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

[kevinh]

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

I used the Thoebe (sp?) Pre Amp with the Ampzilla.

 

[levimax]

Haffler DH-500 ... reasonable priced option with lots of power.

 

[fredoamigo]

In spite of the sarcastic glance of some "audiophiles" I could never part with my .Hafler 9505
There was a time when I had two of them that I used in bridged mode.
it is equivalent to the bryston 2/3/4 BST often compared to krell too.
The 9500 is the same beast but without the balanced outputs. stereophile https://www.stereophile.com/content/hafler-transnova-9500-power-amplifier

""
In 1987 Hafler sold his namesake to Rockford Corporation where chief engineer Jim Strickland took on the challenge of moving Hafler towards building high end amplifiers. This culminated with the 9505 which by all accounts is one of the most musical power amps ever made.

In 1995, Hafler left the hi-fi market to instead focus on producing amplifiers for the studio market. This is when Radial began the affiliation with Rockford, taking on the distribution of Hafler amplifiers for Canada. Radial purchased the Hafler brand from Rockford in 2014 with a goal of eventually re-launching some of the Hafler classic amplifiers.""

 

[tmtomh]

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.

I don't necessarily disagree. I just think this highlights the importance of being clear about what we're looking for. What does it mean for old or new amplifiers to "challenge" each other or to "approach state of the art"?

My concern is that John has started this thread under a premise that he actually had no intention of the thread really being about. So we end up with a constant shifting of the goal posts: "This is great vintage amp" - "Yes, but it does not challenge or approach current state of the art" - "Well, current state of the art is overkill anyway so it doesn't matter."

That is essentially the discussion so far.

That's why I asked about what we all might consider essential specs and qualities of a "state of the art" - or even just "really good" amp.

Clearly we all want some kind of threshold for THD, IMD, and noise - even if we don't all agree on the threshold we do agree that there exists some threshold beneath which performance is considered compromised and above which performance is considered good enough, yes?

And clearly we all want durability and good build quality, yes?

And clearly we all want some degree of performance robustness, aka a certain amount of wattage available on a sustained basis across the entire audible frequency range; a certain degree of thermal management and speaker protection to promote longevity of both the amp itself and any speakers connected to it; and a certain amount of gain to enable proper gain staging with a reasonable variety of setups and use cases.

If we can't get clarity on these issues, then we end up in the kind of ill-defined, sort of half-agreeing/half-disagreeing discussion that John often takes us into, where folks end up comparing one amp's/topology's noise and distortion against another amp's/topology's power supply construction. It's apples and oranges.

 

[Speedskater]

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

Gee, I have one of the original Ampzilla kits up in the attic. Used it for several years. Now it's in need of repair.

 

[Doodski]

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've replaced many many capacitors and FETs in switching power supplies in large class AB car amps and as the products matured the power supply microprocessors improved and the protection circuitry engaged before too much damage occurred. I've chatted @March Audio about the protection circuitry in his class D amplifiers and it is apparently comprehensive and fast. If the capacitor(s) failed in a class D with a proper microprocessor protection circuitry then I think that should be the end of the failure(s) but don't quote me on that because stuff happens.

 

[Doodski]

Since the caps are through hole they should not be hard to replace but if the caps fail do they take out other components?

and to add... The class AB car amps run veryyyy hot and go through capacitors often but the class D amps run cooler and so there is going to be a trade-off. Cooler running class D with square waves being filtered or hot, baked and blown in a hot running class AB car amp. Only time will tell if the class D amplifiers last decades.

 

[RayDunzl]

I have a Krell KAV250a/3.

I have the 2-channel box, probably the same hardware.

I'll pull it out sometime and see what it will do at 5W.

 

[Wes]

apt

and at the other side of the cosmetic spectrum... Accuphase

also how about the Nakamichi that Nelson Pass designed?

 

[Vini darko]

and to add... The class AB car amps run veryyyy hot and go through capacitors often but the class D amps run cooler and so there is going to be a trade-off. Cooler running class D with square waves being filtered or hot, baked and blown in a hot running class AB car amp. Only time will tell if the class D amplifiers last decades.

I'm using a 1991 pioneer class D amp right now. Apart from beefed up power caps it's on all the stock elna caps and is fine.

 

[robertozappala]

Questo è il mio amplificatore dal 2002, Metaxas Icarus, che ne pensi?
Roberto

 

[fredoamigo]

Questo è il mio amplificatore dal 2002, Metaxas Icarus, che ne pensi?
Roberto

hi ....At more than 500 euros per watt, it would be preferable that it does not present any defects. (MSRP: $32.000 USD)

 

[robertozappala]

[QUOTE = "fredoamigo, post: 437749, membro: 1531"] ciao .... A più di 500 euro per watt, sarebbe preferibile che non presentasse difetti. (Prezzo consigliato: $ 32.000 USD) [/ PREVENTIVO]

Noooo, his price was 1.600 euro

 

[MakeMineVinyl]

My vote for iconic solid state amp would be the Crown DC300. Not saying it didn't have massive flaws though, but some audiophiles fell all over themselves to own one. For tube amps it would be the Dynaco ST-70.

 

[restorer-john]

My concern is that John has started this thread under a premise that he actually had no intention of the thread really being about. So we end up with a constant shifting of the goal posts: "This is great vintage amp" - "Yes, but it does not challenge or approach current state of the art" - "Well, current state of the art is overkill anyway so it doesn't matter."

I started this thread so as to not derail one of @amirm 's review threads. I figured otherwise, the discussion would go down a rabbithole and result in another quality review thread getting trashed.

