Amps for NX-tremes

NoahH · « **on:** 26 Feb 2022, 11:53 pm »

Folks - I am interested in some more experiences around amps for NX-tremes.

I have been playing with amps with a friend today. I had initially started with a McIntosh MC275 on the speakers. My friend brought a little Hypex amp that kicked the McIntosh's butt several times over. I know the McIntosh is good in a lot of combinations, and suspect it is an interaction with the Xtremes. My best idea is it is a complex load that the Mac can't manhandle with 75 wpc, but given the sensitivity of the speakers that is a surprise.

I am about to start the complex process of getting my Ayre out of it's primary system and trying it, but am really interested in other recommended amps. In particular, it would be good to hear of slightly more mainstream stuff as well that I may know from experience or characteristics of amps that mate well. Ex I know the Odysseys are well liked in here but they obscure enough that I can't really know much about those without cold-ordering one online.

Thanks all!

mkrawcz · « **Reply #1 on:** 27 Feb 2022, 12:45 am »

The best non-diy amps I’ve ever heard are the PS Audio BHK 300 Monoblocks. They power my NX-Oticas still.

subsonic1050 · « **Reply #2 on:** 27 Feb 2022, 03:44 am »

I have had a similar experience with the nxtremes- in that they seem to want more power than you'd expect given the nearly 95dB efficiency. I have a theory about that. Everyone knows that speaker efficiency is defined as SPL with 1 watt of power at 1 meter - but what's often forgotten is that it is also specified to be at 400Hz. My thought is that the efficiency is actually a little misleading on these speakers, as I'm sure they do produce 94.5dB with 1 watt at 1 meter at 400Hz - but how much power does it really take to drive all those 6.5" woofers? I have no idea if I'm correct about that or not, but I have found that to get the best out of them they need considerably more power than you'd expect- most specifically in the bass region.

Hobbsmeerkat · « **Reply #3 on:** 27 Feb 2022, 04:21 am »

I have one of the battery powered chip amps and I've noticed the same thing between my NX-studio which sounds killer, while the same amp driving my X-Statiks where the bass and lower mids just feels sluggish and lacking vs the studio where it's still incredibly articulate, even down low. My little Class-D Sprout 100 has no issues gripping the bass on my X-statiks by comparison.

Same thing on Danny's system. The bass and mids on thr NX-Tremes are lacking the speed and control when they being driven by the little chip amp. It still sounds good, but not "WOW" like i expected with his bigger monoblock chip amps.

Talking to Folsom, who is making the little chip amps for us, thinks the issue likely comes down to their damping factor, and that seems to reveal itself most when a speaker has multiple drivers, like the X-Statik or NX-Otica/Treme.

So if you notice that the bass/mids are "lacking" that control/speed I wonder if that's the major factor you're getting as well?
And i imagine that's often where synergy plays roll.

Jaytor · « **Reply #4 on:** 27 Feb 2022, 04:30 am »

I've tried quite a few different amps of all types on my NX-Oticas. The best match so far is the Pass XA60.8 monoblocks. These have plenty of power to play as loud as I want and are smooth, sweet and dynamic.

My 300B parallel SET monoblocks sound wonderful at low volumes, but sound a bit strained when I play them at volumes that I often like to listen to, particularly with music that has a wider dynamic range.

Other amps I've used included DIY Neurochrome 286 monoblocks, DIY Purifi monoblocks using a large linear power supply and a variety of input buffers, DIY Pass F5 Turbo (50w) monoblocks, Parasound JC5, and a handful of tube amps that friends have brought over (don't recall the models).

subsonic1050 · « **Reply #5 on:** 27 Feb 2022, 04:30 am »

Hobbs - interesting you also referenced the chips amps. I built a neurochrome chip amp that puts out 40w/ch and that was the amp which I most noticed the power deficit. The NX-Treme's are a truly amazing speaker, but I do think they benefit from some backup reserves in the power department to get the most out of the bass and lower midrange.

Tyson · « **Reply #6 on:** 27 Feb 2022, 04:32 am »

2nd the Pass rec.

NoahH · « **Reply #7 on:** 27 Feb 2022, 05:25 am »

Helpful thoughts, all.

Jaytor - did the Purifis not work well? The NAD M23 was one idea that crossed my mind.

The BHK and the XA60.8s both were ones I was thinking of. I am in Boulder so trying the PS units would be easy.

mkrawcz · « **Reply #8 on:** 27 Feb 2022, 10:54 am »

The nice thing about the PS Audio amps is you get a 30 day in home trial and you can return them for a full refund…..But you won’t

mkrawcz · « **Reply #9 on:** 27 Feb 2022, 05:01 pm »

Quote from: subsonic1050 on 27 Feb 2022, 03:44 am

I have had a similar experience with the nxtremes- in that they seem to want more power than you'd expect given the nearly 95dB efficiency. I have a theory about that. Everyone knows that speaker efficiency is defined as SPL with 1 watt of power at 1 meter - but what's often forgotten is that it is also specified to be at 400Hz. My thought is that the efficiency is actually a little misleading on these speakers, as I'm sure they do produce 94.5dB with 1 watt at 1 meter at 400Hz - but how much power does it really take to drive all those 6.5" woofers? I have no idea if I'm correct about that or not, but I have found that to get the best out of them they need considerably more power than you'd expect- most specifically in the bass region.

