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Vintage amplifiers that could challenge or approach current state of the art amplifiers

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restorer-john

restorer-john

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Just curious did you ever run across a Great American Sound, GAS Ampzilla, first Audiophile Amp I owned in 1976.

Yes, but it was many years ago and the amplifier was a wreck inside. Not its fault, but it was written off by insurance (lightning strike). Always wanted an Ampzilla too, just for fun. I have reviews of Ampzilla someplace. It's pretty much the first piece of HiFi to have a fun model name.
 
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Yes, but it was many years ago and the amplifier was a wreck inside. Not its fault, but it was written off by insurance (lightning strike). Always wanted an Ampzilla too, just for fun. I have reviews of Ampzilla someplace. It's pretty much the first piece of HiFi to have a fun model name.

Had the Ampzilla partnered with the Thaedra mid seventies, lovely amps. Sold when I moved to Africa.
 

Willem

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I would love to see one of the Quad current dumpers measured. They were a common sight among European music lovers, and were a very innovative design with their feed forward topology. I own a refurbished 405-2 and a refurbished 606-2 and both are still offering excellent service, but that is just an impression as I have no measuring gear.
I also still have the Quad 303 that I bought as a student, but that is by now an outdated design, of course.
What is your view on them, John, as you are likely to have one or more of them, assuming that with their British origin quite a few were sold in Australia (is that true?).
 

ripvw

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The best James Bongiorno name was his Sumo Charlie the Tuner - Bongiorno was an engineer with Dynaco, SAE, then his own GAS and finally Sumo companies

http://www.tnt-audio.com/edcorner/january13.html

https://fmtunerinfo.com/charlie.html

In the US, the StarKist Tuna company ran commercials for years with a cartoon character named Charlie the Tuna

https://en.wikipedia.org/wiki/Charlie_the_Tuna

but by far the best FM tuner I ever owned was an Accuphase T-101

https://fmtunerinfo.com/reviewsA-C.html#accuphase
 

carlob

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Some of big vintage Perreauxes I've owned would be contenders, except for their residual noise. In all other parameters, they were/are pretty much unbeatable.

I remember having read something on the Perreaux many many years ago, weren't they an exact copy of an Hitachi application note?
 

BDWoody

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So what suggestions do you guys have for vintage challengers? We may have some of these classics sitting in member's basements or still humming along in their equipment racks.

I have a Krell KAV250a/3. (3x250w into 8r, 500w into 4r, 1000w into 8r bridged)

Not a fancy looking box...but I've always wonfered about some of the 'dumbed down' versions of products (like this one) from some of the top companies. What corners were cut compared to the higher price lines, and what difference will it make to me?

I currently use it for subwoofer duty...driving a pair of HSU Research Tubes, and it has worked flawlessly for me for years. Any experience with these?

PSX_20200622_062004.jpg
krell-KAV250-reviewed-thumb-800xauto-4059.gif

1371817-8d1333e1-krell-kav-250a3-3-channel-amplifier-just-freshened-up-by-krell.jpg
 
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Ceburaska

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Sony TAF808?
I’ve had mine a few years now and just love it. Features, sound, power, phono amp, remote. The only thing I’d change is have a mute button on the remote.
image.jpg
 

Ceburaska

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Yes.

The Pioneer A-717 and A-91D (both circa 1989) pulled out of storage tested as new. They both have THD below what I can reliably test. I have four Sony TAE-77es/esD preamplifiers here and they all test identically and they are all 100% original, made in 1990. I have three TAN77es (1989/90) power amplifiers here, all original, all beyond my test gear's resolution at high powers (<.002% for 30V and up).
That’s just greedy!
 

DonH56

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2150B, 3150. Both Hitachi MOSFET application note designs. Residual noise from the gigantic transformer and it's proximity to the front end made for low level, but audible hum/buzz. Otherwise, flawless. But you can't really fix the problem. Later models tried with shielding, but it didn't really work.

The only thing that fails is the power switches in the older Perreaux amps from the massive turn-on arc (no slow/surge turn on).



Yes. The MX-600/800/1000 power amplifiers were pretty amazing, although the APS (switching rail) made them a little unreliable in the 1000. I'd say they would be more than competitive in the noise, THD and power output stakes with modern amps. I only have an MX-600 and MX-630 here I could do limited tests on. They have pretty obscenely high short term dynamic power as well.

The M-80/85 were damn fine amplifiers too, but suffered from bond-glue issues.

I never saw an MX-10000 Centennial (1987) power amplifier in the flesh. I don't know if it was ever properly reviewed, but it should be right up there for sure.

The one I'd like to get my hands on is a 1980 Denon POA-3000 or 3000z.

View attachment 70132

1kVA transformer, 100,000uF filtering. FTC continuous rated 180+180W@8R, 122dB S/N etc.