As for shifting the goal posts, the first post discusses where the goal posts should be, and asks for input. It seems there is just as much interest in integrated as power amplifiers, and, considering how much more time, effort and expense went into the development of the then SOTA integrated amplifiers (especially for the Japanese home market where integrateds ruled), I tend to agree.

But, getting a fully equipped integrated amplifier to challenge a modern simple power amplifier is not really a fair comparison, as half the amplifier simply isn't there. All the low level preamplification is conveniently scratched from the equation. A benchmark AHB-2 for instance achieves its fabulous figures by being a low gain, medium output, power amplifier with nothing else to worry about. There is no moving coil preamplifier, filters, tone controls or any facilities one requires in a fully fledged HiFi system. We have integrated amplifiers with 100uV MC sensitivities from such inputs and output stages that deliver >200W, so getting them dead quiet and performant is a significantly greater challenge isn't it?

I guess it is contenders I/we/others have had hands on experience with, either on the bench, testing, or owning for decades where the important parameters are excellent or near modern SOTA offerings. That is what the thread is about.

I'll pull out a few pieces today, take some pics and put them up for discussion. Then we'll see what testing will uncover.

 

[restorer-john]

My vote for iconic solid state amp would be the Crown DC300. Not saying it didn't have massive flaws though,

What were its massive flaws? (Considering it is a 50 year old design and taking that into account)

 

[MakeMineVinyl]

What were its massive flaws? (Considering it is a 50 year old design and taking that into account)

I suppose considering it through the lens of the times, it might be considered "perfect". But it sounded bad to my ears like many early solid state designs. Also, I haven't seen a DC300 which has physically and electrically aged gracefully, but then again I've never seen a solid state amp that old which has. On the tube side, I have seen (and own) unaltered examples of amps from the early 1960s, one with its original tubes which still meet spec.

 

[tmtomh]

I started this thread so as to not derail one of @amirm 's review threads. I figured otherwise, the discussion would go down a rabbithole and result in another quality review thread getting trashed.

As for shifting the goal posts, the first post discusses where the goal posts should be, and asks for input. It seems there is just as much interest in integrated as power amplifiers, and, considering how much more time, effort and expense went into the development of the then SOTA integrated amplifiers (especially for the Japanese home market where integrateds ruled), I tend to agree.

But, getting a fully equipped integrated amplifier to challenge a modern simple power amplifier is not really a fair comparison, as half the amplifier simply isn't there. All the low level preamplification is conveniently scratched from the equation. A benchmark AHB-2 for instance achieves its fabulous figures by being a low gain amplifier with nothing else to worry about. There is no moving coil preamplifier, filters, tone controls or any facilities one requires in a fully fledged HiFi system. We have integrated amplifiers with 200uV MC sensitivities from such inputs and output stages that deliver >200W, so getting them dead quiet and performant is a significantly greater challenge isn't it?

I guess it is contenders I/we/others have had hands on experience with, either on the bench, testing, or owning for decades where the important parameters are excellent or near modern SOTA offerings. That is what the thread is about.

I'll pull out a few pieces today, take some pics and put them up for discussion. Then we'll see what testing will uncover.

Thanks for your reply, John.

I completely agree about comparing simple power amps to full-featured vintage integrated amps. I agree in particular about the Benchmark, because even at its highest-gain setting it provides only 23dB of gain - to get the THX norm of 29dB (which is also the top of what I believe is the customary 27-29dB of gain range for classic/vintage Class AB amps), you have to bridge it to mono, at which point you're talking about $6,000 plus tax and shipping. If one has the money for that, great, but for a lot of us, yikes!

At the same time, I still think there's a difference between:

1. A fun, partially anecdotal discussion about solidly built and decently performing vintage amps, and
2. A discussion more rigorously focused on vintage amps that can challenge the best new amps on performance.

I don't care if the preference is to have the former discussion - that's just fine by me! But I do think at a site like ASR in particular, it's a problem to have the former discussion in a thread that claims to be the latter discussion.

So I'd still like to see some effort to define performance metrics for "close enough to state of the art to be considered audibly transparent/excellent in most home use cases." I know you've stated you're just one guy on the internet - but you're a guy with decades of experience, 100 amps, and the thread starter.

So personally I'd love for you to weigh in on some sensible metrics in your view and give us a couple of examples of vintage amps - power or integrated - that meet these metrics.

Otherwise it's a dog's breakfast of excellent equipment mixed in with stuff like old Crown power amps, which no doubt provide gobs of power and robust build quality, but likely fall notably short on noise and probably distortion (and don't necessarily outperform Crown's lighter, cooler-running, less-expensive current-day Class D offerings that have similarly so-so noise and distortion ratings). Ditto for the Hafler amps - they're awesome, but their THD and crosstalk specs are orders of magnitude worse than high-quality modern amps (and modestly worse than the best amps of their era).

No disrespect to that gear - as noted in another thread, I happy lived with Adcom power amps from the summer of 1991 until about 3 weeks ago, and their THD rating is scandalously high compared to today's (or yesteryear's for that matter) state of the art. (Although they kick the crap out of the Hafler on crosstalk, so go figure.)

But if we're going for apples to apples, then we need to set up a basis for comparison, no?

 

[Archsam]

Yes.

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).

Oh John sometimes you really need to put a face to the name, and what a face! And it weights 55 pounds!

How did you ended up having four of them??

 

[Doodski]

Oh John sometimes you really need to put a face to the name, and what a face! And it weights 55 pounds!

How did you ended up having four of them??

View attachment 70243

I don't about that Sony TA-N77ES. It gets a bad review here. My suggestion of the Luxman R117 receiver out-powers it
https://www.kenrockwell.com/audio/sony/ta-n77es.htm