool you: it is rated for 4Ω and even 2Ω. I never even bothered with using the soft-clipping switch on my NAD when I was driving 3-6Ω speakers with only 82.5 dB efficiency.

Have you tired the T758 yet? I haven’t tried any of their most recent offerings, but NAD is very much a music first philosophy, and ratings in the past have been conservative. Hopefully, they’ve stayed true to that.

audioluvr

I like the NAD sound. They are a lot like B&K stuff IMHO

honestaquarian

I remember once back around the turn of the century when I was working at a HiFi shop that sold both NAD and Rotel. Once of my coworkers was doing a demo comparison between an NAD amp and a Rotel amp. The Rotel played first, followed by the NAD. Everyone in the store heard the difference immediately as it was not subtle. The Rotel was much brighter than the NAD!
Both sounded perfectly fine on their own. However when compared back to back it quite literally sounded like someone turned the treble control down when switching from the Rotel to the NAD.

audioluvr

Too much treble gives me a headache.

msg

Is this for music or theater?

If for music, I recommend letting the RTi10s go, and moving over to something like the Signatures or LSiM if you want to stick with Polk.

I tried a lot of different stuff trying to warm up RTi10s. Just never got there. Had the Signature series been available when I first got into this, I don't think I'd have gotten (fallen?) so deeply into audio. Find a speaker you like and build around that. At this level, the speaker is going to have the biggest effect on sound presentation.

msg

msg wrote: »

Is this for music or theater?

Duh, you answered that. Sorry, t'was urlee.

SoundSolution

Thanks for the comments, I am more confident that I'm going in the right direction with NAD amps. I will probably get the C272 if it's still available in a week but I wish I could find more information about the S250.

Kex wrote: »

Have you tired the T758 yet?

Yes, it sounds great but I figured the 60 watts per channel isn't doing the RTi10's justice.

One question I have about the C272: On the back there's four pairs of speaker terminals intended for bi-wiring according to the manual. What is the suggested way to wire this amp to RTi10's? Using two sets of terminals per speaker? Is there actually a benefit to this?

msg wrote: »

If for music, I recommend letting the RTi10s go, and moving over to something like the Signatures or LSiM if you want to stick with Polk.

I tried a lot of different stuff trying to warm up RTi10s. Just never got there.

To be fair, I do like the extra sparkle on the top end, I just want to make sure I don't add any excess brightness combining them with the wrong amp. What equipment did you try to warm up the RTi's?

msg

Ah, gotcha.

I tried a B&K Sonata EX-442 amp and MC-101 preamp. Next was a Parasound Halo C2 processor and HCA-2205 amp. I abandoned the RTi10s at that point, and stashed them.

Months later I tried them again on a B&K AVR 507 in a padded room. No go. Didn't last 20 minutes.

I really wanted to like those speakers. They were good for theater, but just sounded thin in the mids and lows. If I turned them up to get performance in the mids and lows, the tweeters would be absolutely screaming, making them unlistenable for rock. I suspect now the mids and lows may not necessarily be lacking, but possibly the tweeters just overwhelming everything else for music play.

None of that equipment made them worse, just not better enough to make me want to keep them. None of that gear "tamed" them. All of that equipment did handle them with significantly greater authority. Bass was definitely more impactful and controlled, and that was fun.

Kex

SoundSolution wrote: »

Yes, it sounds great but I figured the 60 watts per channel isn't doing the RTi10's justice.

You might be surprised.

I haven’t tried the latest generation of NAD, but even the “entry level” receivers can be surprising. By NAD descriptions, the more beefy T777 still “only” puts out 80 wpc (20 watts more than the T758), but in both cases, that’s measured with all seven channels driven simultaneously, and at <0.08% distortion.

The RTi10 can be reputedly tough(ish) to drive - to get the most from the bass, in particular. The specifications at 8Ω and 89dB efficiency don’t reflect that, and it would be my suspicion that you may - or may not - hear a significant difference with the addition of the C272.

SoundSolution wrote: »

One question I have about the C272: On the back there's four pairs of speaker terminals intended for bi-wiring according to the manual. What is the suggested way to wire this amp to RTi10's? Using two sets of terminals per speaker? Is there actually a benefit to this?

I would ignore the second set of terminals completely.

msg

I remember looking into NAD and Anthem when I had all this going on. Never got a chance to try those, but also wanted to share that I tried Pioneer Elite and Marantz AVRs. I forget which ones, but they were 120wpc+ units. I returned them both.

I'd be curious to hear whether you find a significant improvement with NAD options.

