One brand that has been constant from the mid 1970s till now is Naim Audio. It seems they kind of invented the current Hi-Fi's networked Streaming Server products. I've been playing stuff from a computer for so long I hadn't noticed.
The Power Amplifier I currently have in my small studio is a 50W per channel GainClone I put together from modules from ebay with a few modifications. Some $24 for the supply board and 2 stereo amps. I added to that Zobel networks on the output and a relay speaker protection de-thump circuit. This is based on the LM3886 power opamp and very similar to the very expensive, Audiophile 47 Laboratory Gaincard amplifier. Sounds great, but only cost around $100 to build using the other parts I had on hand. Well, I have experimented with power amplifiers and their design since the early 1980s so had heatsinks and other hardware, but not the 2U rack case needed. I did a blog post on this a year or so ago.
I happened to notice the recent Naim NAP 100 Power Amp , 50W per channel, (equivalent to my own GainClone) and that these products still seem to have a good reputation like the old NAP160, 120, 140 and 250 amplifiers. Making things sound "musical", which in the Audiophile world actually doesn't necessarily mean accurate. I always liked the way they mechanically designed them. Very clean.
Naim Nap 120 |
Naim NAP 100 rear |
Naim NAP 100 Front |
Naim NAP 100 internal view |
NAP 250 Power Amplifier Schematic |
Their highest powered Naim NAP 500, some USD$21,950, uses 2 of their power amps in bridged mode per channel, 4 total to make a stereo amplifier to get around their self inflicted need to not parallel output stage transistors. That is probably a far more complicated approach.
None of these design choices justifies the price, but I think that is part of the wonder of the current world of Hi-Fi. Prices, claims and reality are only indirectly connected. As much style as technology. Still, makes any Naim a desirable product. They are cool and have that X Factor.
Not better than what I have built myself though, for much less $. You can even buy clones of the NAP 140 power amplifier PCBs on ebay, for very reasonable prices.
And a random comment comparing the GainClone and NAP 140:
Just finished a gainclone type power amp with LM3886 chips and bog-standard circuit as in the National Semiconductor data sheet, plus a 280 VA power supply. With a simple double potentiometer.Fascinating. Truly fascinating.
Connected it up to a Naim CD3 and speakers and lo, wonder and horror at the same time, it sounds better than my Naim 72/140. In particular, the bass is just as strong, but less woolly, more detailed, more "tactile" if that makes any sense. Like an image in sharper focus. While the treble is gentle and sweet. This is after a few hours use.
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I've been a big believer in MOSFET class D amplification for a while. Call me a heretic. :)
ReplyDeleteThen again, I was an early adopter of switched mode power supplies in audio amplifiers.
Most people can't hear anything worth a damn above 10kHz anyway. Those that claim they can and do are often revealed to be fooling themselves, when careful evidence is gathered.
I have a 50W channel Class-T Amp here myself. It needs a speaker protection circuit, as these things sound great, until they do DC. I must say it does sound different from my LM3886 based unit. Not better or worse, just a "little" different.
ReplyDeleteCan anybody guide me how to repair the right channel on my Naim NAP100? Answers other than “send it to Naim for £230+VAT service and repair”, please :-)
ReplyDeleteOn the subject of quasi complementary output, this "older" technique is allso employed by the lm3886. It seems because it's hard to diffuse power pnp on chip ? Anyways , it doesn't seem to affect the perceived sound quality of this chip amp , taking into regard the many raving reviews of gainclones. Probably no one hears the difference between a well designed quasi or fully complementary output stage, I don't for sure.
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