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$500 amplifiers to test and review?

JohnBooty

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Awesome again. (bell sound) I had these two ideas rolling around in my head, but I did not realize "sensitivity" was that metric.
It's unfortunately only sorta, kinda that metric. How quickly and precisely that magnet is able to move the diaphragm depends a lot on the amplifier as well. And other things. For example, when powered by a solid 50W amp, these small and somewhat inefficient DIY speakers are surpremely detailed in a small or medium room. They just need a solid amp to do it. They also have ribbon tweeters, which have some disadvantages, but also crazy advantages like being incredibly stiff and unburdened by a dome tweeter's need to flop around on a little foam rubber surround ring.

In my experience it's fairly safe to assume that high-efficiency speakers have that sort of magical "effortless" quality. Though one can't assume that lower-efficiency speakers lack it. Personally, I'm planning on sticking with 90dB+ efficient speakers when possible in the future. But not as an iron clad rule.
 

HuskerDu

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It's unfortunately only sorta, kinda that metric. How quickly and precisely that magnet is able to move the diaphragm depends a lot on the amplifier as well. And other things. For example, when powered by a solid 50W amp, these small and somewhat inefficient DIY speakers are surpremely detailed in a small or medium room. They just need a solid amp to do it. They also have ribbon tweeters, which have some disadvantages, but also crazy advantages like being incredibly stiff and unburdened by a dome tweeter's need to flop around on a little foam rubber surround ring.

In my experience it's fairly safe to assume that high-efficiency speakers have that sort of magical "effortless" quality. Though one can't assume that lower-efficiency speakers lack it. Personally, I'm planning on sticking with 90dB+ efficient speakers when possible in the future. But not as an iron clad rule.
@JohnBooty You are super patient. Thanks.

Okay, so your tweak takes us in the direction of pairing amp to speakers, I think... (Try brut rose instead of champagne or cab sometime. The better ones - Oregon usually - are dry, but just a little more tongue-friendly. Surprising pairing with umami-rich foods, when you want a break from the "same ol'".)

I guess highly efficient, low impedance speakers ...would be ...ideal? Then you would get (efficiency?) the speaker parts moving precisely with the first trickle of electrons, AND (impedance?) you would get a whole lotta shakin' as electron volume increased...? This feels like I'm missing something, but I can't tell what, in order to search it. I am working from the idea that maggies need a lot of watts. Really efficient speakers don't need a lot of watts, have great bass, but can be harsh? As you can see, I'm having trouble working out all the reviews printed with "IMHO" appended to them. (I haven't looked to see where they fall in this matrix, but the first audiophile I ever met was making himself deaf while exploring the awesome dynamic range of Klipschorns...now that you mention your hearing. I have the "hearing self-test" thread on my "read next" list...)
 

JohnBooty

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@JohnBooty
Okay, so your tweak takes us in the direction of pairing amp to speakers, I think... (Try brut rose instead of champagne or cab sometime. The better ones - Oregon usually - are dry, but just a little more tongue-friendly. Surprising pairing with umami-rich foods, when you want a break from the "same ol'".)

Haha. "Amp pairing" seems a little ominously complex. Apparently Maggies are legendarily picky about amplifiers, but that's not the norm with speakers. Usually you just want to make sure you have plenty of clean power on tap in order to hit 105+ dB (for transients, not average volume) in the intended listening space.

Your typical speaker manufacturer isn't going to design speakers with insane-o impedence curves that require specially blessed amps made from unobtanium. At least not if they want to stay in business. Magnepan has the reputation and following (and the great speakers, apparently) to do it, but this is not the norm.

I guess highly efficient, low impedance speakers ...would be ...ideal? [...] Really efficient speakers don't need a lot of watts, have great bass, but can be harsh?

There's always a series of tradeoffs because of physics. Hoffman's Iron Law: "bass, efficiency, small enclosure" - you can only pick two.

High efficiency speakers aren't intrinsically harsh. I think that's just the impression many have because affordable Klipsches were harsh, and they were the ones bearing the high-ish efficiency torch in the mainstream for years. The only high-ish efficiency speakers in Best Buy were Klipsch, and they were harsh, so people conflated things. I'm told newer affordable Klipsches aren't necessarily that way. And of course many of their classic high-end models weren't.

You might be overthinking this. Good to have knowledge grounding but ultimately you need to get out there and hear some stuff. Like cars or wines or anything you will also probably decide that there is no one perfect speaker for everything but you'll find some you really enjoy. I'll be really interested to hear what you decide on!
 

HuskerDu

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Haha. "Amp pairing" seems a little ominously complex.

You might be overthinking this...

I'll be really interested to hear what you decide on!

