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

dlaloum

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Nice! I own a 535 and 5400 and enjoyed both for many years.

According to this Ken Rockwell review, which includes plenty of measurements, it's a killer unit:

https://www.kenrockwell.com/audio/adcom/gfa-555-ii.htm

He reviewed the MKII version, but it's likely the original (which has a more vaunted reputation) measures very similarly.

I was also struck that the 555 he reviewed measured notably better than the 545 and the two 535s he also measured.

Only issue I'm aware of with these old Adcom amps is that they lack speaker protection.

In fact, aside from a lack of speaker protection (and the mechanics of the power switch, which apparently has a habit of going south), I would think this amp would tick all the boxes for the subject of this thread - it provides gobs of low-distortion power and an argument can be made that in terms of specs it's close enough to modern state of the art to be similarly audibly transparent.

@restorer-john , I hesitate to even ask, but would you agree that this is one of those amps that "could challenge or approach current state of the art amplifiers"? It seems like it is, yes?

The only historical knock I've seen on this amp is a series of subjective reports that it sounds "dry," "etched," or "unrefined." But surely that kind of subjective claim wouldn't disqualify an amp at this forum, yes?
Would like to see it measured...

My own experience with the 555 - both into Klipsch Forte and into Quad ESL63 - did match the "etched" and "unrefined" top end description - The Quad 405 I had at the time sounded a lot better on both speakers... so I got rid of the 555... my guess is a bit too much distortion...
 

dlaloum

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The mkII?

I would actually rate the GFA-555 mk1 or 2 as arguably one of the most significant audiophile products of all time.

Just a wonderful, well built, honest US made product by a respected designer. If there was a HiFi equivalent to the rock'n'roll hall of fame, it'd be in there for sure.
My experience with it was.... variable - it didn't sound as good as the Quad amps.... lacked smoothness - was a bit rough, perhaps "shouty" in the high end....
 
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restorer-john

restorer-john

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So bias never leads folks to believe a superior piece of gear is inferior to the inferior piece?

Just fault finding Sal. You know, ears/brain/experience. Like the guy with a stethoscope that can tell you which bearing in your engine needs replacing by just listening.
 

frullo

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Uh huh.

If it 'd be that easy lots of amps would follow this design. Pity that almost all recordings are mixed and mastered through active speakers sporting class AB or D power amps with tons of global negative feedback (Hint: it's almost impossible to design a power amp without any negative feedback - most of those which claim no feedback use local negative feedback).
I agree. Local feedback reduces distortion and output impedance, widens and flatten bandwidth.
 

anmpr1

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Production is guided by preference, what the producer or listener likes. Reproduction is guided by accuracy to the source. ... what the microphone heard, that's all that's important.
The older I get the less impressed I am with any notion that reproduced sound is ever going to match 'the source'. I suppose, however, that that is the goal; but it is not my goal. Frankly, I don't think it will ever be a realizable, or practical goal.

Through numerous gear I've never, ever heard any reproduction (i.e. of a recorded musical event) that made me think, "Yes, that really sounds like Ella." Instead, my experience was always, "Yeah, it's the Memorex."

For me, the 'problem' with reproduction turns on the variance in the production--that is what I notice, more often that not. Whether I am listening to records or digit files, it is the production that annoys me, and often makes me unhappy. It is hardly ever the quality of the reproduced sound (I mean the difference in loudspeakers), which, in any case, my ears get used to pretty quickly. In fine, I tend to overlook/ignore the gear, understanding its intrinsic limitations, but instead concentrate more on what the producer was doing, at the console. Some do it 'better' than others. Some producers make a more pleasing product. I guess that is a personal preference, too.

That said, there is a point where the reproduction is low enough, or weird enough, to mask vagaries within the production. We want to avoid that. Probably a table radio or boom box is at the limit. Maybe a Bose 901. But reproduction on any 'decent' hi-fi is usually good enough to show off production values.

Also, there is a point in reproduction where 'what the microphone hears' is so far removed from anything that sounds realistic... that is to say, the performance that the microphone is attempting to pick up. There is a point where the reproduced listening experience becomes completely removed from reality. Here, I'm talking about headphones. The idea that a headphone can be 'natural' sounding in any way is an idea that has pretty much always escaped me. It is not the FR/distortion (and so on) that I'm talking about, but rather the experience of having sound 'direct injected' into the ear canals. Others certainly think differently. Headphones are now the big thing in hi-fi. I am not the customer for high priced headphones, for sure.

