Audio Research 100.2 Power Amplifier Review

[Cahudson42]

Toshiba 2SA1303 and 2SC3281)

Seems you can still get them:


5 Pairs of 2SA1303 + 2SC3284 Audio Power Transistor https://www.amazon.com/dp/B00LQSXOP8/

 

[maxxevv]

Jeez, Amir - you've done it again. I can't wait until you are able to test one of their revered tube amplifiers

View attachment 44494

From Stereophile reader comments:

He did do a test on one of those much vaunted Woo Audio tube amps some time back ..

https://www.audiosciencereview.com/...-wa7-wa7tp-dac-and-headphone-amp-review.7028/

 

[Cahudson42]

Hmmm..Nice case and heatsinks. Scrap the innards (except possibly the PS if it's modular? 50v rails nothing to write home about, though) ..add your own?

 

[Steve H]

This shows some gear which was highly regarded in it's day has passed its sell by date.

And yet my NAD 3020 seems to keep going and going.

 

[NTomokawa]

5 Pairs of 2SA1303 + 2SC3284 Audio Power Transistor https://www.amazon.com/dp/B00LQSXOP8/

How can you tell whether those are NOS parts, dismantled/recycled parts, or fake/imitation?

 

[JJB70]

I sort of think the market got what it wanted. In the 70's and 80's a lot of hifi manufacturers designed around measured performance and objective criteria and applied good engineering practice. The response of reviewers was to deride such equipment and go off praising boutique gear with often poor performance and shoddy build to the point where excellent specifications almost became a negative point for the golden eared crowd. Given that it isn't surprising that smaller high end manufacturers went for that market and weren't too worried about measured performance. Even companies like Sony, Marantz and Pioneer (all of which made some remarkable gear in their prime) learnt lessons which handily coincided with the market changing and the bottom falling out of audio equipment R&D.

 

[pozz]

I sort of think the market got what it wanted. In the 70's and 80's a lot of hifi manufacturers designed around measured performance and objective criteria and applied good engineering practice. The response of reviewers was to deride such equipment and go off praising boutique gear with often poor performance and shoddy build to the point where excellent specifications almost became a negative point for the golden eared crowd. Given that it isn't surprising that smaller high end manufacturers went for that market and weren't too worried about measured performance. Even companies like Sony, Marantz and Pioneer (all of which made some remarkable gear in their prime) learnt lessons which handily coincided with the market changing and the bottom falling out of audio equipment R&D.

Someone really needs to write a history of hifi.

 

[DonH56]

My opinions.

ARC produced a series of amplifiers like this that essentially targeted their tube audience. Poorer objective performance in favor of more "musical" tube-like sound. (How many times have we heard that before?) The past few years they've had a lot of churn in their product offerings, wonder how much of that is driven by their new owner trying to get better profitability. Or maybe just relevance. Like McIntosh they have a dedicated fan base but don't appear to be growing and expanding like McIntosh these days (again, my opinion, based on what little I see over the past few years in the way of products, reviews, adverts, and online chatter at various audio fora).ARC has been in and out of the SS arena couple of times but I don;t think their SS products ever did that well. They were always overshadowed by their competition and ARC was and is known for its dedication to tubed gear.

I sold my D-79 years ago but still have my old heavily-modified SP3a1. I was tempted to send it to them to update a few years ago when they were offering that but would have had to get it back to stock (even though they were replacing the boards entirely). Back when I worked for a dealer (late 1970's/early 1980's) they were highly-regarded by audiophiles but IME (as a tech) they were not all that reliable and often costly to repair. I was also a little put off by the way they made tweaks minor and major in fairly rapid succession, annoying even some of their most ardent fans. SP3, SP3a, SP3a1, SP3a2, SP3b, etc.

Again IME their preamps tended to measure pretty well in comparison to the competition even if the specs weren't great (underspec'd). Their power amps tended to be aligned with what you'd expect from tube gear, though often a bit better in terms of things like power supply design. Though again their more "stiff" and regulated supplies tended to be more problem-prone...

FWIWFM - Don

 

[Midwest Blade]

Another eye opener, I love these vintage reviews. I really wonder just how much gear has been made and sold over the years that is anything but hi-fi. I suspect some audio afficianado heads will be popping like the Martians listening to country music in the "Mars Attacks" movie.

