Class D power amplifiers

[Mikado463]

I definitely don't like lifting the Denon X8500HA box of 62 LBS.

Enough with HEAVY amps over 50 LBS.

LOL, those are mere light weights ! try 445 lbs !!!!

SoundStage! Global | SoundStageGlobal.com - Gryphon Stereo Amplifiers and Me

 

[DJ7675]

NC502MP, and the Purifi one is the Eigentakt Eval1

SoundStage! Hi-Fi | SoundStageHiFi.com - The Purifi Puzzle, Part One: The Measured Performance of the Eigentakt Amplifier

NAD M28 Seven Channel Power Amplifier Review | Audio Science Review (ASR) Forum

Buckeye Nc502mp Review (6 Channel Amplifer) | Audio Science Review (ASR) Forum

Although the M28 replace it, the M27 which used the NC400 module instead of the Purifi Module, is also an excellent option in the used market... usually it can be had for around $2500 and you get 7 channels of NC400.

Review and Measurements of NAD M27 PWR Amp

This is a review and detailed measurements of the NAD M27 7-channel surround audio amplifier. It is on kind loan from a member. Seems like the M27 came out back in 2014 and costs US $4,400. The M27 has the same design language as the excellent M17 Home Theater Processor (looks only): The...

www.audiosciencereview.com

 

[PENG]

Although the M28 replace it, the M27 which used the NC400 module instead of the Purifi Module, is also an excellent option in the used market... usually it can be had for around $2500 and you get 7 channels of NC400.

Review and Measurements of NAD M27 PWR Amp

This is a review and detailed measurements of the NAD M27 7-channel surround audio amplifier. It is on kind loan from a member. Seems like the M27 came out back in 2014 and costs US $4,400. The M27 has the same design language as the excellent M17 Home Theater Processor (looks only): The...

www.audiosciencereview.com

If one can get it for $2,500 and still comes with factory warranty then I think it could be the best value for a 7 channel amp based on $ per quality watt.

 

[DJ7675]

If one can get it for $2,500 and still comes with factory warranty then I think it could be the best value for a 7 channel amp based on $ per quality watt.

I doubt there are any left that are new with warranty any more. On these kinds of things warranty should always be a consideration for sure. Or if you for some reason need crazy amount of power, you can bridge the M27 and get over 600w 8ohm and over 1000w of instantaneous power for peaks (requires a special cable).

 

[dlaloum]

I would say some Class D amps are ready for prime time but others are not. I'm still seeing Class D amps having problems driving a reactive load and keeping the frequency response flat. I really don't care about the efficiency or weight but am curious. The Buckeye amps look tempting but only to see for myself. I'd likely sell it after a couple of weeks though.

I have tried a number of "traditional" amps on difficult loads (my Gallo Nucleus Ref 3.2 speakers) - and Crown XLS class D...

The traditional amps mostly do not/did not double down on W as speaker impedance drops... in theory 1w @ 8ohm should= 2W @ 4ohm and 4W @ 2ohm.

Traditional class a / ab amps that can do that are rare / expensive.

Most class D amps can't do it either.

The XLS series from Crown do - and into a difficult speaker load - that does the magic.

Ultimately it is not whether it is class A or Class D (or anything else) - but how well it handles the speaker load.

With easy to drive 8ohm to 6ohm speakers.... you can probably use any amp and get decent results... you won't experience the same thing if your speakers drop below 2 ohm, and some exotics go as low as 0.5 ohm. (many amps go up in a puff of smoke at that point!)

 

[lovinthehd]

I have tried a number of "traditional" amps on difficult loads (my Gallo Nucleus Ref 3.2 speakers) - and Crown XLS class D...

The traditional amps mostly do not/did not double down on W as speaker impedance drops... in theory 1w @ 8ohm should= 2W @ 4ohm and 4W @ 2ohm.

Traditional class a / ab amps that can do that are rare / expensive.

Most class D amps can't do it either.

The XLS series from Crown do - and into a difficult speaker load - that does the magic.

Ultimately it is not whether it is class A or Class D (or anything else) - but how well it handles the speaker load.

With easy to drive 8ohm to 6ohm speakers.... you can probably use any amp and get decent results... you won't experience the same thing if your speakers drop below 2 ohm, and some exotics go as low as 0.5 ohm. (many amps go up in a puff of smoke at that point!)

OTOH speakers that dip to below 2 ohms are probably better simply avoided.

 

[dlaloum]

Well - I have always chosen speakers based on the sound...

And after years (1985 - 2010) of listening to electrostatic panels - almost every "box" speaker I hear... I can hear "the box"...

Electrostatics, also have a history of requiring "appropriate" amps.

