Orthodynamic Roundup - Page 908

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Originally Posted by dBel84 if you do read this thread , big old mosfet receivers are FOTM

Har! Over the last 5 years I think I've talked 2 people into trying this flavor of the month, and, though I think they appreciate what they got for their money, their enthusiasm is, shall we say, well damped.

We compared the Kyocera R-851 (bone stock, built in 1985) to the fancy amps at the local meet recently, and though it didn't sound as good, you could tell it was heading in the same direction as the new amps, plus it came with extra toys: phono stage (MM and MC), preamp (volume, EQ, filters, mono/stereo, balance) and enough power to drive difficult speakers. Plus it has that cool Freon heat pipe cooler for the outputs. But if you want any 25-year-old audio gear to sound the way it was supposed to sound, judicious replacement of certain old parts, usually capacitors, is necessary.

 

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Originally Posted by dBel84 Travagan's Red taste any good? sounds like it should.

Yes, it's got a better sounding name than Yellow Tail, which sounds like a hamster disease.

 

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Originally Posted by dBel84 - grab the HP3 , the small driver Yamaha's have some of the best magic

Agreed. Just be aware that there's a lot of production variation with the 3. Some are bassy, some are nearly flat.

 

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Originally Posted by jp_zer0 Something like this? :|D

Well, the Marantz 2216 doesn't have MOSFET outputs, but it's not a bad receiver. If you can get it cheap, why not. But note that its tone controls (EQ to us) are rudimentary and not very flexible... and that it is what it is, a decent mid-'70s transistor amp with a tuner and preamp, with a sound that doesn't transcend its time.

If you want to stick a toe in to test the waters, I found a simple CMoy sounded very nice with the modded YH-100-- which is certainly not the most efficient headphone ever produced-- and gave it a good kick in the bass when I added some boost. You can work your way up from there if you decide you like what you hear. Total expenditure so far, including refurb 2GB Sansa Clip: $60 or so, ballpark. Assuming you can indeed get the HP-3 for a song, or the price of a CD.

It IS gnarly! verily!

Smeggy, out with it-- have you had a B-2 all this time and were holding back?

I should point out to those of you who might begin to think about getting yesterday's state-of-the-art audio gear for pennies on the dollar that there are pitfalls. Blow the outputs on a B-2, for example, and you have an expensive bootjack, since the VFETs it used have been out of production for decades. I've already mentioned the capacitor situation.

There were two streams of '70s transistor sound: The power FET amps, which appeared in 1974 with the Sony and Yamaha VFETs and handed off around '78 to Hitachi's MOSFETs ...   ...and then there was everything else. Perhaps I should mention Fujitsu's ring-emitter bipolar power transistor, used in Mitsubishi amps.

A VFET amp will make you want to turn your tweeters up. A regular transistor amp from that era will usually make you want to turn them down. That's the difference in a nutshell.

But the VFET amps tend to be rare, pricey and old-- they went out of production well before the decade of the '70s was out. MOSFET amps and receivers were made and sold by the [comparative] zillion and can be had for reasonable prices (less than $100 shipped via online auction). Still, if a VFET amp shows up and you can swing the cost plus the extra $ to put it in first-class shape, grab it. You'll own one of the last amps using transistors designed exclusively for audio (not to say audiophile) duty. MOSFET is almost as good and costs much less, and continues to be used today, though the number of audio (linear, as opposed to switching) MOSFETs seems to be on the dwindle.

UPDATE: there's one exception to this: Nelson Pass recently (2009) discovered a small Mississippi semiconductor fab making power FETs from silicon carbide (!), not for audio but for power management in electric cars and solar farms (!!) but which just happened to have the prized triode characteristic the VFETs had 35 years ago. Pass calls his amp the J2. Only one problem: it costs $4,000.

Then there are Panasonic's now out-of-production digital amplifiers built into cheezy looking receivers. A canny (heh) ortho-headphone person can get a lot of bang for the buck shopping for speaker amps of modest power, and the Pans put out about 35 to 50 "real" watts per channel, with 6 or 7 channels. Dang good, as long as you're using digital sources.

Anyway, enough of the Cheapskate Audio proselytizing. On with the Pants of Thunder and the Getting Of The HP-3.

 

YAMAHA B-2 VFET AMP

SONY TA-8550 VFET AMP