Overthinking? Meeee? I have never been accused of overth... wait... :oops:
  1. Speakers will be a pair of Zu Audio "Omen Dirty Weekend" with a "clarity cap" upgrade, whatever that is (Cuz, upgrade! ;-)
  2. Emotiva TA-100 integrated amp
My reasoning was this:
  1. The wireless KEFs are rocking the world right now, of course. So I started with the KEFs for a default solution, and tried to "back into" a chain of components that would get similar reviews, for less money.
  2. The KEFs are wireless, but it turns out the CCA solves that problem acceptably too, leaving me with a fat-ish budget for speakers.
  3. I was shooting for a (cost) ratio of speaker-to-widgets that would meet the "speakers first" test. Reading between the lines, I get the impression that the KEFs (and stand-mounts in general) won't move quite enough air to feel like "live" music... (Yeah that's wildly speculative of me, I know. And a marginal concept.) ...anyway, I landed on floor-standers, if possible.
  4. Surveying review sites, Zu Audio seems to be well loved, with few or no "haters." And my timing was right, because Zu makes the DWs only once-in-a-while. I'm at $1,400/pair, all in. (I don't want to fiddle around with Maggies to get them to sound right, though I realize the good-enough ones are about this price point...) That left me with about $500-ish to shop for some kind of amp solution.
  5. Working backwards from the speakers, I need at least 5-8 watts to drive the speakers, so purist tube amps price themselves out. I want a physical volume knob, even though I usually tell Google Home to set the volume.
  6. Again surveying reviews, Emotiva comes up a lot, with no haters. (here and here) And in the course of reading, it looks like the market for cheap amps is fairly "price efficient." (As you and others have said, too.) The TA-100's "extra" features and frequent comparison to the little NAD seemed to ice that discussion. And I kinda like the idea that I can use it as a preamp if this turns out to be a mistake. (The simplest $250 Emotiva box seems just too, er, ...simple. (Hey, I'm working a learning curve here!)
  7. I didn't find anything on ASR that suggested my approach was out in the weeds or could be improved. -- Unless @amirm posts a review of that little $150 Klipsch gateway amp-thing while they're still available. ;-) -- And I guess I could put the Emotiva next to a TV at some point, since it has a DAC of its own and I can plug a sub into it.
I'm still within the returns window for the Emotiva. The speakers are being built.
...So I still have an "undo" option if it comes to my attention that I'm nuts. ;-)
 

estuardo4

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[QUOTE="HuskerDu, post: 167269, member: 7034"
I'm still within the returns window for the Emotiva. The speakers are being built.
...So I still have an "undo" option if it comes to my attention that I'm nuts. ;-)[/QUOTE]

As many people here could tell you, the best way to check if a speaker is any good in your room, is to narrow your list to two or three models from different vendors to try them out on your room. My vote for speakers are the Tekton Perfect SET 12" ones. At $1,800 delivered. Everybody loves them and will provide you plenty of refinement and bass. And they are built for efficiency, at 96dB 2.83V@1m sensitivity and 8 ohms

They have a 60 day policy to try them out at your home.

As for amp options, I would try the Hypex NC400 that Amir tested and provided a recommendation. It's the only sub$1,000 USD that Amir recommends for now.

So, for about $3,200 you'll have a really nice set of well tested system.
 

The Mule

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I'd be curious to see this one tested:

https://www.nvahifi.co.uk/ap10h-headphone-amplifier

I'm a sucker for good looks. But there are no specs except for the case dimension. Supposedly the headphone jack was originally meant for high impedance cans, but if you tell them you want it to drive low impedance models, they'll repurpose the original line outs to the headphone jack (see here: https://www.nvahifi.co.uk/ap10p-integrated-amplifier).

Available here:

https://www.ebay.co.uk/itm/NVA-AP10H-Headphone-Amplifier/223230321980

When I emailed the guy about what the power specs were, he was a little standoffish about any kind of measurements and specs, so I eventually switched gears to a Burson Fun.

But I'd still be curious to see one measured though. :)
 

The Mule

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Just read the Woo Audio WA7 review. At least I'm a consistent sucker for good looks, yes I have one. :) (I've used it with the orginal ODAC and now the Topping D30, never with its own internal DAC, it being a rev 1 unit. The WA7 on top of the D30 makes for a *very* nice looking, and nice sounding stack!)

To that end, I also have a Valhalla 2, and now I'd be curious to see how that one measures. (I also think it's a good looking amp!) I use the Valhalla 2 with an SDAC, which fits nicely on top to the left of the 4 tubes. Might you see a pattern here? ;)
 

DKT88

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I'd be curious to see this one tested:

https://www.nvahifi.co.uk/ap10h-headphone-amplifier

I'm a sucker for good looks. But there are no specs except for the case dimension. Supposedly the headphone jack was originally meant for high impedance cans, but if you tell them you want it to drive low impedance models, they'll repurpose the original line outs to the headphone jack (see here: https://www.nvahifi.co.uk/ap10p-integrated-amplifier).