When due to WAF, I had to find an alternate to the stats, I ended up with the Gallo Nucleus Ref 3.2 - another design which is "boxless" - eschews crossovers in the critical midrange area, uses an exotic tweeter to achieve the kind of transparency usually reserved for stats.

The criteria for selection didn't include "easy on the amp".

Interestingly, the Quad 606 / 707 amps I was using for my Quad ESL989 speakers (unconditionally stable into any load...) - although they sounded good with the Gallo's - did not sound as good as the Crowns. (current version of that Quad current dumping amp design is the Artera - which apparently has much improved capability into low impedance loads... but also costs 3x what the Crown does)

Is "ease of driving" your prime criteria for speaker selection?

 

[Cos]

I did my class D Dive with the ATI AT524NC, to replace one of my Parasound A31s and I was very happy with the outcome. I don't feel I lost anything sonically, the amps are dead silent and I no longer have tweeter buzz on my personas. Lost a little bit in the weight department which is nice.

Primary reason I went with ATI is the warranty. I know they will be around for the 5+ years I will own the amp.

 

[PENG]

Primary reason I went with ATI is the warranty. I know they will be around for the 5+ years I will own the amp.

That is true and a good reason but for those who don't mind the minimum diy repair I would still recommend the likes of the Buckeye amp and VTV amps.

Take a look of how simple/empty they are, one only need a screw driver and a tiny hex wrench to replace any failed modules:

 

[}Fear_Inoculum{]

I'm really loving the look of those VTV Hypex NC252MP amps. Looking at the 8 channel one. It's a little more than I wanted to spend, but the power per channel to number of channels to cost ratio seems to be about the best out there, especially for having fully balanced XLR.

 

[PENG]

I'm really loving the look of those VTV Hypex NC252MP amps. Looking at the 8 channel one. It's a little more than I wanted to spend, but the power per channel to number of channels to cost ratio seems to be about the best out there, especially for having fully balanced XLR.

If you are using an AVR, you can always go with a 4 channel one to save some money and use the internal amps for the surround channels.

 

[}Fear_Inoculum{]

If you are using an AVR, you can always go with a 4 channel one to save some money and use the internal amps for the surround channels.

Moved to a pre pro (13.3) currently running an Outlaw 5000 and using my Yamaha RX-A2040 in pre out mode to power the rest of my system. So I need the 8 channel.

 

[PENG]

Moved to a pre pro (13.3) currently running an Outlaw 5000 and using my Yamaha RX-A2040 in pre out mode to power the rest of my system. So I need the 8 channel.

Are you keeping the 2040? It looks like the 2040 is one of those dinosaur amps that has the 7.1 channel analog inputs. So with a 4 channel Hypex amps you will have a total of 4+5+7= 16 channels.

 

[lovinthehd]

Are you keeping the 2040? It looks like the 2040 is one of those dinosaur amps that has the 7.1 channel analog inputs. So with a 4 channel Hypex amps you will have a total of 4+5+7= 16 channels.

How do you do that with a 9.2 avr, tho?

 

[PENG]

How do you do that with a 9.2 avr, tho?

Just use the 7 channel analog inputs. You can do the same with your 4520.

 

[lovinthehd]

Just use the 7 channel analog inputs. You can do the same with your 4520.

But what would the channels be particularly and how would they be coordinated without the dsp that you lose when using the analog ext.in set of inputs? I tried to come up with something and couldn't so was trying to see where you were going with that.

 

[PENG]

But what would the channels be particularly and how would they be coordinated without the dsp that you lose when using the analog ext.in set of inputs? I tried to come up with something and couldn't so was trying to see where you were going with that.

Using an AVR as a power amp is just that, anything else will be done on the AVP as usual. May be I misunderstood your question?

 

[lovinthehd]

Using an AVR as a power amp is just that, anything else will be done on the AVP as usual. May be I misunderstood your question?

LOL I missed the capable avp....now I see the posts I missed....never mind (in true Roseannadanna style ).

 

[}Fear_Inoculum{]

@PENG

Any QC or customer service issues with VTV that you're aware of? I mentioned VTV on the AVS forums and was told there were. I'm now looking at a 3 channel to power my LCR, and a 6 channel for my surrounds instead of a single 8 channel.

 

[PENG]

@PENG

Any QC or customer service issues with VTV that you're aware of? I mentioned VTV on the AVS forums and was told there were. I'm now looking at a 3 channel to power my LCR, and a 6 channel for my surrounds instead of a single 8 channel.

On ASR, one member reported QC issue but iirc that was over a year ago when they first started building those amps. As far as I know VTV no longer have qc related issues. I have been very happy with mine.