As an aside, when I was younger, headphones were never that important, for anyone. I would guess they really took off with the introduction of 'personal' sound--Walkmans, Discmans, and the later Apple digit-pods, now turned into cell-phones. We have a generation or two that probably only 'knows' sound via headphones.

Back in the day one could buy headphone-oriented 'binaural' recordings which were supposed to give a good facsimile of what the ears were supposed to have heard, within a natural sound field. I never listened to any of those, but only read about them.

Sometimes I think I need to get another hobby, but I might be too old to start anything new! :)
 

Robin L

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The older I get the less impressed I am with any notion that reproduced sound is ever going to match 'the source'. I suppose, however, that that is the goal; but it is not my goal. Frankly, I don't think it will ever be a realizable, or practical goal.

Through numerous gear I've never, ever heard any reproduction (i.e. of a recorded musical event) that made me think, "Yes, that really sounds like Ella." Instead, my experience was always, "Yeah, it's the Memorex."

For me, the 'problem' with reproduction turns on the variance in the production--that is what I notice, more often that not. Whether I am listening to records or digit files, it is the production that annoys me, and often makes me unhappy. It is hardly ever the quality of the reproduced sound (I mean the difference in loudspeakers), which, in any case, my ears get used to pretty quickly. In fine, I tend to overlook/ignore the gear, understanding its intrinsic limitations, but instead concentrate more on what the producer was doing, at the console. Some do it 'better' than others. Some producers make a more pleasing product. I guess that is a personal preference, too.

That said, there is a point where the reproduction is low enough, or weird enough, to mask vagaries within the production. We want to avoid that. Probably a table radio or boom box is at the limit. Maybe a Bose 901. But reproduction on any 'decent' hi-fi is usually good enough to show off production values.

Also, there is a point in reproduction where 'what the microphone hears' is so far removed from anything that sounds realistic... that is to say, the performance that the microphone is attempting to pick up. There is a point where the reproduced listening experience becomes completely removed from reality. Here, I'm talking about headphones. The idea that a headphone can be 'natural' sounding in any way is an idea that has pretty much always escaped me. It is not the FR/distortion (and so on) that I'm talking about, but rather the experience of having sound 'direct injected' into the ear canals. Others certainly think differently. Headphones are now the big thing in hi-fi. I am not the customer for high priced headphones, for sure.

As an aside, when I was younger, headphones were never that important, for anyone. I would guess they really took off with the introduction of 'personal' sound--Walkmans, Discmans, and the later Apple digit-pods, now turned into cell-phones. We have a generation or two that probably only 'knows' sound via headphones.

Back in the day one could buy headphone-oriented 'binaural' recordings which were supposed to give a good facsimile of what the ears were supposed to have heard, within a natural sound field. I never listened to any of those, but only read about them.

Sometimes I think I need to get another hobby, but I might be too old to start anything new! :)
It isn't "what the microphone heard", it's what the microphone says it heard, which is not the same thing.

Also, it's usually a bunch of microphones with their own opinions about what something is supposed to sound like, and very often those microphone feeds will be balanced in a way that wouldn't have happened without microphones, mixing boards, or compressors. The Sound Liaison folks are doing a good job using a three-diaphragm microphone that produces realistic balances and perspectives, but they are the rare exception. Most of the time you will hear drums that are limited and compressed in the mix, pianos recorded with perspectives that never obtain without electronic aid, vocals recorded from an inch away producing huge sonic images from short, svelte sopranos.

The notion of "The Absolute Sound" is not in the cards for most commercial recordings.
 

Robin L

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This is well put, and worthy of bearing in mind (I'd opine).
When I started recording, there were two small diaphragm condenser microphones that would be the default choices for recording the standard acoustic steel-strung guitar, instruments like Martin D-28s or Gibson Hummingbirds. The Neumann KM 84 and the AKG C451. These are both very high-quality microphones, their descendants are still in production. However, the difference in sound between these two microphones is very much like the difference between the D-28 and the Hummingbird, the AKG more like the Gibson. That's the degree that 2 different good microphones can alter the sound of what they are recording. You want brighter, more "wiry"? AKG. More "mellow", a little "darker"? KM 84.
 
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anmpr1

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This is well put, and worthy of bearing in mind (I'd opine).
With 'modern' recording techniques, multi-miking, 24 track (plus) recorders, mixing consoles and ancillary devices, it probably makes no sense to even talk about individual microphones, at least in the context of the end listener at home. Or even possibly the engineer in the booth, who is putting it all together in a form that will have little in common with whatever each individual microphone is picking up, at that particular location.