Available here:

https://www.ebay.co.uk/itm/NVA-AP10H-Headphone-Amplifier/223230321980


But I'd still be curious to see one measured though. :)

I was looking at the NVA stuff recently and I was also suspicious about the lack of any performance measures. Their web site has also has some nonsense stuff such as "magnetic contamination":

"The case design has been created for sonic reasons with the case sides bonded together with acrylic weld and the top plate with structural adhesives to avoid the magnetic contamination of steel screws. No ferrous materials are used, only four screws for the cover, so the case's constituent parts are glued together to prevent induced circulating currents as well as high frequency and high voltage static charge problems associated with normal designs. The concept extends to gluing the circuit boards, power supply caps, and diode bridge to the thick anodized aluminium baseplate. All high current wiring is via heavy gauge uninsulated copper wire to avoid dielectric effects. The case is unvented."

Just what I need, an amp with all the schiit glued together.
 
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BillG

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just what I need, an amp with all the schiit glued together.

And then there's this statement on their website:

"NVA AMPLIFIERS AND SPEAKER CABLES – WARRANTY
Only NVA LS1, LS2, LS3, LS5, LS6 and LS7 is recommended for use with this amplifier, other cables will invalidate the warranty."


:facepalm:
 

DKT88

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And then there's this statement on their website:

"NVA AMPLIFIERS AND SPEAKER CABLES – WARRANTY
Only NVA LS1, LS2, LS3, LS5, LS6 and LS7 is recommended for use with this amplifier, other cables will invalidate the warranty."


:facepalm:
From what I've read, his amps are borderline unstable and will oscillate at HF with too much capacitance on the output. Here's a quote "I have designed amplifiers for very flat frequency response and low distortion, but I do not like the music they create. I design my amps to enjoy music it is that simple! The only valid test equipment is the human ear. We go to a concert with ears not distortion analysers." Hence, the lack of specs.
 

sergeauckland

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From what I've read, his amps are borderline unstable and will oscillate at HF with too much capacitance on the output. Here's a quote "I have designed amplifiers for very flat frequency response and low distortion, but I do not like the music they create. I design my amps to enjoy music it is that simple! The only valid test equipment is the human ear. We go to a concert with ears not distortion analysers." Hence, the lack of specs.
What surprises me about NVA, is that Richard Dunn is a talented engineer, being the man behind Tresham amplifiers, really solid pro amplifiers, so he knows how to design properly. Yet, for his current company, he sells marginally stable amplifiers, with no short-circuit or overload protection, in glued-together acrylic boxes, and make a virtue of them being so.

He refuses to publish detailed specifications, on the basis that we don't listen to specs, (and the implication that few of his customers would understand them anyway), but to his credit, he sells direct (so no dealer margin) and with a money-back guarantee if the purchaser doesn't like it, (loans are also possible before purchase) and with a full refund for upgrades within two years. As much as I deprecate the lack of specs and the marginal stability/no protection nature of the designs, it's hard to deprecate his business ethics.

Don't like it? Send it back for a full refund. Want to upgrade, just pay the price difference.

S.
 
H

Hifihedgehog

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I don’t know if anyone owns this amp but if they do, I would love if they could loan it out to see just how good the AMB Beta 22 measures on Amir’s equipment. Besides, it can power up to 18W unbalanced or 50W balanced and who doesn’t want their headphones vaporized to a smoking pile of ash. On a more serious note, judging by what I see on Reference Audio, if I am not mistaken, the Beta 22 is the best measuring device in their test pool. This means it could very possibly meet or even beat the THX 789 in some key measurements. That makes for a battle of the ages if you ask me. :)
 
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Willem

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Indeed intetesting. However power is spacified at 4 Ohm and it only has 1 optical and no coaxial input. A Yamaha as701 will have more juice and has more digital inputs.
 

BillG

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Indeed intetesting. However power is spacified at 4 Ohm and it only has 1 optical and no coaxial input. A Yamaha as701 will have more juice and has more digital inputs.

The Yamaha also has a list price of $800USD... :p

Edit: Make that $900USD... :facepalm:
 

Willem

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But cheaper in Europe. Sorry US prices are sometimes higher and sometimes lower than in the EU so it is hard to keep track. Anyway, the only slightly less powerfull AS501 sells for 339 euro including 21 percent value added tax, i.e. about 375 dollar.
 

bunkbail

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Allo Volt+ D 60W x2 TPA3116D2 Dual Mono ($147 w/ PSU, $129 w/o PSU)

No specs but Allo usually makes good engineered stuffs so I'm confident this would do competently, at least within its price tag. Would love to see some more measurements by Amir for power amps in this price bracket.
 
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