BlueFox

I tried a NAD AVR from one company, and the background noise was unacceptable. I returned it, and ordered the same AVR from another company, and it had the same issue. Granted, it couldn’t be heard playing movies, but it was still unacceptable. While I don’t know what caused it, my suspicion was the plug in cards.

Kex

Not sure about that, @BlueFox. I’ve had three NAD’s over the years (the first two didn’t have any of the modular cards), and still use one. Completely silent for me, but maybe your system is more revealing. It is a lot more sophisticated than mine.

Kex

msg wrote: »

I remember looking into NAD and Anthem when I had all this going on. Never got a chance to try those, but also wanted to share that I tried Pioneer Elite and Marantz AVRs. I forget which ones, but they were 120wpc+ units. I returned them both.

I'd be curious to hear whether you find a significant improvement with NAD options.

I’m familiar with Pioneer Elite, but not Marantz.

I was totally unimpressed with Pioneer Elite, but in my experience, no receiver I’ve tried comes close to NAD in sheer power delivery, in spite of the modest specifications on paper. The newest stuff may be different, and audio perceptions can be very personal sometimes.

The C272 is getting a bit long in the tooth (2003-ish, methinks). The current equivalent is the C275BEE, I believe.

BlueFox

Kex wrote: »

Not sure about that, @BlueFox. I’ve had three NAD’s over the years (the first two didn’t have any of the modular cards), and still use one. Completely silent for me, but maybe your system is more revealing. It is a lot more sophisticated than mine.

These things happen. Maybe it was the model, which I have forgotten. However, it did occur.

SoundSolution

Reliability is actually one of my concerns with the C272. I'm aware that a handful had some disastrous issues back in their day. From NAD:

We have seen a small number of filter capacitor failures in and C372/C272 that we would like to bring to your attention. While the actual number of affected units is extremely small (about a dozen units over the last 5 years), the failure is quite spectacular. The problem is that one of the main filter capacitors overheats and blows open. There is a flash and smoke and in some cases the top cover paint melts. This can be alarming as there is an electrical burning smell. In all cases to date, the safety measures built into NAD products have contained the damage to the unit itself.

We have done a lot of research into this problem and have implemented some additional safety measures in order to reduce the number of failures to zero. This failure tends to occur when the mains voltage is high (+10 % of normal mains levels) which is typical in just some parts of the world. However, the main finding of our research is that failure is caused through poor ventilation. It is very important to ensure clear airflow around the unit and that it not be installed in close proximity to a shelf or has anything standing on top that impedes heat dissipation through the vents in the top cover. This includes avoiding having another unit standing on top and if so this must be avoided from now on.

These units were made I believe 2003-2007. I asked the seller if it has been serviced. They said no servicing that they know of & that it had no hiss or noise issues, functions 100%. Should I assume it's a safe unit to own if it has made it this many years without... blowing up?

Kex

Personally, it’s not something I would worry about. If it were one of the affected units, it should really have blown up by now (after fifteen years or thereabouts)! 😂

No used purchase is ever entirely risk free, but if you’re still concerned, there’s always This C275BEE, refurbished by NAD, and sold by a very reputable dealer, with an official one year warranty, for $840, including free shipping.

It will match your T758 better (color of finish and styling). The older units have a much lighter color of grey.

Clipdat

Safe and Sound is a good retailer in my experience. They will take care of you post-sale if you ever need it.

SoundSolution

Thanks for the suggestions. I'd jump on that deal but I'm in Canada & they don't ship here unfortunately.

I have a question about the NAD T955 5x100 watts amp. Is there an ability to bi-wire (or is it bi-amping?) two of the amps to each speaker & double the power while leaving the 5th amp to spare?

Edit: I've found one instance of someone doing this:

Bi amping my mains with 200w each has added a much cleaner, deeper sound allowing the speakers to perform to their potential. Had to split the main left and right pre outs with a Y connector to allow for bi amping my mains with 2 channels each.

Something tells me no but figured I should ask the more experienced. Otherwise I'm pretty much settled on the C272.

SoundSolution

Just to update in case this helps anyone in the future, I ended up getting the NAD C272. Seemed to add more oomph & headroom but I'd say the amp more or less mirrored the tone of whichever receiver I hooked it up to.

I ended up returning the NAD T758 receiver due to a host of bugs & engineering "quirks" & settled on an Anthem MRX-520. I have to say this is the most balanced sounding receiver I've heard. The "sparkle" of the RTi's is still there but everything seems a lot more natural for music now. I've seen another post on here where someone went on raving about Anthem receivers & I am now a big fan as well.