Purifi Eigentakt-based monoblock amps - suitability for Magnepan 1.7i

[ethanhallbeyer]

I'm very interested in the new Purifi Eigentakt-based monoblock amps which are supposedly the successor to the NC400 Hypex, bringing with it improved bass among other things.

I was looking at high current Class AB amps for the Magnepan 1.7i, as I hear that is what is optimal, but they would run hotter and cost significantly more.

VTV seems to be making Purifi Eigentakt-based monoblocks for about 1/3 the price of the new NAD C298. It seems that they would be very similar in features/performance/sound quality.

My concern, however, is that I was informed the VTV Purifi amps wouldn't be a good option if any of my speakers go below 4 ohms at any time. I'm not sure if the Magnepans ever do? I also have some KEF LS50 and I'm not sure if they ever do either. I do know that both are low-sensitivity speakers.

It was recommended to me that if I need higher current, the NC400 solutions would be more appropriate than the Purifi, but I think my preference is to either go with Purifi or class AB.

I just wanted to get some knowledgeable input on how suitable those VTV Purifi monoblocks would be with Magnepans 1.7i and KEF LS50. Would I be better off going with high current class AB?

 

[Matias]

The impedance of the older 1.7 model is somewhat stable around 4 ohms and little phase changes in the bass area, where there is more energy in the music content and where amplifiers are more demanded. The 1.7i should be similar.

I would buy a Purifi with their better buffer and opamps for a little more.

 

[ethanhallbeyer]

The impedance of the older 1.7 model is somewhat stable around 4 ohms and little phase changes in the bass area, where there is more energy in the music content and where amplifiers are more demanded. The 1.7i should be similar.

View attachment 89176

I would buy a Purifi with their better buffer and opamps for a little more.

Thanks for your reply! I was just told by a seller of hypex and purifi amps that the purifi wouldn't be as good a match for Magnepans as the hypex nc1200, which is supposed to be better than the nc400/500. I guess it's due to higher current. But I read the Purifi are supposed to have sound improvements and are considered the successor to hypex.

 

[Matias]

Thanks for your reply! I was just told by a seller of hypex and purifi amps that the purifi wouldn't be as good a match for Magnepans as the hypex nc1200, which is supposed to be better than the nc400/500. I guess it's due to higher current. But I read the Purifi are supposed to have sound improvements and are considered the successor to hypex.

Honestly at those prices, I would just buy an Purifi amp, try it myself, and since they are so hot in the market right now, worst case you sell it and lose a little and buy an NC1200 amp. Best case you find that its 425W in 4 ohms is enough.

 

[Vasr]

Within Class D, you are overthinking this. None of them will make an audible difference with the Magnepans (or most speakers) relative to the change in sound that occurs with these speakers by just changing the placement slightly. Just buy based on price, having sufficient power (anything above 180W into 4ohms is "safe" for these speakers, between 200 and 300 more than sufficient), not being current limited too much due to power supply design/constraints, reliability reputation, support, quality of build and connectors and warranty.

The major reason to buy Class D over Class AB is efficiency/heat if the criterion is pure transparency with few exceptions to the latter like the Benchmark.

The major reason to buy Class AB over Class D is that there are a lot more choices to buy below 300W/ch into 4ohms from vendors/manufacturers with a good reputation for support, longevity and dealer network and often at discounted prices.

Some Class AB amplifiers are built to color the sound by design that one may prefer subjectively.

All of the Purify vs Hypex vs X talk is left-brained rationalization of nerdy kids in a toy store.

 

[ethanhallbeyer]

Within Class D, you are overthinking this. None of them will make an audible difference with the Magnepans (or most speakers) relative to the change in sound that occurs with these speakers by just changing the placement slightly. Just buy based on price, having sufficient power (anything above 180W into 4ohms is "safe" for these speakers, between 200 and 300 more than sufficient), not being current limited too much due to power supply design/constraints, reliability reputation, support, quality of build and connectors and warranty.

The major reason to buy Class D over Class AB is efficiency/heat if the criterion is pure transparency with few exceptions to the latter like the Benchmark.

The major reason to buy Class AB over Class D is that there are a lot more choices to buy below 300W/ch into 4ohms from vendors/manufacturers with a good reputation for support, longevity and dealer network and often at discounted prices.

Some Class AB amplifiers are built to color the sound by design that one may prefer subjectively.

All of the Purify vs Hypex vs X talk is left-brained rationalization of nerdy kids in a toy store.

With Magnepans the more current the better, right? Someone shared some specs with me and showed the NC1200 as being the one with more current than Purifi. I think that's my main focus.

 

[Vasr]

With Magnepans the more current the better, right?

Not necessarily. There is a point of diminishing returns. It is more of a "hygiene" issue of a minimum than getting as much as possible with no corresponding returns.

A "standard" Class D configuration with the recommended modules (excluding some one-of designs in the past) and required power specs should have enough current output. One reason why they do so well in the lower frequencies and this helps with the Maggies. You just want to make sure that in the particular design you are looking at, it hasn't compromised on the current capability either from design, component selection or by sharing it with multiple channels for its power specs.

An example of a Class D amp with likely power supply-limited headroom is the Parasound NewClassic 200 integrated
https://parasound.com/200_Integrated.php
Given its limited power/headroom into 8 or 4 ohms, that is the kind of amp you would rather not consider with a Maggie even if it satisfied other requirements (and not just because it uses Pascal modules). Even that would be fine at low volumes though.

 

[ethanhallbeyer]

sounds like i ought to be able to drive 1.7i with purifi monoblocks then. VTV said it would be fine with caveat of ”as long as your speakers do not go below 4 ohms”

 

[AndrewDavis]

All of the Purify vs Hypex vs X talk is left-brained rationalization of nerdy kids in a toy store.

I went to a comic book store last week to buy a birthday gift for my 13 year old daughter. Turned out this was a serious comic book store for serious comic book people. Two of them were arguing with the clerk on some finer point or other of comic book lore.

Their discussion was as passionate and unintelligible as any argument about class D vs class AB that we have..

 

[goryu]

purifi states that their amp is stable into less than 2 ohm loads. Should be fine.

 

[MasterApex]

sounds like i ought to be able to drive 1.7i with purifi monoblocks then. VTV said it would be fine with caveat of ”as long as your speakers do not go below 4 ohms”

What did you decide? any outcome you can share?
Thanks