View attachment 70133

https://audio-database.com/DENON-COLUMBIA/amp/poa-3000-e.html

I still remember the Perreaux amps; at the time, their schtick was to drop one off the truck loading gate, then bring it in and show how it still played. My vague memory is same as John's; great amps, but didn't really stand out form the pack of similar "high-end" amps except by and large more power, and a bit noisy.

The DENON was a great amp, but I have bad memories from spending a couple of weeks (I was part-time tech at the time) working on one... The THD measured something like 0.005% instead of the spec 0.002% or whatever it was. Blown amps are easy, finding that last fraction of a percent nearly drove me mad. Or maybe you can strike "nearly"...

Do you want to narrow down the date range, maybe the price range? I'd guess the late 1970's through maybe 1980's was when a lot of the most revered amplifiers were made. Before that, there are some classics, but probably would not match today's performance; after that, the market seemed to split into more expensive "esoteric" components and more mundane "audiophile" products. Then HT hit and we all know what happened then...
 

tmtomh

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I would see it as this way. Probably sufficiently good performance was achieved long back. Modern high performance components are just a notch or two above. But some modern components don't even reach levels that were achieved in the past. So thread title is appropriate as challenging modern amps instead of better than modern amp. I suppose everyone likes to take a peek inside and measure and discuss a very well made electronic product/s regardless of time.
Best Regards

I totally agree, well-said! I don't mean to be disagreeable - but I do feel the need to push back a little bit against how John frames these comparisons. It is rare for a Class D review to be posted here where John will not weigh in on the thread about fraudulent power ratings and criticisms of ultrasonic noise in the 400kHz and above range. In order to be complete, objective, and not misleading, we should be equally open about the high noise levels and relatively high distortion levels of some of the vaunted old "big iron" that he repeatedly touts as superior to today's "fraudulent," "fragile" Class D units.

Now, if we want to say that, for example, -90 SINAD and 0.05% THD are sufficient, that they produce hi-fi that is audibly transparent listening to speakers (as opposed to headphones) given how humans hear and given the ambient noise level in most home listening spaces, that's fine. But that is most definitely not the same thing as saying older amps with those specs "challenge or approach current state of the art."

So if the current state of the art is not worth using as a benchmark, cool. If your thread subject sets it as the standard, though, then let's actually look at which old amps meet that standard - and BTW let's also go beyond anecdotal reports of "testing like new" and determine a "half life," so to speak, of caps and other components in older amps, aka how old is such a unit where you can feel confident that a randomly purchased sample will measure close to original spec, vs how old is it where it becomes likely it will have to be serviced and have components replaced because they've degraded or drifted too much from spec?
 
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sergeauckland

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Rated THD of 0.02% and Crosstalk at -60dB doesn't seem to challenge or approach current state of the art.
Yes, but today's SOTA is totally overkill, and has become specsmanship, because they can. There's no need for it and no benefit from it. The DH-200, was and still is transparent, as was Quad's SS amplifiers, and pretty much all amplifiers since the late 1970s if not earlier. The only specs that have genuinely improved are power output and load tolerance, but that won't affect audibility if the load is chosen sensibly.

S.
 

Frank Dernie

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Rated THD of 0.02% and Crosstalk at -60dB doesn't seem to challenge or approach current state of the art.
I think the basis of any disagreement is what is state of the art?
I am an engineer and I learned early on that making something better than it needs to be is stupid, and usually expensive.
That said one has to then decide what is good enough, ie to what standard is it pointless to exceed...

Longevity in a component is infinitely more important to me than any improvement in a parameter that is already audibly transparent.
So is being nicely made and attractive.
 

levimax

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[QUOTE="Frank Dernie, post: 437412, member: 70"
Longevity in a component is infinitely more important to me than any improvement in a parameter that is already audibly transparent.
[/QUOTE]

Is there any information out in the wild about how the good class-D amp modules hold up or are they too new? I don't see any mean time to failure specs. My understanding is that the caps are under a very heavy load both in the switching PS and in the amp and it doesn't look like they are using particularly high quality caps. Since the caps are through hole they should not be hard to replace but if the caps fail do they take out other components? I guess thinking like this is old school and if a PS or amp module stops working just swap another one in.... but that assumes you will be able to get a new one that will fit. Maybe module switching is too old school as well and just get a new amp if the old one stops working.... but that is not green ... but either is using twice as much energy during the long life of an AB amp. These are high level issues but since transparency is met by good vintage, new Class AB and new Class D there really isn't much else to base your purchasing decisions on... well except cost, size, weight, and looks.
 

Neddy

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Bryston 2B, 3Bs from the early 90s? Esp 'unmolested' ones w/original components to see how well they age?
 

BDWoody

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Bryston 2B, 3Bs from the early 90s? Esp 'unmolested' ones w/original components to see how well they age?

Even the multichannel 9B's. I have one I'm not using...if enough interest I could send it somewhere to be measured. Also, variation between channels might be interesting to see, especially given the likelihood of very different usage rates between channels over a long period of time. See how well it's burning in...and all...
 
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