 

[bambadoo]

Not 100.2 but had an AR D200 for a month or so before I sold it.
I do remember it as decent sounding. It was bipolar based I think? Very heavy and solid yes.

 

[suttondesign]

I believe Amir's measurements must be wrong because the amp has a thick, solid metal front plate with attractive lettering. It oozes quality and heft, so the measurements are wrong.

 

[Tks]

Jeez, Amir - you've done it again. I can't wait until you are able to test one of their revered tube amplifiers

From Stereophile reader comments:

Odd, I thought distortion was what we wanted. You know, as an answer to all the lifeless-sterile-dry-emotionless sound coming from well measuring stuff.

Jokes aside, it's funny how there is only seemingly a nostalgia-based benchmark for how much distortion is acceptable. While most normal folks who are seeking fidelity like us, have a preference where there is virtually no limit to the appreciable value of reducing any additional artifacts as much as possible.

I've seen this sort of corollary in display-tech recently. There are folks who wish we still had CRT's being produced and worked on for some classic viewing of old footage, or playing old video game consoles. At least with those people CRT's are appreciated for aspects LCD's and OLED's seemingly cannot achieve (input latency, blur elimination, black-levels, and a few other bits), while the rest of CRT's aspects can be emulated to an appreciable degree, like the aesthetics of scanlines etc...

In audio I don't understand what the allure is toward purposefully signal-marring chain of devices... These aspects can be virtually emulated in software if you ever wanted things like vinyl scratch even. Lo-Fi is perhaps a whole genre of music that demonstrates this.

So aside from nostaligic allure or novelty, I simply cannot understand this affinity to having all your audio passed through some sewage first.. (nevermind the mess when you have music mastered using w Lo-Fi approach, now you have artifical and natural disotortion packed up on top of one another, and that just sounds blah, with no way of changing that). At least with high fidelity chains, you can choose to mar your signal if you want through software. But you can never remove it in software if your hardware natively is suffering from poor performance.

 

[jsrtheta]

Peter Aczel was brutal on Audio Research, leading to some pretty funny copy.

This kind of crap is why.

 

[SEKLEM]

I wonder how Krell gear would look under this scrutiny.

 

[jsrtheta]

I wonder how Krell gear would look under this scrutiny.

Much better, I imagine.

 

[Sal1950]

Draining the main reservoir capacitors.

My Adcoms are the same, for better or worse the lack relays or and type of output protection outside of power rail fuses.
The GFA 535's all make a wrinkleing paper sound at low levels as they decay.

These kind of reviews make me wonder how my 1996 $2000 MSRP Marantz PM16 integrated would do. Would that also be bad nineties tech?

No, I would expect your Marantz to make a better showing. Japanese gear has mostly been build to spec well and return good numbers while boutique gear like the ARC is build to sound a certain way.

 

[mitchco]

I peaked in there and they are rated at 63 volts. I read some place that the original caps were 50 volts so I am assuming they are replaced.

Thanks Amir, would be great to get confirmation as this is typical of power supply caps that have dried out and lost their ability to filter, which results in higher power supply noise and fluctuation in low frequency response as you have measured. Especially if the amp runs hot, really reduces the life of the caps. If however, the caps have been recently replaced (like within the last 5 years), then this is indeed abysmal performance.

 

[Koeitje]

My Adcoms are the same, for better or worse the lack relays or and type of output protection outside of power rail fuses.
The GFA 535's all make a wrinkleing paper sound at low levels as they decay.

No, I would expect your Marantz to make a better showing. Japanese gear has mostly been build to spec well and return good numbers while boutique gear like the ARC is build to sound a certain way.

I guess, I used to have a review with measurements from a German audio magazine that were better than its direct Accuphase competition from the time.

 

[Matias]

I wonder how Krell gear would look under this scrutiny.

According to this interview, Dan D'Agostino was admitedly very measurement centric during his final Krell years. Later with his own brand he relaxed on metrics and focused on subjective.

 

[Blumlein 88]

According to this interview, Dan D'Agostino was admitedly very measurement centric during his final Krell years. Later with his own brand he relaxed on metrics and focused on subjective.

I think what he focused on was money. His products went down in spec and way, way, way up in price.