Subsonic, in your case, I think your issue may be 2 things, the gain of the Neurochrome and the input buffer opamp. I found that increasing the gain from 20db to 26 or 29db gave the amp much more dynamic headroom. I would advise adding a resister to the empty spot of your Mod86 boards as per the values noted in the documentation. I also highly recommend replacing the LM4562 opamp in the input buffer position with a Burison Audio discrete opamp. The stock opamp completely robs the amp of life.

Jaytor · « **Reply #10 on:** 27 Feb 2022, 05:24 pm »

Quote from: NoahH on 27 Feb 2022, 05:25 am

Helpful thoughts, all.

Jaytor - did the Purifis not work well? The NAD M23 was one idea that crossed my mind.

The BHK and the XA60.8s both were ones I was thinking of. I am in Boulder so trying the PS units would be easy.

The Purifis worked pretty well, particularly with the right input buffer. Just not as nice as the XA60.8s. Of the various amps I've tried, I'd rank the Purifi-based amps as 2nd after the Pass amps (of the amps I've tried) for all-around use.

The 300B SET amps have a gorgeous sound for vocals and acoustic guitar, but fall a bit short when the music gets louder and more dynamic, or with more mid-bass energy. The NX-tremes are a bit higher efficiency though, and my room is fairly large (17' x 29') with lots of treatments, so may need more power than your system. I'm hoping they'll be a better match with the Line Forces when I get these done.

subsonic1050 · « **Reply #11 on:** 28 Feb 2022, 01:04 am »

Quote from: mkrawcz on 27 Feb 2022, 05:01 pm

Subsonic, in your case, I think your issue may be 2 things, the gain of the Neurochrome and the input buffer opamp. I found that increasing the gain from 20db to 26 or 29db gave the amp much more dynamic headroom. I would advise adding a resister to the empty spot of your Mod86 boards as per the values noted in the documentation. I also highly recommend replacing the LM4562 opamp in the input buffer position with a Burison Audio discrete opamp. The stock opamp completely robs the amp of life.

You are the man with stuff related to these amps. I loved certain things about it but not others. I was considering selling it, maybe I will try those modifications first!

Endo2112 · « **Reply #12 on:** 28 Feb 2022, 08:52 pm »

Input buffers are a big deal with most class D designs, I have a buddy that makes them for his purifi amps and for him to build no compromise the buffers cost twice a much as the actual power modules, just for perspective. Also, when i had my NX-Tremes I had great success with the AS1200 ice modules that can be had for a fair price these days, that extra bit of horse power in the lower region really made the 165 drivers sing, that said, they sounded great with all the amps that I threw at them.

Cheers,

Don

NoahH · « **Reply #13 on:** 1 Mar 2022, 03:02 am »

On input buffers, agree there, as well as on the power supply. I actually pinged Tom C. @ Neurochrome about getting some consulting help to tackle a class D build. He is not too excited about a customer power supply or different buffers being worthwhile, but I have not heard his stock buffer so perhaps it is amazing (would stand to reason that he made it as well as possible - not a lot of reason for him to compromise it).

This thread raised one other idea - have folks done much passive bi-amping with Xtremes? Note that I was thinking of separating the tweets and mids from the woofers, not tweeters alone. And I am not thinking it will be an amazing power change, but just that it makes the load massively simpler that way.

AKLegal · « **Reply #14 on:** 1 Mar 2022, 05:37 pm »

Quote from: NoahH on 1 Mar 2022, 03:02 am

On input buffers, agree there, as well as on the power supply. I actually pinged Tom C. @ Neurochrome about getting some consulting help to tackle a class D build. He is not too excited about a customer power supply or different buffers being worthwhile, but I have not heard his stock buffer so perhaps it is amazing (would stand to reason that he made it as well as possible - not a lot of reason for him to compromise it).

He isn't but when a longtime poster, Early B, asked him to game plan out a linear power supply for a Purifi amp he was very helpful.

Jaytor might be able to shed some light on the benefits of a linear power supply over a switcher with class D amps since he built a killer one for his Purifi amps. I am not sure if he ever heard the Purifis with a switching PS though.

Jaytor · « **Reply #15 on:** 1 Mar 2022, 05:58 pm »

I have built a stereo Purifi amp with a Hypex SMPS, but I ended up using the SMPS3KA700 instead of the SMPS1200A700, primarily because the 1200 wasn't available when I was ready make the purchase. The 3K obviously has more power reserves, but is designed to be used with the high-power Hypex modules which are bridged amplifiers. It is not intended to drive half-bridge power modules like the Purifi since it can't handle the large reverse currents at low frequencies.