If you surf over to the Neve page, you can watch their little video blurb extolling the merits of their 8424. The first thing the 'engineer/producer' does, is put on a set of headphones before diving into the controls! Well, that sure tells us that a 'natural' mix is coming! LOL

I kind of understand a comment someone once made here on ASR, in another thread. The poster stated how they wanted to 'hear' exactly what the engineer heard when he was mixing the thing. That is what they wanted out of their home loudspeaker. Ok. That is kind of possible. But if that's the case, you need to find out whatever speakers were on the console. That will get you pretty close. But then you'll need a dedicated room of all the different brands, and that could get expensive.
 

sarumbear

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We need a reconditioned Phase Linear 700B tested. If not to show the world how good Mr. Carver was before he lost the plot.

 
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levimax

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We need a reconditioned Phase Linear 700B tested. If not to show the world how good Mr. Carver was before he lost the plot.

With the reputation "Flame Linear" amps have not sure how good that makes him look.
 

sarumbear

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With the reputation "Flame Linear" amps have not sure how good that makes him look.
Never heard that phrase before. We used tens of 700B at Abbey Road studios during the 70s and none burned, neither mine did.

They run hot, they produce 0.7 KILO watt! If you are stupid enough not to give enough ventilation, what do you expect?
 

levimax

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Never heard that phrase before. We used tens of 700B at Abbey Road studios during the 70s and none burned, neither mine did.

They run hot, they produce 0.7 KILO watt! If you are stupid enough not to give enough ventilation, what do you expect?
"Flame Linear" is all over the internet.... I have no idea if it is "real" or urban legend. Reading the stories it sounds like they are fine with 8 ohm loads at home or in a studio but they ran into trouble when used (abused) for live performances.
 

sarumbear

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"Flame Linear" is all over the internet.... I have no idea if it is "real" or urban legend. Reading the stories it sounds like they are fine with 8 ohm loads at home or in a studio but they ran into trouble when used (abused) for live performances.
Internet legends older than half century are not reliable. Take this one from me.

I was 20 when 700B was introduced and when Instarted working in audio. During the following decade when the amplifier was in production, I never heard the phrase nor heard any fire caused by it. However, I have advised many friends even professionals that they need ventilation.
 

sarumbear

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"Flame Linear" is all over the internet.... I have no idea if it is "real" or urban legend. Reading the stories it sounds like they are fine with 8 ohm loads at home or in a studio but they ran into trouble when used (abused) for live performances.
All over the Internet is actually three entries even when a forced search is done.

 

mhardy6647

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With the reputation "Flame Linear" amps have not sure how good that makes him look.
I suspect that poor @amirm might be dealing with more than just popped mains fuses if he pressure-tests even a rehabilitated 700B... and I think he's got enough home ownership angst goin' right now already! :(

Metastabilty seems (to me!) to have been a trademark of many [Bob] Carver designs.
 

DSJR

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Let me give an example of a device. Many years ago, after having listened to dozens and dozens of CD players (for every price range), I chose Rega Planet I. From the point of view of the technical measures available, nothing exceptional; but overall more euphonic, less screaming and unbalanced than 90% of CD players. It still defends itself today; however, I believe that now there are better machines (regardless of price), capable of returning excellent results in terms of numbers and sound. Anyway only the measures (which, then?) I still would not trust!
I still trust my most refined reference system, blind or not.
You see, if you'd also heard the two box Rega player at almost double the price of the mk1 'clamshell' Planet, you'd start to hear what 'we're' all going on about, as the Jupiter/Io pair (- the Io model name was originally a dac they made -) better reproduced differences in recordings, production and so on. The Planet, bless it, tended to make things sound more 'the same' and it's very high output impedance (the Apollo R to this day is the same apparently) makes it harder to match with modern 10k loading in amps. We sold all our Planets with the Klotz AC110 based 'Couple' interconnect and the remote and it was still competitive with the Arcam direct competition of the time... yes, I'm fully aware that a baby Topping or latest Schiit among other dacs would eat it alive, but it was a good buy back in 1998 or so before home theatre took the interest away and people refused a top loading CD player :(
 

frullo

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My mention: Accuphase (old, starting from E 202 and E 203... And new); Sansui BA F1 (1979-1980).
 
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