A work-around with a stereo amp is to wire the two modules out of phase and flip the phase connections on the inputs and outputs, and since the bass frequencies (< 100Hz) on most music is very similar between the two channels, this balances out the current (one channel is drawing current while the other is sourcing it).

I built this amp to power a pair of NX-Studios in my bedroom system, and it doesn't get played terribly loud. It sounds fabulous on the NX-Studios.

My monoblocks with linear power supply have a wider sound stage (probably more to do with them being monoblocks with separate power supplies) and a bit more weight in the mid bass. For some music, I think I noticed a bit cleaner upper-mids and high frequencies, but I could be imagining this.

Bottom line, the differences are pretty subtle and using an SMPS is a LOT easier to build and much more compact. The Purifi module has very high feedback, so power supply rejection is extremely high. I think you'd have to be pushing them pretty hard to really notice much difference, particularly if you built monoblocks with the SMPS1200A700 supplies.

subsonic1050 · « **Reply #16 on:** 3 Mar 2022, 11:56 pm »

I'm going to piggyback on this. I have the opportunity to purchase a PS Audio BHK preamp and the PS Audio BHK 250 stereo amp for 8k. Thoughts on this setup for the NX-Treme's? Currently the best overall sound I've gotten from them is with a PrimaLuna Evo 300 integrated amp. I've tried the Neurochrome Mod 86 v3 as previously mentioned, but also a Lyngdorf TDAI-2170, and a pair of Benchmark AHB2's set up as mono blocks.

The Benchmark's had the punchiest bass, but in all other respects were too sterile for me. No real life or excitement in the music. The Neurochrome amp was very lacking in bass for me - almost sounds like there is a low pass filter on the system the bass is almost nonexistent. The Lyngdorf sounds good in all respects, but the PrimaLuna has produced a wonderful rich, full sound with fantastic vocals, soundstage, imaging, etc.

It's a significant chunk of change to drop on the PS Audio stuff, so curious if anyone has spent time with that equipment - especially on the NX line of speakers.

NoahH · « **Reply #17 on:** 4 Mar 2022, 12:13 am »

I don't have feedback on the BHK but can I pile on the Benchmark comments?

That is the most over-rated amp I have ever touched. I think it is the feedback - that thing is one giant feedback machine, and it rips all emotion from the music. Weird.

mkrawcz · « **Reply #18 on:** 4 Mar 2022, 12:34 am »

Quote from: subsonic1050 on 3 Mar 2022, 11:56 pm

I'm going to piggyback on this. I have the opportunity to purchase a PS Audio BHK preamp and the PS Audio BHK 250 stereo amp for 8k. Thoughts on this setup for the NX-Treme's? Currently the best overall sound I've gotten from them is with a PrimaLuna Evo 300 integrated amp. I've tried the Neurochrome Mod 86 v3 as previously mentioned, but also a Lyngdorf TDAI-2170, and a pair of Benchmark AHB2's set up as mono blocks.

The Benchmark's had the punchiest bass, but in all other respects were too sterile for me. No real life or excitement in the music. The Neurochrome amp was very lacking in bass for me - almost sounds like there is a low pass filter on the system the bass is almost nonexistent. The Lyngdorf sounds good in all respects, but the PrimaLuna has produced a wonderful rich, full sound with fantastic vocals, soundstage, imaging, etc.

It's a significant chunk of change to drop on the PS Audio stuff, so curious if anyone has spent time with that equipment - especially on the NX line of speakers.

It’s a very subjective thing and everyone has different tastes.If you find that you like your Primaluna the best, I would say you will love the BHKs. Especially the pre/amp combo. They have all the benefits of tubes and all the benefits of SS. I tend to always end up back at the BHKs on my NX-Oticas. They just seem to be the most complete amps with the least amount of trade offs. I should note that I have the BHk300 monoblocks. I have not heard the 250.

subsonic1050 · « **Reply #19 on:** 4 Mar 2022, 07:48 am »

Noah - Yeah the Benchmark amps are not mine - a relative of mine purchased them but for reasons that are too lengthy to get into I have use of them. To me they are a great example of why measurements aren't everything. Sure they measure great, but they are so underwhelming for me. "Ripping emotion from the music" is a perfect description for them.

mkrawcz - that's great to hear regarding the BHK amps! I still hope to upgrade my Neurochrome amp as you have suggested, but this deal sort of fell into my lap today and it seems like it should probably be an upgrade from what I have. The guy is actually bringing them here later today and I'm going to get a chance to try them out in my own room and my own system before I buy them - how cool is that? I'm really hoping they give me the tube flavor I'm looking for while retaining the dynamics and detail of some of the SS stuff.